Patent Publication Number: US-2023148714-A1

Title: Foamed articles and methods of making the same

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 63/263,951 filed on Nov. 12, 2021, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure is directed to foamed articles. More specifically, the present disclosure relates to foamed articles including a foamed thermoplastic elastomeric material, methods of making such foamed articles, and method for manufacturing articles of footwear including such foamed articles. 
     BACKGROUND 
     The design of athletic equipment and apparel as well as footwear involves a variety of factors from the aesthetic aspects, to the comfort and feel, to the performance and durability. While design and fashion may be rapidly changing, the demand for increasing performance in the market is unchanging. To balance these demands, designers employ a variety of materials and designs for the various components that make up athletic equipment and apparel as well as footwear. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further aspects of the present disclosure will be readily appreciated upon review of the detailed description, described below, when taken in conjunction with the accompanying drawings. 
         FIGS.  1 A- 1 M  illustrate various articles of footwear, apparel, and athletic equipment, including containers, electronic equipment, and vision wear, that are or comprise foamed articles in accordance with the present disclosure, while  FIGS.  1 N (a)- 1 Q(e) illustrate additional details regarding different types of footwear. 
         FIG.  2    illustrates, in a side view, a thermoplastic elastomeric material for forming a foamed thermoplastic elastomeric material during an early fabrication stage in accordance with an exemplary embodiment. 
         FIG.  3    illustrates, in cross-sectional view, the thermoplastic elastomeric material depicted in  FIG.  2    along line  202 - 202 . 
         FIG.  4    illustrates, in a partial cross-sectional side view, a thermoplastic elastomeric material in a vessel for forming a foamed thermoplastic elastomeric material during an intermediate fabrication stage in accordance with an exemplary embodiment. 
         FIG.  5    illustrates, in a partial cross-sectional side view, a carbon dioxide-infused foamable article during exposing at a second temperature and second pressure in accordance with an exemplary embodiment. 
         FIG.  6    illustrates, in a partial cross-sectional side view, a carbon dioxide-infused foamable article being introduced to a water bath for forming a foamed article during a subjecting step in accordance with an exemplary embodiment. 
         FIG.  7    illustrates a flow chart of a method for making a foamed article in accordance with an exemplary embodiment. 
         FIGS.  8 A- 8 C  illustrate various configurations of single-sided, foamable articles incorporating one or more strata in accordance with an exemplary embodiment, wherein the foamable articles can incorporate gaps or pockets within or among the strata or portions of the strata. 
         FIG.  9 A  illustrates a configuration of a foamable article comprising various regions in accordance with an exemplary embodiment.  FIGS.  9 B- 9 C  illustrate various scenarios for selectively foaming regions of the foamable article according to other exemplary embodiments. 
         FIGS.  10 A- 10 F  are schematics of multilayered articles according to an exemplary embodiment, prior to foaming ( FIGS.  10 A,  10 C, and  10 E ) and after foaming ( FIGS.  10 B,  10 D, and  10 F ). 
         FIGS.  11 A- 11 K  are schematics of foamable articles according to an exemplary embodiment, wherein selected portions of foamable articles can be foamed through controlled infusion and diffusion of carbon dioxide into and/or out of all or part of the articles prior to performing the expanding step disclosed herein, while leaving other portions of the articles unfoamed. 
     
    
    
