Patent Publication Number: US-2022212377-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. 63/134,104 filed on Jan. 5, 2021 and of U.S. Provisional Application No. 63/150,193, filed on Feb. 17, 2021, both of which are incorporated herein by reference in their entireties. 
    
    
     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. 1A-1M  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. 1N (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. 8A-8F  are schematics of multilayered articles according to an exemplary embodiment, prior to foaming ( FIGS. 8A, 8C, and 8E ) and after foaming ( FIGS. 8B, 8D, and 8F ). 
         FIGS. 9A-9K  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 
     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. 1A-1M  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. 1N (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 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. 
     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 a foamed article, the method comprising: 
     placing an article and carbon dioxide (CO 2 ) 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 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 accordance with Aspect 2, the present disclosure is directed to the method of aspect 1, further comprising 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. 
     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 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 accordance with Aspect 4, the present disclosure is directed to the method of aspect 3, wherein the 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. 
     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 foamed article is substantially opaque. 
     In accordance with Aspect 7, the present disclosure is directed to the e 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 40 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 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 10, the present disclosure is directed to the method of aspect 9, 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 11, the present disclosure is directed to the method of aspect 9 or 10, 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 12, the present disclosure is directed to the method of any one of aspects 9-11, wherein the first one or more thermoplastic elastomers comprise or consist essentially of polyether block polyamide (PEBA) copolymer elastomers. 
     In accordance with Aspect 13, the present disclosure is directed to the method of any one of aspects 9-12, 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 14, the present disclosure is directed to the method of any one of aspects 9-13, 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 15, the present disclosure is directed to the method of any one of aspects 9-14, 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 16, the present disclosure is directed to the method of any one of aspects 9-15, 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 17, the present disclosure is directed to the method of any one of aspects 9-16, 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 18, the present disclosure is directed to the method of any one of aspects 9-16, 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 19, the present disclosure is directed to the method of any one of aspects 9-18, 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 20, the present disclosure is directed to the method of any one of aspects 9-18, wherein the one or more first thermoplastic elastomers comprises or consists essentially of thermoplastic elastomeric ethylene-vinyl acetate copolymers. 
     In accordance with Aspect 21, the present disclosure is directed to the method of aspect 20, wherein the thermoplastic elastomeric ethylene-vinyl acetate copolymers include from about 25 to about 50 weight percent vinyl acetate content. 
     In accordance with Aspect 22, the present disclosure is directed to the method of any one of aspect 9-21, 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 23, the present disclosure is directed to the method of any one of aspects 9-22, wherein the one or more first thermoplastic elastomers comprises or consists essentially of one or more recycled first thermoplastic elastomers. 
     In accordance with Aspect 24, the present disclosure is directed to the method of any one of aspects 9-20, 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 25, the present disclosure is directed to the method of any one of aspects 9-24, 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 26, the present disclosure is directed to the method of aspect 25, 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 27, the present disclosure is directed to the method of aspect 25 or 26, 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 28, the present disclosure is directed to the method of any one of aspects 24-27, wherein the one or more second thermoplastics comprise or consist essentially of one or more thermoplastic polyethylene copolymers. 
     In accordance with Aspect 29, the present disclosure is directed to the method of any one of aspects 24-28, wherein the one or more second thermoplastics comprise or consist essentially of one or more thermoplastic ethylene-vinyl alcohol copolymers. 
     In accordance with Aspect 30, the present disclosure is directed to the method of aspect 24, 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 31, the present disclosure is directed to the method of aspect 30, 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 32, the present disclosure is directed to the method of any one of aspects 24-31, wherein the blend comprises one or more recycled first thermoplastic elastomers, or one or more recycled second thermoplastics, or both. 
     In accordance with Aspect 33, the present disclosure is directed to the method of aspect 32, 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 34, the present disclosure is directed to the method of aspect 33, 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 35, the present disclosure is directed to the method of any one of aspects 24-34, 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 36, the present disclosure is directed to the method of any of aspects 24-35, 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 37, 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 38, 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 39, the present disclosure is directed to the method of aspect 37 or 38, 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 40, the present disclosure is directed to the method of any of aspects 37-39, wherein the additional material comprises a plasticizer. 
     In accordance with Aspect 41, the present disclosure is directed to the method of aspect 39 or 40, wherein during the expanding step, the additional material remains substantially unfoamed. 
     In accordance with Aspect 42, the present disclosure is directed to the method of aspect 41, 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 43, the present disclosure is directed to the method of any one of aspects 37-42, 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 44, the present disclosure is directed to the method of any one of aspects 37-43, 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 45, the present disclosure is directed to the method of aspect 44, 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 46, the present disclosure is directed to the method of any one of aspects 37-43, 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 47, the present disclosure is directed to the method of aspect 46, 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 48, the present disclosure is directed to the method of any one of aspects 37-47, 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 49, the present disclosure is directed to the method of aspect 37 or 38, 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 50, the present disclosure is directed to the method of aspect 49, 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 51, the present disclosure is directed to the method of aspect 50, 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 52, the present disclosure is directed to the method of aspect 49, 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 53, the present disclosure is directed to the method of aspect 49, 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 54, the present disclosure is directed to the method of aspect 49, 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 55, the present disclosure is directed to the method of aspect 54, 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 9-23 or 240-252. 
     In accordance with Aspect 56, the present disclosure is directed to the method of aspect 54 or 55, 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 26-29. 
     In accordance with Aspect 57, the present disclosure is directed to the method of aspect 56, 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 58, the present disclosure is directed to the method of aspect 56 or 57, 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 59, the present disclosure is directed to the method of any of aspects 56-58, 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 60, the present disclosure is directed to the method of any one of aspects 54-59, 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 61, the present disclosure is directed to the method of any one of aspects 54-60, 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 62, the present disclosure is directed to the method of any of aspects 54-59, 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 63, the present disclosure is directed to the method of any of aspects 54-62, 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 64, the present disclosure is directed to the method of any one of aspects 55-63, wherein the recycled material comprises a recycled foamed article produced by the method of any one of aspects 1-54, optionally wherein the recycled foamed article is a reground foamed article. 
     In accordance with Aspect 65, the present disclosure is directed to the method of any one of aspects 55-63, wherein the recycled material comprises foamable material, wherein the foamable material is an unfoamed material. 
     In accordance with Aspect 66, the present disclosure is directed to the method of any of aspects 55-65, 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 67, the present disclosure is directed to the method of any of aspects 58-66, 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 68, the present disclosure is directed to the method of any one of aspects 55-67, wherein the solid foamable material is a recycled material. 
     In accordance with Aspect 69, the present disclosure is directed to the method of any one of aspects 55-67, 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 70