     DESCRIPTION 
     In one aspect, disclosed herein is a method for making an additive manufactured foamed article, the method comprising placing a foamable article and carbon dioxide (CO 2 ) in a vessel, wherein the foamable article includes a solid foamable material assembled using an additive manufacturing process, wherein the solid foamable material is a thermoplastic elastomeric material comprising one or more first thermoplastic elastomers; after the placing, maintaining the vessel at a first pressure and first temperature, wherein the first pressure and first temperature are a pressure and temperature at which the carbon dioxide is a liquid and the liquid carbon dioxide is soluble in the solid foamable material, and wherein the maintaining includes holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the solid foamable material of the foamable article; following the maintaining and holding, optionally exposing the infused article to a second pressure and second temperature at which the carbon dioxide remains infused within at least a portion of the solid foamable material; following the maintaining and holding and the optional exposing, subjecting the foamable article to a third pressure and third temperature at which the carbon dioxide infused in the solid foamable material phase transitions to a gas, thereby expanding the solid foamable material into a foamed material and forming the foamed article. 
     In another aspect, the method further comprises following the subjecting and expanding, bringing the additive manufactured foamed article to a fourth temperature and fourth pressure, and holding the foamed article at or below the fourth temperature, the fourth pressure, or both, for a duration of time. In still another aspect, the method further comprises following the subjecting and expanding or following the optional bringing, stabilizing the additive manufactured foamed article at a fifth pressure and fifth temperature at which the carbon dioxide diffuses out of the foamed material of the foamed article while maintaining the foamed material in a foam structure, forming a stabilized additive manufactured foamed article. 
     In one aspect, manufacturing the foamable article using an additive manufacturing method comprises arranging a plurality of foamable particles, wherein the arranged plurality of foamable particles comprises a solid foamable material, optionally wherein the plurality of particles comprises a blend according to any one of claims  138 - 151 , and optionally wherein the arranged plurality of foamable particles has a number average particle size of about 0.001 millimeters to about 10 millimeters in a longest dimension, or of about 0.04 millimeters to about 10 millimeters in a longest dimension, or of about 1 millimeters to about 5 millimeters in a longest dimension. 
     In another aspect, manufacturing the foamable article using an additive manufacturing method comprises extruding at least one first filament or pellet comprising the foamable material to form the foamable article. 
     In another aspect, the foamable article can be configured as a series of two or more strata including a first strata comprising a first strata material and a second strata comprising a second strata material, wherein the first strata material or the second strata material or both the first strata material and the second strata material are a solid foamable material; optionally wherein the first strata material and the second strata material are individually a blend, optionally wherein the first strata or the second strata forms an outermost surface of the article, or wherein both the first strata and the second strata individually or jointly form the outermost surface of the foamable article. 
     The following list of exemplary aspects supports and is supported by the disclosure provided herein. 
     In accordance with Aspect 1, the present disclosure is directed to a method for making an additive manufactured foamed article, the method comprising: 
     placing a foamable article and carbon dioxide (CO 2 ) in a vessel, wherein the foamable article includes a solid foamable material assembled using an additive manufacturing process, wherein the solid foamable material is a thermoplastic elastomeric material comprising one or more first thermoplastic elastomers; 
     after the placing, maintaining the vessel at a first pressure and first temperature, wherein the first pressure and first temperature are a pressure and temperature at which the carbon dioxide is a liquid and the liquid carbon dioxide is soluble in the solid foamable material, and wherein the maintaining includes holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the solid foamable material of the foamable article; 
     following the maintaining and holding, optionally exposing the infused article to a second pressure and second temperature at which the carbon dioxide remains infused within at least a portion of the solid foamable material; 
     following the maintaining and holding and the optional exposing, subjecting the foamable article to a third pressure and third temperature at which the carbon dioxide infused in the solid foamable material phase transitions to a gas, thereby expanding the solid foamable material into a foamed material and forming the foamed article. 
     In accordance with Aspect 2, the present disclosure is directed to the method of aspect 1, further comprising following the subjecting and expanding, bringing the additive manufactured foamed article to a fourth temperature and fourth pressure, and holding the foamed article at or below the fourth temperature, the fourth pressure, or both, for a duration of time. 
     In accordance with Aspect 3, the present disclosure is directed to the method of aspect 1 or 2, further comprising following the subjecting and expanding or following the optional bringing, stabilizing the additive manufactured foamed article at a fifth pressure and fifth temperature at which the carbon dioxide diffuses out of the foamed material of the foamed article while maintaining the foamed material in a foam structure, forming a stabilized additive manufactured foamed article. 
     In accordance with Aspect 4, the present disclosure is directed to the method of aspect 3, wherein the stabilizing comprises holding the additive manufactured foamed article at the fifth pressure and fifth temperature for a duration of time sufficient to remove substantially all of the carbon dioxide from the foamed material. 
     In accordance with Aspect 5, the present disclosure is directed to the method of any one of the preceding aspects, wherein, at the first pressure and temperature, the liquid carbon dioxide is soluble in the solid foamable material at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent. 
     In accordance with Aspect 6, the present disclosure is directed to the method of any one of the preceding aspects, wherein the foamed material of the additive manufactured foamed article is substantially opaque. 
     In accordance with Aspect 7, the present disclosure is directed to the method of any one of the preceding aspects, wherein the foamed material has a split-tear value of from about 2.5 kilograms per centimeter to about 3.0 kilograms per centimeter. 
     In accordance with Aspect 8, the present disclosure is directed to the method of any one of the preceding aspects, wherein the foamed material has an Asker C hardness of from about 10 to about 50. 
     In accordance with Aspect 9, the present disclosure is directed to the method of any one of the preceding aspects, wherein the foamable article is an additive manufactured article. 
     In accordance with Aspect 10, the present disclosure is directed to the method of any one of the preceding aspects, further comprising manufacturing the foamable article using an additive manufacturing method. 
     In accordance with Aspect 11, the present disclosure is directed to the method of aspect 10, wherein manufacturing the foamable article using an additive manufacturing method comprises arranging a plurality of foamable particles, wherein the arranged plurality of foamable particles comprises a solid foamable material, optionally wherein the plurality of particles comprises a blend according to any one of aspects 138-151, and optionally wherein the arranged plurality of foamable particles has a number average particle size of about 0.001 millimeters to about 10 millimeters in a longest dimension, or of about 0.04 millimeters to about 10 millimeters in a longest dimension, or of about 1 millimeters to about 5 millimeters in a longest dimension. 
     In accordance with Aspect 12, the present disclosure is directed to the method of aspect 11, wherein the particles are uniform in size, shape, or both size and shape. 
     In accordance with Aspect 13, the present disclosure is directed to the method of aspect 11, wherein the particles are heterogeneous in size and shape. 
     In accordance with Aspect 14, the present disclosure is directed to the method of any one of aspects 11-13, further comprising directly sintering the particles to each other to form the foamable article. 
     In accordance with Aspect 15, the present disclosure is directed to the method of aspect 14, wherein directly sintering the particles comprises increasing a temperature of a portion of the particles with a directed energy beam so as to at least partially soften or melt defining surfaces of only a portion of the arranged plurality of foamable particles, but not of all of the arranged plurality of foamable particles. 
     In accordance with Aspect 16, the present disclosure is directed to the method of aspect 15, wherein the directed energy beam comprises a visible or infrared light beam, optionally wherein the light beam is a laser beam, optionally wherein the laser beam is emitted by a gas dynamic laser, a diode laser, or a lead salt laser. 
     In accordance with Aspect 17, the present disclosure is directed to the method of aspect 15 or 16, wherein the laser beam has a wavelength within the infrared spectrum. 
     In accordance with Aspect 18, the present disclosure is directed to the method of aspect any one of aspects 10-17, wherein manufacturing the foamable article using an additive manufacturing method further comprises depositing a binding material in a binding material target area, wherein the binding material target area comprises at least a portion of the arranged plurality of foamable particles, and wherein the depositing coats at least a portion of defining surfaces of the arranged plurality of foamable particles with the binding material; and affixing at least a portion of the arranged plurality of foamable particles to each other within the target area, optionally wherein the affixing comprises curing. 
     In accordance with Aspect 19, the present disclosure is directed to the method according to aspect 18, wherein the curing comprises solidifying the deposited binding material and binding the deposited binding material to the coated at least a portion of the defining surfaces of the arranged plurality of foamable particles. 
     In accordance with Aspect 20, the present disclosure is directed to the method according to aspect 18 or 19, wherein the curing comprises: applying energy to the deposited binding material and the arranged plurality of foamable particles in an amount and for a duration sufficient to soften the solid foamable material of the coated at least a portion of the defining surfaces of the arranged plurality of foamable particles into softened foamable material; and decreasing a temperature of the region of the arranged plurality of foamable particles to a temperature at or below which the softened foamable material re-solidifies into the solid foamable material; thereby affixing at least a portion of the coated at least a portion of the defining surfaces of the arranged plurality of foamable particles in the binding material target area. 
     In accordance with Aspect 21, the present disclosure is directed to the method according to aspect 20, wherein the applying energy comprises applying energy to substantially all of the arranged plurality of foamable particles. 
     In accordance with Aspect 22, the present disclosure is directed to the method according to aspect 20 or 21, wherein the applying energy comprises applying energy to at least a portion of the binding material target area using a directed energy beam, optionally wherein the directed energy beam is a laser beam. 
     In accordance with Aspect 23, the present disclosure is directed to the method according to any one of aspects 20-22, wherein the applying energy comprises applying energy within the infrared spectrum, optionally the far infrared spectrum, the near infrared spectrum, or the mid infrared spectrum. 
     In accordance with Aspect 24, the present disclosure is directed to the method according to any one of aspects 20-22, wherein the applying energy comprises applying a thermal energy source, optionally wherein the thermal energy source is an infrared energy source or a microwave energy source. 
     In accordance with Aspect 25, the present disclosure is directed to the method according to any one of aspects 20-24, wherein the applying energy comprises applying energy to substantially all of the arranged plurality of foamable particles. 
     In accordance with Aspect 26, the present disclosure is directed to the method according to any one of aspects 11-25, wherein the arranging a plurality of foamable particles comprises forming one or more strata comprising the plurality of foamable particles. 
     In accordance with Aspect 27, the present disclosure is directed to the method according to aspect 26, wherein the article is formed from a single strata comprising the plurality of foamable particles. 
     In accordance with Aspect 28, the present disclosure is directed to the method according to aspect 27, wherein an iteration of the arranging comprises forming a strata comprising the plurality of foamable particles. 
     In accordance with Aspect 29, the present disclosure is directed to the method according to aspect 28, wherein the article is formed from a plurality of strata in a layer-wise fashion, wherein each strata comprises a plurality of foamable particles, and wherein, in the foamable article, each strata is affixed to at least a portion of another strata. 
     In accordance with Aspect 30, the present disclosure is directed to the method of any one of the preceding aspects, wherein the foamable article is configured as a series of two or more strata including a first strata comprising a first strata material and a second strata comprising a second strata material, wherein the first strata material or the second strata material or both the first strata material and the second strata material are a solid foamable material; optionally wherein the first strata material and the second strata material are individually a blend according to any one of aspects 139-152, optionally wherein the first strata or the second strata forms an outermost surface of the article, or wherein both the first strata and the second strata individually or jointly form the outermost surface of the foamable article. 
     In accordance with Aspect 31, the present disclosure is directed to the method of aspect 30, wherein the two or more strata individually comprise a plurality of particles, an extruded material, or any combination thereof, optionally wherein the plurality of particles, the extruded material, or both are a solid foamable material. 
     In accordance with Aspect 32, the present disclosure is directed to the method of aspect 30 or 31, wherein the first strata comprises a first plurality of particles and the second strata comprises a second plurality of particles. 
     In accordance with Aspect 33, the present disclosure is directed to the method of aspect 30 or 31, wherein the first strata comprises a first extruded material and the second strata comprises a second plurality of particles. 
     In accordance with Aspect 34, the present disclosure is directed to the method of aspect 30 or 31, wherein the first strata comprises a first plurality of particles and the second strata comprises a second extruded material. 
     In accordance with Aspect 35, the present disclosure is directed to the method of aspect 30 or 31, wherein the first strata comprises a first extruded material and the second strata comprises a second extruded material. 
     In accordance with Aspect 36, the present disclosure is directed to the method of any one of aspects 30-35, wherein, in the additive manufactured foamable article, the first strata forms the outermost surface of the additive manufactured article and the second strata forms an inner layer of the additive manufactured article. 
     In accordance with Aspect 37, the present disclosure is directed to the method of any one of aspects 30-36, wherein, in the foamable article, the first strata comprises or consists essentially of the solid foamable material, the solid foamable material of the first strata is a first strata solid foamable material, and in the steps of subjecting and expanding, the first strata solid foamable material either remains as the first strata solid foamable material, or expands into the foamed material wherein the foamed material of the first strata is a first strata foamed material. 
     In accordance with Aspect 38, the present disclosure is directed to the method of any one of 30-37, wherein, in the foamable article, the second strata comprises or consists essentially of the solid foamable material, the solid foamable material of the second strata is a second strata solid foamable material, and in the steps of subjecting and expanding, the second strata solid foamable material either remains as the second solid strata foamable material, or expands into the foamed material wherein the foamed material of the second strata is a second strata foamed material. 
     In accordance with Aspect 39, the present disclosure is directed to the method of any one of 30-38, wherein the first strata solid foamable material, or the second strata solid foamable material, or both, is individually a solid foamable material according to any of aspects 1-9 or 124-152. 
     In accordance with Aspect 40, the present disclosure is directed to the method of any one of 30-38, wherein the first strata foamed material, or the second strata foamed material, or both, individually are a foamed material according to any of aspects 1-9 or 124-152. 
     In accordance with Aspect 41, the present disclosure is directed to the method of any one of aspects 30-40, wherein the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata, or wherein the duration of time is sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second strata, or wherein the duration of time is sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata and into at least a portion of the second strata; optionally wherein the duration of time is sufficient for the at least a portion of the liquid carbon dioxide to infuse into substantially all of the first strata, or substantially all of the second strata, or into substantially all of the first strata and the second strata. 
     In accordance with Aspect 42, the present disclosure is directed to the method of aspect 41, wherein 
     the first strata comprises or consists essentially of the first strata solid foamable material, 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata solid foamable material, and 
     the steps of subjecting and expanding include expanding the at least a portion of the first strata solid foamable material into the foamed material, wherein the foamed material of the first strata comprises a first strata foamed material, 
     optionally wherein the expanding includes expanding substantially all of the solid foamable material of the first strata into the first strata foamed material. 
     In accordance with Aspect 43, the present disclosure is directed to the method of aspect 41, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata, wherein the duration of time is not sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second strata; 
     and the steps of subjecting and expanding include expanding the at least a portion of the first strata solid foamable material into the first strata foamed material without expanding the second strata material; 
     optionally wherein, following the steps of maintaining and holding, the second strata is substantially free of infused carbon dioxide, and 
     optionally wherein the second strata comprises or consists essentially of a barrier material. 
     In accordance with Aspect 44, the present disclosure is directed to the method of aspect 41, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata and into the at least a portion of the second strata, and the method further comprises the step of exposing the infused article to the second pressure and second temperature for a duration of time such that the at least a portion of carbon dioxide infused into the at least a portion of the second strata diffuses out of the at least a portion of the second strata, while at least a portion of the infused carbon dioxide infused in the first strata remains infused in the at least a portion of the first strata following the exposing; 
     and the steps of subjecting and expanding include expanding the at least a portion of the solid foamable material of the first strata into the first strata foamed material without expanding the second strata material of the second strata, thereby forming a foamed first strata while maintaining the second strata in a solid unfoamed state; 
     optionally wherein, following the step of exposing, the second strata is substantially free of infused carbon dioxide. 
     In accordance with Aspect 45, the present disclosure is directed to the method of any one of aspects 30-40, wherein the step of placing comprises placing the foamable article in the liquid carbon dioxide in the vessel such that the article is not fully immersed in the liquid carbon dioxide. 
     In accordance with Aspect 46, the present disclosure is directed to the method of aspect 45, wherein the first strata is immersed in the liquid carbon dioxide and the second strata is not immersed in the liquid carbon dioxide, and wherein, following the step of exposing, the second strata is substantially free of infused carbon dioxide. 
     In accordance with Aspect 47, the present disclosure is directed to the method of any one of aspects 30-40, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second strata, or 
     wherein the duration of time is sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata and into at least a portion of the second strata; 
     optionally wherein the duration of time is sufficient for the at least a portion of the liquid carbon dioxide to infuse into substantially all of the second strata, or substantially all of the second strata, or into substantially all of the first strata and the second strata. 
     In accordance with Aspect 48, the present disclosure is directed to the method of aspect 47, wherein 
     the second strata comprises or consists essentially of the solid foamable material, 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second strata solid foamable material, and 
     the steps of subjecting and expanding include expanding the at least a portion of the second strata solid foamable material into the foamed material, wherein the foamed material of the second strata comprises a second strata foamed material, 
     optionally wherein the expanding includes expanding substantially all of the second strata solid foamable material into the strata regional foamed material. 
     In accordance with Aspect 49, the present disclosure is directed to the method of aspect 47, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second strata, wherein the duration of time is not sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata; 
     and the steps of subjecting and expanding include expanding the at least a portion of the second strata solid foamable material into the second strata foamed material without expanding the first strata material, thereby forming a foamed second strata while maintaining the first strata in a solid unfoamed state; 
     optionally wherein, following the steps of maintaining and holding, the first strata is substantially free of infused carbon dioxide. 
     In accordance with Aspect 50, the present disclosure is directed to the method of aspect 47, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata and into the at least a portion of the second strata, and the method further comprises the step of exposing the infused article to the second pressure and second temperature for a duration of time such that the at least a portion of carbon dioxide infused into the at least a portion of the first strata diffuses out of the at least a portion of the first strata, while at least a portion of the infused carbon dioxide infused in the second strata remains infused in the at least a portion of the second strata following the exposing; 
     and the steps of subjecting and expanding include expanding the at least a portion of the second strata solid foamable material into the second strata foamed material without expanding the first strata material; 
     optionally wherein, following the step of exposing, the first strata is substantially free of infused carbon dioxide. 
     In accordance with Aspect 51, the present disclosure is directed to the method of any one of aspects 30-40, wherein 
     the first strata comprises or consists of the solid foamable material, the solid foamable material of the first strata being a first strata solid foamable material; 
     the second strata comprises or consists essentially of the solid foamable material, the solid foamable material of the second strata being a second solid strata foamable material; 
     the step of maintaining and holding includes holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata and into at least a portion of the second strata; and 
     the steps of subjecting and expanding expands at least a portion of the first strata solid foamable material into a first strata foamed material, and expands at least a portion of the second regional strata foamable material into a second strata foamed material, 
     optionally wherein the expanding includes expanding substantially all of the first strata solid foamable material or substantially all of the second strata solid foamable material, or expanding substantially all of the first strata solid foamable material and substantially all of the second strata solid foamable material. 
     In accordance with Aspect 52, the present disclosure is directed to the method of aspect 51, wherein, in the additive manufactured foamed article, the first strata foamed material and the second strata foamed material are in contact with each other. 
     In accordance with Aspect 53, the present disclosure is directed to the method of aspect 51, wherein, in the additive manufactured foamed article, the first strata foamed material and the second strata foamed material are not in contact with each other. 
     In accordance with Aspect 54, the present disclosure is directed to the method of any one of aspects 30-53, wherein the foamable article is configured as a series of three or more strata, further comprising a third strata including a third comprising or consisting essentially of a third strata material, 
     optionally wherein the third strata material comprises or consists essentially of a third strata solid foamable material, 
     optionally wherein the third strata foamable material is a blend according to any one of aspects 138-151, and 
     optionally wherein the third strata is positioned between the first strata and the second strata. 
     In accordance with Aspect 55, the present disclosure is directed to the method of aspect 54, wherein the third strata comprises a third plurality of particles. 
     In accordance with Aspect 56, the present disclosure is directed to the method of aspect 54, wherein the third strata comprises a third extruded material. 
     In accordance with Aspect 57, the present disclosure is directed to the method of aspect 54, wherein the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the first strata, or into the first strata and the second strata, or into the second strata, or into the second strata and the third strata, or into the third strata, or into the third strata and the first strata. 
     In accordance with Aspect 58, the present disclosure is directed to the method of any one of aspects 54-57, wherein the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for liquid carbon dioxide to infuse into one or two of the three strata but not into the other of the three strata; 
     optionally wherein the carbon dioxide infuses into the first strata but not substantially into the second strata, or into the first strata but not substantially into the third strata, or into the second strata but not substantially into the first strata, or into the second strata but not substantially into the third strata, or into the third strata but not substantially into the first strata, or into the third strata but not substantially into the second strata; or 
     optionally wherein the carbon dioxide infuses into the first strata and into the second strata but not substantially into the third strata, or into the first strata and the third strata but not substantially into the second strata, or into the second strata and the third strata but not substantially into the first strata. 
     In accordance with Aspect 59, the present disclosure is directed to the method of any one of aspects 54-58, wherein the method includes the step of exposing, and the exposing step comprises exposing the foamable article to the second pressure and second temperature at which the carbon dioxide remains infused within one or two of the three strata while the carbon dioxide diffuses out of the other of the three strata, 
     optionally wherein the carbon dioxide remains infused in the first strata but not substantially in the second strata, or in the first strata but not substantially in the third strata, or in the second strata but not substantially in the first strata, or in the second strata but not substantially in the third strata, or in the third strata but not substantially in the first strata, or in the third strata but not substantially in the second strata; or 
     optionally wherein the carbon dioxide remains infused in the first strata and the second strata and substantially diffuses out of the third strata, or remains infused in the first strata and the third strata and substantially diffuses out of the second strata, or remains infused in the second strata and the third strata and substantially diffuses out of the first strata; or 
     optionally wherein the carbon dioxide substantially diffuses out of the first strata and the second strata and remains infused in the third strata, or substantially diffuses out of the first region and the third strata and remains infused in the second strata, or substantially diffuses out of the second strata and the third strata and remains infused in the first strata. 
     In accordance with Aspect 60, the present disclosure is directed to the method of any one of aspects 54-58, wherein the steps of subjecting and expanding expands material(s) of one or two of the three strata into foamed material(s) while maintaining the other of the three strata in a solid, unfoamed state; 
     optionally wherein the steps of subjecting and expanding expand at least a portion of the first strata material into a first strata foamed material, or expand at least a portion of the second strata material into a second strata foamed material, or expand at least a portion of the third strata material into a third strata foamed material, or any combination thereof; or 
     optionally wherein the steps of subjecting and expanding expand the first strata material into a first strata foamed material and the second strata material into a second strata foamed material, or expand the first strata material into a first strata foamed material and the third strata material into a third strata foamed material, or expand the second strata material into a second strata foamed material and expands the third strata material into a third regional strata material; or 
     optionally wherein, following the steps of subjecting and expanding, the first strata material remains a first strata solid unfoamed material, or the second strata material remains a second strata solid unfoamed material, or the third strata material remains a third strata solid unfoamed material, or the first strata material and the second strata material both remain as first strata and second strata solid unfoamed materials, or the first strata material and the third strata material both remain as first strata and third strata solid unfoamed materials, or the second strata material and the third strata material both remain as second strata and third strata solid unfoamed materials. 
     In accordance with Aspect 61, the present disclosure is directed to the method of any one of aspects 1-60 wherein manufacturing the foamable article using an additive manufacturing method comprises extruding at least one first filament or pellet comprising the foamable material to form the foamable article. 
     In accordance with Aspect 62, the present disclosure is directed to the method of aspect 61, wherein the depositing comprises depositing the foamable material on a substrate. 
     In accordance with Aspect 63, the present disclosure is directed to the method of aspect 62, wherein the substrate comprises a two-dimensional substrate. 
     In accordance with Aspect 64, the present disclosure is directed to the method of aspect 62, wherein the substrate comprises a three-dimensional substrate. 
     In accordance with Aspect 65, the present disclosure is directed to the method of aspect 62-64, further comprising following the depositing, removing the substrate from the foamable article. 
     In accordance with Aspect 66, the present disclosure is directed to the method of aspect 65, wherein removing the substrate comprises dissolving the substrate in a solvent, wherein the foamable article is not soluble in the solvent. 
     In accordance with Aspect 67, the present disclosure is directed to the method of aspect 66, wherein the solvent comprises water. 
     In accordance with Aspect 68, the present disclosure is directed to the method of aspect 65, wherein removing the substrate comprises physically separating the substrate from the foamable article. 
     In accordance with Aspect 69, the present disclosure is directed to the method of any one of aspects 65-68, wherein following the removing, the foamable article comprises a lattice structure. 
     In accordance with Aspect 70, the present disclosure is directed to the method of any one of aspects 65-69, further comprising adding one or more additional materials according to aspect 153-183 to the foamable article. 
     In accordance with Aspect 71, the present disclosure is directed to the method of aspect 70, wherein adding the one or more additional materials comprises spraying, brushing, extruding, pressing, or pouring the one or more additional materials onto the foamable article, or dipping the foamable article into the one or more additional materials. 
     In accordance with Aspect 72, the present disclosure is directed to the method of any one of aspects 61-71, wherein the manufacturing the foamable article further comprises extruding a second filament or pellet, wherein the second filament or pellet comprises a second extruded material. 
     In accordance with Aspect 73, the present disclosure is directed to the method of aspect 72, wherein the second extruded material comprises an additional material according to any of aspects 153-183. 
     In accordance with Aspect 74, the present disclosure is directed to the method according to aspect 72 or 73, wherein the foamable material and the second extruded material are deposited sequentially and wherein the foamable material is deposited before the second extruded material or wherein the foamable material is deposited after the second extruded material. 
     In accordance with Aspect 75, the present disclosure is directed to the method according to aspect 72 or 73, wherein the foamable material and the second extruded material are deposited simultaneously. 
     In accordance with Aspect 76, the present disclosure is directed to the method according to any one of aspects 72-75, wherein the foamable material is deposited from one or more first nozzles; and wherein the second extruded material is deposited from one or more second nozzles. 
     In accordance with Aspect 77, the present disclosure is directed to the method according to any one of aspects 72-76, wherein the foamable material and the second extruded material are deposited via the same nozzle or plurality of nozzles. 
     In accordance with Aspect 78, the present disclosure is directed to the method according to any one of aspects 72-77, wherein the second extruded material comprises a second foamable material according to any one of aspects 1-9 or 124-152. 
     In accordance with Aspect 79, the present disclosure is directed to the method according to aspect 78, wherein the liquid carbon dioxide is soluble in the foamable material at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent; and optionally wherein the liquid carbon dioxide is soluble in the second foamable material at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent. 
     In accordance with Aspect 80, the present disclosure is directed to the method according to aspect 78 or 79, wherein the liquid carbon dioxide is about 80 percent as soluble in the second extruded material as in the foamable material, optionally about 60 percent as soluble, 40 percent as soluble, or about 20 percent as soluble. 
     In accordance with Aspect 81, the present disclosure is directed to the method according to aspect 78 or 79, wherein the liquid carbon dioxide is soluble at a concentration of at less than 1 weight percent based on a total weight of the second extruded material, optionally less than 0.1 weight percent, or optionally wherein the liquid carbon dioxide is substantially insoluble in the second extruded material. 
     In accordance with Aspect 82, the present disclosure is directed to the method according to aspect 81, wherein following the expanding and foaming, the second extruded material remains substantially unfoamed. 
     In accordance with Aspect 83, the present disclosure is directed to the method of any one of aspects 78-80, wherein following the expanding and forming, the foamable material has a first foamed density and the second extruded material has a second foamed density. 
     In accordance with Aspect 84, the present disclosure is directed to the method of aspect 83, wherein the first foamed density and the second foamed density are substantially the same. 
     In accordance with Aspect 85, the present disclosure is directed to the method of aspect 83 or 84, wherein the first foamed density is at least 20 percent greater than the second foamed density, optionally at least 40 percent greater, at least 60 percent greater, or at least 80 percent greater than the second foamed density. 
     In accordance with Aspect 86, the present disclosure is directed to the method of aspect 83 or 84, wherein the second foamed density is at least 20 percent greater than the second foamed density, optionally at least 40 percent greater, at least 60 percent greater, or at least 80 percent greater than the first foamed density. 
     In accordance with Aspect 87, the present disclosure is directed to the method of any one of aspects 78-86, further comprising applying a coating to the additive manufactured foamed article following the expanding and foaming. 
     In accordance with Aspect 88, the present disclosure is directed to the method of aspect 87, wherein the coating comprises a decoration, a protective coating, a waterproof coating, a barrier coating comprising a barrier material according to any one of aspects 154-163, or any combination thereof. 
     In accordance with Aspect 89, the present disclosure is directed to the method of any one of the preceding aspects, wherein the foamable article is configured as a series of two or more regions including a first region including a first regional material and a second region including a second regional material, wherein the first regional material or the second regional material or both the first regional material and the second regional material are a solid foamable material; optionally wherein the first region or the second region forms an outermost surface of the article, or wherein both the first region and the second region individually or jointly form the outermost surface of the additive manufactured article. 
     In accordance with Aspect 90, the present disclosure is directed to the method of 89, wherein the regions include layers, and wherein the first region or the second region forms an inner layer of the foamable article, or both the first region and the second region individually form separate inner layers of the foamable manufactured article, optionally wherein the article is a layered sheet. 
     In accordance with Aspect 91, the present disclosure is directed to the method of aspect 89 or 90, wherein, in the foamable article, the first region forms the outermost surface of the additive manufactured article and the second region forms an inner layer of the foamable article. 
     In accordance with Aspect 92, the present disclosure is directed to the method of any one of aspects 89-91, wherein, in the foamable article, the first region comprises or consists essentially of the solid foamable material, the solid foamable material of the first region is a first regional solid foamable material, and in the steps of subjecting and expanding, the first regional solid foamable material either remains as the first regional solid foamable material, or expands into the foamed material wherein the foamed material of the first region is a first regional foamed material. 
     In accordance with Aspect 93, the present disclosure is directed to the method of any one of 89-92, wherein, in the foamable article, the second region comprises or consists essentially of the solid foamable material, the solid foamable material of the second region is a second regional solid foamable material, and in the steps of subjecting and expanding, the second regional solid foamable material either remains as the second solid regional foamable material, or expands into the foamed material wherein the foamed material of the second region is a second regional foamed material. 
     In accordance with Aspect 94, the present disclosure is directed to the method of any one of 89-93, wherein the first regional solid foamable material, or the second regional solid foamable material, or both, is individually a solid foamable material according to any of aspects 1-9 or 124-152 
     In accordance with Aspect 95, the present disclosure is directed to the method of any one of 89-94, wherein the first regional foamed material, or the second regional foamed material, or both, individually are a foamed material according to any of aspects 1-9 or 124-152. 
     In accordance with Aspect 96, the present disclosure is directed to the method of any one of 89-95, wherein the first regional material or the second regional material is a barrier material according to any one of aspects 155-164. 
     In accordance with Aspect 97, the present disclosure is directed to the method of any one of aspects 89-96, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first region, or 
     wherein the duration of time is sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second region, or 
     wherein the duration of time is sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first region and into at least a portion of the second region; 
     optionally wherein the duration of time is sufficient for the at least a portion of the liquid carbon dioxide to infuse into substantially all of the first region, or substantially all of the second region, or into substantially all of the first region and the second region. 
     In accordance with Aspect 98, the present disclosure is directed to the method of aspect 97, wherein 
     the first region comprises or consists essentially of the first regional solid foamable material, 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first regional solid foamable material, and 
     the steps of subjecting and expanding include expanding the at least a portion of the first regional solid foamable material into the foamed material, wherein the foamed material of the first region comprises a first regional foamed material, 
     optionally wherein the expanding includes expanding substantially all of the solid foamable material of the first region into the first regional foamed material. 
     In accordance with Aspect 99, the present disclosure is directed to the method of aspect 97, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first region, wherein the duration of time is not sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second region; 
     and the steps of subjecting and expanding include expanding the at least a portion of the first regional solid foamable material into the first regional foamed material without expanding the second regional material; 
     optionally wherein, following the steps of maintaining and holding, the second region is substantially free of infused carbon dioxide, and optionally wherein the second region comprises or consists essentially of a barrier material. 
     In accordance with Aspect 100, the present disclosure is directed to the method of aspect 97, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first region and into the at least a portion of the second region, and the method further comprises the step of exposing the infused article to the second pressure and second temperature for a duration of time such that the at least a portion of carbon dioxide infused into the at least a portion of the second region diffuses out of the at least a portion of the second region, while at least a portion of the infused carbon dioxide infused in the first region remains infused in the at least a portion of the first region following the exposing; 
     and the steps of subjecting and expanding include expanding the at least a portion of the solid foamable material of the first region into the first regional foamed material without expanding the second regional material of the second region, thereby forming a foamed first region while maintaining the second region in a solid unfoamed state; 
     optionally wherein, following the step of exposing, the second region is substantially free of infused carbon dioxide, and 
     optionally wherein the second region comprises or consists essentially of a barrier material. 
     In accordance with Aspect 101, the present disclosure is directed to the method of any one of aspects 89-96, wherein the step of placing comprises placing the foamable article in the liquid carbon dioxide in the vessel such that the article is not fully immersed in the liquid carbon dioxide. 
     In accordance with Aspect 102, the present disclosure is directed to the method of aspect 101, wherein the first region is immersed in the liquid carbon dioxide and the second region is not immersed in the liquid carbon dioxide, and wherein, following the step of exposing, the second region is substantially free of infused carbon dioxide. 
     In accordance with Aspect 103, the present disclosure is directed to the method of any one of aspects 89-96, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second region, or 
     wherein the duration of time is sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first region and into at least a portion of the second region; 
     optionally wherein the duration of time is sufficient for the at least a portion of the liquid carbon dioxide to infuse into substantially all of the second region, or substantially all of the second region, or into substantially all of the first region and the second region. 
     In accordance with Aspect 104, the present disclosure is directed to the method of aspect 103, wherein 
     the second region comprises or consists essentially of the solid foamable material, 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second regional solid foamable material, and 
     the steps of subjecting and expanding include expanding the at least a portion of the second regional solid foamable material into the foamed material, wherein the foamed material of the second region comprises a second regional foamed material, 
     optionally wherein the expanding includes expanding substantially all of the second regional solid foamable material into the second regional foamed material. 
     In accordance with Aspect 105, the present disclosure is directed to the method of aspect 103, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second region, wherein the duration of time is not sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first region; 
     and the steps of subjecting and expanding include expanding the at least a portion of the second regional solid foamable material into the second regional foamed material without expanding the first regional material, thereby forming a foamed second region while maintaining the first region in a solid unfoamed state; 
     optionally wherein, following the steps of maintaining and holding, the first region is substantially free of infused carbon dioxide, and 
     optionally wherein the first region comprises or consists essentially of a barrier material. 
     In accordance with Aspect 106, the present disclosure is directed to the method of aspect 103, wherein 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first region and into the at least a portion of the second region, and the method further comprises the step of exposing the infused article to the second pressure and second temperature for a duration of time such that the at least a portion of carbon dioxide infused into the at least a portion of the first region diffuses out of the at least a portion of the first region, while at least a portion of the infused carbon dioxide infused in the second region remains infused in the at least a portion of the second region following the exposing; 
     and the steps of subjecting and expanding include expanding the at least a portion of the second regional solid foamable material into the second regional foamed material without expanding the first regional material; 
     optionally wherein, following the step of exposing, the first region is substantially free of infused carbon dioxide, and 
     optionally wherein the first region comprises or consists essentially of a barrier material. 
     In accordance with Aspect 107, the present disclosure is directed to the method of any one of aspects 89-96, wherein 
     the first region comprises or consists of the solid foamable material, the solid foamable material of the first region being a first regional solid foamable material; 
     the second region comprises or consists essentially of the solid foamable material, the solid foamable material of the second region being a second solid regional foamable material; 
     the step of maintaining and holding includes holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first region and into at least a portion of the second region; and 
     the steps of subjecting and expanding expands at least a portion of the first regional solid foamable material into a first regional foamed material, and expands at least a portion of the second regional solid foamable material into a second regional foamed material, optionally wherein the expanding includes expanding substantially all of the first regional solid foamable material or substantially all of the second regional solid foamable material, or expanding substantially all of the first regional solid foamable material and substantially all of the second regional solid foamable material. 
     In accordance with Aspect 108, the present disclosure is directed to the method of aspect 107, wherein, in the additive manufactured foamed article, the first regional foamed material and the second regional foamed material are in contact with each other. 
     In accordance with Aspect 109, the present disclosure is directed to the method of aspect 107, wherein, in the additive manufactured foamed article, the first regional foamed material and the second regional foamed material are not in contact with each other. 
     In accordance with Aspect 110, the present disclosure is directed to the method of any one of aspects 89-109, wherein 
     the first region comprises or consists essentially of the first regional solid foamable material and the second region comprises or consists essentially of a barrier material, or wherein the first region comprises or consists essentially of the barrier material and the second region comprises or consists essentially of the solid foamable material; 
     the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the solid foamable material, wherein the duration of time is not sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the barrier material; 
     and the steps of subjecting and expanding include expanding the solid foamable material into the foamed material without expanding the barrier material; 
     optionally wherein, in the foamed article, the foamed material and the barrier material are in contact with each other, or the foamed material and the barrier material are not in contact with each other. 
     In accordance with Aspect 111, the present disclosure is directed to the method of any one of aspects 89-110, wherein the foamable article is configured as a series of three or more regions, further comprising a third region comprising or consisting essentially of a third regional material, 
     optionally wherein the third regional material comprises or consists essentially of a barrier material, or comprises or consists essentially of a third regional solid foamable material, or 
     optionally wherein the third region is positioned between the first region and the second region. 
     In accordance with Aspect 112, the present disclosure is directed to the method of aspect 111, wherein the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the first region, or into the first region and the second region, or into the second region, or into the second region and the third region, or into the third region, or into the third region and the first region. 
     In accordance with Aspect 113, the present disclosure is directed to the method of aspect 111 or 112, wherein the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for liquid carbon dioxide to infuse into one or two of the three regions but not into the other of the three regions; 
     optionally wherein the carbon dioxide infuses into the first region but not substantially into the second region, or into the first region but not substantially into the third region, or into the second region but not substantially into the first region, or into the second region but not substantially into the third region, or into the third region but not substantially into the first region, or into the third region but not substantially into the second region; or 
     optionally wherein the carbon dioxide infuses into the first region and into the second region but not substantially into the third region, or into the first region and the third region but not substantially into the second region, or into the second region and the third region but not substantially into the first region. 
     In accordance with Aspect 114, the present disclosure is directed to the method of any one of aspects 111-113, wherein the method includes the step of exposing, and the exposing step comprises exposing the foamable article to the second pressure and second temperature at which the carbon dioxide remains infused within one or two of the three regions while the carbon dioxide diffuses out of the other of the three regions, 
     optionally wherein the carbon dioxide remains infused in the first region but not substantially in the second region, or in the first region but not substantially in the third region, or in the second region but not substantially in the first region, or in the second region but not substantially in the third region, or in the third region but not substantially in the first region, or in the third region but not substantially in the second region; or 
     optionally wherein the carbon dioxide remains infused in the first region and the second region and substantially diffuses out of the third region, or remains infused in the first region and the third region and substantially diffuses out of the second region, or remains infused in the second region and the third region and substantially diffuses out of the first region; or 
     optionally wherein the carbon dioxide substantially diffuses out of the first region and the second region and remains infused in the third region, or substantially diffuses out of the first region and the third region and remains infused in the second region, or substantially diffuses out of the second region and the third region and remains infused in the first region. 
     In accordance with Aspect 115, the present disclosure is directed to the method of any one of aspects 111-113, wherein the steps of subjecting and expanding expands material(s) of one or two of the three regions into foamed material(s) while maintaining the other of the three regions in a solid, unfoamed state; 
     optionally wherein the steps of subjecting and expanding expand at least a portion of the first regional material into a first regional foamed material, or expand at least a portion of the second regional material into a second regional foamed material, or expand at least a portion of the third regional material into a third regional foamed material, or any combination thereof; or 
     optionally wherein the steps of subjecting and expanding expand the first regional material into a first regional foamed material and the second regional material into a second regional foamed material, or expand the first regional material into a first regional foamed material and the third regional material into a third regional foamed material, or expand the second regional material into a second regional foamed material and expands the third regional material into a third regional foamed material; or 
     optionally wherein, following the steps of subjecting and expanding, the first regional material remains a first regional solid unfoamed material, or the second regional material remains a second regional solid unfoamed material, or the third regional material remains a third regional solid unfoamed material, or the first regional material and the second regional material both remain as first regional and second regional solid unfoamed materials, or the first regional material and the third regional material both remain as first regional and third regional solid unfoamed materials, or the second regional material and the third regional material both remain as second regional and third regional solid unfoamed materials. 
     In accordance with Aspect 116, the present disclosure is directed to the method of any one of aspects 111-115, wherein the foamable article is configured as a series of four or more regions, the fourth region comprising or consisting essentially of a fourth regional material, optionally wherein the fourth regional material comprises or consists essentially of a barrier material, or of a solid foamable material; 
     optionally wherein the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the fourth region; or 
     optionally wherein the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for liquid carbon dioxide to infuse into one or more of the first region, the second region, and the third region, but not into the fourth region; or 
     optionally wherein the method includes the step of exposing, and the exposing step comprises exposing the foamable article to the second pressure and second temperature at which the carbon dioxide remains infused within one or more of the first region, the second region, and the third region, while the carbon dioxide diffuses out of the fourth region; or 
     optionally wherein the method includes the step of exposing, and the exposing step comprises exposing the foamable article to the second pressure and second temperature at which the carbon dioxide remains infused within the fourth region. 
     In accordance with Aspect 117, the present disclosure is directed to the method of aspect 116, wherein, following the steps of subjecting and expanding, the fourth regional material remains a fourth regional solid unfoamed material, or the fourth regional material expands into a fourth regional foamed material. 
     In accordance with Aspect 118, the present disclosure is directed to a method of manufacturing an article, the method comprising: 
     affixing a first component to a second component, wherein the first component is an additive manufactured foamed article made by the method of any one of the preceding aspects. 
     In accordance with Aspect 119, the present disclosure is directed to the method of aspect 118, wherein the first component is a first component of an article of apparel, the second component is a second component of an article of apparel, and the article is an article of apparel. 
     In accordance with Aspect 120, the present disclosure is directed to the method of aspect 118, wherein the first component is a first component of an article of footwear, the second component is a second component of an article of footwear, and the article is an article of footwear. 
     In accordance with Aspect 121, the present disclosure is directed to the method of aspect 120, wherein the first component is a cushioning element, and the second element is a sole component or an upper component. 
     In accordance with Aspect 122, the present disclosure is directed to the method of aspect 118, wherein the first component is a first component of an article of sporting equipment, the second component is a second component of an article of sporting equipment, and the article is an article of sporting equipment. 
     In accordance with Aspect 123, the present disclosure is directed to a foamed article made by the method of any one of aspects 1-122. 
     In accordance with Aspect 124, the present disclosure is directed to the method of any one of the preceding aspects, wherein the foamable material comprises a polymeric component including all of the polymers present in the foamable material, and the polymeric component consists of the one or more first thermoplastic elastomers. 
     In accordance with Aspect 125, the present disclosure is directed to the method of aspect 124, wherein the one or more first thermoplastic elastomers comprise one or more thermoplastic elastomeric polyolefin homopolymers or copolymers, one or more thermoplastic elastomeric polyamide homopolymers or copolymers, one or more thermoplastic elastomeric polyester homopolymers or copolymers, one or more thermoplastic elastomeric polyurethane homopolymers or copolymers, one or more thermoplastic elastomeric styrenic homopolymers or copolymers, or any combination thereof. 
     In accordance with Aspect 126, the present disclosure is directed to the method of aspect 124 or 125, wherein the one or more first thermoplastic elastomers comprise or consist essentially of one or more thermoplastic elastomeric polyamide homopolymers or copolymers. 
     In accordance with Aspect 127, the present disclosure is directed to the method of any one of aspects 124-126, wherein the first one or more thermoplastic elastomers comprise or consist essentially of polyether block polyamide (PEBA) copolymer elastomers. 
     In accordance with Aspect 128, the present disclosure is directed to the method of any one of aspects 124-127, wherein the one or more first thermoplastic elastomers comprise or consist essentially of one or more thermoplastic elastomeric styrenic homopolymers or copolymers. 
     In accordance with Aspect 129, the present disclosure is directed to the method of any one of aspects 124-128, wherein the one or more first thermoplastic elastomers comprise or consist essentially of styrene butadiene styrene (SBS) block copolymer elastomers, styrene ethylene butylene styrene (SEBS) copolymer elastomers, styrene acrylonitrile (SAN) copolymer elastomers, or any combination thereof. 
     In accordance with Aspect 130, the present disclosure is directed to the method of any one of aspects 124-129, wherein the one or more first thermoplastic elastomers comprise or consist essentially of one or more thermoplastic polyurethane elastomeric homopolymers or copolymers. 
     In accordance with Aspect 131, the present disclosure is directed to the method of any one of aspects 124-130, wherein the one or more first thermoplastic elastomers comprise or consist essentially of thermoplastic polyester-polyurethane elastomers, polyether-polyurethane elastomers, polycarbonate-polyurethane elastomers, or combinations thereof. 
     In accordance with Aspect 132, the present disclosure is directed to the method of any one of aspects 124-131, wherein the one or more first thermoplastic elastomers of the foamable material comprises or consists essentially of one or more thermoplastic polyester-polyurethane elastomers, 
     optionally wherein the polymeric component of the foamable material consists of one or more thermoplastic polyester-polyurethane elastomers. 
     In accordance with Aspect 133, the present disclosure is directed to the method of any one of aspects 124-131, wherein the one or more first thermoplastic elastomers comprise or consist essentially of one or more thermoplastic polyolefin elastomeric homopolymers or copolymers. 
     In accordance with Aspect 134, the present disclosure is directed to the method of any one of aspects 124-133, wherein the one or more first thermoplastic elastomers comprise or consist essentially of thermoplastic elastomeric polypropylene homopolymers or copolymers, thermoplastic elastomeric polyethylene homopolymers or copolymers, thermoplastic elastomeric polybutylene homopolymers or copolymers, or any combination thereof. 
     In accordance with Aspect 135, the present disclosure is directed to the method of any one of aspects 124-133, wherein the one or more first thermoplastic elastomers comprises or consists essentially of thermoplastic elastomeric ethylene-vinyl acetate copolymers. 
     In accordance with Aspect 136, the present disclosure is directed to the method of aspect 135, wherein the thermoplastic elastomeric ethylene-vinyl acetate copolymers include from about 25 to about 50 weight percent vinyl acetate content. 
     In accordance with Aspect 137, the present disclosure is directed to the method of any one of aspect 124-136, wherein the foamable material comprises a mixture of the polymeric component and a non-polymeric component consisting of one or more non-polymeric additives, optionally wherein the foamable material comprises from about 0.005 to about 20 percent by weight of the non-polymeric component based on a total weight of the foamable material, or about 0.5 to about 10 percent by weight of the non-polymeric additive based on a total weight of the foamable material. 
     In accordance with Aspect 138, the present disclosure is directed to the method of any one of aspects 124-137, wherein the one or more first thermoplastic elastomers comprises or consists essentially of one or more recycled first thermoplastic elastomers. 
     In accordance with Aspect 139, the present disclosure is directed to the method of any one of aspects 124-135, wherein the foamable material comprises or consists essentially of a blend of the one or more first thermoplastic elastomers and a second material, optionally wherein the second material comprises or consists essentially of one or more second polymers, optionally wherein the one or more second polymers comprise or consist essentially of one or more second thermoplastics. 
     In accordance with Aspect 140, the present disclosure is directed to the method of any one of aspects 124-139, wherein the polymeric component of the foamable material consists of a blend of the one or more first thermoplastic elastomers and the one or more second thermoplastics, optionally wherein the blend foams during the steps of subjecting and expanding. 
     In accordance with Aspect 141, the present disclosure is directed to the method of aspect 140, wherein the one or more second thermoplastics comprise one or more thermoplastic polyolefin homopolymers or copolymers, one or more thermoplastic polyamide homopolymers or copolymers, one or more thermoplastic polyester homopolymers or copolymers, one or more thermoplastic polyurethane homopolymers or copolymers, one or more thermoplastic styrenic homopolymers or copolymers, or any combination thereof. 
     In accordance with Aspect 142, the present disclosure is directed to the method of aspect 140 or 141, wherein the one or more second thermoplastics comprise or consist essentially of thermoplastic polypropylene homopolymers or copolymers, thermoplastic polyethylene homopolymers or copolymers, thermoplastic polybutylene homopolymers or copolymers, or any combination thereof. 
     In accordance with Aspect 143, the present disclosure is directed to the method of any one of aspects 139-142, wherein the one or more second thermoplastics comprise or consist essentially of one or more thermoplastic polyethylene copolymers. 
     In accordance with Aspect 144, the present disclosure is directed to the method of any one of aspects 139-143, wherein the one or more second thermoplastics comprise or consist essentially of one or more thermoplastic ethylene-vinyl alcohol copolymers. 
     In accordance with Aspect 145, the present disclosure is directed to the method of aspect 139, wherein the polymeric component of the foamable material consists of one or more first thermoplastic elastomeric polyurethane homopolymers or copolymers, and one or more second thermoplastic ethylene-vinyl alcohol copolymers. 
     In accordance with Aspect 146, the present disclosure is directed to the method of aspect 145, wherein the polymeric component consists of one or more first thermoplastic elastomeric polyester-polyurethane copolymers and one or more second thermoplastic ethylene-vinyl alcohol copolymers. 
     In accordance with Aspect 147, the present disclosure is directed to the method of any one of aspects 139-146, wherein the blend comprises one or more recycled first thermoplastic elastomers, or one or more recycled second thermoplastics, or both. 
     In accordance with Aspect 148, the present disclosure is directed to the method of aspect 147, wherein the blend is a phase-separated blend of the one or more first thermoplastic elastomers and the one or more second thermoplastics. 
     In accordance with Aspect 149, the present disclosure is directed to the method of aspect 148, wherein the phase-separated blend includes one or more phase-separated regions including interfaces between the one or more first thermoplastic elastomers and the one or more second thermoplastics. 
     In accordance with Aspect 150, the present disclosure is directed to the method of any one of aspects 139-149, wherein the blend comprises about 95 percent by weight of the one or more first thermoplastic elastomers and about 5 percent by weight of the one or more second thermoplastics based on a total weight of the blend. 
     In accordance with Aspect 151, the present disclosure is directed to the method of any one of aspects 140-150, wherein the second thermoplastic has a hardness at least 10 Shore A units greater than the foamable material, or optionally at least 20 Shore A units greater, at least 30 Shore A units greater, or at least 40 Shore A units greater than the foamable material. 
     In accordance with Aspect 152, the present disclosure is directed to the method of any one of aspects 139-151, wherein the liquid carbon dioxide is soluble in the one or more first thermoplastic elastomers at a concentration of from about 1 weight percent to about 30 weight percent based on a total weight of the one or more first thermoplastic elastomers present in the foamable material, optionally from about 5 weight percent to about 20 weight percent, and wherein the liquid carbon dioxide is soluble in the one or more second thermoplastics at a concentration of at less than 1 weight percent based on a total weight of the one or more second thermoplastics present in the foamable material, optionally less than 0.1 weight percent, or optionally wherein the liquid carbon dioxide is substantially insoluble in the one or more second thermoplastics. 
     In accordance with Aspect 153, the present disclosure is directed to the method of any one of the preceding aspects, wherein the article comprises an additional material, wherein the additional material is a separate material from the foamable material, wherein the additional material comprises or consists essentially of one or more polymers, and includes an additional material polymeric component consisting of all the polymers present in the additional material; optionally wherein the additional material is comprises or consists essentially of a second material, optionally wherein the second material is a thermoplastic material optionally wherein the additional material comprises the additional material polymeric component mixed with an additional material non-polymeric component consisting of all non-polymeric components present in the additional material. 
     In accordance with Aspect 154, the present disclosure is directed to the method of any one of the preceding aspects, wherein the article comprises one or more first portions of the foamable material, and one or more second portions of the additional material, and wherein the one or more first portions are distinct from the one or more second portions. 
     In accordance with Aspect 155, the present disclosure is directed to the method of aspect 153 or 154, wherein the additional material comprises a barrier material comprising one or more barrier polymers, the barrier material comprising a barrier polymeric component consisting of all polymers present in the barrier material. 
     In accordance with Aspect 156, the present disclosure is directed to the method of any one of aspects 153-155, wherein the additional material comprises a plasticizer. 
     In accordance with Aspect 157, the present disclosure is directed to the method of aspect 155 or 156, wherein during the expanding step, the additional material remains substantially unfoamed. 
     In accordance with Aspect 158, the present disclosure is directed to the method of aspect 157, wherein the barrier material has a hardness at least 10 Shore A units greater than the foamable material, or optionally at least 20 Shore A units greater, at least 30 Shore A units greater, or at least 40 Shore A units greater than the foamable material. 
     In accordance with Aspect 159, the present disclosure is directed to the method of any one of aspects 153-158, wherein the barrier material has a nitrogen gas transmission rate at least 50 percent lower than a nitrogen gas transmission rate of the foamable material, optionally less than or equal to 10 cubic centimeters per square meter per 24 hours, or less than or equal to 1 cubic centimeter per square meter per 24 hours. 
     In accordance with Aspect 160, the present disclosure is directed to the method of any one of aspects 153-159, wherein the barrier polymeric component of the barrier material consists of one or more barrier polymers each individually having a nitrogen gas transmission rate of less than or equal to 30 cubic centimeters per square meter per 24 hours, or less than or equal to 10 cubic centimeter per square meter per 24 hours, or less than or equal to 1 cubic centimeter per square meter per 24 hours. 
     In accordance with Aspect 161, the present disclosure is directed to the method of aspect 160, wherein the one or more barrier polymers comprise or consist essentially of one or more vinylidene chloride polymers, one or more acrylonitrile polymers or copolymers, one or more polyamides, one or more epoxy resins, one or more amine polymers or copolymers, one or more thermoplastic polyolefin homopolymers or copolymers, one or more thermoplastic polyolefin copolymers, one or more thermoplastic polyethylene copolymers, one or more thermoplastic ethylene-vinyl alcohol copolymers, or one or more thermoplastic elastomeric ethylene-vinyl alcohol copolymers. 
     In accordance with Aspect 162, the present disclosure is directed to the method of any one of aspects 153-159, wherein, at the first temperature and first pressure, the liquid carbon dioxide is soluble in the foamable material at a first concentration, the liquid carbon dioxide is soluble in the barrier material at a second concentration, and the first concentration is at least 20 percent greater than the second concentration, optionally wherein the first concentration is at least 50 percent greater than the second concentration, or is at least 70 percent greater than the second concentration. 
     In accordance with Aspect 163, the present disclosure is directed to the method of aspect 162, wherein the second concentration is less than 1 weight percent, optionally less than 0.1 weight percent, or optionally wherein the liquid carbon dioxide is substantially insoluble in the barrier material. 
     In accordance with Aspect 164, the present disclosure is directed to the method of any one of aspects 153-163, wherein the barrier material comprises one or more ethylene-vinyl alcohol copolymers, optionally wherein the one or more ethylene-vinyl alcohol copolymers are thermoplastic, 
     optionally wherein the one or more ethylene-vinyl alcohol thermoplastic copolymers include one or more thermoplastic elastomeric copolymers; optionally wherein the barrier polymeric component consists of one or more ethylene-vinyl alcohol copolymers, optionally wherein the one or more ethylene-vinyl alcohol copolymers are thermoplastic, optionally wherein the one or more ethylene-vinyl alcohol thermoplastic copolymers include one or more thermoplastic elastomeric copolymers. 
     In accordance with Aspect 165, the present disclosure is directed to the method of aspect 153 or 154, wherein the additional material is a thermoplastic material, optionally wherein the additional material is an additional thermoplastic elastomeric material, optionally wherein the additional thermoplastic elastomeric material is an additional foamable material. 
     In accordance with Aspect 166, the present disclosure is directed to the method of aspect 165, wherein the additional material is an additional foamable material, and, during the expanding step, the additional foamable material expands into an additional foamed material. 
     In accordance with Aspect 167, the present disclosure is directed to the method of aspect 166, wherein, in the foamed article, a density of the first foamed material differs from a density of the additional foamed material by at least 5 percent, or at least 10 percent, or at least 20 percent. 
     In accordance with Aspect 168, the present disclosure is directed to the method of aspect 165, wherein the article comprises a first foamable material comprising or consisting essentially of the solid foamable material and further comprises the additional material, wherein the additional material is an additional foamable material, the steps of maintaining and holding comprise holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the first foamable material but not into the additional foamable material, and the steps of subjecting and expanding comprise expanding the first foamable material into a first foamed material while maintaining the additional foamable material as a substantially unfoamed additional foamable material. 
     In accordance with Aspect 169, the present disclosure is directed to the method of aspect 165, wherein the article comprises the solid first foamable material and further comprises the additional material, wherein the additional material is an additional foamable material, the steps of maintaining and holding include holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the solid first foamable material and into the solid additional foamable material, the method includes the optional step of exposing and the exposing comprises exposing the article to a second pressure and second temperature at which the carbon dioxide remains infused within the solid additional foamable material but at which the carbon dioxide diffuses out of the sold first foamable material, and the steps of subjecting and expanding comprise expanding the additional foamable material into an additional foamed material while maintaining the solid first foamable material as a substantially unfoamed first foamable material. 
     In accordance with Aspect 170, the present disclosure is directed to the method of aspect 165, wherein the additional material is a recycled material comprising one or more recycled polymers, optionally wherein the one or more recycled polymers comprises one or more recycled thermoplastics, optionally wherein the one or more recycled thermoplastics comprises one or more recycled thermoplastic elastomers; optionally wherein the recycled material comprises a recycled material polymeric component consisting of one or more recycled thermoplastics, optionally wherein the recycled material polymeric component comprises or consists essentially of one or more recycled thermoplastic elastomers. 
     In accordance with Aspect 171, the present disclosure is directed to the method of aspect 170, wherein the recycled material comprises one or more recycled first thermoplastic elastomers, optionally wherein the one or more recycled first thermoplastic elastomers comprise one or more reground first thermoplastic elastomers, optionally wherein the one or more recycled or reground first thermoplastic elastomers includes a thermoplastic elastomer according to any one of aspects 124-138. 
     In accordance with Aspect 172, the present disclosure is directed to the method of aspect 170 or 171, wherein the recycled material further comprises one or more recycled second thermoplastics, optionally wherein the one or more recycled second thermoplastics comprise one or more reground second thermoplastics, optionally wherein the one or more recycled or reground second thermoplastics includes a thermoplastic according to any one of aspects 139-152. 
     In accordance with Aspect 173, the present disclosure is directed to the method of aspect 172, wherein the recycled material comprises one or more recycled or reground thermoplastic polyurethane elastomers or one or more recycled or reground thermoplastic ethylene-vinyl alcohol copolymers or both. 
     In accordance with Aspect 174, the present disclosure is directed to the method of aspect 172 or 173, wherein the recycled material comprises a blend of the one or more recycled or reground thermoplastic elastomers and one or more second thermoplastics, or wherein the recycled material comprises a blend of one or more thermoplastic elastomers and one or more recycled thermoplastics or one or more recycled second thermoplastics, optionally wherein the blend is a phase-separated blend, and optionally wherein the phase-separated blend comprises one or more interfaces between the one or more first thermoplastic elastomers and the one or more second thermoplastics. 
     In accordance with Aspect 175, the present disclosure is directed to the method of any one of aspects 172-174, wherein the recycled material comprises about 99 percent to about 90 percent by weight of the one or more first thermoplastic elastomers and about 1 percent to about 10 percent by weight of the second thermoplastics based on a total weight of the recycled material, optionally wherein the recycled material comprises about 99 percent to about 93 percent by weight of the one or more first thermoplastic elastomers and about 1 percent to about 7 percent by weight of the one or more second thermoplastics, or about 99 percent to about 95 percent by weight of the one or more first thermoplastic elastomers and about 1 percent to about 5 percent by weight of the one or more second thermoplastic elastomers. 
     In accordance with Aspect 176, the present disclosure is directed to the method of any one of aspects 170-175, wherein the recycled material comprises about 99 percent to about 50 percent by weight of recycled or reground polymers based on a total weight of recycled material, optionally from about 99 percent to about 75 percent by weight of recycled or reground polymers. 
     In accordance with Aspect 177, the present disclosure is directed to the method of any one of aspects 170-176, wherein the liquid carbon dioxide is soluble in the recycled material at a concentration of from about 1 weight percent to about 30 weight percent based on a total weight of the recycled material, optionally from about 5 weight percent to about 20 weight percent. 
     In accordance with Aspect 178, the present disclosure is directed to the method of any one of aspects 170-175, wherein the liquid carbon dioxide is soluble in the one or more recycled or reground thermoplastic elastomers at a concentration of from about 1 weight percent to about 30 weight percent based on a total weight of the one or more recycled or reground thermoplastic elastomers, 
     optionally from about 5 weight percent to about 20 weight percent. 
     In accordance with Aspect 179, the present disclosure is directed to the method of any one of aspects 170-178, wherein the liquid carbon dioxide is soluble in the one or more recycled or reground second thermoplastics at less than 1 weight percent, optionally less than 0.1 weight percent based on a total weight of the one or more recycled or reground second thermoplastics, or optionally wherein the liquid carbon dioxide is substantially insoluble in the one or more recycled or reground second thermoplastics. 
     In accordance with Aspect 180, the present disclosure is directed to the method of any one of aspects 171-179, wherein the recycled material comprises a recycled foamed article produced by the method of any one of the preceding aspects, optionally wherein the recycled foamed article is a reground foamed article. 
     In accordance with Aspect 181, the present disclosure is directed to the method of any one of aspects 171-179, wherein the recycled material comprises foamable material, wherein the foamable material is an unfoamed material. 
     In accordance with Aspect 182, the present disclosure is directed to the method of any one of aspects 171-181, wherein the recycled material further comprises one or more virgin first thermoplastic elastomers, optionally wherein the one or more virgin first thermoplastic elastomers includes one or more virgin thermoplastic polyurethane elastomers. 
     In accordance with Aspect 183, the present disclosure is directed to the method of any one of aspects 174-182, wherein the recycled material includes one or more nucleating agents or nucleating sites for foaming the recycled material, optionally wherein the one or more nucleating sites include one or more interfaces between phase-separated polymers. 
     In accordance with Aspect 184, the present disclosure is directed to the method of any one of aspects 171-183, wherein the solid foamable material is a recycled material. 
     In accordance with Aspect 185, the present disclosure is directed to the method of any one of aspects 171-183, wherein the article comprises a first solid foamable material and an additional solid foamable material, and the first solid foamable material is a recycled material, or the additional solid foamable material is a recycled material, or both the first solid foamable material and the additional solid foamable material are recycled materials. 
     In accordance with Aspect 186, the present disclosure is directed to the method of any one of the preceding aspects, wherein the article comprises a barrier layer comprising or consisting essentially of a barrier material. 
     In accordance with Aspect 187, the present disclosure is directed to the method of aspect 186, wherein the barrier material is an additional material according to any one of aspects 153-183. 
     In accordance with Aspect 188, the present disclosure is directed to the method of any one of the preceding aspects, wherein the article comprises a structural layer comprising or consisting essentially of a structural material. 
     In accordance with Aspect 189, the present disclosure is directed to the method of aspect 188, wherein the structural material is an additional material according to any one of aspects 153-183, optionally wherein the structural material comprises a blend of two or more additional materials, optionally wherein at least one of the two or more additional materials is a recycled material. 
     In accordance with Aspect 190, the present disclosure is directed to the method of any one of the preceding aspects, wherein the article comprises one or more tie layers, each of the one or more tie layers individually comprising or consisting essentially of a tie material, wherein the each of the one or more tie layers increases a bond strength between two adjacent layers, optionally wherein the tie material is a solid foamable material according to any one of the aspects 1-9 or 124-152, optionally wherein the solid foamable material is a recycled material. 
     In accordance with Aspect 191, the present disclosure is directed to the method of any one of the preceding aspects, wherein the article comprises one or more protective layers, each of the one or more protective layers individually comprising or consisting essentially of a protective material, wherein the each of the one or more protective layers is adjacent a core layer and has a protective layer thickness, wherein a combination of the one or more protective layers and the adjacent core layer has a minimum curve radius which is greater than a minimum curve radius which causes cracking of the core layer, or of one or more individual layers within the core layer, optionally wherein the protective material is a solid foamable material according to any one of the aspects 1-9 or 124-152, optionally wherein the solid foamable material is a recycled material. 
     In accordance with Aspect 192, the present disclosure is directed to the method of any one of aspects 149-152 wherein the steps of maintaining and expanding comprise nucleating foaming at the one or more interfaces in the foamable material. 
     In accordance with Aspect 193, the present disclosure is directed to the method of any one of the preceding aspects, wherein the steps of maintaining and holding comprise maintaining the first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals), optionally about 15 pounds per square inch (103.4 kilopascals) to about 5500 pounds per square inch (37,900 kilopascals), from about 100 pounds per square inch (689.5 kilopascals) to about 5000 pounds per square inch (34,500 kilopascals), from about 500 pounds per square inch (3450 kilopascals) to about 2000 pounds per square inch (13,790 kilopascals) or from about 1000 pounds per square inch (6895 kilopascals) to about 1500 pounds per square inch (10,300 kilopascals). 
     In accordance with Aspect 194, the present disclosure is directed to the method of any one of the preceding aspects, wherein the steps of maintaining and holding comprise maintaining the first temperature of from about −57 degrees Celsius to about 31 degrees Celsius. 
     In accordance with Aspect 195, the present disclosure is directed to the method of any one of the preceding aspects, wherein the steps of maintaining and holding comprise holding the article at the first pressure and the first temperature for a duration of from about 20 seconds to about 72 hours. 
     In accordance with Aspect 196, the present disclosure is directed to the method of any one of the preceding aspects, wherein the optional step of exposing comprises exposing the article to the second pressure of from about 1 atmosphere (101 kilopascals) to about 85 atmospheres (8613 kilopascals). 
     In accordance with Aspect 197, the present disclosure is directed to the method of any one of the preceding aspects, wherein the optional step of exposing comprises exposing the article to the second temperature of more than about 30 degrees below the softening point of the solid foamable material, or more than about 50 degrees below the softening point of the solid foamable material, 
     optionally more than about 100 degrees below the softening point of the solid foamable material. 
     In accordance with Aspect 198, the present disclosure is directed to the method of any one of the preceding aspects, wherein the optional step of exposing comprises exposing the article to the second pressure and the second temperature for a duration of from about 30 minutes to about 4 weeks. 
     In accordance with Aspect 199, the present disclosure is directed to the method of any one of the preceding aspects, wherein the steps of subjecting and expanding comprise subjecting the article to the third pressure of from about 13 pounds per square inch (89.6 kilopascals) to about 16 pounds per square inch (110.3 kilopascals). 
     In accordance with Aspect 200, the present disclosure is directed to the method of any one of the preceding aspects, wherein the steps of subjecting and expanding comprise subjecting the article to the third temperature of from about 20 degrees Celsius to about 150 degrees Celsius. 
     In accordance with Aspect 201, the present disclosure is directed to the method of any one of the preceding aspects, wherein the steps of subjecting and expanding comprise subjecting the article to the third pressure and the third temperature for a duration of from about 2 seconds to about 5 minutes. 
     In accordance with Aspect 202, the present disclosure is directed to the method of any one of the preceding aspects, wherein the optional step of bringing comprises bringing the foamed article to the fourth pressure of from about 0.03 atmospheres (3.04 kilopascals) to about 2 atmospheres (202.65 kilopascals). 
     In accordance with Aspect 203, the present disclosure is directed to the method of any one of the preceding aspects, wherein the optional step of bringing comprises bringing the foamed article to the fourth temperature of from about 30 degrees Celsius to about 70 degrees Celsius. 
     In accordance with Aspect 204, the present disclosure is directed to the method of any one of the preceding aspects, wherein the optional step of bringing comprises bringing the foamed article to the fourth pressure and the fourth temperature for a duration of from about 15 minutes to about 1 hour. 
     In accordance with Aspect 205, the present disclosure is directed to the method of any one of aspects 2-204, wherein, in the optional step of bringing, the fourth temperature is at or below a glass transition temperature of the solid foamable material. 
     In accordance with Aspect 206, the present disclosure is directed to the method of any one of aspects 2-204, wherein, in the optional step of bringing, the fourth temperature is from about 10 degrees Celsius less than to about 10 degrees Celsius greater than the glass transition temperature of the solid foamable material. 
     In accordance with Aspect 207, the present disclosure is directed to the method of any one of the preceding aspects, wherein, in the foamed article, the foamed material has a density of from about 0.01 gram per cubic centimeter to about 3.0 grams per cubic centimeter, optionally of from about 0.01 gram per cubic centimeter to about 0.1 gram per cubic centimeter, from about 0.01 gram per cubic centimeter to about 0.05 grams per cubic centimeter, from about 0.01 gram per cubic centimeter to about 0.025 grams per cubic centimeter, from about 0.05 grams per cubic centimeter to about 0.1 gram per cubic centimeter, from about 0.1 gram per cubic centimeter to about 3.0 grams per cubic centimeter, from about 0.2 grams per cubic centimeter to about 2.0 grams per cubic centimeter, from about 0.3 grams per cubic centimeter to about 1.5 grams per cubic centimeter, from about 0.3 grams per cubic centimeter to about 1.2 grams per cubic centimeter, or from about 0.4 grams per cubic centimeter to about 1.0 grams per cubic centimeter. 
     In accordance with Aspect 208, the present disclosure is directed to the method of any one of the preceding aspects, wherein, in the foamed article, the foamed material has a volume less than 10 percent greater, optionally less than 5 percent greater, than the foamable material prior to foaming, optionally wherein the foamed article is a stabilized foamed article. 
     In accordance with Aspect 209, the present disclosure is directed to the method of any one of aspects 1-207, wherein, in the foamed article, the foamed material has a volume more than 20 percent greater, optionally more than 30 percent greater or more than 40 percent greater, than the foamable material prior to foaming, optionally wherein the foamed article is a stabilized foamed article. 
     In accordance with Aspect 210, the present disclosure is directed to the method of any one of the preceding aspects, wherein the step of subjecting and expanding comprises expanding the foamable material into the foamed material until the foamed material has a density of from about 0.01 gram per cubic centimeter to about 3.0 grams per cubic centimeter. 
     In accordance with Aspect 211, the present disclosure is directed to the method of any one of the preceding aspects, wherein, following the steps of subjecting and expanding, the foamed material has an expansion ratio of from about 3:1 to about 120:1 relative to the solid foamable material prior to the subjecting and expanding. 
     In accordance with Aspect 212, the present disclosure is directed to the method of any one of the preceding aspects, wherein the solid foamable material has a Shore A hardness of from about 35 A to about 95 A, optionally from about 55 A to about 90 A. 
     In accordance with Aspect 213, the present disclosure is directed to the method of any one of the preceding aspects, wherein the foamed material of the foamed article has a Shore A hardness of from about 35 A to about 95 A, optionally from about 55 A to about 90 A. 
     In accordance with Aspect 214, the present disclosure is directed to the method of any one of the preceding aspects, further comprising forming the solid foamable material using an extrusion process prior to the step of placing. 
     In accordance with Aspect 215, the present disclosure is directed to the method of any one of the preceding aspects, further comprising forming the solid foamable material using an injection molding process prior to the step of placing. 
     In accordance with Aspect 216, the present disclosure is directed to the method of any one of the preceding aspects, further comprising forming the solid foamable material using a thermal and/or vacuum forming process prior to the step of placing. 
     In accordance with Aspect 217, the present disclosure is directed to the method of any one of the preceding aspects, further comprising forming the solid foamable material using an additive manufacturing process prior to the step of placing. 
     In accordance with Aspect 218, the present disclosure is directed to the method of any one of the preceding aspects, wherein the optional step of exposing occurs in the vessel. 
     In accordance with Aspect 219, the present disclosure is directed to the method of any one of the preceding aspects, wherein the steps of subjecting and expanding occur in the vessel. 
     In accordance with Aspect 220, the present disclosure is directed to the method of any one of the preceding aspects, wherein the optional step of exposing further comprises removing the liquid carbon dioxide-infused article from the vessel prior to exposing the article to the optional second pressure and second temperature. 
     In accordance with Aspect 221, the present disclosure is directed to the method of any one of aspects 1-219, wherein the step of subjecting further comprises removing the liquid carbon dioxide-infused article from the vessel prior to subjecting the article to the third pressure and third temperature. 
     In accordance with Aspect 222, the present disclosure is directed to the method of aspect 221, wherein the step of placing the carbon dioxide in the vessel comprises introducing carbon dioxide vapor into the vessel prior to the steps of maintaining and holding. 
     In accordance with Aspect 223, the present disclosure is directed to the method of aspect 222, wherein the introducing the carbon dioxide vapor comprises charging the vessel with the carbon dioxide vapor at a pressure and temperature condition that is a liquid/vapor equilibrium for carbon dioxide. 
     In accordance with Aspect 224, the present disclosure is directed to the method of any one of aspects 221-223, wherein the method further comprises discharging the liquid carbon dioxide from the vessel after the steps of maintaining and holding, prior to the optional step of exposing, or prior to the steps of subjecting and expanding. 
     In accordance with Aspect 225. The method of aspect 224, wherein discharging the liquid carbon dioxide from the vessel comprises converting the liquid carbon dioxide to carbon dioxide vapor prior to or during the discharging. 
     In accordance with Aspect 226, the present disclosure is directed to the method of any one of the preceding aspects, wherein the step of subjecting the article to the third temperature and third pressure comprises introducing the article to a fluid bath, optionally wherein the fluid bath is a water bath. 
     In accordance with Aspect 227, the present disclosure is directed to the method of aspect 226, wherein the fluid bath has a temperature of from about 20 degrees Celsius to about 90 degrees Celsius. 
     In accordance with Aspect 228, the present disclosure is directed to the method of aspect 226 or 227, wherein, during the subjecting, the article is held in the fluid bath for a time of from about 15 seconds to about 5 minutes. 
     In accordance with Aspect 229, the present disclosure is directed to the method of any one of aspects 1-224, wherein the step of subjecting comprises subjecting the article to a source of energy or heat, optionally wherein the source of energy or heat comprises steam, microwave energy, infrared (IR) energy, radio frequency (RF) energy, or any combination thereof. 
     In accordance with Aspect 230, the present disclosure is directed to the method of aspect 229, wherein the step of subjecting the article to the source of energy or heat increases the temperature of at least a portion of the foamable material of the article to a temperature of from about 60 degrees Celsius to about 150 degrees Celsius, optionally wherein the subjecting is for a duration of from about 2 seconds to about 5 minutes. 
     In accordance with Aspect 231, the present disclosure is directed to the method of any one of aspects 3-230, wherein the optional step of stabilizing at the fifth pressure and the fifth temperature comprises placing the foamed article in an oven. 
     In accordance with Aspect 232, the present disclosure is directed to the method of any one of aspects 3-231, wherein the optional step of stabilizing comprises stabilizing at the fifth pressure of about atmospheric pressure. 
     In accordance with Aspect 233, the present disclosure is directed to the method of any one of aspects 3-232, wherein the optional step of stabilizing comprises stabilizing at the fifth temperature of greater than the glass transition temperature of the solid foamable material. 
     In accordance with Aspect 234, the present disclosure is directed to the method of any one of aspects 3-233, wherein the optional step of stabilizing comprises stabilizing at the fifth temperature of from about 30 degrees Celsius to about 70 degrees Celsius, optionally of about 50 degrees Celsius. 
     In accordance with Aspect 235, the present disclosure is directed to the method of any one of aspects 3-234, wherein the optional step of stabilizing comprises stabilizing the foamed article at the fifth temperature for from about 15 minutes to about 60 minutes, optionally for from about 30 minutes to about 45 minutes. 
     In accordance with Aspect 236, the present disclosure is directed to the method of any one of the preceding aspects, wherein the article is configured as a roll, and wherein the step of placing comprises disposing the roll into the vessel, and wherein the steps of subjecting and expanding comprises unrolling the article prior to or during the subjecting, or prior or during the expanding. 
     In accordance with Aspect 237, the present disclosure is directed to the method of aspect 236, wherein the step of placing further comprises disposing a porous spacer between adjacent portions of the article prior to or during the placing, and wherein the steps of maintaining and holding comprise flowing the liquid carbon dioxide through the porous spacer to the adjacent portions of the article. 
     In accordance with Aspect 238, the present disclosure is directed to the method of any one of the preceding aspects, wherein, during the expanding, at least a portion of the article comprising the solid foamable material expands in length, width, and height due to the expansion of the solid foamable material into the foamable material. 
     In accordance with Aspect 239, the present disclosure is directed to the method of aspect 238, wherein, following the expanding, a size of the additive manufactured foamed article is greater in at least one dimension as compared to a size of the foamable article before the placing, 
     optionally wherein the foam article is at least 5 percent larger, or at least 10 percent larger, or at least 15 percent larger, or at least 20 percent larger in one or more of length, width, and height. 
     In accordance with Aspect 240, the present disclosure is directed to the method of aspect 238 or 239, wherein the method includes the step of stabilizing, and, following the stabilizing, the stabilized additive manufactured foamed article is greater in at least one dimension as compared to a size of the article before the placing, optionally wherein the stabilized foam article is at least 5 percent larger, or at least 10 percent larger, or at least 15 percent larger, or at least 20 percent larger in one or more of length, width, and height. 
     In accordance with Aspect 241, the present disclosure is directed to the method of any one of the preceding aspects, further comprising thermoforming one or more surfaces of the additive manufactured foamed article, optionally wherein the foamed article is a stabilized foamed article. 
     In accordance with Aspect 242, the present disclosure is directed to the method of any one of the preceding aspects, wherein the article is a thermoformed article, optionally wherein the method further comprises a step of thermoforming the article prior to the step of placing. 
     In accordance with Aspect 243, the present disclosure is directed to the method of any one of the preceding aspects, wherein the additive manufactured foamed article is a component of an article of apparel, footwear, or sporting equipment. 
     In accordance with Aspect 244, the present disclosure is directed to the method of any one of the preceding aspects, wherein thermoforming one or more surfaces of the additive manufactured foamed article imparts a texture to the one or more surfaces. 
     In accordance with Aspect 245, the present disclosure is directed to the method of any one of the preceding aspects, wherein thermoforming one or more surfaces of the additive manufactured foamed article imparts a finish to the one or more surfaces, optionally wherein the finish is a glossy finish or a matte finish. 
     In accordance with Aspect 246, the present disclosure is directed to the method of any one of the preceding aspects, wherein thermoforming one or more surfaces of the additive manufactured foamed article increases roughness of the one or more surfaces, optionally where increased roughness promotes mechanical interlocking of a bonded surface to the foamed article, or wherein increased roughness imparts additional surface area, wherein the additional surface area increases contact area for an adhesive. 
     In accordance with Aspect 247, the present disclosure is directed to the method of any one of the preceding aspects, wherein thermoforming one or more surfaces of the additive manufactured foamed article reduces the number and/or surface area of voids in the surface, optionally wherein thermoforming increases surface texture uniformity of the thermoformed surface, optionally wherein the increase in surface texture uniformity increases bonding strength between the surface and as second element is as compared to a bond strength to a surface of a substantially identical foamed article which has not been thermoformed, and a substantially identical second element. 
     In accordance with Aspect 248, the present disclosure is directed to the method of any one of the preceding aspects, wherein thermoforming one or more surfaces of the additive manufactured foamed article reduces water uptake of the foamed article as compared to a level of water uptake for a surface of a substantially identical foamed article which has not been thermoformed. 
     In accordance with Aspect 249, the present disclosure is directed to the method of any one of the preceding aspects, wherein thermoforming one or more surfaces of the additive manufactured foamed article increases abrasion resistance of the additive manufactured foamed article as compared to a level of abrasion resistance for a surface of a substantially identical foamed article which has not been thermoformed. 
     In accordance with Aspect 250, the present disclosure is directed to an article comprising: a structure formed of a plurality of affixed foamable particles; wherein each individual foamable particle of the plurality of affixed foamable particles is formed of a foamable material, and includes one or more binding regions on an outer surface of the individual foam particle affixing the individual foam particle to one or more adjacent foamable particles; wherein the one or more adjacent foamable particles comprise the foamable material; wherein the binding regions include a portion of binding material from the individual foam particle, a portion of binding material from at least one of the one or more adjacent foamable particles, a portion of the thermoplastic foamable from the individual foam particle intermingled with a portion of the foamable material from at least one of the one or more adjacent foamable particles, or any combination thereof; wherein the structure formed of the plurality of affixed foamable particles includes a plurality of gaps between particles, with the gaps occupying at least 10 percent of a total volume of the structure; wherein, prior to affixing, at least 20 percent of the plurality of foamable particles are ellipsoid in shape and have a number average particle size of about 0.04 millimeters to about 10 millimeters in a longest dimension; and wherein at least 20 percent of the ellipsoid foamable particles in the structure retain a substantially ellipsoid shape. 
     In accordance with Aspect 251, the present disclosure is directed to an additive-manufactured article comprising a structure formed from one or more extruded materials, wherein one or more of the extruded materials comprise a foamable material according to any one of aspects 1-9 or 124-152, optionally wherein one or more of the extruded materials comprise a blend according to any one of aspects 139-152. 
     In accordance with Aspect 252, the present disclosure is directed to an additive manufactured foamed article comprising: 
     a foamed material which is a physically-expanded foam formed of a thermoplastic elastomeric material comprising one or more first thermoplastic elastomers. 
     In accordance with Aspect 253, the present disclosure is directed to the additive manufactured foamed article of aspect 252, wherein the foamed material is a product of placing an unfoamed additive manufactured article comprising a solid foamable material in liquid carbon dioxide, infusing the solid foamable material with the liquid carbon dioxide, and expanding the infused solid foamable material by phase transitioning the infused carbon dioxide into a gas under conditions which do not soften the solid foamable material, thereby forming the foamed material of the additive manufactured foamed article. 
     In accordance with Aspect 254, the present disclosure is directed to the additive manufactured foamed article of aspect 252 or 253, wherein the additive manufactured foamed article is a stabilized additive manufactured foamed article comprising the stabilized foamed material, wherein the stabilized foamed material is free of or substantially free of infused carbon dioxide. 
     In accordance with Aspect 255, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-254, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals), and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the liquid carbon dioxide is soluble in the foamed material, or in the solid foamable material, or in both, at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent. 
     In accordance with Aspect 256, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-255, wherein the foamed material of the additive manufactured foamed article is substantially opaque. 
     In accordance with Aspect 257, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-256, wherein the foamed material has a split-tear value of from about 2.5 kilograms per centimeter to about 3.0 kilograms per centimeter. 
     In accordance with Aspect 258, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-257, wherein the foamed material has an Asker C hardness of from about 10 to about 50. 
     In accordance with Aspect 259, the present disclosure is directed to the additive manufactured article according to any one of aspects 252-258, comprising: a structure formed of a plurality of affixed foamed particles; wherein each individual foamed particle of the plurality of affixed foamed particles is formed of a foamed material, and includes one or more binding regions on an outer surface of the individual foamed particle affixing the individual foamed particle to one or more adjacent foamed particles; wherein the one or more adjacent foamed particles comprise the foamed material; 
     wherein the binding regions include a portion of binding material from the individual foamed particle, a portion of binding material from at least one of the one or more adjacent foamed particles, a portion of the thermoplastic foamed material from the individual foamed particle intermingled with a portion of the foamed material from at least one of the one or more adjacent foamed particles, or any combination thereof; wherein the structure formed of the plurality of affixed foamed particles includes a plurality of gaps between particles, with the gaps occupying at least 10 percent of a total volume of the structure; wherein, prior to affixing, at least 20 percent of the plurality of foamed particles are ellipsoid in shape and have a number average particle size of about 0.04 millimeters to about 10 millimeters in a longest dimension; and wherein at least 20 percent of the ellipsoid foamed particles in the structure retain a substantially ellipsoid shape. 
     In accordance with Aspect 260, the present disclosure is directed to the additive manufactured foamed article according to aspect 259, wherein the article is formed from a plurality of strata arranged in a layers, wherein each strata comprises a plurality of foamed particles or a foamed extruded material, and wherein, in the additive manufactured foamed article, each strata is affixed to at least a portion of another strata. 
     In accordance with Aspect 261, the present disclosure is directed to the additive manufactured foamed article of any one of the preceding aspects, wherein the article is configured as a series of two or more strata including a first strata including comprising a first strata material and a second strata comprising a second strata material, wherein the first strata material or the second strata material or both the first strata material and the second strata material are a foamed material according to any one of aspects 1-9 or 124-152; optionally wherein the first strata material and the second material are individually a blend according to any one of aspects 138-151, optionally wherein the first strata or the second strata forms an outermost surface of the article, or wherein both the first strata and the second strata individually or jointly form the outermost surface of the additive manufactured foamed article. 
     In accordance with Aspect 262. The additive manufactured foamed article of aspect 261, wherein the two or more strata individually comprise a plurality of foamed particles, a foamed extruded material, or any combination thereof. 
     In accordance with Aspect 263, the present disclosure is directed to the additive manufactured foamed article of aspect 261 or 262, wherein, in the article, the first strata forms the outermost surface of the foamed article and the second strata forms an inner layer of the foamed article. 
     In accordance with Aspect 264, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 261-263, wherein the first strata material is a solid material. 
     In accordance with Aspect 265, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 261-263, wherein the first strata material is the foamed material. 
     In accordance with Aspect 266, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 261-263, wherein the second strata material is a solid material. 
     In accordance with Aspect 267, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 261-263, wherein the second strata material is the foamed material. 
     In accordance with Aspect 268, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 261-263, wherein the first strata comprises or consists essentially of the foamed material, and the second strata comprises or consists essentially of a solid material. 
     In accordance with Aspect 269, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 261-263, wherein the first strata comprises or consists essentially of a solid material, and the second strata comprises or consists essentially of the foamed material. 
     In accordance with Aspect 270, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 261-263, wherein both the first strata and the second strata comprise or consist essentially of the foamed material. 
     In accordance with Aspect 271, the present disclosure is directed to the additive manufactured foamed article of any one of 261-270 wherein the first strata material, the second strata material, or both, are individually a thermoplastic elastomeric material according to any of aspects 124-138. 
     In accordance with Aspect 272, the present disclosure is directed to the additive manufactured foamed article of any one of 261-271, wherein the first strata material or the second strata material is a second material according to any of aspects 139-152. 
     In accordance with Aspect 273, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 261-272, wherein the article is configured as a series of three or more strata and includes a third strata comprising or consisting essentially of a third strata material, optionally wherein the third strata is positioned between the first strata and the second strata. 
     In accordance with Aspect 274. The additive manufactured foamed article of aspect 273, wherein the third strata material is a third strata foamed material, optionally wherein the third strata foamed material is an additional foamed material, optionally wherein the third strata foamed material is the foamed material. 
     In accordance with Aspect 275. The additive manufactured foamed article of aspect 273 or 274, wherein the third strata material is a third strata solid material, optionally wherein the third strata material is an additional solid material. 
     In accordance with Aspect 276, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-258, wherein the foamed article is configured as a series of two or more regions including a first region including a first regional foamed material and a second region including a second regional material, optionally wherein the second regional material is a second regional foamed material; optionally wherein the first region or the second region forms an outermost surface of the additive manufactured foamed article, or wherein both the first region and the second region individually or jointly form the outermost surface of the additive manufactured foamed article. 
     In accordance with Aspect 277, the present disclosure is directed to the additive manufactured foamed article of 276, wherein the regions include layers, and wherein the first region or the second region forms an inner layer of the foamed article, or both the first region and the second region individually form separate inner layers of the additive manufactured foamed article, optionally wherein the additive manufactured foamed article is a layered sheet including one or more foamed layers. 
     In accordance with Aspect 278, the present disclosure is directed to the additive manufactured foamed article of aspect 276 or 277, wherein, in the foamed article, the first region forms the outermost surface of the additive manufactured foamed article and the second region forms an inner layer of the additive manufactured foamed article. 
     In accordance with Aspect 279, the present disclosure is directed to the additive manufactured foamed article of aspect 276 or 277, wherein, in the additive manufactured foamed article, the first region forms an inner layer of the additive manufactured foamed article and the second region forms the outermost surface of the additive manufactured foamed article. 
     In accordance with Aspect 280, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-279, wherein the first region comprises or consists essentially of a first regional material, and the first regional material is a solid material. 
     In accordance with Aspect 281, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-279, wherein the first region comprises or consists essentially of a first regional material, and the first regional material is the foamed material. 
     In accordance with Aspect 282, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-279, wherein the second region comprises or consists essentially of a second regional material, and the second regional material is a solid material. 
     In accordance with Aspect 283, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-279, wherein the second region comprises or consists essentially of a second regional material, and the second regional material is the foamed material. 
     In accordance with Aspect 284, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-279, wherein the first region comprises or consists essentially of the foamed material, and the second region comprises or consists essentially of a solid material. 
     In accordance with Aspect 285, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-279, wherein the first region comprises or consists essentially of a solid material, and the second region comprises or consists essentially of the foamed material. 
     In accordance with Aspect 286, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-279, wherein both the first region and the second region comprise or consist essentially of the foamed material. 
     In accordance with Aspect 287, the present disclosure is directed to the additive manufactured foamed article of any one of 276-286, wherein the first regional material, the second regional material, or both, are individually a thermoplastic elastomeric material according to any of aspects 124-138. 
     In accordance with Aspect 288, the present disclosure is directed to the additive manufactured foamed article of any one of 276-287, wherein the first regional material, the second regional material, or both, individually are a foamed material according to any of aspects 1-9 or 124-152. 
     In accordance with Aspect 289, the present disclosure is directed to the additive manufactured foamed article of any one of 276-288, wherein the first regional material or the second regional material is a second material according to any of aspects 138-151. 
     In accordance with Aspect 290, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-288, wherein the first region comprises or consists essentially of the foamed material and the second region comprises or consists essentially of a barrier material. 
     In accordance with Aspect 291, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-288, wherein the first region comprises or consists essentially of a barrier material and the second region comprises or consists essentially of the foamed material. 
     In accordance with Aspect 292, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-291, wherein the foamed article is configured as a series of three or more regions and includes a third region comprising or consisting essentially of a third regional material, optionally wherein the third region is positioned between the first region and the second region. 
     In accordance with Aspect 293, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-291, wherein the third regional material is a third regional foamed material, optionally wherein the third regional foamed material is an additional foamed material, optionally wherein the third regional foamed material is the foamed material. 
     In accordance with Aspect 294, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-291, wherein the third regional material is a third regional solid material, optionally wherein the third regional material is an additional solid material, optionally wherein the additional solid material is a barrier material. 
     In accordance with Aspect 295, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-294, wherein the foamed article is configured as a series of four or more regions and includes a fourth region comprising or consisting essentially of a fourth regional material, optionally wherein the fourth region is positioned between the third region and the second region. 
     In accordance with Aspect 296, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-294, wherein the fourth regional material is a fourth regional foamed material, optionally wherein the fourth regional foamed material is an additional foamed material, optionally wherein the fourth regional foamed material is the foamed material. 
     In accordance with Aspect 297, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-296, wherein the fourth regional material is a fourth regional solid material, optionally wherein the fourth regional material is an additional solid material, optionally wherein the additional solid material is a barrier material. 
     In accordance with Aspect 298, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 276-297, wherein the thermoplastic elastomeric material comprises a polymeric component including all of the polymers present in the thermoplastic elastomeric material, and the polymeric component consists of the one or more first thermoplastic elastomers. 
     In accordance with Aspect 299, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-298, wherein the one or more first thermoplastic elastomers comprise one or more thermoplastic elastomeric polyolefin homopolymers or copolymers, one or more thermoplastic elastomeric polyamide homopolymers or copolymers, one or more thermoplastic elastomeric polyester homopolymers or copolymers, one or more thermoplastic elastomeric polyurethane homopolymers or copolymers, one or more thermoplastic elastomeric styrenic homopolymers or copolymers, or any combination thereof. 
     In accordance with Aspect 300, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-299, wherein the one or more first thermoplastic elastomers comprise or consist essentially of one or more thermoplastic elastomeric polyamide homopolymers or copolymers. 
     In accordance with Aspect 301, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-300, wherein the one or more first thermoplastic elastomers comprise or consist essentially of polyether block polyamide (PEBA) copolymer elastomers. 
     In accordance with Aspect 302, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-301, wherein the one or more first thermoplastic elastomers comprise or consist essentially of one or more thermoplastic elastomeric styrenic homopolymers or copolymers. 
     In accordance with Aspect 303, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-302, wherein the one or more first thermoplastic elastomers comprise or consist essentially of styrene butadiene styrene (SBS) block copolymer elastomers, styrene ethylene butylene styrene (SEBS) copolymer elastomers, styrene acrylonitrile (SAN) copolymer elastomers, or any combination thereof. 
     In accordance with Aspect 304, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-303, wherein the one or more first thermoplastic elastomers comprise or consist essentially of one or more thermoplastic polyurethane elastomeric homopolymers or copolymers. 
     In accordance with Aspect 305, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-304, wherein the one or more first thermoplastic elastomers comprise or consist essentially of thermoplastic polyester-polyurethane elastomers, polyether-polyurethane elastomers, polycarbonate-polyurethane elastomers, or any combination thereof. 
     In accordance with Aspect 306, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-305, wherein the one or more first thermoplastic elastomers comprises or consists essentially of one or more thermoplastic polyester-polyurethane elastomers. 
     In accordance with Aspect 307, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-306, wherein the polymeric component of the thermoplastic elastomeric material consists of one or more thermoplastic polyester-polyurethane elastomers. 
     In accordance with Aspect 308, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-307, wherein the one or more first thermoplastic elastomers comprises or consists essentially of one or more thermoplastic polyolefin elastomeric homopolymers or copolymers. 
     In accordance with Aspect 309, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-308, wherein the one or more first thermoplastic elastomers comprises or consists essentially of thermoplastic elastomeric polypropylene homopolymers or copolymers, thermoplastic elastomeric polyethylene homopolymers or copolymers, thermoplastic elastomeric polybutylene homopolymers or copolymers, or any combination thereof. 
     In accordance with Aspect 310, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-309, wherein the one or more first thermoplastic elastomers comprises or consists essentially of thermoplastic elastomeric ethylene-vinyl acetate copolymers. 
     In accordance with Aspect 311, the present disclosure is directed to the additive manufactured foamed article of aspect 310, wherein the thermoplastic elastomeric ethylene-vinyl acetate copolymers include from about 25 to about 50 weight percent vinyl acetate content. 
     In accordance with Aspect 312, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-311, wherein the thermoplastic elastomeric material comprises a mixture of the polymeric component and a non-polymeric component consisting of one or more non-polymeric additives, optionally wherein the foamable material comprises from about 0.005 to about 20 percent by weight of the non-polymeric component based on a total weight of the foamable material, or about 0.5 to about 10 percent by weight of the non-polymeric additive based on a total weight of the foamable material. 
     In accordance with Aspect 313, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-312, wherein the one or more first thermoplastic elastomers comprises or consists essentially of one or more recycled first thermoplastic elastomers. 
     In accordance with Aspect 314, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-313, wherein the thermoplastic elastomeric material comprises or consists essentially of a blend of the one or more first thermoplastic elastomers and a second material, optionally wherein the second material comprises or consists essentially of one or more second polymers, optionally wherein the one or more second polymers comprise or consist essentially of one or more second thermoplastics. 
     In accordance with Aspect 315, the present disclosure is directed to the additive manufactured foamed article of aspect 314, wherein the polymeric component of the thermoplastic elastomeric material consists of a blend of the one or more first thermoplastic elastomers and the one or more second thermoplastics. 
     In accordance with Aspect 316, the present disclosure is directed to the additive manufactured foamed article of aspect 314 or 315, wherein the one or more second thermoplastics comprise one or more thermoplastic polyolefin homopolymers or copolymers, one or more thermoplastic polyamide homopolymers or copolymers, one or more thermoplastic polyester homopolymers or copolymers, one or more thermoplastic polyurethane homopolymers or copolymers, one or more thermoplastic styrenic homopolymers or copolymers, or any combination thereof. 
     In accordance with Aspect 317, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 314-316, wherein the one or more second thermoplastics comprise or consist essentially of thermoplastic polypropylene homopolymers or copolymers, thermoplastic polyethylene homopolymers or copolymers, thermoplastic polybutylene homopolymers or copolymers, or any combination thereof. 
     In accordance with Aspect 318, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 314-317, wherein the one or more second thermoplastics comprise or consist essentially of one or more thermoplastic polyethylene copolymers. 
     In accordance with Aspect 319, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 314-318, wherein the one or more second thermoplastics comprise or consist essentially of one or more thermoplastic ethylene-vinyl alcohol copolymers. 
     In accordance with Aspect 320, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 314-319, wherein the polymeric component of the thermoplastic elastomeric material consists of one or more first thermoplastic elastomeric polyurethane homopolymers or copolymers, and one or more second thermoplastic ethylene-vinyl alcohol copolymers. 
     In accordance with Aspect 321, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 314-320, wherein the polymeric component of the thermoplastic elastomeric material consists of one or more first thermoplastic elastomeric polyester-polyurethane copolymers and one or more second thermoplastic ethylene-vinyl alcohol copolymers. 
     In accordance with Aspect 322, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 314-321, wherein the blend comprises one or more recycled first thermoplastic elastomers, or one or more recycled second thermoplastics, or both. 
     In accordance with Aspect 323, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 314-322, wherein the blend is a phase-separated blend of the one or more first thermoplastic elastomers and the one or more second thermoplastics. 
     In accordance with Aspect 324, the present disclosure is directed to the additive manufactured foamed article of aspect 323, wherein the phase-separated blend includes one or more phase-separated regions including interfaces between the one or more first thermoplastic elastomers and the one or more second thermoplastics. 
     In accordance with Aspect 325, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 314-324, wherein the blend comprises about 95 percent by weight of the one or more first thermoplastic elastomers and about 5 percent by weight of the one or more second thermoplastics based on a total weight of the blend. 
     In accordance with Aspect 326, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 314-325, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals), and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the liquid carbon dioxide is soluble in the one or more first thermoplastic elastomers at a concentration of from about 1 weight percent to about 30 weight percent based on a total weight of the one or more first thermoplastic elastomers present in the thermoplastic elastomeric material, optionally from about 5 weight percent to about 20 weight percent, and wherein the liquid carbon dioxide is soluble in the one or more second thermoplastics at a concentration of at less than 1 weight percent based on a total weight of the one or more second thermoplastics present in the thermoplastic elastomeric material, optionally less than 0.1 weight percent, or optionally wherein the liquid carbon dioxide is substantially insoluble in the one or more second thermoplastics. 
     In accordance with Aspect 327, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-326, wherein the foamed article comprises an additional material, wherein the additional material is a separate material from the foamed material, wherein the additional material comprises or consists essentially of one or more polymers, and includes an additional material polymeric component consisting of all the polymers present in the additional material; optionally wherein the additional material comprises or consists essentially of a second material, optionally wherein the second material is a thermoplastic material; optionally wherein the additional material comprises the additional material polymeric component mixed with an additional material non-polymeric component consisting of all non-polymeric components present in the additional material. 
     In accordance with Aspect 328, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-327, wherein the foamed article comprises one or more first portions of the foamed material and one or more second portions of the additional material, and wherein the one or more first portions are distinct from the one or more second portions. 
     In accordance with Aspect 329, the present disclosure is directed to the additive manufactured foamed article of aspect 327 or 328, wherein the additional material comprises a barrier material comprising one or more barrier polymers, the barrier material comprising a barrier polymeric component consisting of all polymers present in the barrier material. 
     In accordance with Aspect 330, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 327-329, wherein the additional material comprises a plasticizer. 
     In accordance with Aspect 331, the present disclosure is directed to the additive manufactured foamed article of aspect 329 or 330, wherein, in the foamed article, the additional material is substantially unfoamed. 
     In accordance with Aspect 332, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 329-331, wherein the barrier material has a hardness of at least 10 Shore A units greater than the thermoplastic elastomeric material in solid form, or 
     optionally at least 20 Shore A units greater, at least 30 Shore A units greater, or at least 40 Shore A units greater than the thermoplastic elastomeric material in solid form. 
     In accordance with Aspect 333, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 329-332, wherein the barrier material has a nitrogen gas transmission rate at least 50 percent lower than a nitrogen gas transmission rate of the thermoplastic elastomeric material in solid form, optionally less than or equal to 10 cubic centimeters per square meter per 24 hours, or less than or equal to 1 cubic centimeter per square meter per 24 hours. 
     In accordance with Aspect 334, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 329-333, wherein the barrier polymeric component of the barrier material consists of one or more barrier polymers each individually having a nitrogen gas transmission rate of less than or equal to 30 cubic centimeters per square meter per 24 hours, or less than or equal to 10 cubic centimeters per square meter per 24 hours, or less than or equal to 1 cubic centimeter per square meter per 24 hours. 
     In accordance with Aspect 335, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 329-334, wherein the one or more barrier polymers comprise or consist essentially of one or more vinylidene chloride polymers, one or more acrylonitrile polymers or copolymers, one or more polyamides, one or more epoxy resins, one or more amine polymers or copolymers, one or more thermoplastic polyolefin homopolymers or copolymers, one or more thermoplastic polyolefin copolymers, one or more thermoplastic polyethylene copolymers, one or more thermoplastic ethylene-vinyl alcohol copolymers, or one or more thermoplastic elastomeric ethylene-vinyl alcohol copolymers. 
     In accordance with Aspect 336, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 329-335, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals) and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the liquid carbon dioxide is soluble in the thermoplastic elastomeric material at a first concentration, the liquid carbon dioxide is soluble in the barrier material at a second concentration, and the first concentration is at least 20 percent greater than the second concentration, optionally wherein the first concentration is at least 50 percent greater than the second concentration, or is at least 70 percent greater than the second concentration. 
     In accordance with Aspect 337, the present disclosure is directed to the additive manufactured foamed article of aspect 336, wherein the second concentration is less than 1 weight percent, optionally less than 0.1 weight percent, or optionally wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals) and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the liquid carbon dioxide is substantially insoluble in the barrier material. 
     In accordance with Aspect 338, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 329-337, wherein the barrier material comprises one or more ethylene-vinyl alcohol copolymers, optionally wherein the one or more ethylene-vinyl alcohol copolymers are thermoplastic, optionally wherein the one or more ethylene-vinyl alcohol thermoplastic copolymers include one or more thermoplastic elastomeric copolymers; optionally wherein the barrier polymeric component consists of one or more ethylene-vinyl alcohol copolymers, optionally wherein the one or more ethylene-vinyl alcohol copolymers are thermoplastic, optionally wherein the one or more ethylene-vinyl alcohol thermoplastic copolymers include one or more thermoplastic elastomeric copolymers. 
     In accordance with Aspect 339, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 330-338, wherein the additional material is a thermoplastic material, optionally wherein the additional material is an additional thermoplastic elastomeric material. 
     In accordance with Aspect 340, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 330-339, wherein the foamed article comprises the foamed material, wherein the foamed material is a first foamed material, and the foamed article further comprises a second foamed material, wherein the second foamed material comprises or consists essentially of the additional material. 
     In accordance with Aspect 341, the present disclosure is directed to the additive manufactured foamed article of aspect 340, wherein, in the foamed article, a density of the first foamed material differs from a density of the second foamed material by at least 5 percent, at least 10 percent, or at least 20 percent. 
     In accordance with Aspect 342, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 340 or 341, wherein the second foamed material is a second physically-expanded foam. 
     In accordance with Aspect 343, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 340-342, wherein the second physically-expanded foam is a product of placing the unfoamed article comprising the solid additional material in liquid carbon dioxide, infusing the solid additional material with the liquid carbon dioxide, and expanding the infused solid additional material by phase transitioning the infused carbon dioxide into a gas under conditions which do not soften the solid additional material, thereby forming the foamed additional material of the foamed article. 
     In accordance with Aspect 344, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 340-343, wherein the additional material is a recycled material comprising one or more recycled polymers, optionally wherein the one or more recycled polymers comprise one or more recycled thermoplastics, optionally wherein the one or more recycled thermoplastics comprise one or more recycled thermoplastic elastomers; optionally wherein the recycled material comprises a recycled material polymeric component consisting of one or more recycled thermoplastics, optionally wherein the recycled material polymeric component consists of one or more recycled thermoplastic elastomers. 
     In accordance with Aspect 345, the present disclosure is directed to the additive manufactured foamed article of aspect 344, wherein the recycled material comprises one or more recycled first thermoplastic elastomers, optionally wherein the one or more recycled first thermoplastic elastomers comprise one or more reground first thermoplastic elastomers, optionally wherein the one or more recycled or reground first thermoplastic elastomers include a thermoplastic elastomer according to any one of aspects 124-138. 
     In accordance with Aspect 346, the present disclosure is directed to the additive manufactured foamed article of aspect 344 or 345, wherein the recycled material further comprises one or more recycled second thermoplastics, optionally wherein the one or more recycled second thermoplastics comprise one or more reground second thermoplastics, optionally wherein the one or more recycled or reground second thermoplastics include a thermoplastic according to any one of aspects 139-152. 
     In accordance with Aspect 347, the present disclosure is directed to the additive manufactured foamed article of aspect 346, wherein the recycled material comprises one or more recycled or reground thermoplastic polyurethane elastomers, one or more recycled or reground thermoplastic ethylene-vinyl alcohol copolymers, or both. 
     In accordance with Aspect 348, the present disclosure is directed to the additive manufactured foamed article of aspect 346 or 347, wherein the recycled material comprises a blend of the one or more recycled or reground thermoplastic elastomers and one or more second thermoplastics, or wherein the recycled material comprises a blend of one or more thermoplastic elastomers and one or more recycled thermoplastics or one or more recycled second thermoplastics, optionally wherein the blend is a phase-separated blend and optionally wherein the phase-separated blend comprises one or more interfaces between the one or more first thermoplastic elastomers and the one or more second thermoplastics. 
     In accordance with Aspect 349, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 346-348, wherein the recycled material comprises about 99 percent to about 90 percent by weight of the one or more first thermoplastic elastomers and about 1 percent to about 10 percent by weight of the second thermoplastics based on a total weight of the recycled material, optionally wherein the recycled material comprises about 99 percent to about 93 percent by weight of the one or more first thermoplastic elastomers and about 1 percent to about 7 percent by weight of the one or more second thermoplastics, or about 99 percent to about 95 percent by weight of the one or more first thermoplastic elastomers and about 1 percent to about 5 percent by weight of the one or more second thermoplastic elastomers. 
     In accordance with Aspect 350, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 344-349, wherein the recycled material comprises about 99 percent to about 50 percent by weight of recycled or reground polymers based on a total weight of recycled material, optionally from about 99 percent to about 75 percent by weight of recycled or reground polymers. 
     In accordance with Aspect 351, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 344-350, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals), and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the liquid carbon dioxide is soluble in the recycled material at a concentration of from about 1 weight percent to about 30 weight percent based on a total weight of the recycled material, optionally from about 5 weight percent to about 20 weight percent. 
     In accordance with Aspect 352, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 344-351, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals), and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the liquid carbon dioxide is soluble in the one or more recycled or reground thermoplastic elastomers at a concentration of from about 1 weight percent to about 30 weight percent based on a total weight of the one or more recycled or reground thermoplastic elastomers, optionally from about 5 weight percent to about 20 weight percent. 
     In accordance with Aspect 353, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 344-352, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals), and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the liquid carbon dioxide is soluble in the one or more recycled or reground second thermoplastics at less than 1 weight percent, optionally less than 0.1 weight percent based on a total weight of the one or more recycled or reground second thermoplastics, or optionally wherein the liquid carbon dioxide is substantially insoluble in the one or more recycled or reground second thermoplastics. 
     In accordance with Aspect 354, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 344-353, wherein the recycled material comprises a recycled foamed article, optionally wherein the recycled foamed article is a reground foamed article, 
     optionally wherein the recycled foamed article is a foamed article produced according to the method of any one of aspects 1-251. 
     In accordance with Aspect 355, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 344-353, wherein the recycled material comprises a solid material, wherein the solid material is a thermoplastic elastomeric material. 
     In accordance with Aspect 356, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 344-355, wherein the recycled material further comprises one or more virgin first thermoplastic elastomers, optionally wherein the one or more virgin first thermoplastic elastomers includes one or more virgin thermoplastic polyurethane elastomers. 
     In accordance with Aspect 357, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 348-356, wherein the recycled material includes one or more nucleating agents or one or more interfaces between phase-separated polymers. 
     In accordance with Aspect 358, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 344-357, wherein the thermoplastic elastomeric material is a recycled material, or comprises a recycled material, or consists essentially of a recycled material. 
     In accordance with Aspect 359, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 344-358, wherein the foamed material is a first foamed material, the foamed article comprises a second foamed material, the second foamed material is an additional material, and the thermoplastic elastomeric material of the first foamed material is a recycled material, or the additional material of the second foamed material is a recycled material, or both the thermoplastic elastomeric material and the additional material are recycled materials. 
     In accordance with Aspect 360, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-359, wherein the foamed article comprises a barrier layer or a barrier region, and the barrier layer or the barrier region comprises or consists essentially of a barrier material. 
     In accordance with Aspect 361, the present disclosure is directed to the additive manufactured foamed article of aspect 360, wherein the barrier material is an additional material according to any one of aspects 153-183. 
     In accordance with Aspect 362, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-361, wherein the foamed article comprises a structural layer or structural region, and the structural layer or structural region comprises or consists essentially of a structural material. 
     In accordance with Aspect 363, the present disclosure is directed to the additive manufactured foamed article of aspect 362, wherein the structural material is an additional material according to any one of aspects 153-183, optionally wherein the structural material comprises a blend of two or more additional materials, optionally wherein at least one of the two or more additional materials is a recycled material. 
     In accordance with Aspect 364, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-363, wherein the foamed article comprises one or more tie layers or tie regions, each of the one or more tie layers or tie regions individually comprising or consisting essentially of a tie material, wherein each of the one or more tie layers or tie regions increases a bond strength between two adjacent layers or regions, optionally wherein the tie material is a thermoplastic elastomeric material according to any one of aspects 124-138, optionally wherein the thermoplastic elastomeric material is a recycled material. 
     In accordance with Aspect 365, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-364, wherein the foamed article comprises one or more protective layers, each of the one or more protective layers individually comprising or consisting essentially of a protective material, wherein the each of the one or more protective layers is adjacent a core layer and has a protective layer thickness, wherein a combination of the one or more protective layers and the adjacent core layer has a minimum curve radius which is greater than a minimum curve radius which causes cracking of the core layer, or of one or more individual layers within the core layer, optionally wherein the protective material is a solid foamable material according to any one of the aspects 171-243, optionally wherein the solid foamable material is a recycled material. 
     In accordance with Aspect 366, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-365, wherein the foamed material has a density of from about 0.01 gram per cubic centimeter to about 3.0 grams per cubic centimeter, optionally wherein the foamed material is a stabilized foamed material having a density of from about 0.01 gram per cubic centimeter to about 3.0 grams per cubic centimeter. 
     In accordance with Aspect 367, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-366, wherein, the foamed material has a volume less than 10 percent greater, optionally less than 5 percent greater, than the foamable material prior to foaming, optionally wherein the foamed article is a stabilized foamed article. 
     In accordance with Aspect 368, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-367, wherein the foamed material has a volume more than 20 percent greater, optionally more than 30 percent greater or more than 40 percent greater, than the foamable material prior to foaming, optionally wherein the foamed article is a stabilized foamed article. 
     In accordance with Aspect 369, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-366, wherein the foamed material has a Shore A hardness of from about 35 A to about 95 A, optionally from about 55 A to about 90 A. 
     In accordance with Aspect 370, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-367, wherein the foamed article is configured as a roll, optionally comprising a spacer or protective layer between adjacent portions of the foamed article. 
     In accordance with Aspect 371, the present disclosure is directed to the additive manufactured foamed article of any one of aspects 252-370, wherein the article is a layered sheet including one or more one foamed layers. 
     In accordance with Aspect 372, the present disclosure is directed to a method of manufacturing an article, the method comprising: 
     affixing a first component to a second component, wherein the first component is an additive manufactured foamed article according to any one of aspects 252-367. 
     In accordance with Aspect 373, the present disclosure is directed to a foamed article made by the method of any one of aspects 1-251, optionally wherein the foamed article is a foamed article according to any one of aspects 252-372. 
     In accordance with Aspect 374, the present disclosure is directed to a foamable additive-manufactured article produced by the method according to aspect 372 or 373. 
     In accordance with Aspect 375, the present disclosure is directed to an additive manufactured foamed article produced by subjecting the foamable additive-manufactured article of aspect 374 to the method of any one of aspects 1-251. 
     In accordance with Aspect 376, the present disclosure is directed to a method for making a consumer product, the method comprising affixing the additive manufactured foamed article of aspect 375 to a second component. 
     In accordance with Aspect 377, the present disclosure is directed to a consumer product produced by the method of aspect 376. 
     In accordance with Aspect 378, the present disclosure is directed to the consumer product of aspect 377, wherein the consumer product comprises an article of footwear, an article of sporting equipment, or an article of apparel. 
     New foamed articles including a foamed thermoplastic elastomeric material and methods for making such foamed articles have been identified. The methods described herein include a step of infusing carbon dioxide into a solid foamable material of an article, i.e., a solid article. Following the infusing, the infused solid foamable material is foamed without thermally softening the solid foamable material by expanding the infused carbon dioxide, e.g., by phase transitioning the infused carbon dioxide to carbon dioxide gas, which in turn expands the solid foamable material into a foamed material into a foam, e.g., a foam having a multi-cellular foam structure. In this way, the solid foamable material is physically foamed without being melted in the process. The foamed articles described herein include one or more foamed materials which are physically foamed materials. It has been found that these physically foamed materials, which comprise a thermoplastic elastomeric material as described herein have a low density, a uniform multi-cellular foam structure, and/or other beneficial properties making the foamed materials suitable for use in many mass-produced consumer products, including articles of apparel, footwear, and sporting equipment.  FIGS.  1 A- 1 M  illustrate various articles of footwear, apparel, and athletic equipment, including containers, electronic equipment, and vision wear, that are or comprise foamed articles in accordance with the present disclosure, while  FIGS.  1 N (a)- 1 Q(e) illustrate additional details regarding different types of footwear. 
     It has also been found that the multi-step foaming processes described herein can be easily adapted for use with conventional materials and manufacturing lines, as they use simpler, less expensive and more energy-efficient equipment and processes than other physical foaming processes. For example, maintaining the carbon dioxide as a liquid and holding the solid foamable material in the liquid carbon dioxide requires maintaining less extreme temperatures and pressures (and thus requires less expensive, more energy-efficient equipment) than using supercritical carbon dioxide to infuse the solid foamable material. In many aspects, the step of expanding the solid foamable material into the foamed material can be conducted at or near atmospheric pressure and at relatively low temperatures well below the melting temperature of the foamable material, and so can be conducted using simple, inexpensive heating methods and equipment, making the overall foaming process efficient and cost-effective. Additionally, the present disclosure can be applied to a wide range of solid foamable materials, and to articles have a number of different geometries, including but not limited to sheets of solid foamable material(s). Further, by using articles comprising two or more types of solid foamable materials, articles comprising two or more portion or regions of solid foamable material, and articles comprising a combination of one or more solid foamable material and one or more solid non-foamable material, and/or by varying the processing conditions, the processes for foaming solid articles described herein can be adapted to selectively foam portions or regions of an article without the need for additional tooling or equipment. 
     Using a foamed thermoplastic elastomeric material in the foamed articles disclosed herein can reduce the weight or density of the articles as compared to articles without foamed materials, i.e., articles comprising only solid materials. Additionally or alternatively, by using a foamed material in place of an unfoamed material, the total amount of material needed to provide the same volume is reduced, reducing material costs and making the foamed article more sustainable as compared to a comparable article without foamed material. Furthermore, by using a foamed thermoplastic elastomeric material, alone or in combination with one or more additional thermoplastic material, to form the foamed article, components of the foamed article or the entire foamed article can comprise recycled thermoplastic materials, and, in turn, the components or the entire foamed article can be recycled themselves. In some aspect, by controlling the foaming conditions and, optionally, controlling the optional stabilization process, the overall volume of the foamed article may be increased within a predicted or pre-determined range. The increase in volume can be relatively small, for example, an increase in volume of less than 10 percent, or less than 5 percent, as compared to the total volume of the article prior to undergoing the foaming process Alternatively, the increase in volume can be relatively large, for example, an increase in volume of greater than 20 percent, or greater than 40 percent as compared to the total volume of the article prior to undergoing the foaming process. 
     In some aspects, the foamed material of the foamed article is a stabilized foam material which has undergone a stabilization process. In some aspects, the foamed article includes layers or regions of foamed material adjacent to layers or regions of solid (i.e., unfoamed) material. In some aspects, the foamed article can be a cushioning element, such as a fluid-filled bladder. In some aspects, the thermoplastic elastomeric material can comprise one or more thermoplastic polyurethanes. In some aspects, in addition to the thermoplastic elastomeric material, the foamed article can further include a second material, such as a second thermoplastic material, including a second thermoplastic material which does not foam during the foaming process. 
     In one aspect, the present disclosure is directed to a method for making a foamed article. The foaming process as disclosed herein is a multi-step process which includes first infusing a solid foamable material with carbon dioxide, and then exposing the infused article to conditions which cause the carbon dioxide infused in the solid foamable material to undergo a phase change, which expands and foams the solid foamable material into a foamed material. Optionally, prior to the foaming step, the infused article can be exposed to and held (e.g., stored) at a pressure and temperature at which the infused carbon dioxide remains infused in the article, allowing the infused article to be foamed at a later time. Alternatively, the infused article can be exposed to and held conditions at which a portion of the infused carbon dioxide diffuses out of it, for a duration of time to allow diffusion of carbon dioxide out of a selected portion of the infused article. In this manner, infused carbon dioxide can be removed from selected regions or portions of the article prior to foaming, which results in only selected regions or portions of the article foaming when exposed to the foaming conditions. Optionally, after undergoing foaming, the foamed article can be stabilized to release residual carbon dioxide and/or to release residual stress in the article. 
     In another aspect, the present disclosure is directed to a foamed article. The foamed article comprises or consists essentially of a foamed material, wherein the foamed material is a physically-expanded foam formed of a thermoplastic elastomeric material comprising one or more first thermoplastic elastomers. The foamed material is the product of infusing carbon dioxide into a solid foamable comprising the thermoplastic elastomeric material, and producing a phase change causing the infused carbon dioxide to expand, thereby foaming the solid foamable material into the foamed material without thermally softening the solid foamable material. Optionally, the foamed article can comprise additional foamed materials, or additional unfoamed materials. Optionally, the foamed article can be a stabilized foam article, from which residual carbon dioxide has been removed, or from which residual stresses created during the foaming process have been reduced or removed. 
     In one aspect, disclosed herein is a method for making a foamed article, the method comprising: 
     placing an article and carbon dioxide in a vessel, wherein the article comprises a solid foamable material which is a thermoplastic elastomeric material comprising one or more first thermoplastic elastomers; 
     after the placing, maintaining the vessel at a first pressure and a first temperature, wherein the first pressure and first temperature are a pressure and temperature at which the carbon dioxide is a liquid and the liquid carbon dioxide is soluble in the solid foamable material, and wherein the maintaining includes holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the solid foamable material of the article; 
     following the maintaining and holding, optionally exposing the infused article to a second pressure and second temperature at which the carbon dioxide remains infused within at least a portion of the solid foamable material; 
     following the maintaining and holding and the optional exposing, subjecting the article to a third pressure and third temperature at which the carbon dioxide infused in the solid foamable material phase transitions to a gas, thereby expanding the solid foamable material into a foamed material and forming the foamed article. 
     In some aspects, following the subjecting and expanding, the method optionally comprises bringing the foamed article to a fourth temperature and a fourth pressure and holding the foamed article at or below the fourth temperature, the fourth pressure, or both, for a duration of time. In another aspect, following the subjecting and expanding or following the optional bringing, the method further comprises stabilizing the foamed article at a fifth pressure and fifth temperature at which the carbon dioxide diffuses out of the foamed material of the foamed article while maintaining the foamed material in a foam structure, forming a stabilized foamed article. 
     In another aspect, disclosed herein is a foamed article manufactured by the disclosed method. In one aspect, the foamable article is an additive manufactured article. 
     In yet another aspect, disclosed herein is a foamed article comprising a foamed material which is a physically-expanded foam formed of a thermoplastic elastomeric material comprising one or more first thermoplastic elastomers. In one aspect, the foamed article is manufactured by the disclosed method. 
     Method for Making an Additive-Manufactured Article 
     Arranging a Plurality of Particles. In one aspect, disclosed herein is a method of making a foamable article using an additive manufacturing method. In a further aspect, manufacturing the foamable article using an additive manufacturing method comprises arranging a plurality of foamable particles, wherein the arranged plurality of foamable particles comprises a solid foamable material, optionally wherein the plurality of particles comprises a blend, and optionally wherein the arranged plurality of foamable particles has a number average particle size of from about 0.001 millimeters to about 10 millimeters in a longest dimension, or of from about 0.04 millimeters to about 10 millimeters in a longest dimension, or of from about 1 millimeters to about 5 millimeters in a longest dimension. In some aspects, the particles can be uniform in size or uniform in shape or uniform in both size and shape. In another aspect, the particles can be heterogeneous in size and shape. 
     In any of these aspects, the method further comprises directly sintering the particles to each other to form the foamable article. In one aspect, directly sintering the particles comprises increasing a temperature of a portion of the particles with a directed energy beam so as to at least partially soften or melt defining surfaces of only a portion of the arranged plurality of foamable particles, but not of all of the arranged plurality of foamable particles. In an aspect, the directed energy beam comprises a visible or infrared light beam, optionally wherein the light beam is a laser beam, 
     optionally wherein the laser beam is emitted by a gas dynamic laser, a diode laser, or a lead salt laser. In one aspect, the laser beam has a wavelength within the infrared spectrum. 
     In one aspect, manufacturing the foamable article using an additive manufacturing method further comprises depositing a binding material in a binding material target area, wherein the binding material target area comprises at least a portion of the arranged plurality of foamable particles, and wherein the depositing coats at least a portion of defining surfaces of the arranged plurality of foamable particles with the binding material; and affixing at least a portion of the arranged plurality of foamable particles to each other within the target area, optionally wherein the affixing comprises curing. In some aspects, curing can comprise solidifying the deposited binding material and binding the deposited binding material to the coated at least a portion of the defining surfaces of the arranged plurality of foamable particles. In another aspect, the curing can comprise applying energy to the deposited binding material and the arranged plurality of foamable particles in an amount and for a duration sufficient to soften the solid foamable material of the coated at least a portion of the defining surfaces of the arranged plurality of foamable particles into softened foamable material; and decreasing a temperature of the region of the arranged plurality of foamable particles to a temperature at or below which the softened foamable material re-solidifies into the solid foamable material; thereby affixing at least a portion of the coated at least a portion of the defining surfaces of the arranged plurality of foamable particles in the binding material target area. 
     In one aspect, applying energy comprises energy to substantially all of the arranged plurality of foamable particles, or to at least a portion of the binding material target area using a directed energy beam, optionally wherein the directed energy beam is a laser beam. In another aspect, applying energy comprises applying energy within the infrared spectrum, optionally the far infrared spectrum, the near infrared spectrum, or the mid infrared spectrum. In some aspects, applying energy comprises applying a thermal energy source, optionally wherein the thermal energy source is an infrared energy source or a microwave energy source. In one aspect, applying energy comprises applying energy to substantially all of the arranged plurality of foamable particles. 
     Extruded Materials. In one aspect, manufacturing the foamable article using an additive manufacturing method comprises extruding at least one first filament or pellet comprising the foamable material to form the foamable article. In another aspect, depositing comprises depositing the foamable material on a substrate. In an aspect, the substrate can comprise a two-dimensional substrate or a three-dimensional substrate. In a further aspect, following the depositing, optionally, the substrate can be removed from the foamable article. In a further aspect, removing the substrate can comprise dissolving the substrate in a solvent, wherein the foamable article is not soluble in the solvent. In a further aspect, the solvent can be water. In an alternative aspect, removing the substrate comprises physically separating the substrate from the foamable article. In one aspect, following the removing, the foamable article can comprise a lattice structure. 
     In any of these aspects, the method can further comprise adding one or more additional materials to the foamable article. In another aspect, adding the one or more additional materials comprises spraying, brushing, extruding, pressing, or pouring the one or more additional materials onto the foamable article, or dipping the foamable article into the one or more additional materials. 
     In a further aspect, manufacturing the foamable article further comprises extruding a second filament or pellet, wherein the second filament or pellet comprises a second extruded material. In one aspect, the second extruded material comprises an additional material. 
     In one aspect, the foamable material and the second extruded material are deposited sequentially and the foamable material is deposited before the second extruded material or the foamable material is deposited after the second extruded material. In another aspect, the foamable material and the second extruded material are deposited simultaneously. In a further aspect, the foamable material is deposited from one or more first nozzles and the second extruded material is deposited from one or more second nozzles. In an alternative aspect, the foamable material and the second extruded material are deposited via the same nozzle or plurality of nozzles. In one aspect, the second extruded material comprises a second foamable material. 
     In an aspect, the liquid carbon dioxide is soluble in the foamable material at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent; and optionally the liquid carbon dioxide is soluble in the second foamable material at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent. In another aspect, the liquid carbon dioxide is about 80 percent as soluble in the second extruded material as in the foamable material, optionally about 60 percent as soluble, 40 percent as soluble, or about 20 percent as soluble. In still another aspect, the liquid carbon dioxide is soluble at a concentration of at less than 1 weight percent based on a total weight of the second extruded material, optionally less than 0.1 weight percent, or optionally wherein the liquid carbon dioxide is substantially insoluble in the second extruded material. 
     In an aspect, following the expanding and foaming, the second extruded material remains substantially unfoamed. In another aspect, following the expanding and foaming, the foamable material has a first foamed density and the second extruded material has a second foamed density. In an aspect, the first foamed density and the second foamed density are substantially the same, or the first foamed density is at least 20 percent greater than the second foamed density, optionally at least 40 percent greater, at least 60 percent greater, or at least 80 percent greater than the second foamed density. In another aspect, the second foamed density is at least 20 percent greater than the first foamed density, optionally at least 40 percent greater, at least 60 percent greater, or at least 80 percent greater than the first foamed density. 
     Coatings. In one aspect, the method further comprises applying a coating to the additive manufactured foamed article following the expanding and foaming. In another aspect, the coating can comprise a decoration, a protective coating, a waterproof coating, a barrier coating comprising a barrier material, or any combination thereof. 
     Method for Making a Foamed Article 
     In one aspect, provided herein is a method for making a foamed article. The method comprises placing an article and carbon dioxide in a vessel, wherein the article comprises a solid foamable material, and wherein the foamable material is a thermoplastic elastomeric material comprising one or more thermoplastic elastomers. After the placing, the method further comprises maintaining the vessel at a first pressure and first temperature, wherein the first pressure and first temperature are a pressure and temperature at which the carbon dioxide is a liquid and the liquid carbon dioxide is soluble in the solid foamable material, and wherein the maintaining includes holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the solid foamable material of the article. As used herein “infuse” and “infused” carbon dioxide are understood to mean carbon dioxide, which is solubilized in, contained in, or otherwise absorbed and/or taken up in the solid foamable material. In some aspects, following the maintaining and holding, the method optionally comprises exposing the article to a second pressure and second temperature at which the carbon dioxide remains infused within at least a portion of the solid foamable material. In any of these aspects, following the maintaining and holding and the optional exposing of the article, the method comprises subjecting the article to a third pressure and a third temperature at which the carbon dioxide infused in the solid foamable material phase transitions to a gas, thereby expanding the solid foamable material into a foamed material and forming the foamed article. The foamed material has a multi-cellular foam structure. In one aspect, the foamed material has a multi-cellular closed-cell structure. In another aspect, the foamed material has a multi-cellular open-cell structure. In some aspects, subjecting the article to a third temperature and a third pressure and causing the carbon dioxide to phase transition to a gas also serves to cool the foamable material and/or the foamed material. 
     Placing in the vessel. In one aspect, the step of placing the carbon dioxide in the vessel comprises introducing carbon dioxide in the form of a solid, liquid, gas, or supercritical fluid into the vessel prior to the steps of maintaining and holding the carbon dioxide in the form of a liquid. In another aspect, introducing the carbon dioxide comprises charging the vessel with the carbon dioxide gas at a pressure and temperature condition that is a liquid/vapor equilibrium for carbon dioxide. 
     In one aspect, when the article is a sheet, the article can be configured as a roll optionally comprising a spacer or protective layer between adjacent portions of the foamed article. In some aspects, the article can be a layered sheet including one or more foamed layers. Further in this aspect, the step of placing comprises disposing the roll into the vessel and wherein the steps of subjecting and expanding comprise unrolling the article prior to or during the subjecting, or prior to or during the expanding. In some aspects, the step of placing further comprises disposing a porous spacer can be disposed between adjacent portions of the article prior to or during the placing, and wherein the steps of maintaining and holding comprise flowing the carbon dioxide through the porous spacer to the adjacent portions of the article. In other aspects, the article or sheet is not configured as a roll, but can be a sheet, a yarn or fibril, a fabric, a bladder, or any other foamable structure such as, for example, those disclosed herein. 
     In some aspects, the foamable article can be a foamable bladder, or a foamable component of a bladder. In other words, the foamable articles disclosed herein can be used to form bladders, or components of bladders, and these bladders or components of bladders can be foamed using the foaming process disclosed herein. In other aspects, the foamed article can be a foamed bladder or a foamed component of a bladder, where, either before, during or following formation of the bladder or the component of a bladder, the bladder or the component of the bladder is foamed using the foaming process disclosed herein. 
     Maintaining and holding at the first temperature and first pressure. After the step of placing the article and the carbon dioxide in the vessel, the article and carbon dioxide in the vessel are maintained at a first pressure and a first temperature. The first pressure and the first temperature are a pressure and a temperature at which the carbon dioxide is a liquid, and the liquid carbon dioxide is soluble in the solid foamable material. This step includes holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the solid foamable material. During this step, the liquid carbon dioxide contacts the article and infuses into one or more materials present in the article, including the solid foamable material. In order for the carbon dioxide to infuse into the solid foamable material of the article, the carbon dioxide in contact with the article must be present in a form that is soluble in and that will infuse into the solid foamable material. Once infused into the solid foamable material, the infused carbon dioxide also needs to be present in a phase that is capable of phase transitioning into a gas during the foaming process, and must also be present in a sufficient concentration in the solid foamable material to expend at least a portion of the solid foamable material in to a foam having a multi-cellular structure. Although solid carbon dioxide will expand directly from a solid to a gas under certain conditions, when solid carbon dioxide is placed in contact with the solid foamable materials disclosed herein, under most conditions, the solid carbon dioxide does not infuse into the solid foamable material at a rate or in sufficient concentrations to make it useful as a physical foaming agent for mass manufacturing. Although supercritical carbon dioxide can also phase transition and expand to a gas, and supercritical carbon dioxide typically is highly soluble in many polymeric materials, extreme temperatures and pressures are required to maintain carbon dioxide in a supercritical state, greatly increasing equipment and energy requirements for the process. However, liquid carbon dioxide has been found to be soluble in the solid foamable materials disclosed herein in sufficient concentrations to act as a physical foaming agent. 
     In one aspect, the method further comprises discharging any remaining carbon dioxide from the vessel after the steps of maintaining and holding, prior to the optional step of exposing, or prior to the steps of subjecting and expanding. Further in this aspect, discharging the carbon dioxide from the vessel comprises converting the liquid carbon dioxide to carbon dioxide gas prior to or during the discharging. 
     In one aspect, at the first pressure and first temperature, the carbon dioxide is soluble in the solid foamable material at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent, from about 5 weight percent to about 10 weight percent, or from about 10 weight percent to about 20 weight percent. 
     In another aspect, the steps of maintaining and holding comprise maintaining the first pressure at from about 0.05 pounds per square inch (about 0.345 kilopascals) to about 6000 pounds per square inch (about 41,300 kilopascals). In another aspect, the first pressure is from about 15 pounds per square inch (103.4 kilopascals) to about 5500 pounds per square inch (37,900 kilopascals), optionally about 100 pounds per square inch (689.5 kilopascals) to about 5000 pounds per square inch (34,500 kilopascals), from about 500 pounds per square inch (3,450 kilopascals) to about 2000 pounds per square inch (about 13,790 kilopascals), or from about 1000 pounds per square inch (6895 kilopascals) to about 1500 pounds per square inch (10,300 kilopascals). 
     In yet another aspect, the steps of maintaining and holding can comprise maintaining the first temperature at from about −57 degrees Celsius to about 31 degrees Celsius, optionally from about −40 degrees Celsius to about 25 degrees Celsius, or from about −40 degrees Celsius to about 0 degrees Celsius. In one aspect, the steps of maintaining and holding comprise holding the article at the first pressure and the first temperature for a duration of from about 20 seconds to about 72 hours, optionally from about 20 seconds to about 24 hours, from about 1 minute to about 24 hours, or from about 1 minute to about 1 hour. 
     Optionally, in any of these aspects, during the performance of the maintaining and holding step and the subjecting and expanding step of the methods disclosed herein, the temperature of the foamable material is maintained at a temperature below a softening temperature of the foamable material. For example, the thermoplastic elastomeric material can be maintained at a temperature at least 10 degrees Celsius, or at least 20 degrees Celsius below the Vicat softening temperature of the foamable material. While it is possible to conduct additional processing steps on the foamed article which may thermally soften a portion or a region of the solid foamable material or the foamed material, in these aspects, these steps involving thermally softening the solid foamable material or melting the foamed material are conducted either before the maintaining an holding step, or after the subjecting and expanding step. The avoidance of thermally softening the foamable material can reduce or prevent thermal degradation of the foamable material. 
     In an aspect, the article comprises a solid first foamable material and a second material, wherein the second material is a second foamable material. Further in this aspect, the steps of maintaining and holding comprise holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the solid first foamable material but not into the solid second foamable material. Further in this aspect, the steps of subjecting and expanding comprise expanding the first foamable material into a first foamed material while maintaining the solid second foamable material as a substantially unfoamed second foamable material. 
     In an aspect, the foamable article can comprise a foamable region or foamable layer including the first foamable material. In some aspects, the foamable article further comprises a second region or layer comprising a second material (wherein the foamable region or foamable layer including the foamable material is a first foamable region or first foamable layer). The second material can be a second foamable material as disclosed herein, or can be a second unfoamable material. In another aspect, as disclosed herein, the foamed article can comprise a foamed region or foamed layer including the foamed material, and in some aspects, the foamed article can comprise a second foamed region or second foamed layer comprising a second foamable material, or can comprise a second unfoamed region or second unfoamed layer comprising a second unfoamed material. 
     In another aspect, the article comprises a solid first foamable material and further comprises an additional material, wherein the additional material is an additional foamable material. Further in this aspect, the steps of maintaining and holding include holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the solid first foamable material and into the solid additional foamable material. In another aspect, the method includes the optional step of exposing, and the exposing comprises exposing the article to a second pressure and second temperature at which the carbon dioxide remains infused within the solid additional foamable material but at which the carbon dioxide diffuses out of the solid first foamable material. Further in this aspect, the steps of subjecting and expanding comprise expanding the solid foamable material into a second foamed material while maintaining the solid first foamable material as a substantially unfoamed first foamable material. 
     Optional exposing to the second pressure and temperature. In some aspects, following the maintaining and holding, the method optionally comprises exposing the article to a second pressure and second temperature at which the carbon dioxide remains infused within at least a portion of the solid foamable material. In some aspects, this optional step can involve increasing or decreasing the temperature of the foamed article, for example, in order to bring the foamed article to a higher temperature or to a lower temperature. In other aspects, this optional step can involve increasing or decreasing the pressure under which the foamed article is held, for example, in order to expose the foamed article to a higher pressure or to a lower pressure. In yet other aspects, this optional step of exposing can comprise exposing the infused article to an increased or decreased pressure as compared to the first pressure, and/or to an increased or decreased temperature as compared to the first temperature. The optional step of exposing can comprise exposing the infused article to a second pressure and temperature under which the infused carbon dioxide substantially remains infused in the infused article. For example, the second pressure and temperature can be a pressure and a temperature under which little if any carbon dioxide diffuses out of the infused article, over the duration at which the infused article is exposed to the second pressure and/or temperature. In one aspect, the exposing can comprise storing the infused article in a conventional freezer under atmospheric pressure at a temperature at which the infused carbon dioxide has a low rate of diffusion out of the infused article. Alternatively, the optional step of exposing can comprise exposing the infused article to a second pressure and temperature under which an amount of infused carbon dioxide diffuses out of the infused article. For example, when the rate at which the carbon dioxide diffuses out of a thermoplastic material is known for a particular second pressure and temperature, the duration of time required for an amount of carbon dioxide to diffuse out of a particular portion of the infused article can be determined, and the infused article can be held at the second pressure and temperature for the determine duration of time, in order to reduce the concentration of carbon dioxide in a portion or region of the infused article. For example, the exposing step can be used to first create regions or portions of the infused article which will expand into a relatively more dense foam as compared to other regions or portions of the infused article, or which will remain substantially unfoamed during the foaming step, based on allowing some or all of the carbon dioxide to diffuse out of the first regions or portions. In this way, it has been found to be possible to achieve well-controlled variability in the extent to which an article is foamed, without the need for expensive, complicated equipment or tooling. 
     In one aspect, the optional step of exposing comprises exposing the article to the second pressure of from about 1 atmosphere (101 kilopascals) to about 85 atmospheres (8613 kilopascals), optionally from about 1 atmosphere (101 kilopascals) to about 40 atmospheres (4053 kilopascals), or from about 1 atmosphere (101 kilopascals) to about 20 atmospheres (2026.5 kilopascals). 
     In some aspects, the optional step of exposing comprises exposing the article to the second temperature of more than about 30 degrees Celsius below the softening point of the solid foamable material, optionally more than about 50 degrees Celsius below the softening point of the solid foamable material, or more than about 100 degrees below the softening point of the solid foamable material. 
     In any of these aspects, the optional step of exposing comprises exposing the article to the second pressure and second temperature for a duration of from about 30 minutes to about 4 weeks, optionally from about 1 hour to about 1 week, or from about 1 hour to about 24 hours. 
     In some aspects, the optional step of exposing can occur in the vessel. In other aspects, the optional step of exposing further comprises removing the carbon dioxide-infused article from the vessel prior to exposing the article to the optional second pressure and second temperature. 
     Subjecting to a third pressure and third temperature, expanding the solid foamable material. As stated above, the method comprises subjecting the article to a third pressure and a third temperature at which the carbon dioxide infused in the solid foamable material phase transitions to a gas, thereby expanding the solid foamable material into a foamed material and forming the foamed article. The third pressure can be a higher or lower pressure as compared to the first pressure or the optional second pressure, and the third temperature can be a higher or lower temperature as compared to the first temperature or the optional second pressure, so long as the third pressure and temperature are a condition under which the infused carbon dioxide present in the infused article phase transitions to a gas, and does so at a rate sufficient to expand at least a portion of the solid foamable material of the article. In many aspects, the third pressure can be a pressure at or near atmospheric pressure, and the third pressure can be at or near room temperature, or an elevated temperature which is below the softening temperature of the solid foamable material, i.e., conditions which can be achieved using inexpensive equipment and low energy consumption. 
     In one aspect, the steps of subjecting and expanding comprise subjecting the article to third pressure of from about 13 pounds per square inch (89.6 kilopascals) to about 16 pounds per square inch (110.3 kilopascals), optionally from about 13 pounds per square inch (kilopascals) to about 15 pounds per square inch (103.4 kilopascals), or from about 14 pounds per square inch (96.5 kilopascals) to about 15 pounds per square inch (103.4 kilopascals). 
     In some aspects, the steps of subjecting and expanding comprise subjecting the article to third temperature of from about 20 degrees Celsius to about 150 degrees Celsius, optionally from about 20 degrees Celsius to about 100 degrees Celsius, from about 25 degrees Celsius to about 70 degrees Celsius, from about 50 degrees Celsius to about 70 degrees Celsius, or is about 60 degrees Celsius. 
     In any of these aspects, the steps of subjecting and expanding comprise subjecting the article to the third pressure and third temperature for a duration of from about 2 seconds to about 5 minutes, optionally from about 5 seconds to about 2 minutes, or from about 30 seconds to about 1 minute. 
     In some aspects, the steps of subjecting and expanding can occur in the vessel. In other aspects, the step of subjecting further comprises removing the carbon dioxide-infused article from the vessel prior to subjecting the article to the third pressure and third temperature. 
     In one aspect, the step of subjecting the article to the third temperature and third pressure comprises introducing the article to a fluid bath, optionally wherein the fluid bath is a water bath. In some aspects, the fluid bath has a temperature of from about 20 degrees Celsius to about 90 degrees Celsius, optionally from about 40 degrees Celsius to about 80 degrees Celsius, or from about 50 degrees Celsius to about 70 degrees Celsius. In another aspect, during the subjecting, the article is held in the fluid bath for a duration of time of from about 15 seconds to about 5 minutes, optionally from about 30 seconds to about 3 minutes, or from about 1 minute to about 2 minutes. 
     In an alternative aspect, the step of subjecting comprises subjecting the article to a source of energy or heat, optionally wherein the source of energy or heat comprises steam, microwave energy, infrared (IR) energy, or radio frequency (RF) energy. Further in this aspect, the step of subjecting the article to the source of energy or heat increases the temperature of at least a portion of the foamable material of the article to a temperature of from about 60 degrees Celsius to about 150 degrees Celsius, optionally from about 70 degrees Celsius to about 100 degrees Celsius, or from about 75 degrees Celsius to about 90 degrees Celsius. In one aspect, the subjecting is for a duration of from about 2 seconds to about 5 minutes, optionally from about 15 seconds to about 3 minutes, or from about 1 minute to about 2 minutes. 
     In another aspect, the step of subjecting and expanding comprises expanding the foamable material into the foamed material until the foamed material has a density of from about 0.01 gram per cubic centimeter to about 3.0 grams per cubic centimeter, optionally of from about 0.01 gram per cubic centimeter to about 0.1 gram per cubic centimeter, from about 0.01 gram per cubic centimeter to about 0.05 grams per cubic centimeter, from about 0.01 gram per cubic centimeter to about 0.025 grams per cubic centimeter, from about 0.05 grams per cubic centimeter to about 0.1 gram per cubic centimeter, from about 0.1 gram per cubic centimeter to about 3.0 grams per cubic centimeter, from about 0.2 grams per cubic centimeter to about 2.0 grams per cubic centimeter, from about 0.3 grams per cubic centimeter to about 1.5 grams per cubic centimeter, from about 0.3 grams per cubic centimeter to about 1.2 grams per cubic centimeter, or from about 0.4 grams per cubic centimeter to about 1.0 grams per cubic centimeter. 
     In still another aspect, following the steps of subjecting and expanding, the foamed material has an expansion ratio of from about 3:1 to about 120:1 relative to the solid foamable material prior to the subjecting and expanding, optionally from about 3:1 to about 100:1, or from 3:1 to about 50:1, or from about 5:1 to about 10:1 relative to the thermoplastic elastomeric material in a non-foamed condition. In one aspect, during the expanding, at least a portion of the article comprising the solid foamable material expands in length, width, and height due to the expansion of the solid foamable material into the foamed material. 
     In one aspect, following the expanding, a size of the foamed article is greater in at least one dimension as compared to a size of the article before the placing, optionally wherein the foamed article is at least 5 percent larger, optionally at least 10 percent larger, at least 15 percent larger, or at least 20 percent larger in one or more of length, width, and height. 
     In some aspects, the article is a layered sheet and the steps of subjecting and expanding foam at least one layer of the sheet. Further in this aspect, following the subjecting and expanding, a thickness of the foamed layered sheet is at least 5 percent greater, optionally at least 10 percent greater, at least 15 percent greater, or at least 20 percent greater than a thickness of the layered sheet in its unfoamed state. 
     Optional exposing to fourth temperature and fourth pressure. In some aspects, the method further comprises the optional step of, following the subjecting and expanding, bringing the foamed article to a fourth temperature and fourth pressure, and holding the foamed article at or below the fourth temperature, the fourth pressure, or both, for a duration of time. This optional step can involve increasing or decreasing the temperature of the foamed article, for example, in order to bring the foamed article to room temperature. Similarly, in some aspects, this optional step can involve increasing or decreasing the pressure under which the foamed article is being held, for example, bringing the foamed article to atmospheric pressure and/or room temperature. 
     In one aspect, the optional step of bringing comprises bringing the foamed article to the fourth pressure of from about 0.03 atmospheres (3.04 kilopascals) to about 2 atmospheres (202.65 atmospheres), optionally from about 0.5 atmospheres (50.7 kilopascals) to about 1.5 atmospheres (152 kilopascals), or is about 1 atmosphere (101.3 kilopascals). 
     In another aspect, the optional step of bringing comprises bringing the foamed article to the fourth temperature of from about 30 degrees Celsius to about 70 degrees Celsius, optionally from about 40 degrees Celsius to about 60 degrees Celsius, or from about 45 degrees Celsius to about 55 degrees Celsius. In some aspects, in the optional step of bringing, the fourth temperature is at or below a glass transition temperature of the solid foamable material, or is from about 10 degrees Celsius less than to about 10 degrees Celsius greater than the glass transition temperature of the solid foamable material as measured by the Melting Temperature, Glass Transition Temperature, and Enthalpy of Melting Test Protocol. In one aspect, the glass transition temperature of the solid foamable material is less than 0 degrees Celsius, optionally less than −10 degrees Celsius, less than −20 degrees Celsius, less than −30 degrees Celsius, or less than −40 degrees Celsius. 
     In any of these aspects, optional step of bringing comprises bringing the foamed article to the fourth pressure and the fourth temperature for a duration of from about 15 minutes to about 1 hour, optionally from about 20 minutes to about 45 minutes, or from about 20 minutes to about 30 minutes. 
     Optional stabilizing at a fifth temperature and fifth pressure. In still other aspects, the method further comprises, following the subjecting and expanding or following the optional bringing, stabilizing the foamed article at a fifth pressure and fifth temperature. The fifth pressure and temperature can be a pressure and temperature at which the carbon dioxide diffuses out of the foamed material of the foamed article while maintaining the foamed material in a foam structure, thereby forming a stabilized foamed article. In some aspects, stabilizing comprises holding the foamed article at the fifth pressure and fifth temperature for a duration of time sufficient to remove substantially all of the carbon dioxide from the foamed material. The fifth pressure can be at or near atmospheric pressure, or can be at a pressure at which the rate at which air diffuses into the foam and/or the rate at which carbon dioxide diffuses out of the foam is greater than the rate(s) at atmospheric pressure. The fifth temperature can be at or near room temperature, or can be at a temperature at which the rate at which air diffuses into the foam and/or the rate at which carbon dioxide diffuses out of the foam is greater than the rate(s) at room temperature. Stabilizing the foamed article can also comprise releasing stresses in the foamed article, such as stresses in the foamed thermoplastic elastomeric material, or stresses in a solid material present in the foamed article. In such aspects, the fifth pressure and/or fifth temperature can be atmospheric pressure and/or room temperature, or can be a pressure and/or temperature at which stresses in the foamed article are released at faster rate(s) than at atmospheric pressure or room temperature. In one example, the stabilization can be conducted at atmospheric pressure and at a temperature above room temperature and at least 5 degrees Celsius below the softening temperature of the foamed material. The stabilization can be conducted using conventional heating equipment, such as a convection, microwave or infrared oven, or a heating tunnel. Stabilization can be particularly useful when the foamed material is present in the form of a sheet, and/or when the foamed article includes a layered structure including layers of foamed materials adjacent to layers of solid (unfoamed) materials, as it can release stresses in the solid materials which developed during the foaming process. 
     In one aspect, the optional step of stabilizing comprises stabilizing at the fifth pressure of about atmospheric pressure. In another aspect, the optional step of stabilizing comprises stabilizing at the fifth temperature of greater than the glass transition temperature of the foamed material as measured by the Melting Temperature, Glass Transition Temperature, and Enthalpy of Melting Test Protocol. Further in this aspect, the optional step of stabilizing comprises stabilizing at the fifth temperature of from about 30 degrees Celsius to about 70 degrees Celsius, optionally from about 40 degrees Celsius to about 60 degrees Celsius, or about 50 degrees Celsius. In one aspect, the optional step of stabilizing comprises stabilizing the foamed article at the fifth temperature for from about 15 minutes to about 60 minutes, optionally from about 30 minutes to about 45 minutes. 
     In one aspect, the optional step of stabilizing at the fifth pressure and the fifth temperature comprises placing the foamed article in an oven. In some aspects, stabilizing the foamed article at the fifth pressure and the fifth temperature releases stresses in the foamed article. In another aspect, stabilizing the foamed article at the fifth pressure and the fifth temperature removes substantially all of the residual carbon dioxide in the foamed article. In another aspect, if carbon dioxide gas remains in individual foam cells, stabilizing can remove the carbon dioxide gas. In a further aspect, if carbon dioxide remains infused in foamed or unfoamed materials, stabilizing can remove the infused carbon dioxide. In still another aspect, stresses may be introduced when foamable materials transition to foamed materials while remaining bonded to unfoamed materials; further in this aspect, stabilizing can release these stresses. 
     In some aspects, shrinkage of the foamed article may be a concern, or may be desirable. The step of stabilizing the foamed article at the fifth pressure and the fifth temperature can be used to reduce or control the level of shrinkage of the foamed article following the foaming. For example, the rate of shrinkage under particular conditions can be used determine the time, temperature, and pressure to obtain the desired level of shrinkage for the foam article. In an aspect, stabilizing can reduce or release stresses that would otherwise lead to an undesired level of shrinkage. 
     In any of these aspects, the method can include the step of stabilizing, and following the stabilizing, the stabilized foamed article is greater in at least one dimension as compared to a size of the article before the placing, optionally wherein the stabilized foamed article is at least 5 percent larger, at least 10 percent larger, at least 15 percent larger, or at least 20 percent larger in one or more of length, width, and height. 
     Further Processing of the Foamable Material and Foamed Materials and Articles. In an aspect, the foamable material can optionally be formed using a variety of processes. In one aspect, the solid foamable material can be formed using an extrusion process prior to the step of placing. In one aspect, the solid foamable material can be formed using an injection molding process prior to the step of placing. In another aspect, the solid foamable material can be formed using a thermal and/or vacuum forming process prior to the step of placing. In one aspect, the thermal and/or vacuum forming process can use pressure and/or thermal energy to conform the foamable material to the shape of a mold. In one aspect, the mold can include one or more curved surfaces. In another aspect, the mold can be an open mold or a closed mold. In some aspects, the mold can be configured to form a single surface of the foamable material or multiple surfaces of the foamable material. Alternatively or additionally, an additive manufacturing process such as extrusion, deposition printing, and/or selective sintering can be used to form and/or shape the foamable material prior to the step of placing. 
     In one aspect, the method further comprises thermoforming the foamed article, optionally wherein the foamed article is a stabilized foamed article. In some aspects, the article can be a thermoformed article. In any of these aspects, the foamed article can be a component of an article of apparel, an article of footwear, or an article of sporting equipment. 
     In a further aspect, a thermoforming step can be conducted prior to the step of placing. In another aspect, thermoforming one or more surfaces of the additive manufactured foamed article imparts a texture to one or more surfaces, and/or imparts a finish to the one or more surfaces, optionally wherein the finish is a glossy finish or a matte finish. 
     In one aspect, thermoforming one or more surfaces of the additive manufactured foamed article increases roughness of the one or more surfaces, optionally where increased roughness promotes mechanical interlocking of a bonded surface to the foamed article, or wherein increased roughness imparts additional surface area, wherein the additional surface area increases contact area for an adhesive. In another aspect, thermoforming one or more surfaces of the additive manufactured foamed article reduces the number and/or surface area of voids in the surface, optionally wherein thermoforming increases surface texture uniformity of the thermoformed surface, optionally wherein the increase in surface texture uniformity increases bonding strength between the surface and as second element is as compared to a bond strength to a surface of a substantially identical foamed article which has not been thermoformed, and a substantially identical second element. In still another aspect, thermoforming one or more surfaces of the additive manufactured foamed article reduces water uptake of the foamed article as compared to a level of water uptake for a surface of a substantially identical foamed article which has not been thermoformed. In yet another aspect, thermoforming one or more surfaces of the additive manufactured foamed article increases abrasion resistance of the additive manufactured foamed article as compared to a level of abrasion resistance for a surface of a substantially identical foamed article which has not been thermoformed. In any of these aspects, water uptake can be measured using the Water Uptake Test Protocol found in the Property Analysis and Characterization Procedures, while abrasion resistance and/or loss can be measured using the Akron Abrasion Test Protocol and/or the DIN Abrasion Test Protocol found in the Property Analysis and Characterization Procedures. 
     Additive Manufactured Foamed Articles 
     In one aspect, disclosed herein is an article comprising a structure formed of a plurality of affixed foamable particles; wherein each individual foamable particle of the plurality of affixed foamable particles is formed of a foamable material, and includes one or more binding regions on an outer surface of the individual foam particle affixing the individual foam particle to one or more adjacent foamable particles; wherein the one or more adjacent foamable particles comprise the foamable material; wherein the binding regions include a portion of binding material from the individual foam particle, a portion of binding material from at least one of the one or more adjacent foamable particles, a portion of the thermoplastic foamable from the individual foam particle intermingled with a portion of the foamable material from at least one of the one or more adjacent foamable particles, or any combination thereof; wherein the structure formed of the plurality of affixed foamable particles includes a plurality of gaps between particles, with the gaps occupying at least 10 percent of a total volume of the structure; wherein, prior to affixing, at least 20 percent of the plurality of foamable particles are ellipsoid in shape and have a number average particle size of about 0.04 millimeters to about 10 millimeters in a longest dimension; and wherein at least 20 percent of the ellipsoid foamable particles in the structure retain a substantially ellipsoid shape. 
     In another aspect, disclosed herein is additive-manufactured article comprising a structure formed from one or more extruded materials, wherein one or more of the extruded materials comprise a foamable material, optionally wherein one or more of the extruded materials comprise a blend. 
     Foamed Articles 
     In one aspect, disclosed herein is a foamed article comprising a foamed material that is a physically-expanded foam formed of a thermoplastic elastomeric material comprising one or more first thermoplastic elastomers. In another aspect, the foamed material is a product of placing an unfoamed article comprising a solid foamable material in liquid carbon dioxide, infusing the solid foamable material with the carbon dioxide, and expanding the infused solid foamable material by expanding the infused carbon dioxide without thermally softening the solid foamable material, for example by phase transitioning the infused carbon dioxide into a gas under conditions that do not soften the solid foamable material, thereby expanding the solid foamable material into the foamed material of the foamed article. In some aspects, the foamed article is a stabilized foamed article comprising the stabilized foamed material, wherein the stabilized foamed material is free or substantially free of infused carbon dioxide. 
     In another aspect, in the foamed articles described herein, the foamed material is a first foamed material, the foamed article comprises a second foamed material, the second foamed material is an additional material as disclosed herein, and the thermoplastic elastomeric material of the first foamed material is a recycled material, or the additional material of the second foamed material is a recycled material, or both the thermoplastic elastomeric material and the additional material are recycled materials. 
     In another aspect, when first pressure is from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (about 41,300 kilopascals), optionally about 15 pounds per square inch (103.4 kilopascals) to about 5500 pounds per square inch (37,900 kilopascals), about 100 pounds per square inch (689.5 kilopascals) to about 5000 pounds per square inch (34,500 kilopascals), from about 500 pounds per square inch (3,450 kilopascals) to about 2000 pounds per square inch (about 13,790 kilopascals), or from about 1000 pounds per square inch (6895 kilopascals) to about 1500 pounds per square inch (10,300 kilopascals) and the first temperature can be from about −57 degrees Celsius to about 31 degrees Celsius, optionally from about −40 degrees Celsius to about 25 degrees Celsius, or from about −40 degrees Celsius to about 0 degrees Celsius, the carbon dioxide is soluble in the foamed material or in the solid foamable material, or in both, at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent, from about 5 weight percent to about 10 weight percent, or from about 10 weight percent to about 20 weight percent. 
     In one aspect, the foamed material of the foamed article is substantially opaque. In another aspect, the foamed material has a split-tear value of from about 2.5 kilograms per centimeter to about 3.0 kilograms per centimeter, optionally of from about 2.5 kilograms per centimeter to about 2.8 kilograms per centimeter, from about 2.5 kilograms per centimeter to about 2.75 kilograms per centimeter, or from about 2.75 kilograms per centimeter to about 3.0 kilograms per centimeter, as measured using the Split-Tear Test Protocol. In another example, the foamed article is formed having an Asker C hardness of from about 10 to about 50, or of from about 15 to about 50, from about 15 to about 45, from about 20 to 45, or from about 20 to about 40, as measured using the Asker C Hardness Test Protocol. 
     Strata of the Foamable Materials and Foamed Articles and Arrangement Thereof 
     In one aspect, the articles disclosed herein, before undergoing a foaming process as disclosed herein, can comprise or consist essentially of a single strata of solid foamable material as illustrated, for example, in  FIG.  8 A . In this exemplary embodiment, article  401 , before undergoing the foaming process, includes solid foamable material  412   a  having a first surface  412   a ′ and a second surface  412   a ″ and a thickness  410   a . In one aspect, first surface  412   a ′ and second surface  412   a ″ can be continuous or can comprise one or more openings or discontinuous areas. The solid foamable material  412   a  can be formed into the strata using one or more additive manufacturing processes (e.g., by extruding a pellet or a filament, by depositing solid particles, a combination thereof, etc.). Alternatively or additionally, the solid foamable material  412   a  can be formed into the strata using conventional process such as extruding a film, one of various conventional molding processes such as injection molding and/or compression molding, and the like. Within the strata, the solid foamable material can be essentially continuous, or can include gaps or pockets between portions of the solid foamable material  412   a . In a further aspect, the gaps or pockets can be created during the forming process, for example, by spacing apart segments of extruded filament, or by depositing solid particles varying density within the strata. In some aspects, the gaps or pockets can fully enclosed by the solid foamable material, or can be in fluid communication with openings or discontinuous areas on the first surface  412   a ′ and/or second surface  412   a ″. In certain aspects, the gaps or pockets can be filled with air, or can be filled with a different polymeric material, such as a polymeric material in which the solubility of liquid carbon dioxide is greater than or less than the solubility of liquid carbon dioxide in the solid foamable material  412   a . During the foaming process, at least a portion of the solid foamable material  412   a  of the single strata expands to have a foam structure, thereby increasing its volume. The increase in volume of the foamed material increases at least one dimension (length, width, or thickness) of the foamed article. In examples where the length and width of the article are significantly larger than its thickness, the change in volume following foaming will have a larger impact on its thickness. After undergoing the foaming process, in the foamed article, in one aspect, the thickness  410   a  of the single strata is increased as compared to its thickness before foaming. 
     In another aspect, the articles disclosed herein, before undergoing a foaming process as disclosed herein, can comprise multiple strata, at least one of which comprises a solid foamable material according to the present disclosure, as illustrated, for example, in  FIG.  8 B . In this exemplary embodiment, the article  402  includes a first strata  412   a  having thickness  410   a , and a second strata  416  having a thickness  414 . 
     In one such aspect in accordance with the example of  FIG.  8 B , the first strata  412   a  can comprise or consist essentially of a first solid foamable material. In such an aspect, the second strata  416  can also comprise or consist essentially of a second solid foamable material, or can comprise or consist essentially of a barrier material. In either of these aspects, the first strata  412   a  can have a first surface  412   a ′ and a second surface  412   a ″, and the second strata  416  can have a first surface  416   a  and a second surface  416   b . In one aspect, first surface  412   a ′ and second surface  412   a ″ of first strata  412   a , and the first surface  416   a  and second surface  416   b  of the second strata  416  when the second strata  416  comprises or consists essentially of a second solid foamable material, can be continuous or can comprise one or more openings or discontinuous areas. In some aspects, the second surface  412   a ″ of the first strata  412   a  and the first surface  416   a  of the second strata  416  can be adjacent to one another or otherwise in contact with one another. In some aspects, first surface  412   a ′ of the first strata  412   a  can optionally be an outer surface of article  402 . In some aspects, as with first strata  412   a , second strata  416  can have gaps or pockets, which can fully enclosed by the solid foamable material, or can be in fluid communication with openings or discontinuous areas on the first surface  416   a  and/or second surface  416   b.    
     During the foaming process, at least a portion of the first solid foamable material of the first strata  412   a  and, in instances wherein the second strata  416  comprises or consists essentially of a second solid foamable material, optionally at least a portion of the second solid foamable material of the second strata  416 , expands to have a foam structure, thereby increasing its volume. The increase in volume of the foamed material increases at least one dimension (length, width, or thickness) of the foamed article. In examples where the length and width of the article are significantly larger than its thickness, and/or wherein the first and/or second solid foamable material is constrained in the length-wise and/or width-wise dimension, such as by being bonded to another material, the change in volume following foaming will have a larger impact on its thickness. 
     After undergoing the foaming process, in the foamed article, the thickness  410   a  of the second strata  412   a  is increased as compared to before foaming. In aspects where the second layer  416  comprises a second foamable material, the second foamable material can also expand and foam, increasing the thickness  414  of the second layer  416  as compared to its thickness before foaming. Alternatively, the second layer  416  may not foam during the foaming process, and thus its thickness  414  will stay substantially the same before and after undergoing the foaming process. In one such aspect where the second layer  416  remains unfoamed, the second layer  416  comprises or consists essentially of a barrier material, and thus does not expand and foam during the foaming process. In an alternative such aspect where the second layer  416  remains unfoamed, the second layer  416  may comprise a second foamable material, but the second foamable material either is not infused with carbon dioxide during the maintaining and holding step, or infused carbon dioxide is diffused out of the second layer  416  prior to the subjecting and expanding step. 
     Intermediate Strata. In another aspect, the foamed article comprises an intermediate strata located between the first strata and the second strata and the intermediate strata comprises or consists essentially of a structural material. In one aspect, the structural material can be an additional material as disclosed herein, optionally wherein the structural material comprises a blend of two or more additional materials, optionally wherein at least one of the two or more additional materials is a recycled material. 
     In another aspect, the articles disclosed herein, before undergoing a foaming process as disclosed herein, can comprise multiple strata, at least one of which comprises a solid foamable material according to the present disclosure, as illustrated, for example, in  FIG.  8 C . In this exemplary embodiment, the article  403  includes a first strata  412   a  having thickness  410   a , an intermediate strata  420   a  having a thickness  418   a , and a second strata  416  having a thickness  414 . 
     In one such aspect in accordance with the example of  FIG.  8 C , the first strata  412   a  can comprise or consist essentially of a first solid foamable material. In such an aspect, the intermediate strata  420   a  can also comprise or consist essentially of a third solid foamable material, or can comprise or consist essentially of a barrier material. In such an aspect, the second strata  416  can comprise or consist essentially of a second solid foamable material, or can comprise or consist essentially of a barrier material. In any of these aspects, the first strata  412   a  can have a first surface  412   a ′ and a second surface  412   a ″, the intermediate strata can have a first surface  420   a ′ and a second surface  420   a ″, and the second strata can have a first surface  416   a  and a second surface  416   b . In some aspects, the second surface  412   a ″ of the first strata  412   a  and the first surface  420   a ′ of the intermediate strata  420   a  can be adjacent to one another or otherwise in contact with another. In a further aspect, the second surface  420   a ″ of the intermediate strata  420   a  and the first surface  416   a  of the second strata  416  can be adjacent to one another or otherwise in contact with one another. In some aspects, first surface  412   a ′ of the first strata  412   a  can optionally be an outer surface of article  403 . 
     In an aspect, during the foaming process, at least a portion of the first solid foamable material of the first strata  412   a  and, in instances, wherein the intermediate strata  420   a  comprises or consists essentially of a third solid foamable material and the second strata  416  comprises or consists essentially of a second solid foamable material, optionally at least a portion of the third solid foamable material of the intermediate strata  420   a  and/or at least a portion of the second solid foamable material of the second strata  416 , expands to have a foam structure, thereby increasing its volume. The increase in volume of the foamed material increases at least one dimension (length, width, or thickness) of the foamed article. In examples where the length and width of the article are significantly larger than its thickness, and/or wherein the first, second, and/or third solid foamable material is constrained in the length-wise and/or width-wise dimension, such as by being bonded to another material, the change in volume following foaming will have a larger impact on its thickness. 
     After undergoing the foaming process, in the foamed article, thickness  410   a  of the first strata  412   a  is increased as compared to before foaming. In aspects where the intermediate strata  420   a  comprises a third foamable material, the third foamable material can also expand and foam, increasing the thickness  418   a  of the intermediate strata  420   a  as compared to its thickness before foaming. Alternatively, the intermediate strata  420   a  may not foam during the foaming process, and thus its thickness  418   a  will stay substantially the same before and after undergoing the foaming process. In aspects where the third strata  416  comprises a second foamable material, the second foamable material can also expand and foam, increasing the thickness  414  of the second strata  416  as compared to its thickness before foaming. Alternatively, the second strata  416  may not foam during the foaming process, and thus its thickness  414  will stay substantially the same before and after undergoing the foaming process. In one such aspect where the intermediate strata  420   a  and/or the second strata  416  remains unfoamed, the intermediate strata  420   a  and/or the second strata  416  comprises or consists essentially of a barrier material, and thus does not expand and foam during the foaming process. In an alternative aspect such as where the intermediate strata  420   a  remains unfoamed, the intermediate strata  420   a  may comprise a third foamable material, but the third foamable material either is not infused with carbon dioxide during the maintaining and holding step, or infused carbon dioxide is diffused out of the intermediate strata  420   a  prior to the subjecting and expanding step. In another aspect such as when the second strata  416  remains unfoamed, the second strata  416  may comprise a second foamable material, but the second foamable material either is not infused with carbon dioxide during the maintaining and holding step, or infused carbon dioxide is diffused out of the second strata  416  prior to the subjecting and expanding step. 
     In one aspect, arranging a plurality of foamable particles comprises foaming one or more strata comprising the plurality of foamable particles. In one aspect, the article is formed from a single strata comprising the plurality of foamable particles. In another aspect, an iteration of the arranging comprises forming a strata comprising the plurality of foamable particles. In some aspects, the article is formed from a plurality of strata in a layer-wise fashion, wherein each strata comprises a plurality of foamable particles, and wherein, in the foamable article, each strata is affixed to at least a portion of another strata. 
     Two Strata. In one aspect, the article can be configured as a series of two or more strata including a first strata comprising a first strata material and a second strata comprising a second strata material, wherein the first strata material or the second strata material or both the first strata material and the second strata material are a solid foamable material; optionally wherein the first strata material and the second strata material are individually a blend, optionally wherein the first strata or the second strata forms an outermost surface of the article, or wherein both the first strata and the second strata individually or jointly form the outermost surface of the foamable article. In some aspects, the two or more strata individually comprise a plurality of particles, an extruded material, or any combination thereof, optionally wherein the plurality of particles, the extruded material, or both, are a solid foamable material. 
     In one aspect, the first strata comprises a first plurality of particles and the second strata comprises a second plurality of particles. In another aspect, the first strata comprises a first extruded material and the second strata comprises a second plurality of particles. In one aspect, the first strata comprises a first plurality of particles and the second strata comprises a second extruded material. In one aspect, the first strata comprises a first extruded material and the second strata comprises a second extruded material. In any of these aspects, the first strata can form an outermost surface of the foamable article and the second strata forms an inner layer of the additive manufactured article. 
     In an aspect, in the foamable article, the first strata comprises or consists essentially of the solid foamable material, the solid foamable material of the first strata is a first strata solid foamable material, and in the steps of subjecting and expanding, the first strata solid foamable material either remains as the first strata solid foamable material, or expands into the foamed material wherein the foamed material of the first strata is a first strata foamed material. In another aspect, in the foamable article, the second strata comprises or consists essentially of the solid foamable material, the solid foamable material of the second strata is a second strata solid foamable material, and in the steps of subjecting and expanding, the second strata solid foamable material either remains as the second solid strata foamable material, or expands into the foamed material wherein the foamed material of the second strata is a second strata foamed material. In one aspect, the first strata solid foamable material, or the second strata solid foamable material, or both, is individually a solid foamable material. In another aspect, the first strata foamed material, or the second strata foamed material, or both, are individually a foamed material. 
     In one aspect, in the disclosed methods, the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata, or the duration of time is sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second strata, or the duration of time is sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata and into at least a portion of the second strata; 
     optionally the duration of time is sufficient for the at least a portion of the liquid carbon dioxide to infuse into substantially all of the first strata, or substantially all of the second strata, or into substantially all of the first strata and the second strata. 
     In another aspect, in the disclosed methods, the first strata comprises or consists essentially of the first strata solid foamable material, the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata solid foamable material, and the steps of subjecting and expanding include expanding the at least a portion of the first strata solid foamable material into the foamed material, wherein the foamed material of the first strata comprises a first strata foamed material, optionally wherein the expanding includes expanding substantially all of the solid foamable material of the first strata into the first strata foamed material. 
     In still another aspect, in the disclosed methods, the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata, wherein the duration of time is not sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second strata; and the steps of subjecting and expanding include expanding the at least a portion of the first strata solid foamable material into the first strata foamed material without expanding the second strata material; optionally, following the steps of maintaining and holding, the second strata is substantially free of infused carbon dioxide, and optionally the second strata comprises or consists essentially of a barrier material. 
     In one aspect, in the disclosed methods, the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata and into the at least a portion of the second strata, and the method further comprises the step of exposing the infused article to the second pressure and second temperature for a duration of time such that the at least a portion of carbon dioxide infused into the at least a portion of the second strata diffuses out of the at least a portion of the second strata, while at least a portion of the infused carbon dioxide infused in the first strata remains infused in the at least a portion of the first strata following the exposing; and 
     the steps of subjecting and expanding include expanding the at least a portion of the solid foamable material of the first strata into the first strata foamed material without expanding the second strata material of the second strata, thereby forming a foamed first strata while maintaining the second strata in a solid unfoamed state; and optionally, following the step of exposing, the second strata is substantially free of infused carbon dioxide. 
     In one aspect, in the disclosed method, the step of placing comprises placing the foamable article in the liquid carbon dioxide in the vessel such that the article is not fully immersed in the liquid carbon dioxide. In one aspect, the first strata is immersed in the liquid carbon dioxide and the second strata is not immersed in the liquid carbon dioxide and, following the step of exposing, the second strata is substantially free of infused carbon dioxide. 
     In another aspect, in the disclosed method, the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second strata, or the duration of time is sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata and into at least a portion of the second strata; optionally the duration of time is sufficient for the at least a portion of the liquid carbon dioxide to infuse into substantially all of the second strata, or substantially all of the second strata, or into substantially all of the first strata and the second strata. 
     In an aspect, in the disclosed method, the second strata comprises or consists essentially of the solid foamable material, the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second strata solid foamable material, and the steps of subjecting and expanding include expanding the at least a portion of the second strata solid foamable material into the foamed material, wherein the foamed material of the second strata comprises a second strata foamed material, and optionally the expanding includes expanding substantially all of the second strata solid foamable material into the strata regional foamed material. 
     In another aspect, the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the second strata, wherein the duration of time is not sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata; and the steps of subjecting and expanding include expanding the at least a portion of the second strata solid foamable material into the second strata foamed material without expanding the first strata material, thereby forming a foamed second strata while maintaining the first strata in a solid unfoamed state; and optionally, following the steps of maintaining and holding, the first strata is substantially free of infused carbon dioxide. 
     In one aspect, in the disclosed methods, the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata and into the at least a portion of the second strata, and the method further comprises the step of exposing the infused article to the second pressure and second temperature for a duration of time such that the at least a portion of carbon dioxide infused into the at least a portion of the first strata diffuses out of the at least a portion of the first strata, while at least a portion of the infused carbon dioxide infused in the second strata remains infused in the at least a portion of the second strata following the exposing; and 
     the steps of subjecting and expanding include expanding the at least a portion of the second strata solid foamable material into the second strata foamed material without expanding the first strata material; and optionally, following the step of exposing, the first strata is substantially free of infused carbon dioxide. 
     In a further aspect, the first strata comprises or consists of the solid foamable material, the solid foamable material of the first strata being a first strata solid foamable material; the second strata comprises or consists essentially of the solid foamable material, the solid foamable material of the second strata being a second solid strata foamable material; the step of maintaining and holding includes holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first strata and into at least a portion of the second strata; and the steps of subjecting and expanding expands at least a portion of the first strata solid foamable material into a first strata foamed material, and expands at least a portion of the second regional strata foamable material into a second strata foamed material, and optionally, the expanding includes expanding substantially all of the first strata solid foamable material or substantially all of the second strata solid foamable material, or expanding substantially all of the first strata solid foamable material and substantially all of the second strata solid foamable material. 
     In one aspect, in the additive manufactured foamed material, the first strata foamed material and the second strata foamed material are in contact with each other. In an alternative aspect, the first strata foamed material and the second strata foamed material are not in contact with each other. 
     Three Strata. In one aspect, the foamable article is configured as a series of three or more strata, further comprising a third strata including a third comprising or consisting essentially of a third strata material, optionally the third strata material comprises or consists essentially of a third strata solid foamable material, optionally the third strata foamable material is a blend according, and optionally the third strata is positioned between the first strata and the second strata. In one aspect, the third strata comprises a third plurality of particles, or comprises a third extruded material. 
     In one aspect, in the disclosed method, the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into the first strata, or into the first strata and the second strata, or into the second strata, or into the second strata and the third strata, or into the third strata, or into the third strata and the first strata. 
     In another aspect, the steps of maintaining and holding include holding the foamable article and the liquid carbon dioxide in the vessel for a duration of time sufficient for liquid carbon dioxide to infuse into one or two of the three strata but not into the other of the three strata; optionally the carbon dioxide infuses into the first strata but not substantially into the second strata, or into the first strata but not substantially into the third strata, or into the second strata but not substantially into the first strata, or into the second strata but not substantially into the third strata, or into the third strata but not substantially into the first strata, or into the third strata but not substantially into the second strata; or optionally the carbon dioxide infuses into the first strata and into the second strata but not substantially into the third strata, or into the first strata and the third strata but not substantially into the second strata, or into the second strata and the third strata but not substantially into the first strata. 
     In still another aspect, the method includes the step of exposing, and the exposing step comprises exposing the foamable article to the second pressure and second temperature at which the carbon dioxide remains infused within one or two of the three strata while the carbon dioxide diffuses out of the other of the three strata, optionally the carbon dioxide remains infused in the first strata but not substantially in the second strata, or in the first strata but not substantially in the third strata, or in the second strata but not substantially in the first strata, or in the second strata but not substantially in the third strata, or in the third strata but not substantially in the first strata, or in the third strata but not substantially in the second strata; or optionally the carbon dioxide remains infused in the first strata and the second strata and substantially diffuses out of the third strata, or remains infused in the first strata and the third strata and substantially diffuses out of the second strata, or remains infused in the second strata and the third strata and substantially diffuses out of the first strata; or optionally the carbon dioxide substantially diffuses out of the first strata and the second strata and remains infused in the third strata, or substantially diffuses out of the first region and the third strata and remains infused in the second strata, or substantially diffuses out of the second strata and the third strata and remains infused in the first strata. 
     In yet another aspect, the steps of subjecting and expanding expands material(s) of one or two of the three strata into foamed material(s) while maintaining the other of the three strata in a solid, unfoamed state; optionally the steps of subjecting and expanding expand at least a portion of the first strata material into a first strata foamed material, or expand at least a portion of the second strata material into a second strata foamed material, or expand at least a portion of the third strata material into a third strata foamed material, or any combination thereof; or optionally the steps of subjecting and expanding expand the first strata material into a first strata foamed material and the second strata material into a second strata foamed material, or expand the first strata material into a first strata foamed material and the third strata material into a third strata foamed material, or expand the second strata material into a second strata foamed material and expands the third strata material into a third regional strata material; or optionally, following the steps of subjecting and expanding, the first strata material remains a first strata solid unfoamed material, or the second strata material remains a second strata solid unfoamed material, or the third strata material remains a third strata solid unfoamed material, or the first strata material and the second strata material both remain as first strata and second strata solid unfoamed materials, or the first strata material and the third strata material both remain as first strata and third strata solid unfoamed materials, or the second strata material and the third strata material both remain as second strata and third strata solid unfoamed materials. 
     Regions of the Foamed Materials and Foamed Articles and Arrangement Thereof 
     Two Regions. In one aspect, the article can be configured as a series of two or more regions including a first region including a first regional material and a second region including a second regional material, wherein the first regional material, the second regional material, or both the first regional material and the second regional material can be a solid foamable material, optionally wherein the first region or the second region or both form an outermost surface of the article, or wherein both the first region and the second region individually or jointly form the outermost surface of the article. In another aspect, following the foaming process disclosed herein, the first regional material becomes a first regional foamed material and, when the second region is a solid foamable material, the second regional material becomes a second regional foamed material. 
     In another aspect, the regions can include layers, and the first region or the second region can form an inner layer of the article, or both the first region and the second region individually form separate inner layers of the article. In any of these aspects, the article can optionally be a layered sheet. In still another aspect, the first region can form the outermost surface of the article and the second region can form an inner layer of the article. 
     In still another aspect, in the article, the first region comprises or consists essentially of the solid foamable material, the solid foamable material of the first region is a first solid regional foamable material, and in the steps of subjecting and expanding, the first solid foamable material either remains as the first solid regional foamable material or expands into the foamed material, wherein the foamed material of the first region is a first regional foamed material. 
     In another aspect, in the article, the second region comprises or consists essentially of the solid foamable material, the solid foamable material of the second region is a second regional solid foamable material, and, in the steps of subjecting and expanding, the second solid foamable material either remains as the second solid regional foamable material or expands into the foamed material, wherein the foamed material of the second region is a second regional foamed material. 
     In any of these aspects, the first solid regional foamable material, the second solid regional foamable material, or both can individually be a solid foamable material as described herein. In another aspect, the first foamed material, the second foamed material, or both can individually be a foamed material as described herein. In some aspects, the first regional material or the second regional material can be a barrier material as described herein. 
     In an aspect, in the foamed article, the first region comprises or consists essentially of the foamed material and the second region comprises or consists essentially of a solid material. In an alternative aspect, the first region comprises or consists essentially of a solid material, and the second region comprises or consists essentially of the foamed material. In another aspect, both the first region and the second region comprise or consist essentially of the foamed material. 
     In an aspect, the first regional material, the second regional material, or both, are individually a thermoplastic elastomeric material as disclosed herein. In another aspect, the first regional material, the second regional material, or both, are individually a foamed material as disclosed herein. In an alternative aspect, the first regional material or the second regional material can be a second material as described herein. 
     In one aspect, in the foamed article, the first region comprises or consists essentially of the foamed material and the second region comprises or consists essentially of a barrier material. In another aspect, the first region can comprise or consist essentially of a barrier material and the second region can comprise or consist essentially of the foamed material. 
     In still another aspect, the second region can comprise or consist essentially of the solid second regional foamable material, the steps of maintaining and holding include holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the solid second regional foamable material, and the steps of subjecting and expanding include expanding the at least a portion of the second regional solid foamable material into the second regional foamed material, wherein the second regional foamed material comprises a second regional foamed material, optionally wherein the expanding includes expanding substantially all of the second regional solid foamable material into the second regional foamed material. 
     In some aspects, the first region comprises or consists essentially of the first regional solid foamable material, the first regional solid foamable material being a first solid foamable material; 
     the second region comprises or consists essentially of the second regional solid foamable material, the second regional solid foamable material being a second regional solid foamable material; the step of maintaining and holding includes holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the first region and into at least a portion of the second region; and the steps of subjecting and expanding expand at least a portion of the first regional solid foamable material into a first regional foamed material, and expand at least a portion of the second regional solid foamable material into a second regional foamed material, optionally wherein the expanding includes expanding substantially all of the first regional solid foamable material or substantially all of the second regional solid foamable material, or expanding substantially all of the first regional solid foamable material and substantially all of the second regional solid foamable material. 
     In one aspect, in the disclosed methods, in the foamed article, the first regional foamed material and the second regional foamed material are in contact with each other. In an alternative aspect, the first regional foamed material and the second regional foamed material are not in contact with each other. 
     Barrier Region. In one aspect, in the methods disclosed herein, the first region comprises or consists essentially of the solid foamable material and the second region comprises or consists essentially of a barrier material, or wherein the first region comprises or consists essentially of the barrier material and the second region comprises or consists essentially of the solid, and the steps of maintaining and holding include holding the article and the liquid carbon dioxide in the vessel for a duration of time sufficient for the at least a portion of the liquid carbon dioxide to infuse into at least a portion of the solid foamable material, wherein the duration of time is not sufficient for at least a portion of the liquid carbon dioxide to infuse into at least a portion of the barrier material; the steps of subjecting and expanding include expanding the solid foamable material into the foamed material without expanding the barrier material; and optionally wherein, in the foamed article, the foamed material and the barrier material are in contact with each other, or the foamed material and the barrier material are not in contact with each other. 
     Three Regions. In one aspect, in the disclosed methods, the article can be configured as a series of three or more regions, further comprising a third region comprising or consisting essentially of a third regional material, optionally wherein the third regional material comprises or consists essentially of a barrier material, or comprises or consists essentially of a third regional solid foamable material, or optionally wherein the third region is positioned between the first region and the second region. 
     In another aspect, in the foamed article, the third regional material can be a third regional foamed material. Optionally, the third regional foamed material can be an additional foamed material as defined herein, or can be the foamed material as disclosed herein. In an alternative aspect, the third regional material is a third regional solid material, optionally an additional solid material. In some aspects, the additional solid material can be a barrier material. 
     Turning now to  FIG.  9 A , in an exemplary embodiment, the foamable article can comprise three regions. In one aspect, when the foamable article is an outsole of an article of footwear, heel area  451  can include region  464 , which can comprise or consist essentially of a first regional material, wherein the first regional material can be a first regional foamable material. Further in this aspect, toe area  450  can include region  460 , which can comprise or consist essentially of a second regional material, wherein the second regional material can be a second regional foamable material, or, in some aspects, can be a barrier material. Still further in this aspect, the foamable article can contain a third region  462 , which can comprise or consist essentially of a third regional material, wherein the third regional material can be a third regional foamable material, or, in some aspects, can be a barrier material. In any of these aspects, at least one of the first, second, and/or third regions comprises or consists essentially of a solid foamable material. In some aspects, 
     In an aspect, when a foamable article comprises two or more regions, interfaces between and among the regions will also be present. Thus, in one exemplary aspect as depicted in  FIG.  9 A , the foamable article can include an interface  474  between the first region  464  and the second region  460 , and/or can include an interface  470  between the second region  460  and the third region  462 , and/or can include an interface  472  between the first region  464  and the third region  462 . 
     Four Regions. In another aspect, the article can be configured as a series of four or more regions, wherein the fourth region comprises or consists essentially of a fourth regional material, optionally wherein the fourth region is positioned between the third region and the second region. In some aspects, the fourth regional material can be a fourth regional foamed material and optionally the fourth regional foamed material can be an additional foamed material, or can be the foamed material as disclosed herein. In an alternative aspect, the fourth regional material is a fourth regional solid material, optionally an additional solid material. In some aspects, the additional solid material can be a barrier material. 
     Properties of the Foamed Materials and Foamed Articles 
     In one aspect, in the foamed article, the foamed material has a density of from about 0.01 gram per cubic centimeter to about 3.0 grams per cubic centimeter, optionally of from about 0.01 gram per cubic centimeter to about 0.1 gram per cubic centimeter, from about 0.01 gram per cubic centimeter to about 0.05 grams per cubic centimeter, from about 0.01 gram per cubic centimeter to about 0.025 grams per cubic centimeter, from about 0.05 grams per cubic centimeter to about 0.1 gram per cubic centimeter, from about 0.1 gram per cubic centimeter to about 3.0 grams per cubic centimeter, from about 0.2 grams per cubic centimeter to about 2.0 grams per cubic centimeter, from about 0.3 grams per cubic centimeter to about 1.5 grams per cubic centimeter, from about 0.3 grams per cubic centimeter to about 1.2 grams per cubic centimeter, or from about 0.4 grams per cubic centimeter to about 1.0 grams per cubic centimeter. 
     In one aspect, following foaming, the foamed article is substantially opaque. In a further aspect, opacity of the foamed article eliminates the need for adding pigments to the thermoplastic elastomeric material in order to make it white. 
     In one aspect, the foamed material, the foamed article, or both, have a split-tear value of from about 2.5 kilograms per centimeter to about 3.0 kilograms per centimeter, optionally of about 2.5 kilograms per centimeter to about 2.7 kilograms per centimeter, about 2.5 kilograms per centimeter to about 2.6 kilograms per centimeter, about 2.7 kilograms per centimeter to about 3.0 kilograms per centimeter, or about 2.8 kilograms per centimeter to about 3.0 kilograms per centimeter, as measured using the Split-Tear Test Protocol. 
     Method of Manufacturing an Article Comprising an Additive Manufactured Foamed Article 
     In one aspect, disclosed herein is a method for manufacturing an article, the method comprising affixing a first component to a second component, wherein the first component is an additive manufactured foamed article made by the method disclosed herein. In some aspects, the first component can be a first component of an article of apparel, the second component can be a component of an article of apparel, and the article to be manufactured is an article of apparel. 
     In other aspects, the first component can be a first component of an article of footwear, the second component can be a second component of an article of footwear, and the article to be manufactured is an article of footwear. Further in these aspects, the first component can be a cushioning element and the second component can be a sole component or an upper component. 
     In still other aspects, the first component can be a first component of an article of sporting equipment, the second component can be a component of an article of sporting equipment, and the article to be manufactured is an article of sporting equipment. 
     Foamable Material 
     The solid foamable material of the articles as described herein is a thermoplastic elastomeric material, meaning that the material is a polymeric material having thermoplastic properties as well as elastomeric properties. The solid foamable material is a polymeric material comprising or consisting essentially of one or more first thermoplastic elastomers. In some aspects, the solid foamable material comprises one or more additional thermoplastic polymers, where the one or more additional thermoplastic polymers may be thermoplastic elastomers, or may be thermoplastic but not elastomeric. In some aspects, the solid foamable material comprises additional non-polymeric ingredients. In many of the disclosed foamed articles described herein, the foamed material is a thermoplastic elastomeric material, meaning that, following the expanding, the foamed material retains thermoplastic and elastomeric properties. 
     In any of the disclosed aspects, the foamable material can be described as comprises a polymeric component, wherein the polymeric component includes all of the polymers present in the foamable material. In this regard, the polymeric component can consist essentially of one or more first thermoplastic elastomers, meaning that, in such an aspect, essentially all the polymers present in the foamable material are thermoplastic elastomers. In one aspect, the one or more first thermoplastic elastomers of the foamable material comprise one or more thermoplastic elastomeric polyolefin homopolymers or copolymers, one or more thermoplastic elastomeric polyamide homopolymers or copolymers, one or more thermoplastic elastomeric polyester homopolymers or copolymers, one or more thermoplastic elastomeric polyether homopolymers or copolymers, one or more thermoplastic elastomeric polycarbonate homopolymers or copolymers, one or more thermoplastic elastomeric polyacrylate homopolymers or copolymers, one or more thermoplastic elastomeric polyurethane homopolymers or copolymers, one or more thermoplastic elastomeric styrenic homopolymers or copolymers, or any combination thereof. Similarly, the polymeric component of the foamable material can consist essentially of one or more thermoplastic elastomeric polyolefin homopolymers or copolymers, one or more thermoplastic elastomeric polyamide homopolymers or copolymers, one or more thermoplastic elastomeric polyester homopolymers or copolymers, one or more thermoplastic elastomeric polyether homopolymers or copolymers, one or more thermoplastic elastomeric polycarbonate homopolymers or copolymers, one or more thermoplastic elastomeric polyacrylate homopolymers or copolymers, one or more thermoplastic elastomeric polyurethane homopolymers or copolymers, one or more thermoplastic elastomeric styrenic homopolymers or copolymers, or any combination thereof. 
     In one aspect, the one or more first thermoplastic elastomers of the foamable material comprise one or more thermoplastic elastomeric polyolefin homopolymers or copolymers, one or more thermoplastic elastomeric polyamide homopolymers or copolymers, one or more thermoplastic elastomeric polyester homopolymers or copolymers, one or more thermoplastic elastomeric polyurethane homopolymers or copolymers, one or more thermoplastic elastomeric styrenic homopolymers or copolymers, or any combination thereof. Similarly, the polymeric component of the foamable material can consist essentially of one or more thermoplastic elastomeric polyolefin homopolymers or copolymers, one or more thermoplastic elastomeric polyamide homopolymers or copolymers, one or more thermoplastic elastomeric polyester homopolymers or copolymers, one or more thermoplastic elastomeric polyurethane homopolymers or copolymers, one or more thermoplastic elastomeric styrenic homopolymers or copolymers, or any combination thereof. 
     In one aspect, thermoplastic materials, including thermoplastic elastomeric materials, are advantageous for use in articles described herein, since thermoplastic materials can be reclaimed and reformed into new articles, thus reducing waste and promoting recycling. In another aspect, both foamed and unfoamed thermoplastic materials can be recycled for use in the articles and methods described herein. 
     In one aspect, when the one or more first thermoplastic elastomers comprises or consists essentially of one or more thermoplastic elastomeric polyolefin homopolymers or copolymers, the one or more first thermoplastic elastomers comprise or consist essentially of thermoplastic elastomeric polypropylene homopolymers or copolymers; thermoplastic polyethylene homopolymers or copolymers, including thermoplastic elastomeric ethylene-vinyl acetate copolymers; thermoplastic elastomeric polybutylene homopolymers or copolymers; or any combination thereof. The polymeric component of the foamable material can consist essentially of one or more thermoplastic elastomeric polyolefin homopolymers or copolymers. 
     In one aspect, the one or more thermoplastic elastomeric polyolefin homopolymers or copolymers can comprise or consist essentially of one or more thermoplastic elastomeric ethylene-vinyl acetate copolymers. The polymeric component of the foamable material can consist essentially of one or more thermoplastic elastomeric ethylene-vinyl acetate copolymers. Further in this aspect, the thermoplastic ethylene-vinyl acetate copolymer can include from about 25 weight percent to about 50 weight percent vinyl acetate content, optionally from about 25 weight percent to about 40 weight percent vinyl acetate content, from about 25 weight percent to about 30 weight percent vinyl acetate content, or from about 35 weight percent to about 50 weight percent vinyl acetate content. 
     In another aspect, the foamable material can comprise one or more thermoplastic ethylene-vinyl alcohol copolymer. The polymeric component of the foamable material can comprise one or more thermoplastic ethylene-vinyl alcohol copolymers. Further in this aspect, the thermoplastic ethylene-vinyl alcohol copolymer can include from about 25 weight percent to about 50 weight percent vinyl alcohol content, optionally from about 25 weight percent to about 40 weight percent vinyl alcohol content, from about 25 weight percent to about 30 weight percent vinyl alcohol content, or from about 35 weight percent to about 50 weight percent vinyl alcohol content. 
     In another aspect, the one or more first thermoplastic elastomers of the foamable material comprises or consists essentially of one or more thermoplastic elastomeric polyamide homopolymers or copolymers. The polymeric component of the foamable material can consist essentially of the one or more thermoplastic elastomeric polyamide homopolymers or copolymers. The one or more thermoplastic elastomeric polyamide homopolymers or copolymers can comprise or consist essentially of thermoplastic elastomeric polyether block polyamide (PEBA) copolymer elastomers. 
     The one or more first thermoplastic elastomers can comprise or consist essentially of one or more thermoplastic elastomeric polyester homopolymers or copolymers. The polymeric component of the foamable material can consist essentially of the one or more thermoplastic elastomeric polyester homopolymers or copolymers. The thermoplastic elastomeric polyester homopolymer can include or consist essentially of one or more polyester terephthalate. The thermoplastic elastomeric polyester homopolymer or copolymer can include or consist essentially of one or more thermoplastic elastomeric copolyesters. 
     The one or more first thermoplastic elastomers can comprise or consist essentially of one or more thermoplastic elastomeric polyether homopolymers or copolymers. The polymeric component of the foamable material can consist essentially of the one or more thermoplastic elastomeric polyether homopolymers or copolymers. 
     The one or more first thermoplastic elastomers can comprise or consist essentially of one or more thermoplastic elastomeric polyether homopolymers or copolymers. The polymeric component of the foamable material can consist essentially of the one or more thermoplastic elastomeric polyether homopolymers or copolymers. 
     The one or more first thermoplastic elastomers can comprise or consist essentially of one or more thermoplastic elastomeric polycarbonate homopolymers or copolymers. The polymeric component of the foamable material can consist essentially of the one or more thermoplastic elastomeric polycarbonate homopolymers or copolymers. 
     The one or more first thermoplastic elastomers can comprise or consist essentially of one or more thermoplastic elastomeric polyacrylate homopolymers or copolymers, including polyacrylic acids, polymethacrylates, and the like. The polymeric component of the foamable material can consist essentially of the one or more thermoplastic elastomeric polyacrylate homopolymers or copolymers. 
     Thermoplastic elastomeric polyurethane homopolymers and copolymers have been found to be particularly useful in the methods and articles described herein. In an aspect, the one or more first thermoplastic elastomers comprise or consist of one or more thermoplastic elastomeric polyurethane homopolymers or copolymers, where a thermoplastic polyurethane homopolymer is understood to mean a polymer chain including only urethane segments, and a polyurethane copolymer is understood to mean a polymer chain including urethane segments as well as other types of segments, such as ester segments or ether segments or the like and combinations thereof. When the one or more first thermoplastic elastomers comprise one or more thermoplastic elastomeric polyurethane homopolymers or copolymers, the one or more thermoplastic elastomers can comprise or consist essentially of thermoplastic elastomeric polyester-polyurethane copolymers, thermoplastic elastomeric polyether-polyurethane copolymers, thermoplastic elastomeric polycarbonate-polyurethane copolymers, or combinations thereof. In some aspects, the one or more first thermoplastic elastomers of the foamable material comprises or consists essentially of one or more thermoplastic elastomeric polyester-polyurethane copolymers, optionally wherein the polymeric component of the foamable material consists of the one or more thermoplastic elastomeric polyester-polyurethane copolymers. 
     Thermoplastic polyurethanes can be produced via reaction of diisocyanates with difunctional compounds that are reactive toward isocyanates. In general, the difunctional compounds have two hydroxyl groups (diols) and can have a molar mass of from 62 Daltons (the molar mass of ethylene glycol) to about 10,000 Daltons, or from about 100 Daltons to about 5000 Daltons, or from about 500 Daltons to about 5000 Daltons, or from about 500 Daltons to about 2500 Daltons, or from about 2500 Daltons to about 10,000 Daltons, or from about 5000 Daltons to about 10,000 Daltons, or from about 5000 Daltons to about 7500 Daltons, or from about 7500 Daltons to about 10,000 Daltons although difunctional compounds having other isocyanate-reactive groups (e.g., secondary amines) can be used, generally in minor amounts, and a limited molar fraction of tri-functional and mono-functional isocyanate-reactive compounds can be used. In one example, the polyurethane is linear. Including difunctional compounds with molar masses of about 400 Daltons or greater introduces soft segments into the polyurethane. An increased ratio of soft segments to hard segments in the polyurethane can cause the polyurethane to become increasingly more flexible and eventually elastomeric. In one example, the one or more thermoplastic elastomeric materials include a thermoplastic polyurethane elastomer or a combination of thermoplastic polyurethane elastomers. 
     Suitable thermoplastic polyurethane elastomers include thermoplastic polyester-polyurethanes, polyether-polyurethanes, and polycarbonate-polyurethanes. Nonlimiting examples of these include polyurethanes polymerized using as diol reactants, polyesters diols prepared from diols and dicarboxylic acids or anhydrides, polylactone polyesters diols (for example polycaprolactone diols), polyester diols prepared from hydroxy acids that are monocarboxylic acids containing one hydroxyl group, polytetrahydrofuran diols, polyether diols prepared from alkylene oxides or combinations of alkylene oxides, and polycarbonate diols such as polyhexamethylene carbonate diol and poly(hexamethylene-co-pentamethylene) carbonate diols. The thermoplastic polyurethane elastomers can be prepared by reaction of one of these polymeric diols (polyester diol, polyether diol, polylactone diol, polytetrahydrofuran diol, or polycarbonate diol), one or more polyisocyanates, and optionally, one or more monomeric chain extension compounds. Chain extension compounds are compounds having two or more functional groups, for example two functional groups, reactive with isocyanate groups. In one example, the thermoplastic polyurethane elastomer(s) is substantially linear (i.e., all or substantially all of the reactants are di-functional). 
     In still another aspect, the one or more first thermoplastic elastomers comprise or consist essentially of one or more thermoplastic elastomeric styrene homopolymers or copolymers. The polymeric component of the foamable material can consist essentially of one or more thermoplastic elastomeric styrene homopolymers or copolymers. The one or more thermoplastic elastomeric styrenic homopolymers or copolymers can comprise or consist essentially of one or more styrene butadiene styrene (SBS) block copolymer elastomers, one or more styrene ethylene butylene styrene (SEBS) copolymer elastomers, one or more styrene acrylonitrile (SAN) copolymer elastomers, or any combination thereof. 
     In any of these aspects, the one or more first thermoplastic elastomers comprises or consists essentially of one or more recycled first thermoplastic elastomers. Similarly, the polymeric component of the foamable material can comprise or consist essentially of recycled thermoplastic polymers. In one aspect, the polymeric component of the foamable material comprises or consists essentially of one or more recycled thermoplastic elastomeric polymers. In another aspect, the polymeric component of the foamable material comprises one or more recycled thermoplastic polymers. In yet another aspect, the polymeric component of the foamable material comprises or consists essentially of one or more recycled thermoplastic elastomeric polymers, and one or more thermoplastic non-elastomeric polymers. In yet another aspect, the polymeric component of the foam consists essentially of one or more thermoplastic elastomeric polyurethanes, and one or more thermoplastic polyolefins. 
     In one aspect, the foamable material comprises a mixture of the polymeric component and a non-polymeric component consisting of one or more non-polymeric additives, optionally wherein the foamable material comprises from about 0.005 percent by weight to about 20 percent by weight of the non-polymeric component based on a total weight of the foamable material, optionally about 0.5 percent by weight to about 10 percent by weight, about 1 percent by weight to about 5 percent by weight, or about 1 percent by weight to about 2 percent by weight of the non-polymeric additive based on a total weight of the foamable material. 
     Other materials that can be used to form part of the composition of the foamable material include, without limitation, colorants including pigments and dyes; fillers such as clays, including nanoclays and halloysite clays; nanotubes, nucleating agents, emulsifiers, release agents including surfactant-based release agents, antioxidants, stabilizers, crosslinkers, and/or the like. 
     The foamable material can be a relatively soft material. In some examples, the foamable material has a Shore A hardness of from about 35 A to about 95 A. In other examples, the foamable material has a Shore A hardness of from about 70 A to about 95 A, optionally about 35 A to about 70 A, about 50 A to about 70 A, or about 55 A to about 90 A, as measured using the Shore A Hardness Test Protocol. 
     In any of these aspects, the foamable material does not melt and/or is not molten during the performance of the maintaining and holding step or the subjecting and expanding step of the methods disclosed herein. In accordance with the present disclosure, carbon dioxide is used to infuse at least a portion of the solid foamable material of the article, and the solid foamable material remains as a solid during the infusing. The infused solid foamable material of the article remains in the solid state up until the point that it is expanded by the infused carbon dioxide phase transitioning to a gas, imparting a multi-cellular structure to the foamed material without the foamable material being melted or in a molten state during the expanding. While it is possible to conduct additional processing steps on the foamed article which may melt a portion or a region of the solid foamable material or the foamed material, it is to be understood that any steps involving melting the solid foamable material or melting the foamed material are conducted either before the maintaining an holding step, or after the subjecting and expanding step. In some aspects, the foamed material of the foamed articles is a physically expanded solid material formed without melting the solid material. The avoidance of melting the thermoplastic elastomeric material during the foaming process reduces the “thermal history” of the thermoplastic elastomeric material, i.e., the number of heating and cooling cycles to which the thermoplastic elastomeric material is exposed, which reduces or prevents thermal degradation of the thermoplastic elastomeric material. 
     Blends. In one aspect, the foamable material can comprise or consist essentially of a blend of the one or more first thermoplastic elastomers and a second material. In some aspects, the second material comprises or consists essentially of one or more second polymers, optionally wherein the one or more second polymers comprise or consist essentially of one or more second thermoplastics. In such aspects, the polymeric component of the foamable material comprises or consists essentially of the one or more first thermoplastic elastomers, and the one or more second thermoplastics. 
     In another aspect, the one or more second thermoplastics can comprise or consist essentially of one or more thermoplastic polyolefin homopolymers or copolymers, one or more thermoplastic polyamide homopolymers or copolymers, one or more thermoplastic polyester homopolymers or copolymers, one or more thermoplastic polyether homopolymers or copolymers, one or more thermoplastic polycarbonate homopolymers or copolymers, one or more thermoplastic polyacrylate homopolymers or copolymers, one or more thermoplastic polyurethane homopolymers or copolymers, one or more thermoplastic styrenic homopolymers or copolymers, or any combination thereof. In some aspects, the one or more second thermoplastic polyolefin homopolymers or copolymers comprise or consist essentially of thermoplastic polypropylene homopolymers or copolymers, thermoplastic polyethylene homopolymers or copolymers, thermoplastic polybutylene homopolymers or copolymers, or any combination thereof. In one aspect, the one or more second thermoplastics comprise or consist essentially of one or more thermoplastic polyethylene copolymers, including one or more thermoplastic ethylene-vinyl alcohol copolymers or one or more thermoplastic ethylene-vinyl acetate copolymers. In one aspect, the polymeric component of the foamable material consists essentially of a blend of the one or more first thermoplastic elastomers and the one or more second thermoplastics, optionally wherein the blend foams during the steps of subjecting and expanding. In such an aspect, the one or more second thermoplastics can include one or more thermoplastic polyolefin homopolymers or copolymers. In another aspect, the polymeric component of the foamable material consists essentially of a blend of the one or more first thermoplastic elastomeric polyurethane homopolymers or copolymers and one or more second thermoplastic ethylene-vinyl alcohol copolymers. Further in this aspect, the polymeric component can consist essentially of one or more first thermoplastic elastomeric polyester-polyurethane homopolymers or copolymers and one or more second thermoplastic ethylene-vinyl alcohol copolymers. 
     In one aspect, the blend can comprise one or more recycled first thermoplastic elastomers, one or more recycled second thermoplastics, or both. The one or more recycled first thermoplastic elastomers can include one or more recycled thermoplastic elastomeric polyurethane copolymers, such as one or more recycled thermoplastic elastomeric polyurethane-polyester copolymer, or one or recycled thermoplastic elastomeric polyurethane-polyether copolymer. The one or more recycled second thermoplastics can include one or more recycled thermoplastic polyolefin, such as one or more recycled polyethylene copolymer. 
     Recycled materials. In one aspect, the recycled materials useful in the methods disclosed herein can comprise foamable material that is an unfoamed material (i.e., the foamable material has not previously been foamed). For example, the recycled material can be obtained by recycling (e.g., by regrinding or another method) foamable material that has not been foamed, such as scrap or waste material. In another aspect, the recycled foamable material can be obtained by recycling articles comprising the foamable material before the articles have been foamed (e.g., by recycling defective articles that have been rejected prior to foaming). 
     In one aspect, the blend comprises a phase-separated blend of the one or more first thermoplastic elastomers and the one or more second thermoplastics. In some aspects, the phase-separated blend includes one or more phase-separated regions including interfaces between the one or more first thermoplastic elastomers and the one or more second thermoplastics. Without wishing to be bound by theory, the one or more first thermoplastic elastomers and the one or more second thermoplastics can phase separate, or when the one or more first thermoplastic elastomers comprise at least one copolymer having hard and soft segments, the hard and/or soft segments may have affinity for the second thermoplastic; thus, in some aspects, the phase-separated blend can include some polymeric entanglements in addition to interfaces between portions of the one or more first thermoplastic elastomers and the one or more second thermoplastics. During the step of subjecting and expanding, the presence of one or more interfaces, such as an interface between phase-separated regions, or between different polymeric materials within the article, can act as nucleating site for forming gas bubbles, and so the presence of such nucleating sites in the article can increase the uniformity of the cell structures in the foamed material. 
     The blend can comprise at least 50 weight percent of the one or more first thermoplastic elastomers, and less than 50 weight percent of the one or more second thermoplastics based on a total weight of the blend. The blend can comprise at least 70 weight percent of the one or more first thermoplastic elastomers, and less than 30 weight percent of the one or more second thermoplastics based on a total weight of the blend. The blend can comprise at least 80 weight percent of the one or more first thermoplastic elastomers and less than 20 weight percent of the one or more second thermoplastics based on a total weight of the blend. In an exemplary aspect, the blend comprises about 95 percent by weight of the one or more first thermoplastic elastomers and about 5 percent by weight of the one or more second thermoplastics based on a total weight of the blend. 
     In some aspects, the solubility of carbon dioxide can vary in the different polymeric materials making up the foamable material, such as when the foamable material is a blend of a first thermoplastic elastomeric material with a second, non-elastomeric thermoplastic material, or a blend of reground and virgin materials, as the reground and virgin materials have different thermal histories. In some aspects, the solubility of the carbon dioxide is greater in the one or more thermoplastic elastomers than in the one or more non-elastomeric thermoplastics. In one aspect, the carbon dioxide is soluble in the one or more first thermoplastic elastomers at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent, from about 5 weight percent to about 10 weight percent, or from about 10 weight percent to about 20 weight percent, based on a total weight of the one or more first thermoplastic elastomers present in the foamable material. In another aspect, the carbon dioxide is soluble in the one or more second thermoplastics at a concentration of less than 1 weight percent, optionally less than 0.5 weight percent, less than 0.25 weight percent, or less than 0.1 weight percent, based on a total weight of the one or more second thermoplastic present in the foamable material. In some aspects, the carbon dioxide is substantially insoluble in the one or more second thermoplastics. The solubility of carbon dioxide in the one or more first thermoplastic elastomers and the one or more second thermoplastics can be determined gravimetrically be infusing carbon dioxide into separate samples of the first thermoplastic elastomers and the second thermoplastics at the first temperature 
     Foamed Material 
     In an aspect, disclosed herein is a foamed material. In one aspect, the foamed material can be the product of expanding any of the foamable materials described above. In another aspect, the foamed material can be a thermoplastic material. In still another aspect, the foamed material can be partially or fully crosslinked. In one aspect, when the foamed material is crosslinked, the crosslinking may fully or partially crosslink the foamed material. In some aspects, when the foamed material is partially crosslinked, it may retain some thermoplastic characteristics so that the foam can thermally soften. In an alternative aspect, the foamed material may be crosslinked to the point that it becomes a thermoset foamed material. 
     In one aspect, the foamed material can be crosslinked during or following the steps of subjecting and expanding. In another aspect, the crosslinking can be actinically initiated. In one exemplary aspect, the crosslinking can be initiated using thermal radiation, light (e.g., UV radiation), an electron beam, or any combination thereof. 
     In some aspects, the foamable material further comprises a crosslinking agent such as, for example, a thermally-initiated crosslinking agent or a light-initiated crosslinking agent. 
     In one aspect, the foamed material has a Shore A hardness of from about 35 A to about 95 A. In other examples, the foamed material has a Shore A hardness of from about 70 A to about 95 A, optionally about 35 A to about 70 A, about 50 A to about 70 A, or about 55 A to about 90 A, as measured using the Shore A Hardness Test Protocol. 
     In another aspect, the foamed material can have an Asker C hardness of from about 10 to about 50, optionally of about 15 to about 5, about 15 to about 45, about 20 to about 45, or about 20 to about 40, as measured using the Asker C Hardness Test Protocol. 
     In some aspects, the article, prior to foaming, can be optically clear and colorless). After foaming, the article can be opaque, depending upon the placement and thickness of the foamed material. 
     Additional Material 
     In one aspect, the article comprises an additional material i.e., another material in addition to the solid foamable material. Optionally, the additional material can be an additional thermoplastic material, optionally an additional thermoplastic elastomeric material, optionally wherein the additional thermoplastic elastomeric material is an additional (i.e., second) foamable material. In another aspect, the additional material can be an additional foamable material and, during the expanding step, the additional foamable material expands into an additional foamed material. In a further aspect, in the foamed article, a density of the first foamed material differs from a density of the additional foamed material by at least 5 percent, optionally at least 10 percent, or at least 20 percent. 
     In one aspect, the article comprises an additional material, wherein the additional material is a separate material from the foamable material. In one aspect, the additional material and the foamable material can be bonded to one another or can interface with one another. In another aspect, the additional material and the foamable material may can have some polymer chains that intermingle at the interface (for example, if the foamable material and additional material are heat-bonded). In another aspect, the additional material comprises or consists essentially of one or more polymers and includes an additional material polymeric component consisting of all the polymers present in the additional material. In an optional aspect, the additional material comprises or consists essentially of a second material, optionally wherein the second material is a thermoplastic material. Still further in this aspect, the additional material can optionally comprise the additional material polymeric component mixed with an additional material non-polymeric component consisting of all non-polymeric components present in the additional material. 
     In some aspects, the article comprises one or more first portions of the foamable material, and one or more second portions of the additional material, wherein the one or more first portions are distinct from the one or more second portions. 
     In one aspect, the additional material is separate from the foamable material and/or is not a component of the foamable material. Further in this aspect, the additional material can be present in the article as a distinct element that is separate from the foamable material but which may be in contact with at least a portion of the foamable material. In other aspects, the additional material can be a component of the foamable material, e.g., as part of a blend further comprising the first material. 
     In one aspect, the additional material comprises a barrier material comprising one or more barrier materials, the barrier material comprising a barrier polymeric component consisting of all polymers present in the barrier material. In some aspects, during the expanding step, the additional material remains substantially unfoamed. 
     In some aspects, the additional material can be a recycled material comprising one or more recycled polymers, optionally wherein the one or more recycled polymers comprise one or more recycled thermoplastics, optionally wherein the one or more recycled thermoplastic comprise one or more recycled thermoplastic elastomers, optionally wherein the recycled material comprises a recycled material polymeric component consisting of one or more recycled thermoplastics, optionally wherein the recycled material polymeric component consists of one or more recycled thermoplastic elastomers. In some aspects, the recycled material comprises one or more recycled first thermoplastic elastomers. Optionally, in another aspect, the one or more recycled first thermoplastic elastomers comprise one or more reground first thermoplastic elastomers. Optionally, further in this aspect, the one or more recycled or reground first thermoplastic elastomers include a thermoplastic elastomer as described herein. 
     In another aspect, the recycled material further comprises one or more recycled second thermoplastics. Optionally, in an aspect, the one or more recycled second thermoplastics comprise one or more reground second thermoplastics. Optionally, further in this aspect, the one or more recycled or reground second thermoplastics includes a thermoplastic according to any one of the preceding aspects. In some aspects, the recycled material comprises one or more recycled or reground thermoplastic polyurethane elastomers or one or more recycled thermoplastic ethylene-vinyl alcohol copolymers or both. 
     In one aspect, the recycled material can comprise a blend of the one or more recycled or reground thermoplastic elastomers and one or more second thermoplastics, or can comprise a blend of one or more thermoplastic elastomers and one or more recycled thermoplastics, or one or more recycled second thermoplastics. Optionally, in one aspect, the blend can be a phase-separated blend, optionally wherein the phase separated blend comprises one or more interfaces between the one or more first thermoplastic elastomers and the one or more second thermoplastics. 
     In another aspect, the recycled material can comprise from about 99 percent to about 90 percent by weight of the one or more first thermoplastic elastomers and from about 1 percent to about 10 percent by weight of the second thermoplastics, based on a total weight of the recycled material, optionally from about 99 percent to about 93 percent by weight of the one or more first thermoplastic elastomers and from about 1 percent to about 7 percent by weight of the one or more second thermoplastics, or about 90 percent to about 95 percent by weight of the one or more first thermoplastic elastomers and from about 1 percent to about 5 percent by weight of the one or more second thermoplastic elastomers. 
     In some aspects, the recycled material comprises about 99 percent to about 50 percent by weight of recycled or reground polymers based on a total weight of recycled material, optionally from about 99 percent to about 75 percent by weight of recycled or reground polymers. 
     In any of these aspects, the carbon dioxide is soluble in the recycled material at a concentration of from about 1 weight percent to about 30 weight percent based on a total weight of the recycled material, optionally from about 5 weight percent to about 20 weight percent. In another aspect, the carbon dioxide is soluble in the one or more recycled or reground thermoplastic elastomers at a concentration of from about 1 weight percent to about 30 weight percent based on a total weight of the one or more recycled or reground thermoplastic elastomers, optionally from about 5 weight percent to about 20 weight percent. In still another aspect, the carbon dioxide can be soluble in the one or more recycled or reground second thermoplastics at less than 1 weight percent, optionally less than 0.5 weight percent, less than 0.25 weight percent, or less than 0.1 weight percent, based on a based on a total weight of the one or more recycled or reground second thermoplastics, or optionally wherein the carbon dioxide is substantially insoluble in the one or more recycled or reground second thermoplastics. 
     In an aspect, the recycled material comprises a recycled foamed article produced by the methods disclosed herein, optionally wherein the recycled foamed article is a reground foamed article. In some aspects, the recycled material comprises foamable material, wherein the foamable material is an unfoamed material. In another aspect, the recycled material further comprises one or more virgin first thermoplastic elastomers, optionally wherein the one or more virgin first thermoplastic elastomers includes one or more virgin thermoplastic polyurethane elastomers. In still another aspect, the recycled material includes one or more nucleating agents or nucleating sites for foaming the recycled material, optionally wherein the one or more nucleating sites include one or more interfaces between phase-separated polymers. 
     In one aspect, the barrier material has a hardness of at least 10 Shore A units greater than the foamable material, optionally at least 20 Shore A units greater, at least 30 Shore A units greater, or at least 40 Shore A units greater than the foamable material, as measured using the Shore A Hardness Test Protocol. 
     In any of these aspects, the additional material can be a barrier material having a nitrogen gas transmission rate of less than or equal to 10 cubic centimeters per square meter per 24 hours, or less than or equal to 1 cubic centimeter per square meter per 24 hours. In some aspects, although the second material can stretch or deform slightly during the foaming process, gas transmission rates, gas barrier properties, and durability of this layer remain substantially the same after foaming. 
     In another aspect, the barrier material has a nitrogen gas transmission rate at least 50 percent lower than a nitrogen gas transmission rate of the foamable material, optionally less than or equal to 10 cubic centimeters per square meter per 24 hours, or less than or equal to 1 cubic centimeter per square meter per 24 hours. 
     In some aspects, the barrier polymeric component of the barrier material consists of one or more barrier polymers, each individually having a nitrogen gas transmission rate less than or equal to 30 cubic centimeters per square meter per 24 hours, or less than or equal to 10 cubic centimeters per square meter per 24 hours, or less than or equal to 1 cubic centimeter per square meter per 24 hours. 
     In one aspect, at the first temperature and the first pressure, the carbon dioxide is soluble in the foamable material at a first concentration, the carbon dioxide is soluble in the barrier material at a second concentration, and the first concentration is at least 20 percent greater than the second concentration, optionally at least 50 percent greater than the second concentration, or at least 70 percent greater than the second concentration. In one aspect, the second concentration is less than 1 weight percent, optionally less than 0.5 weight percent, less than 0.25 weight percent, or less than 0.1 weight percent, or optionally the carbon dioxide is substantially insoluble in the barrier material. 
     In one aspect, the barrier material comprises one or more ethylene-vinyl alcohol copolymers, optionally wherein the one or more ethylene-vinyl alcohol copolymers are thermoplastic, optionally wherein the one or more ethylene-vinyl alcohol thermoplastic copolymers include one or more thermoplastic elastomeric copolymers. In one aspect, the barrier polymeric component consists of one or more ethylene-vinyl alcohol copolymers, optionally wherein the one or more ethylene-vinyl alcohol copolymers are thermoplastic, optionally wherein the one or more ethylene-vinyl alcohol copolymers include one or more thermoplastic elastomeric copolymers. In some aspects, the barrier polymeric component optionally consists of one or more thermoplastic polyolefin homopolymers or copolymers, optionally one or more thermoplastic polyolefin copolymers, or one or more thermoplastic polyethylene copolymers. 
     In one aspect, the additional material has a higher degree of crystallinity than the foamable material. In another aspect, the one or more barrier polymers of the additional material comprise or consist essentially of one or more vinylidene chloride polymers, one or more acrylonitrile polymers or copolymers, one or more polyamides, one or more epoxy resins, one or more amine polymers or copolymers, or one or more thermoplastic polyolefin homopolymers or copolymers, optionally wherein the one or more thermoplastic polyolefin copolymers comprise one or more thermoplastic polyethylene copolymers or one or more thermoplastic ethylene-vinyl alcohol copolymers, optionally wherein the one or more thermoplastic ethylene-vinyl alcohol copolymers comprise one or more thermoplastic elastomeric ethylene-vinyl alcohol copolymers. 
     In some aspects, the additional material further comprises a plasticizer. 
     Third Material 
     In some aspects, the article further comprises a third material. In a further aspect, the third material can optionally be a recycled material. In one aspect, the recycled material comprises a reground thermoplastic elastomeric material. In some aspects, the recycled material further comprises a reground second thermoplastic material. In one aspect, the reground thermoplastic elastomeric material comprises one or more thermoplastic polyurethanes and the reground second thermoplastic material comprises one or more ethylene-vinyl alcohol copolymers. 
     In some aspects, the recycled material comprises a phase-separated blend of the one or more reground thermoplastic elastomeric materials and the one or more reground second thermoplastics. Further in this aspect, the phase-separated blend comprises one or more phase-separated regions including interfaces between the one or more first thermoplastic elastomers and the one or more second thermoplastics. In one aspect, the recycled material comprises about 95 percent by weight of the reground thermoplastic elastomeric material and about 5 percent by weight of the second thermoplastics. 
     In some aspects, the carbon dioxide has different solubilities in the reground thermoplastic elastomeric material and the reground second thermoplastic material. In one aspect, the carbon dioxide is soluble in the reground thermoplastic elastomeric material at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent, from about 5 weight percent to about 10 weight percent, or from about 10 weight percent to about 20 weight percent. In another aspect, the carbon dioxide is soluble in the reground second thermoplastic material at less than 1 weight percent, optionally less than 0.5 weight percent, less than 0.25 weight percent, or less than 0.1 weight percent. In some aspects, the carbon dioxide is substantially insoluble in the reground second thermoplastic material. 
     In one aspect, the recycled material comprises a reground foamed article produced by the method disclosed herein. In an alternative aspect, the recycled material comprises an article comprising a foamable material, wherein the foamable material has not previously been foamed. In some aspects, the recycled material further comprises a virgin or pristine thermoplastic polyurethane elastomer. 
     In any of these aspects, the one or more interfaces serve as nucleation sites for foaming in the thermoplastic elastomeric material. 
     Barrier Material 
     In some aspects, the additional material comprises a barrier material comprising one or more barrier polymers, the barrier material comprising a barrier polymeric component consisting of all polymers present in the barrier material. In some aspects, the additional material comprises a plasticizer. In one aspect, in the foamed article, the additional material is substantially unfoamed. 
     In one aspect, in the foamed article, the barrier material has a hardness of at least 10 Shore A units greater than the thermoplastic elastomeric material in solid form, or optionally at least 20 Shore A units greater, at least 30 Shore A units greater, or at least 40 Shore A units greater than the thermoplastic elastomeric material in solid form as measured using the Shore A Hardness Test Protocol. 
     In one aspect, the barrier material has a nitrogen gas transmission rate at least 50 percent lower than a nitrogen gas transmission rate of the thermoplastic elastomeric material in solid form, optionally less than or equal to 10 cubic centimeters per square meter per 24 hours, or less than or equal to 1 cubic centimeter per square meter per 24 hours. In another aspect, the barrier polymeric component of the barrier material consists of one or more barrier polymers each individually having a nitrogen gas transmission rate of less than or equal to 30 cubic centimeters per square meter per 24 hours, or less than or equal to 10 cubic centimeters per square meter per 24 hours, or less than or equal to 1 cubic centimeter per square meter per 24 hours. 
     In any of these aspects, the one or more barrier polymers comprise or consist essentially of one or more vinylidene chloride polymers, one or more acrylonitrile polymers or copolymers, one or more polyamides, one or more epoxy resins, one or more amine polymers or copolymers, or one or more thermoplastic polyolefin homopolymers or copolymers, optionally wherein the one or more thermoplastic polyolefin copolymers comprise one or more thermoplastic polyethylene copolymers or one or more thermoplastic ethylene-vinyl alcohol copolymers, optionally wherein the one or more thermoplastic ethylene-vinyl alcohol copolymers comprise one or more thermoplastic elastomeric ethylene-vinyl alcohol copolymers. 
     In another aspect, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals) and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the carbon dioxide is soluble in the thermoplastic elastomeric material at a first concentration and the carbon dioxide is soluble in the barrier material at a second concentration. In one aspect, the first concentration is at least 20 percent greater than the second concentration, optionally at least 50 percent greater than the second concentration or at least 70 percent greater than the second concentration. In another aspect, the second concentration is less than 1 weight percent, optionally less than 0.5 weight percent, less than 0.25 weight percent, or less than 0.1 weight percent, based on a total weight of the one or more second thermoplastic present in the foamable material, or optionally at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals) and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the carbon dioxide is substantially insoluble in the barrier material. 
     In an aspect, the barrier material comprises one or more ethylene-vinyl alcohol copolymers, optionally wherein the one or more ethylene-vinyl alcohol copolymers are thermoplastic, optionally wherein the one or more ethylene-vinyl alcohol copolymers include one or more thermoplastic elastomeric copolymers, optionally wherein the barrier polymeric component consists of one or more ethylene-vinyl alcohol copolymers, optionally wherein the one or more ethylene-vinyl alcohol copolymers are thermoplastic, optionally wherein the one or more ethylene-vinyl alcohol thermoplastic copolymers include one or more thermoplastic elastomeric copolymers. 
     Second Foamed Material 
     In one aspect, the foamed articles disclosed herein comprise the foamed material, wherein the foamed material is a first foamed material, and the foamed articles further comprise a second foamed material, wherein the second foamed material comprises or consists essentially of the additional material. In the foamed article, in one aspect, the density of the first foamed material can differ from the density of the second foamed material by at least 5 percent, at least 10 percent, or at least 20 percent. In an aspect, the second foamed material can be a second physically-expanded foam. 
     In one aspect, the second physically-expanded foam is a product of placing the unfoamed article comprising the solid additional material in carbon dioxide, infusing the solid additional material with the carbon dioxide, and expanding the infused solid additional material by phase transitioning the infused carbon dioxide into a gas under conditions that do not soften the solid additional material, thereby forming the foamed additional material of the foamed article. 
     Recycled Material 
     In another aspect, the foamable materials and foamable articles disclosed herein can comprise or consist essentially of a recycled material. In a further aspect, the additional material as disclosed herein can be a recycled material. In any of these aspects, the recycled material comprises one or more recycled polymers, optionally wherein the one or more recycled polymers comprise one or more recycled thermoplastics, optionally wherein the one or more recycled thermoplastics comprise one or more recycled thermoplastic elastomers, optionally wherein the recycled material comprises a recycled material polymeric component consisting of one or more recycled thermoplastics, optionally wherein the recycled material polymeric component consists of one or more recycled thermoplastic elastomers. In another aspect, the recycled material comprises one or more recycled first thermoplastic elastomers, optionally wherein the one or more recycled first thermoplastic elastomers are one or more reground first thermoplastic elastomers. In another aspect, the one or more recycled or reground first thermoplastic elastomers include a thermoplastic elastomer as disclosed herein. 
     In a further aspect, the recycled material can further comprise one or more recycled second thermoplastics, optionally wherein the one or more recycle second thermoplastic comprise one or more reground second thermoplastics, optionally wherein the one or more recycled or reground second thermoplastics include a thermoplastic as disclosed herein. 
     In another aspect, in the foamed articles disclosed herein, the recycled material comprises one or more recycled or reground thermoplastic polyurethane elastomers, one or more recycled or reground thermoplastic ethylene-vinyl alcohol copolymers, or both. 
     In still another aspect, the recycled material can comprise a blend of the one or more recycled or reground thermoplastic elastomers and one or more second thermoplastics, or can comprise a blend of one or more thermoplastic elastomers and one or more recycled thermoplastics or one or more recycled second thermoplastics. Optionally, in this aspect, the blend can be a phase-separated blend, optionally wherein a phase-separated blend comprises one or more interfaces between the one or more first thermoplastic elastomers and the one or more second thermoplastics. 
     In any of these aspects, the recycled material can comprise from about 99 percent to about 90 percent by weight of the one or more first thermoplastic elastomers and about 1 percent to about 10 percent by weight of the second thermoplastics based on a total weight of the recycled material, optionally wherein the recycled material comprises about 99 percent to about 93 percent by weight of the one or more first thermoplastic elastomers and about 1 percent to about 7 percent by weight of the one or more second thermoplastics, or from about 99 percent to about 95 percent by weight of the one or more first thermoplastic elastomers and from about 1 percent to about 5 percent by weight of the one or more second thermoplastic elastomers. 
     In some aspects, the recycled material can comprise from about 99 percent to about 50 percent by weight of recycled or reground polymers based on a total weight of recycled material, optionally from about 99 percent to about 75 percent by weight of recycled or reground polymers. 
     In any of these aspects, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals) and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the carbon dioxide is soluble in the recycled material at a concentration of from about 1 weight percent to about 30 weight percent based on a total weight of the recycled material, optionally from about 5 weight percent to about 20 weight percent. 
     In another aspect, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals), optionally about 15 pounds per square inch (103.4 kilopascals) to about 5500 pounds per square inch (37,900 kilopascals), from about 100 pounds per square inch (689.5 kilopascals) to about 5000 pounds per square inch (34,500 kilopascals), from about 500 pounds per square inch (3450 kilopascals) to about 2000 pounds per square inch (13,790 kilopascals) or from about 1000 pounds per square inch (6895 kilopascals) to about 1500 pounds per square inch (10,300 kilopascals) and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, optionally from about −40 degrees Celsius to about 25 degrees Celsius, or from about −40 degrees Celsius to about 0 degrees Celsius, the carbon dioxide is soluble in the foamed material or in the solid foamable material, or in both, at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent, from about 5 weight percent to about 10 weight percent, or from about 10 weight percent to about 20 weight percent. 
     In another aspect, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals) and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, the carbon dioxide is soluble in the one or more recycled or reground second thermoplastics at less than 1 weight percent, optionally less than 0.5 weight percent, less than 0.25 weight percent, or less than 0.1 weight percent, based on a total weight of the one or more second thermoplastic present in the foamable material based on a total weight of the one or more recycled or reground second thermoplastics, or optionally wherein the carbon dioxide is substantially insoluble in the one or more recycled or reground second thermoplastics. 
     In another aspect, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals), optionally about 15 pounds per square inch (103.4 kilopascals) to about 5500 pounds per square inch (37,900 kilopascals), from about 100 pounds per square inch (689.5 kilopascals) to about 5000 pounds per square inch (34,500 kilopascals), from about 500 pounds per square inch (3450 kilopascals) to about 2000 pounds per square inch (13,790 kilopascals) or from about 1000 pounds per square inch (6895 kilopascals) to about 1500 pounds per square inch (10,300 kilopascals) and a first temperature of from about −57 degrees Celsius to about 31 degrees Celsius, optionally from about −40 degrees Celsius to about 25 degrees Celsius, or from about −40 degrees Celsius to about 0 degrees Celsius, the carbon dioxide is soluble in the foamed material or in the solid foamable material, or in both, at a concentration of from about 1 weight percent to about 30 weight percent, optionally from about 5 weight percent to about 20 weight percent, from about 5 weight percent to about 10 weight percent, or from about 10 weight percent to about 20 weight percent. 
     In any of these aspects, the recycled material can be a recycled foamed article, optionally wherein the recycled foamed article is a reground foamed article as disclosed herein. In some aspects, the recycled material can comprise a solid material, wherein the solid material can be a thermoplastic elastomeric material. In another aspect, the recycled material can further comprise one or more virgin first thermoplastic elastomers, optionally wherein the one or more first virgin thermoplastic elastomers includes one or more virgin thermoplastic polyurethane elastomers. 
     In an aspect, the recycled material can include one or more nucleating agents and/or one or more interfaces between phase-separated polymers. In another aspect, in the foamed articles disclosed herein, the thermoplastic elastomeric material can be a recycled material, or comprises a recycled material, or consists essentially of a recycled material. 
     Method for Making a Consumer Product 
     In one aspect, disclosed herein is a method for making a consumer product, the method comprising affixing the additive manufactured foamed article disclosed herein to a second component. Also disclosed are consumer products produced by the disclosed methods. In one aspect, the consumer product comprises an article of footwear, an article of sporting equipment, or an article of apparel. 
     Exemplary Aspects of Articles of Footwear, Articles of Apparel, and Articles of Sporting Equipment 
       FIGS.  1 A- 1 M  illustrate footwear, apparel, athletic equipment, containers, electronic equipment, and vision wear that include the structure (e.g., the foamed article) of the present disclosure. 
       FIGS.  1 N (a)- 1 N(b) illustrate a perspective view and a side view of an article of footwear  100  that include a sole structure  104  and an upper  102 . The sole structure  104  is secured to the upper  102  and extends between the foot and the ground when the article of footwear  100  is worn. The primary elements of the sole structure  104  are a midsole  114  and an outsole  112 . The midsole  114  is secured to a lower area of the upper  102  and can be formed of a polymer foam or another appropriate material. In other configurations, the midsole  114  can incorporate fluid-filled chambers, plates, moderators, and/or other elements that further attenuate forces, enhance stability, or influence motions of the foot. The outsole  112  is secured to a lower surface of the midsole  114  and can be formed from a wear-resistant rubber material that is textured to impart traction, for example. The upper  102  can be formed from various elements (e.g., lace, tongue, collar) that combine to provide a structure for securely and comfortably receiving a foot. Although the configuration of the upper  102  can vary significantly, the various elements generally define a void within the upper  102  for receiving and securing the foot relative to sole structure  104 . Surfaces of the void within upper  102  are shaped to accommodate the foot and can extend over the instep and toe areas of the foot, along the medial and lateral sides of the foot, under the foot, and around the heel area of the foot. The upper  102  can be made of one or more materials such as textiles, a polymer foam, leather, synthetic leather, and the like that are stitched or bonded together. Although this configuration for the sole structure  104  and the upper  102  provides an example of a sole structure that can be used in connection with an upper, a variety of other conventional or nonconventional configurations for the sole structure  104  and/or the upper  102  can also be utilized. Accordingly, the configuration and features of the sole structure  104  and/or the upper  102  can vary considerably. 
       FIGS.  10 ( a )- 10 ( b )  illustrate a perspective view and a side view of an article of footwear  130  that include a sole structure  134  and an upper  132 . The sole structure  134  is secured to the upper  132  and extends between the foot and the ground when the article of footwear  130  is worn. The upper  132  can be formed from various elements (e.g., lace, tongue, collar) that combine to provide a structure for securely and comfortably receiving a foot. Although the configuration of the upper  132  can vary significantly, the various elements generally define a void within the upper  132  for receiving and securing the foot relative to the sole structure  134 . Surfaces of the void within the upper  132  are shaped to accommodate the foot and can extend over the instep and toe areas of the foot, along the medial and lateral sides of the foot, under the foot, and around the heel area of the foot. The upper  132  can be made of one or more materials such as textiles including natural and synthetic leathers, molded polymeric components, polymer foam and the like that are stitched or bonded together. 
     The primary elements of the sole structure  134  are a forefoot component  142 , a heel component  144 , and an outsole  146 . Each of the forefoot component  142  and the heel component  144  are directly or indirectly secured to a lower area of the upper  132  and formed from a polymer material that encloses a fluid, which can be a gas, liquid, or gel. During walking and running, for example, the forefoot component  142  and the heel component  144  compress between the foot and the ground, thereby attenuating ground reaction forces. That is, the forefoot component  142  and the heel component  144  are inflated and can be pressurized with the fluid to cushion the foot. The outsole  146  is secured to lower areas of the forefoot component  142  and the heel component  144  and can be formed from a wear-resistant rubber material that is textured to impart traction. The forefoot component  142  can be made of one or more polymers (e.g., layers of one or more polymeric films) that form a plurality of chambers that includes a fluid such as a gas. The plurality of chambers can be independent or fluidically interconnected. Similarly, the heel component  144  can be made of one or more polymers (e.g., layers of one or more polymeric films) that form a plurality of chambers that includes a fluid such as a gas and can also be independent or fluidically interconnected. In some configurations, the sole structure  134  can include a foam layer, for example, that extends between the upper  132  and one or both of the forefoot component  142  and the heel component  144 , or a foam element can be located within indentations in the lower areas of the forefoot component  142  and the heel component  144 . In other configurations, the sole structure  132  can incorporate plates, moderators, lasting elements, or motion control members that further attenuate forces, enhance stability, or influence the motions of the foot, for example. Although the depicted configuration for the sole structure  134  and the upper  132  provides an example of a sole structure that can be used in connection with an upper, a variety of other conventional or nonconventional configurations for the sole structure  134  and/or the upper  132  can also be utilized. Accordingly, the configuration and features of the sole structure  134  and/or the upper  132  can vary considerably. 
       FIG.  1 O ( c ) is a cross-sectional view of A-A that depicts the upper  132  and the heel component  144 . 
       FIGS.  1 P (a)- 1 P(b) illustrate a perspective view and a side view of an article of footwear  160  that includes traction elements  168 . The article of footwear  160  includes an upper  162  and a sole structure  164 , where the upper  162  is secured to the sole structure  164 . The sole structure  164  can include one or more of a toe plate  166   a , a mid-plate  166   b , and a heel plate  166   c . The plate can include one or more traction elements  168 , or the traction elements can be applied directly to a ground-facing surface of the article of footwear. As shown in  FIGS.  1 P (a)- 1 P(b), the traction elements  168  are cleats, but the traction elements can include lugs, cleats, studs, and spikes as well as tread patterns to provide traction on soft and slippery surfaces. In general, the cleats, studs and spikes are commonly included in footwear designed for use in sports such as global football/soccer, golf, American football, rugby, baseball, and the like, while lugs and/or exaggerated tread patterns are commonly included in footwear (not shown) including boots design for use under rugged outdoor conditions, such as trail running, hiking, and military use. The sole structure  164  is secured to the upper  162  and extends between the foot and the ground when the article of footwear  160  is worn. The upper  162  can be formed from various elements (e.g., lace, tongue, collar) that combine to provide a structure for securely and comfortably receiving a foot. Although the configuration of the upper  162  can vary significantly, the various elements generally define a void within the upper  162  for receiving and securing the foot relative to the sole structure  164 . Surfaces of the void within upper  162  are shaped to accommodate the foot and extend over the instep and toe areas of the foot, along the medial and lateral sides of the foot, under the foot, and around the heel area of the foot. The upper  162  can be made of one or more materials such as textiles including natural and synthetic leathers, molded polymeric components, a polymer foam, and the like that are stitched or bonded together. In other aspects not depicted, the sole structure  164  can incorporate foam, one or more fluid-filled chambers, plates, moderators, or other elements that further attenuate forces, enhance stability, or influence the motions of the foot. Although the depicted configuration for the sole structure  164  and the upper  162  provides an example of a sole structure that can be used in connection with an upper, a variety of other conventional or nonconventional configurations for the sole structure  164  and/or the upper  162  can also be utilized. Accordingly, the configuration and features of the sole structure  164  and/or the upper  162  can vary considerably. 
       FIGS.  1 Q (a)- 1 Q(e) illustrate additional views of exemplary articles of athletic footwear including various configurations of upper  176 .  FIG.  1 Q (a) is an exploded perspective view of an exemplary article of athletic footwear showing insole  174 , upper  176 , midsole or optional lasting board  177 , and outsole  178 .  FIG.  1 Q (b) is a top view of an exemplary article of athletic footwear indicating an opening  183  configured to receive a wearer&#39;s foot as well as cushioning material  181  around a wearer&#39;s ankle. Also illustrated are the lateral side  180  and medial side  179  of the exemplary article of athletic footwear.  FIG.  1 Q (c) is a back view of the article of footwear depicted in  FIG.  1 Q (b), showing heel clip  184 .  FIG.  1 Q (d) shows a side view of an exemplary article of athletic footwear, which can optionally also include a tongue  186 , laces  188 , a toe cap  189 , a heel counter  190 , a decorative element such as a logo  191 , and/or eyestays for the laces  192 . Toe area  193   a , heel area  193   b , and upper  193   c  are also shown. In some aspects, the heel counter  190  can be covered by a layer of knitted, woven, or nonwoven fabric, leather, synthetic leather, or other shoe upper material. In some aspects, the eyestays  192  are formed as one continuous piece; however, they can also comprise several separate pieces surrounding a single eyelet or a plurality of eyelets. While not depicted, foamed articles can be present on the eyestays  192  and/or the laces  188 . In some configurations, the sole structure can include a midsole with a foam or airbag bladder in part or substantially all of the midsole and the foamed article can be disposed on midsole foam or the airbag bladder.  FIG.  1 Q (e) is a side view of another exemplary article of athletic footwear. In certain aspects, the upper can comprise containment elements  194  such as mag wires or a molded plastic piece extending from the lace structure over portions of the medial and lateral sides of the exemplary article of athletic footwear to the top of the sole structure to provide lockdown of the foot to the sole structure, where the containment elements can have a foamed article (not shown) disposed thereon. Also depicted is a biteline  195  between the upper and the sole structure 
     Exemplary Aspects of Disclosed Methods for Making Foamed Articles 
     In one aspect, with reference to the figures,  FIG.  2    illustrates a side view of an article comprising a solid foamable material as described herein. In one aspect, the solid foamable material comprises one or more thermoplastic elastomeric polyurethane copolymers. 
       FIG.  7    illustrates a flow chart of a method  300  for making a foamed article as disclosed herein. Referring to  FIGS.  2  and  7   , optionally, in one aspect, the foamable material  210  is formed (optional step  302 ) into an article  214 . In another aspect, optionally, the article  214  can be configured having a substantially two-dimensional (2-D) shape, or alternatively, the article  214  can be configured having a substantially three-dimensional (3-D) shape or a combination of 2-D and 3-D shapes. 
     Articles comprising the disclosed foamable materials can take various forms. In one non-limiting aspect, as illustrated, the article  214  can be configured as a sheet  216  that has been rolled or otherwise folded into a roll  218 , or the article may not be a sheet, but can be, in some aspects, configured as a roll. In one example, the sheet  216  has a thickness of from about 0.5 millimeters to about 2 centimeters, or from about 0.5 millimeters to about 1 centimeter, or from about 0.5 millimeters to about 100 millimeters, optionally from about 0.5 millimeters to about 5 millimeters, for example about 1.5 millimeters. 
     Referring also to  FIG.  3   , when the article is configured as a roll, an optional porous spacer  220  can be arranged in the roll  218  between adjacent roll sections  222 ,  224 ,  226 , and  228  of the article  216  comprising the foamable material  210 . In one aspect, as will be described in further detail below, the optional porous spacer  220  is sufficiently porous to allow carbon dioxide to advanced or pass through the porous spacer  220  (e.g., through the porous structure and/or along porous passageways) for contact with the foamable material  210 . In one aspect, the optional porous spacer  220  is formed of a thermoplastic material, such as, for example, polyolefin (e.g., melt blown polyethylene) or the like. In an alternative aspect, the optional porous spacer  220  can be formed of a non-thermoplastic material, such as, for example, paper or a cellulose product, a fiber product (e.g., natural or synthetic fiber product), a fabric product, or the like. In one example, the optional porous spacer  220  is formed of a recyclable material. In another aspect, the article  216  and the optional porous spacer  220  can be any desired thickness, for example, so that the sheet  216  and/or article  218  can be arranged in a vessel  234  as discussed in further detail below. The optional porous spacer  220  can have a thickness of from about 0.1 millimeters to about 2 millimeters, or from about 0.1 millimeters to about 1 millimeter, or from about 0.1 millimeters to about 0.5 millimeters, for example about 0.25 millimeters. In one example, the optional porous spacer  220  has a porosity such that the diffusion rate of carbon dioxide (e.g., liquid phase) through the spacer  220  is higher or greater than the diffusion rate of carbon dioxide (e.g., liquid phase) through the foamable material  210 . In other aspects, the article can be folded and the optional porous spacer placed between folded sections of the article, or a porous spacer can be incorporated between a plurality of discrete articles (e.g., multiple sheets of separate articles or bundles or stacks of separate articles, and the like). 
     In  FIGS.  2 - 4  and  7   , as illustrated, the rolls  218  including the solid foamable material  210  are arranged vertically on a base  230  that is operatively coupled to a rod  232  in one exemplary embodiment. The rolls  218  are positioned in the vessel  234  by maneuvering the rod  232  to lower the base  230  through an opening  236  and into the vessel  234 . The opening  236  of the vessel  234  is then covered and sealed with a cover  238  (e.g., clam shell or other pressure-sealing cap). In other aspects (not shown), foamable articles in any suitable shape can be arranged on a base operatively coupled to a rod, where the rod can be maneuvered to lower the base through an opening and into the vessel. Further in this aspect, the opening of the vessel can then be covered and sealed with a cover. 
     Carbon dioxide  240  is provided or received (step  304 ) in the vessel  234  for contact with the foamable material  210 . In one example, in the step of placing, the liquid carbon dioxide  240  is present in the vessel  234  prior to positioning the rolls  218 , articles, or bundles of articles of the foamable material  210  in the vessel  234 . In another example, in the step of placing, liquid or gas carbon dioxide  240  from a liquid or gas carbon dioxide source  242  is passed through a control valve  244  and introduced to the vessel  234  after the rolls, articles, or bundles of articles  218  of foamable material  210  are positioned in the vessel  234 . 
     In another example, in the step of placing, rolls  218  of sheets comprising a foamable material  210 , or in alternative aspects, articles, bundles of articles, or the like are positioned in the vessel  234  and the vessel  234  is sealed with the cover  238 . Carbon dioxide liquid and/or gas  246  from a carbon dioxide liquid and/or gas source  248  is passed through a control valve  250  and is introduced to the vessel  234 . In one aspect, the vessel  234  is charged with the carbon dioxide liquid and/or gas  246  to a pressure and temperature condition that is, for example, at a liquid/vapor equilibrium condition for carbon dioxide. The pressure and temperature of the vessel  234  can be monitored via a pressure measuring device  252  and a temperature measuring device  254 , respectively. In one example, once charged with the carbon dioxide liquid and/or gas  246 , the vessel  234  has a pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 6000 pounds per square inch (41,300 kilopascals), optionally about 15 pounds per square inch (103.4 kilopascals) to about 5500 pounds per square inch (37,900 kilopascals), from about 100 pounds per square inch (689.5 kilopascals) to about 5000 pounds per square inch (34,500 kilopascals), from about 500 pounds per square inch (3450 kilopascals) to about 2000 pounds per square inch (13,790 kilopascals) or from about 1000 pounds per square inch (6895 kilopascals) to about 1500 pounds per square inch (10,300 kilopascals), and a temperature can be from about −57 degrees Celsius to about 31 degrees Celsius, optionally from about 0 degrees Celsius to about 23 degrees Celsius, or can be about ambient (e.g., from about 18 degrees Celsius to about 23 degrees Celsius) or greater as desired. After charging the vessel  234  with carbon dioxide liquid and/or gas, the liquid carbon dioxide  240  is introduced to the vessel  234  as described above. 
     As illustrated, the vessel  234  can be sufficiently filled with the liquid carbon dioxide  240  so that the rolls  218  and/or articles or bundles of articles including foamable material  210  are substantially or fully immersed in the liquid carbon dioxide  240 . As briefly mentioned above, the liquid carbon dioxide  240  advances through the optional porous spacer  220  for contact with adjacent roll sections  222 ,  224 ,  226 , and  228  of the sheets  216  of foamable material  210 , or for contact with adjacent discrete articles or sections of folded articles (not pictured). While in contact with the liquid carbon dioxide  240 , the foamable material  210  absorbs and/or otherwise takes up the liquid carbon dioxide  240  (e.g., by diffusion step  305 ) to form a carbon dioxide-infused article  256 . In one example, during the steps of maintaining and holding at the first pressure and first temperature, the foamable material  210  is in contact with the carbon dioxide  240  for a time of from about 20 seconds to about 72 hours, optionally from about 30 minutes to about 30 hours, from about 1 hour to about 24 hours, from about 6 hours to about 12 hours, or from about 20 seconds to about 1 hour to form the carbon dioxide-infused article  256 . Without being limited by theory, it is believed that during contact with the carbon dioxide  240 , the foamable article  210  is solvated by the carbon dioxide  240  to form the carbon dioxide-infused article  256 . 
     In one exemplary aspect, the process continues by discharging the vessel  234  of the carbon dioxide liquid and/or gas  246  through the control valve  250  and line  258 . Preferably, the vessel  234  is discharged of the carbon dioxide liquid and/or gas  246  at a temperature that is sufficient to substantially prevent the liquid carbon dioxide-containing foamable material  256  from foaming. In one example, the temperature in the vessel  234  during discharge is from about −60 degrees Celsius to about −20 degrees Celsius, or from about −50 degrees Celsius to about −30 degrees Celsius, or from about −45 degrees Celsius to about −38 degrees Celsius. In another aspect, before, during, or after discharging the vessel  234  of the carbon dioxide liquid and/or gas  246 , the liquid carbon dioxide  240  can be removed from the vessel  234  via a pump  260  and line  262 . 
     The carbon dioxide-infused rolls  218  of carbon dioxide- 256  or other carbon dioxide-infused articles or bundles of articles are removed from the vessel  234 , for example, by removing the cover  238  and maneuvering the rod  232  to lift the base  230  through the opening  236 . Optionally and as illustrated in  FIG.  5   , the carbon dioxide-infused rolls  218  of—or other carbon dioxide-infused articles or bundles of articles  256  can be temporarily exposed to the second pressure and second temperature (step  306 ) in a cooling zone  308  prior to heating and foaming the material  256 . As used herein, the term “zone” refers to an area including one or more equipment items and/or one or more sub-zones. Equipment items can include for example one or more vessels, chambers, heaters, exchangers, coolers/chillers, pipes, pumps, compressors, controllers, and the like. Additionally, an equipment item can further include one or more zones or sub-zones. In one example, the rolls  218  of the carbon dioxide-infused article  256  are stored in the cooling zone  308  at a temperature of from about −100 degrees Celsius to about −20 degrees Celsius, optionally from about −60 degrees Celsius to about −20 degrees Celsius, or from −40 degrees Celsius to about −20 degrees Celsius. 
     Referring to  FIGS.  6  and  7   , the process continues by subjecting the article comprising a foamable material  256  (step  310 ) to the third temperature and third pressure in order to cause expansion of the infused carbon dioxide, for example by causing a phase change of the carbon dioxide  240  infused in the foamable material. As the carbon dioxide expand, this expansion foams the foamable material  210  into a foamed material, e.g., a foamed material having a multi-cellular foam structure. In some aspects, nucleating sites within the article promote the formation of gas bubbles which expand and form foam cells. In one aspect, when the article includes a recycled material in the form phase-separated blend, the nucleating sites can be phase-separated interfaces between the one or more first thermoplastic elastomers and the one or more second thermoplastics in the blend. Other nucleating sites and/or nucleating agents are also contemplated and should be considered disclosed. In one example, the carbon dioxide-infused article  255  is subjected to a third temperature of from about 20 degrees Celsius to about 150 degrees Celsius, optionally from about 20 degrees Celsius to about 100 degrees Celsius, from about 40 degrees Celsius to about 80 degrees Celsius, from about 50 degrees Celsius to about 70 degrees Celsius, or at about 60 degrees Celsius, and, independently, for a time of from about 1 seconds to about 5 minutes, optionally from about 10 seconds to about 2 minutes, from about 30 seconds to about 90 seconds, or form about 45 seconds to about 60 seconds, to expand and foam the foamable material  210  and form the foamed article  265 . In some aspects, following the subjecting and expanding, the article retains carbon dioxide gas in the cells of the foamed material, or solubilized carbon dioxide in the foamed article  265 , or solubilized carbon dioxide in an additional polymeric material of the article. 
     In one example, during the subjecting step, the carbon dioxide-infused article  255  is heated by introducing the carbon dioxide-infused article  255  to a water bath  266 . As illustrated in  FIG.  6    for the case of rolled articles, the roll  219  of the carbon dioxide-infused article  255  is unrolled and the porous spacer  220  is removed to expose the carbon dioxide-infused article  255  for introduction to the water bath  266 . Other methods of introducing articles, including articles that have not been rolled, are also contemplated and should be considered disclosed. In the water bath  266 , the carbon dioxide-infused article  255  is in contact with water that is at a higher temperature than the carbon dioxide-infused article  255 . As such, heat is transferred from the water bath  266  to the carbon dioxide-infused article  255  to cause a phase change of the carbon dioxide  240 , thereby expanding and foaming the foamable material  210  to form to the foamed article  265 . In one example, the water bath  266  is at a third temperature of from about 20 degrees Celsius to about 90 degrees Celsius, or from about 50 degrees Celsius to about 70 degrees Celsius, or about 60 degrees Celsius, and, independently, the carbon dioxide-infused article  255  is soaked in the water bath  266  for a time of from about 2 seconds to about 30 minutes, optionally from about 10 seconds to about 30 minutes, from about 30 seconds to about 20 minutes, from about 30 seconds to about 10 minutes, or from about 30 seconds to about 5 minutes, to form the foamed article  265 . In an alternative example, water in the form of steam is used to heat the carbon dioxide-infused article  255 . In particular, the temperature of the carbon dioxide-infused article  255  is increased by subjecting the carbon dioxide-infused article  255  to steam. In one example, steam is used to heat the carbon dioxide-infused article  255  to a third temperature of from about 60 degrees Celsius to about 150 degrees Celsius, optionally from about 60 degrees Celsius to about 100 degrees Celsius, or from about 75 degrees Celsius to about 90 degrees Celsius to cause a phase change of the carbon dioxide  240  to carbon dioxide gas, thereby expanding and foaming the foamable material  210  to form to the foamed article  265 . 
     In another example, the carbon dioxide-infused article  255  can be heated by subjecting the carbon dioxide-infused article  255  to microwave energy using a microwave generating device or to radio frequency (RF) energy using an RF generating device  268  (schematically illustrated in  FIG.  7   ). In particular, heat is generated in the carbon dioxide-infused article  255  by absorbing the microwave energy or RF energy to cause a phase change of the carbon dioxide  240 , thereby expanding and foaming the foamable material  210  to form to the foamed article  265 . In one example, the carbon dioxide-infused article  255  is heated by the microwave energy or RF energy to a third temperature of from about 60 to about 150 degrees Celsius, optionally from about 60 degrees Celsius to about 100 degrees Celsius, or from about 75 degrees Celsius to about 90 degrees Celsius, and, independently, for a time of from about 2 seconds to about 5 minutes, optionally from about 10 seconds to about 2 minutes, or from about 30 seconds to about 1 minute to form the foamed article  265 . 
     Referring to  FIG.  7   , the process continues by optionally bringing (step  311 ) the foamed article  265  to a fourth temperature and fourth pressure and holding the foamed article at or below the fourth temperature, the fourth pressure, or both, to form a stabilized foamed thermoplastic article. The stabilized foamed article can be formed in a net shape or can be trimmed, machined, or otherwise tailored to a desired shape to define the shape of a foamed article. Removal of residual carbon dioxide (step  312 ) is accomplished by optionally holding the foamed article at a fifth temperature and fifth pressure, e.g., in an oven  314 . Following removal of residual carbon dioxide, the foamed article can be cooled to room temperature (step  316 ) by any means including, but not limited to, removing the foamed article from oven  314  and allowing it to equilibrate with room temperature air. 
     Referring to  FIG.  7   , in one aspect, the foamed article can be used to manufacture an article, such as an article of sporting equipment, an article of apparel, or an article of footwear (optional step  317 ). In one aspect, the foamed article  319  can be combined with a second component (e.g., affixed, step  320 ) to form a finished article  317 . In some aspects, the foamed article as described above can be a foamed footwear component. Further in this aspect, the foamed footwear component and a footwear upper  322  and/or a footwear outsole  324  can be affixed (step  320 ) to make a finished article of footwear. 
     Property Analysis and Characterization Procedures 
     Specific Gravity/Density Test Protocol. The specific gravity (S.G.) or density is measured for samples taken using the Component Sampling Procedure as described herein, using a digital balance or a Densicom Tester (Qualitest, Plantation, Fla., USA). Each sample is weighed and then is submerged in a distilled water bath (at 22 degrees Celsius plus or minus 2 degrees Celsius). To avoid errors, air bubbles on the surface of the samples are removed, e.g., by wiping isopropyl alcohol on the sample before immersing the sample in water, or using a brush after the sample is immersed. The weight of the sample in the distilled water is recorded. The specific gravity is calculated using the following formula: 
     
       
         
           
             
               S 
               . 
               G 
               . 
             
             = 
             
               
                 W 
                 ⁢ 
                 eight 
                 ⁢ 
                     
                 of 
                 ⁢ 
                    
                 the 
                 ⁢ 
                     
                 sample 
                 ⁢ 
                     
                 in 
                 ⁢ 
                     
                 air 
                 ⁢ 
                     
                 
                   ( 
                   g 
                   ) 
                 
               
               
                 
                   W 
                   ⁢ 
                   eight 
                   ⁢ 
                       
                   of 
                   ⁢ 
                       
                   sample 
                   ⁢ 
                       
                   in 
                   ⁢ 
                       
                   air 
                   ⁢ 
                       
                   
                     ( 
                     g 
                     ) 
                   
                 
                 - 
                 
                   Weight 
                   ⁢ 
                       
                   of 
                   ⁢ 
                       
                   sample 
                   ⁢ 
                       
                   in 
                   ⁢ 
                       
                   water 
                   ⁢ 
                     
                   
                     ( 
                     g 
                     ) 
                   
                 
               
             
           
         
       
     
     Melting Temperature, Glass Transition Temperature, and Enthalpy of Melting Test Protocol. The melting temperature and glass transition temperature are determined using a commercially available Differential Scanning Calorimeter (“DSC”) in accordance with ASTM D3418-97, using a sample prepared using the Material Sampling Procedure. Briefly, a 10-15 gram sample is placed into an aluminum DSC pan and then the lid is sealed with a crimper press. The DSC is configured to scan from −100 degrees Celsius to 225 degrees Celsius with a 20 degree Celsius per minute heating rate, hold at 225 degrees Celsius for 2 minutes, and then cool down to 25 degrees Celsius at a rate of −10 degrees Celsius per minute. The DSC curve created from this scan is then analyzed using standard techniques to determine the glass transition temperature and the melting temperature. The enthalpy of melting is calculated by integrating the area of the melting endotherm peak and normalizing by the sample mass. 
     Alternatively, glass transition temperature can be determined using Dynamic Mechanical Analysis (DMA). In this technique, a piece of the foamable material in the form of a film about 1 millimeter thick, about 5 millimeters to about 10 millimeters wide and about 20 millimeters long is mounted on a film tension fixture of a DMA apparatus. The sample is heated over a pre-determined temperature range at a fixed rate of, for example, about 1 degree Celsius to about 5 degrees Celsius per minute. During heating, the sample is tested at fixed frequency (e.g., about 1 Hertz) and a small oscillation amplitude (e.g. about 0.05 percent strain). The storage modulus (or complex shear) is recorded. In the DMA plot, G′ is the storage modulus, and G″ is the loss modulus. G′ measures the energy stored and G″ measures the energy lost/dissipated as heat. Tan delta is the ratio of G″/G′ and the peak region in the tan delta curve is indicative of the glass transition temperature of the sample. 
     Shore A Hardness Test Protocol. The hardness of a material is determined according to the test protocol detailed in ASTM D-2240 Durometer Hardness, using a Shore A scale. The sample is prepared using the Material Sampling Procedure and/or the Component Sampling Procedure. 
     Asker C Hardness Test Protocol. For flat foams, the sample is a minimum of 6 millimeters thick for Asker C durometer testing. If necessary, foam samples are stacked to make up the minimum thickness. Foam samples are large enough to allow all measurements to be performed at a minimum of 12 millimeters from the edge of the sample and at least 12 millimeters from any other measurement. Regions tested are flat and parallel with an area at least 6 millimeters in diameter. Standard samples have dimensions of approximately 35 centimeters by 13 centimeters by 1.8 centimeters and a minimum of 5 hardness measurements are taken and tested using a 1 kilogram heat weight. The sample is prepared using the Material Sampling Procedure and/or the Component Sampling Procedure. 
     Split-Tear Test Protocol. The test protocol used to obtain the split-tear values for foam articles is as follows. The sample is prepared using the Material Sampling Procedure and/or the Component Sampling Procedure. Four die-cut, rectangular-shaped samples of slab sheet or molded foam are prepared, each measuring 2.54 centimeters by 15.24 centimeters by 10±1 millimeter (thickness). If the foam material to be tested had a skin or barrier layer, the skin or barrier layer is removed before preparing the four samples. A 3 centimeter long cut is made in the center from one end of the sample. Then, five successive 2 centimeter portions are marked on the sample. 
     The crosshead speed of the tensile test apparatus is set at 50 millimeters per minute. Each separated end of the sample is clamped in an upper grip and a lower grip of the test apparatus. The separation is placed in the middle between both grips. Each section of the sample is held in a clam in such a manner that the original adjacent cut edges forms a straight line joining the centers of the clamps. 
     As needed, the cut is aided with a sharp knife to keep separating the foam material in the center of the sample. Readings caused by cutting with the knife are discarded. The lowest values for each of the five portions of each sample are recorded in kilograms per centimeter. Five values are recorded for each sample and an average of the five values is then obtained and reported. If a portion of a sample includes a portion having an air bubble more than 2 millimeters in diameter, the value for the portion including the air bubble is not included in the average. If more than one portion of a sample is found to include air bubbles having a diameter greater than 2 millimeters, another sample is then tested. 
     Water Uptake Test Protocol. The test protocol is used to obtain the water uptake capacity of a foam sample after a soaking duration of 5 minutes. A 1-centimeter core sample is removed from a foam sample prepared using the Plaque Sampling Procedure or Component Sampling Procedure, starting from the side wall of the foamed article, e.g., the midsole of an article of footwear. The core is then cut to provide a cylindrical sample having a 1-centimeter cylinder height, ensuring that the side wall remains as part of the core sample. The sample is conditioned in an oven for 24 hours at 50 degrees Celsius plus or minus 3 degrees Celsius. After conditioning, the sample is cooled for 30 minutes in a lab environment at a temperature of 22 degrees Celsius plus or minus 2 degrees Celsius, and then is immediately weighed, and the weight recorded in grams (W_0). The surface of the side wall is masked with masking tape, while all other surfaces are sealed with a nonpermeable coating. When the surfaces are fully coated, the sidewall surface is unmasked. The coated sample is then conditioned in an oven for 24 hours at 50 degrees Celsius plus or minus 3 degrees Celsius, cooled for 30 minutes in a lab environment at a temperature of 22 degrees Celsius plus or minus 2 degrees Celsius, and then is immediately weighed and the weight recorded in grams (W_i). The dried sample is fully immersed in a deionized water bath maintained at 22 degrees Celsius plus or minus 2 degrees Celsius, for a duration of 2 hours. After the soaking duration, the sample is removed from the deionized water bath, blotted with a cloth to remove surface water, and the total weight of the soaked sample (W_f) is measured in grams (W_f). The water uptake for the time period is calculated as follows: 
     
       
         
           
             
               Water 
               ⁢ 
                   
               Uptake 
               ⁢ 
                   
               Capacity 
             
             = 
             
               
                 
                   
                     W_f 
                     - 
                     W_i 
                   
                   W_i 
                 
                 ⨯ 
                 100 
               
               ⁢ 
               % 
             
           
         
       
     
     Akron Abrasion Test Protocol. Akron Abrasion Test. Abrasion resistance, including abrasion resistance simulating footwear sole structure scuffing of ground-contacting areas can be measured using the Akron abrasion test, using samples prepared according to the sampling procedures described herein. A sample strip is cut from a sample, wherein the strip is approximately 2-3 millimeters thick, 0.5 inches (127 millimeters) wide, and 8 inches (2032 millimeters) long. The strip is mounted to the perimeter of a rubber wheel, and the wheel is mounted so the strip is pushed against an abrasive grit surface at a slight angle (approximately 15 degrees) and under a known force (approximately 6 pounds or 2.72 kilograms). The strip is run for a number of cycles to prepare the surface, cleaned with a brush and vacuum, and weighed. The strip is then mounted against the abrasive wheel and run for about 3000 additional cycles, then cleaned and weighed again. Mass loss can be adjusted based on the density of the material. The measured mass and volume losses represent the abrasion level of resistance. 
     DIN Abrasion Test Protocol. Samples are prepared according to the sampling procedures described herein. Abrasion loss is tested on cylindrical samples with a diameter of 16±0.2 millimeters and a minimum thickness of 6 millimeters cut using a ASTM standard hole drill. The abrasion loss is measured using Method B of ASTM D 5963-97a on a Gotech GT-7012-D abrasion test machine. The tests are performed as 22 degrees Celsius with an abrasion path of 40 meters. The Standard Rubber #1 used in the tests has a density of 1.336 grams per cubic centimeter (g/cm 3 ). The smaller the abrasion loss volume, the better the abrasion resistance. 
     Sampling Procedures 
     Using the Test Protocols described above, various properties of the materials disclosed herein and articles formed therefrom can be characterized using samples prepared with the following sampling procedures. 
     Material Sampling Procedure. The Material Sampling Procedure can be used to obtain a neat sample of a polymeric material or of a polymer, or, in some instances, a sample of a material used to form a polymeric material or a polymer. The material is provided in media form, such as flakes, granules, powders, pellets, or the like. If a source of the polymeric material or polymer is not available in a neat form, the sample can be cut from a component or element containing the polymeric material or polymer, such as a composite element or a sole structure, thereby isolating a sample of the material. 
     Component Sampling Procedure. This procedure can be used to obtain a sample of a material from a component of an article of footwear, an article of footwear, a component of an article of apparel, an article of apparel, a component of an article of sporting equipment, or an article of sporting equipment. A sample including the material in a non-wet state (e.g., at 25 degrees Celsius and 20 percent relative humidity) is cut from the article or component using a blade. If the material is bonded to one or more additional materials, the procedure can include separating the additional materials from the material to be tested. 
     The sample is taken at a location along the article or component that provides a substantially constant material thickness for the material as present on the article or component (within plus or minus 10 percent of the average material thickness). For many of the test protocols described above, a sample having a surface area of 4 square centimeters is used. The sample is cut into a size and shape (e.g., a dogbone-shaped sample) to fit into the testing apparatus. In cases where the material is not present on the article or component in any segment having a 4 square centimeter surface area and/or where the material thickness is not substantially constant for a segment having a 4 square centimeter surface area, sample sizes with smaller cross-sectional surface areas can be taken and the area-specific measurements are adjusted accordingly. 
     Definitions 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined herein. 
     All publications, patents, and patent applications cited in this specification are cited to disclose and describe the methods and/or materials in connection with which the publications are cited. All such publications, patents, and patent applications are herein incorporated by references as if each individual publication or patent were specifically and individually indicated to be incorporated by reference. Such incorporation by reference is expressly limited to the methods and/or materials described in the cited publications, patents, and patent applications and does not extend to any lexicographical definitions from the cited publications, patents, and patent applications. Any lexicographical definition in the publications, patents, and patent applications cited that is not also expressly repeated in the instant specification should not be treated as such and should not be read as defining any terms appearing in the accompanying claims. 
     This disclosure is not limited to particular aspects, embodiments, or examples described, and as such can, of course, vary. The terminology used herein serves the purpose of describing particular aspects, embodiments, and examples only, and is not intended to be limiting, since the scope of the present disclosure will be limited only by the appended claims. 
     Where a range of values is provided, each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges can independently be included in the smaller ranges and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure. 
     As will be apparent to those of skill in the art upon reading this disclosure, each of the individual aspects, embodiments and examples described and illustrated herein has discrete components and features which can be readily separated from or combined with the features of any of the other several aspects, embodiments, and examples without departing from the scope or spirit of the present disclosure. Any recited method can be carried out in the order of events recited or in any other order that is logically possible. 
     Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described. Functions or constructions well-known in the art cannot be described in detail for brevity and/or clarity. Aspects of the present disclosure will employ, unless otherwise indicated, techniques of nanotechnology, organic chemistry, materials science and engineering and the like, which are within the skill of the art. Such techniques are explained fully in the literature. 
     It should be noted that ratios, concentrations, amounts, and other numerical data can be expressed herein in a range format. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure, e.g. the phrase “x to y” includes the range from ‘x’ to ‘y’ as well as the range greater than ‘x’ and less than ‘y’. The range can also be expressed as an upper limit, e.g. ‘about x, y, z, or less’ and should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and ‘about z’ as well as the ranges of ‘less than x’, less than y’, and ‘less than z’. Likewise, the phrase ‘about x, y, z, or greater’ should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and ‘about z’ as well as the ranges of ‘greater than x’, greater than y’, and ‘greater than z’. In addition, the phrase “about ‘x’ to ‘y’”, where ‘x’ and ‘y’ are numerical values, includes “about ‘x’ to about ‘y’”. It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a numerical range of “about 0.1 percent to 5 percent” should be interpreted to include not only the explicitly recited values of about 0.1 percent to about 5 percent, but also include individual values (e.g., 1 percent, 2 percent, 3 percent, and 4 percent) and the sub-ranges (e.g., 0.5 percent, 1.1 percent, 2.4 percent, 3.2 percent, and 4.4 percent) within the indicated range. 
     As used herein, the term “polymer” refers to a chemical compound formed of a plurality of repeating structural units referred to as monomers. Polymers often are formed by a polymerization reaction in which the plurality of structural units become covalently bonded together. When the monomer units forming the polymer all have the same chemical structure, the polymer is a homopolymer. When the polymer includes two or more monomer units having different chemical structures, the polymer is a copolymer. One example of a type of copolymer is a terpolymer, which includes three different types of monomer units. The co-polymer can include two or more different monomers randomly distributed in the polymer (e.g., a random co-polymer). Alternatively, one or more blocks containing a plurality of a first type of monomer can be bonded to one or more blocks containing a plurality of a second type of monomer, forming a block copolymer. A single monomer unit can include one or more different chemical functional groups. 
     Polymers having repeating units which include two or more types of chemical functional groups can be referred to as having two or more segments. For example, a polymer having repeating units of the same chemical structure can be referred to as having repeating segments. Segments are commonly described as being relatively harder or softer based on their chemical structures, and it is common for polymers to include relatively harder segments and relatively softer segments bonded to each other in a single monomeric unit or in different monomeric units. When the polymer includes repeating segments, physical interactions or chemical bonds can be present within the segments or between the segments or both within and between the segments. Examples of segments often referred to as “hard segments” include segments including a urethane linkage, which can be formed from reacting an isocyanate with a polyol to form a polyurethane. Examples of segments often referred to as “soft segments” include segments including an alkoxy functional group, such as segments including ether or ester functional groups, and polyester segments. Segments can be referred to based on the name of the functional group present in the segment (e.g., a polyether segment, a polyester segment), as well as based on the name of the chemical structure which was reacted in order to form the segment (e.g., a polyol-derived segment, an isocyanate-derived segment). When referring to segments of a particular functional group or of a particular chemical structure from which the segment was derived, it is understood that the polymer can contain up to 10 mole percent of segments of other functional groups or derived from other chemical structures. For example, as used herein, a polyether segment is understood to include up to 10 mole percent of non-polyether segments. 
     The terms “Material Sampling Procedure” and “Component Sampling Procedure” as used herein refer to the respective sampling procedures and test methodologies described in the Property Analysis and Characterization Procedure section. These sampling procedures and test methodologies characterize the properties of the recited materials, films, articles and components, and the like, and are not required to be performed as active steps in the claims. 
     The term “about,” as used herein, can include traditional rounding according to significant figures of the numerical value. In some aspects, the term about is used herein to mean a deviation of 10 percent, 5 percent, 2.5 percent, 1 percent, 0.5 percent, 0.1 percent, 0.01 percent, or less from the specified value. 
     The articles “a” and “an,” as used herein, mean one or more when applied to any feature in aspects of the present disclosure described in the specification and claims. The use of “a” and “an” does not limit the meaning to a single feature unless such a limit is specifically stated. The article “the” preceding singular or plural nouns or noun phrases denotes a particular specified feature or particular specified features and can have a singular or plural connotation depending upon the context in which it is used. 
     As used herein, the terms “about,” “approximate,” “at or about,” and “substantially” mean that the amount or value in question can be the exact value or a value that provides equivalent results or effects as recited in the claims or taught herein. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art such that equivalent results or effects are obtained. In some circumstances, the value that provides equivalent results or effects cannot be reasonably determined. In such cases, it is generally understood, as used herein, that “about” and “at or about” mean the nominal value indicated±10 percent variation unless otherwise indicated or inferred. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about,” “approximate,” or “at or about” whether or not expressly stated to be such. It is understood that where “about,” “approximate,” or “at or about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise. 
     As used herein, the phrase “consists essentially of” or “consisting essentially of” refer to the feature being disclosed as having primarily the listed feature without other active components (relative to the listed feature) and/or those that do not materially affect the characteristic(s) of the listed feature. For example, the foamable material can consist essentially of a foamable material, which means that foamable material can include fillers, colorants, etc. that do not substantially interact with or interact with the change the function or chemical characteristics of the foamable material. In another example, the foamable material can consist essentially of a thermoplastic polyurethane, which means that the thermoplastic polyurethane does not include a sufficient amount of another type of thermoplastic elastomer to alter the properties (e.g., melting temperature, surface energy of the mixture compared to the pure thermoplastic polyurethane, or the like) of the thermoplastic polyurethane. Further in this aspect, when the thermoplastic elastomer consists essentially of one polymer type (e.g., a thermoplastic polyurethane), it may contain less than 1 weight percent of another type of polymer. 
     As used herein, the terms “at least one” and “one or more of” an element are used interchangeably, and have the same meaning that includes a single element and a plurality of the elements, and can also be represented by the suffix “(s)” at the end of the element. For example, “at least one polyurethane”, “one or more polyurethanes”, and “polyurethane(s)” can be used interchangeably and have the same meaning. 
     As used herein, “gas” and “vapor” refer to fluid phases of a substance such as, for example, carbon dioxide, wherein the distance between adjacent molecules is large and there are few or no interactions between the atoms or molecules of the substance. Gases and vapors typically expand to fill containers in which they are placed. In some aspects, “vapor” can be used specifically to refer to a substance in the gas phase that is in equilibrium with or exists within a container alongside a solid or liquid phase of the same substance. 
     As used herein, a “sheet” or “film” refers to a flexible strip comprising one or more polymeric materials, the sheet or film having a thickness that is much smaller than its length and/or width. 
     As used herein, “physically-expanded” refers to foams, foamed materials, and foamed articles, that have been expanded from an initial solid, un-foamed state through the action of a physical expansion agent. In one aspect, the physically-expanded foams, foamed materials, and foamed articles become expanded when carbon dioxide infused in solid foamable materials is brought to temperature and pressure conditions wherein the carbon dioxide phase transitions to a gas, thereby physically expanding the solid foamable materials. 
     As used herein, “solid material” refers to a material in an unfoamed state, i.e., a material which is in its solid phase at room temperature and under atmospheric pressure, and which does not have a multi-cellular foam structure. The solid material may be a foamable material that has not been expanded through a foaming process, or may be a material that is not foamable using the methods described herein, such as, for example, a barrier material. Additionally the solid material can be a thermoplastic material which was previously foamed using a method disclosed herein or using a different foaming method, and which has subsequently been recycled by thermally softening or melting the foamed material to an extent that its foamed structure has fully collapsed. In one aspect, a foamable solid material does not melt during the foaming process. In another aspect, a foamable solid material does not thermally soften during the foaming process. 
     As used herein, “additive manufacturing” refers to a manufacturing process where material is added to build up an article. In some aspects, additive manufacturing can be conducted in several different steps. In one aspect, additive manufacturing uses less raw material than other manufacturing processes (e.g., molding or subtractive manufacturing) as the material to be added can be deposited only where needed, reducing or eliminating the formation of scraps and/or waste. In one aspect, printing, including 3D printing and 2DZ printing, can be an additive manufacturing process. In another aspect, an additive manufactured article can be formed by laying down one or more strata of particles, followed by sintering or otherwise binding some or all of the particles together. In some aspects, an additive manufactured article can be manufactured by one or more iterations of particles being placed, one or more printing steps, or any combination thereof. 
     Examples 
     The present disclosure is more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. 
     Change in Thickness of Foamable Material on Foaming.  FIGS.  10 A- 10 F  are schematics of a cross-section of a sheet consisting of a central core of a barrier material  504  sandwiched between two layers of another material.  FIG.  10 A  shows an exemplary sheet prior to undergoing a foaming process as described herein, while  FIG.  10 B  shows the sheet after undergoing the foaming process, where the foamable material has expanded to foamed material  506 , where a represents a thickness of a first layer of solid foamable material  502  prior to foaming, b represents a thickness of a barrier layer  504  prior to foaming, and c represents a thickness of a second layer of solid foamable material  502  prior to foaming. After foaming, thickness of the first layer of foamed material  506  is shown as a′, thickness of the barrier material  504  is shown as b′, and thickness of the second layer of foamed material  506  is shown as c′, where a′ and c′ are greater than a and c, respectively, while b′ is substantially unchanged compared to b. However, the surface geometry of barrier material  504  may or may not become distorted following foaming as the result of expansion of layers adjacent to barrier material  504  during the foaming process. 
       FIG.  10 C  shows another exemplary sheet prior to undergoing a foaming process as described herein, while  FIG.  10 D  shows the sheet after undergoing the foaming process, where the foamable material has expanded to foamed material  506 , where a represents a thickness of a first layer of material  508  prior to foaming, b represents a thickness of a barrier layer  504  prior to foaming, and c represents a thickness of a layer of solid foamable material  502  prior to foaming. Material  508  can be a foamable material not infused with carbon dioxide, a foamable material infused with carbon dioxide that fully dissipates prior to foaming, or a material with low carbon dioxide solubility. After foaming, thickness of the first layer of material  508  is shown as a′, thickness of the barrier material  504  is shown as b′, and thickness of the layer of foamed material  506  is shown as c′, where c′ is greater than c, while a′ and b′ are substantially unchanged compared to a and b, respectively. The surface geometry of barrier material  504  may or may not become distorted following foaming as the result of expansion of layers adjacent to barrier material  504  during the foaming process. 
       FIG.  10 E  shows another exemplary sheet prior to undergoing a foaming process as described herein, while  FIG.  10 F  shows the sheet after undergoing the foaming process, where at least a portion the foamable material has expanded to foamed material  506 , while another portion of the foamable material  510  does not expand to a foamed material due to dissipation of carbon dioxide from this portion of the foamable material prior to conducting the foaming process. In this instance, a represents a thickness of a first layer of material  502  or  508  prior to foaming, wherein 502 and 508 are consistent with the previous descriptions, b represents a thickness of a barrier layer  504  prior to foaming, and c represents a thickness of a layer of solid foamable material  502  prior to foaming. After foaming, thickness of the first layer of material  502  or  508  is shown as a′, thickness of the barrier material  504  is shown as b′, and the thickness of the layer of foamed material  506  is shown as d′ and the thickness of the portion of the layer of foamable material from which carbon dioxide dissipates is shown as e′, where the sum of d′ and e′ is greater than c, while a′ and b′ are substantially unchanged compared to a and b, respectively. The surface geometry of barrier material  504  may or may not become distorted following foaming as the result of expansion of layers adjacent to barrier material  504  during the foaming process. 
     Different foamable materials can expand in thickness by different amounts depending on experimental conditions. Conditions and results for exemplary systems as demonstrated in  FIGS.  10 A- 10 F  are presented in Table 1 below, where barrier material  504  comprises ethylene vinyl alcohol (“EVOH”) and the foamable material comprises a thermoplastic polyurethane (“TPU”): 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Example Foaming Conditions 
               
            
           
           
               
               
               
            
               
                   
                 Example 
                 Example 
               
               
                   
                 System 1 
                 System 2 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                 Carbon Dioxide Infusion Temperature (degrees 
                 25 
                 25 
               
               
                 Celsius) 
               
               
                 Carbon Dioxide Infusion Pressure (pounds per 
                 1500 
                 1500 
               
               
                 square inch) 
               
               
                 Carbon Dioxide Infusion Time (hours) 
                 1 
                 1 
               
               
                 Water Bath Temperature (degrees Celsius) 
                 40 
                 60 
               
               
                 Water Bath Time (minutes) 
                 1 
                 1 
               
               
                 Oven Temperature (degrees Celsius) 
                 50 
                 50 
               
               
                 Oven Time (minutes) 
                 30 
                 30 
               
               
                 Shrinkage of EVOH Layer Due to Stretching 
                 &lt;3 
                 &lt;4 
               
               
                 (micrometers) 
               
               
                 Increase in Thickness of Thermoplastic 
                 26 (&lt;5 
                 69 (&lt;13 
               
               
                 Polyurethane Layers Due to Foaming 
                 percent) 
                 percent) 
               
               
                 (micrometers) 
               
               
                   
               
            
           
         
       
     
     Foaming Selected Portions of the Articles.  FIGS.  11 A- 11 K  are schematics of a cross-section of a foamable article at various stages during the foaming process and illustrate several different scenarios for selectively foaming one or more portions of a foamable article while leaving other portions unfoamed. While these scenarios are illustrated using an article comprising a single solid foamable material (e.g., a first solid foamable material), it is to be understood that these scenarios apply to articles comprising one or more solid foamable materials (a first solid foamable material, a second solid foamable material, an additional solid foamable material, etc.), alone or in combination with non-foamable materials (e.g., a barrier material, an additional non-foamable material, etc.). 
     A first scenario is illustrated in  FIGS.  11 A- 11 C . In this scenario, as shown in  FIG.  11 A , a foamable article  608  comprising a solid foamable material  620   a  is placed at the bottom of a vessel  602 , or against another surface of the vessel  602 , which is then charged with carbon dioxide such that a single surface  606  of the article  608  including the solid foamable material  620   a  is exposed to liquid carbon dioxide  604 . Since only one surface  606  on one side of the article  608  is exposed to the liquid carbon dioxide  604 , only the exposed portion of the solid foamable material  620   a  of the article  608  becomes infused with carbon dioxide.  FIG.  11 B  shows a cross section of the solid foamable material  620  of foamable article  608  of  FIG.  11 A  at after the infusing and immediately prior to expanding the foamable material. In this stage, the solid foamable material  620   b  of foamable article  608  is partially infused with carbon dioxide and includes both infused  610  portion containing infused solid foamable material  620   b  and uninfused portions  612  containing uninfused solid foamable material  620   a , where f represents a thickness of the infused portion  610  prior to foaming and g represents a thickness of the uninfused portion  612  prior to foaming. Finally,  FIG.  11 C  shows a cross section of the same region of article  608  as shown in  FIG.  11 B  after the step of expanding has been carried out, and the infused solid foamable material has become foamed material  620   c , while the uninfused solid foamable material  620   a  remains unfoamed. The foamed material  620   c  of foamable article  608  that had been infused with carbon dioxide (portion  610  in  FIG.  11 B )  614  has expanded into a foamed state, with the foamed portion  614  having thickness f′, where f′ is greater than f, while the uninfused portion of the solid foamable material  620   a  of the article  612  remains solid and unfoamed, having a thickness g′ which is substantially the same as thickness g. 
     A second scenario is illustrated in  FIGS.  11 D- 11 G . In this second scenario, as illustrated in in  FIG.  11 D , a foamable article  608  comprising a solid foamable material  620   a  is placed in a vessel  602  which has been charged with carbon dioxide such that one or more exterior surfaces  606  of the article  608  comprising the solid foamable material  620   a  are exposed to liquid carbon dioxide  604  and become infused with carbon dioxide. The carbon dioxide can then be discharged from the vessel  602 , or the foamable article  608  can be placed in an oven or other controlled environment  618  such that at least one surface of the article  608  is placed against the side of the vessel or oven, allowing carbon dioxide to diffuse  616  from one or more surfaces of the article  608  comprising the solid foamable material  620   a  that are not in contact with a side of the vessel  602  or oven  618 , as in  FIG.  11 E .  FIG.  11 F  shows a cross section of the foamable article  608  of  FIGS.  11 D- 11 E  after the infusing and immediately prior to expanding the infused portion of the solid foamable material  620   b . In this stage, the solid foamable material of the foamable article  608  is partially infused with carbon dioxide and includes both infused portion  610  containing infused solid foamable material  620   b  and uninfused portion  612  containing uninfused solid foamable material  620   a , where f represents a thickness of the infused portion  610  prior to foaming and g represents a thickness of the uninfused portion  612  prior to foaming. Finally,  FIG.  11 G  shows a cross section of the same region of article  608  from  FIGS.  11 D- 11 F  after the step of expanding has been carried out, and the infused portion of the solid foamable material ( 620   b  in  FIG.  11 F ) has been foamed, forming foamed material  620   c . The portion of the solid foamable material  620   b  of the article that had been infused with carbon dioxide has expanded into a foamed material  620   c  in foamed portion  614  having thickness f′, where f′ is greater than f, while the uninfused portion of the solid foamable material  620   a  of article  612  remains solid and unfoamed, having a thickness g′ which is substantially the same as thickness g. 
     A third scenario is illustrated in  FIGS.  11 H- 11 K . In this third scenario, as illustrated in  FIG.  11 H , a foamable article  608  comprising a solid foamable material  620   a  is be placed in a vessel  602  which has been charged with carbon dioxide  604  such that the solid foamable material  620   a  on all exterior surfaces  606  of the article  608  are exposed to liquid carbon dioxide  604  and become infused with carbon dioxide. The carbon dioxide can then be discharged from the vessel  602 , or the foamable article  608  can be placed in an oven or other controlled environment  618 , allowing carbon dioxide to diffuse from the solid foamable material  620   a  on all surfaces of the article  608  that are not in contact with a side of the vessel  602  or oven  618 , as in  FIG.  11 I .  FIG.  11 J  shows a cross section of the foamable article  608  of  FIGS.  11 H- 11 I  after infusing and immediately prior to expanding the carbon dioxide-infused solid foamable material  620   b . In this stage, the article  608  is partially infused with carbon dioxide and includes both infused portion  610  containing infused solid foamable material  620   b  and uninfused portion  612  containing uninfused solid foamable material  620   a , where f represents a thickness of the infused portion  610  prior to foaming and g 1  and g 2  represent thicknesses of the uninfused portions  612  surrounding the infused portion  610 , prior to foaming. Finally,  FIG.  11 K  shows a cross section of the same region of article  608  as  FIGS.  11 H- 11 J  after the step of expanding the solid foamable material into a foamed material  620   c  has been carried out. The portion of the article  608  that had been infused  610  with carbon dioxide  614  has expanded into a foamed state  614  containing foamed material  620   c  having thickness f′, where f′ is greater than f, while the uninfused portions  612  of the solid foamable material  620   a  of article  608  remain solid and unfoamed, having thicknesses g 1 ′ and g 2 ′ which are substantially the same as thicknesses g 1  and g 2 , respectively. 
     Combinations of the above scenarios are also envisioned. For example, a combination of the first scenario and the second scenario, where carbon dioxide  614  is first infused into two or more surfaces  606  of the article and then the carbon dioxide  614  is then dissipated from two or more surfaces  606  of the article  608 , could result in an article comprising both foamed and unfoamed material having a cross section similar to that shown in  FIG.  11 K . 
     As a person skilled in the art will readily appreciate, the above description is meant as an illustration of the implementation of the principles of this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation, and change, without departing from the spirit of this invention as defined in the following claims.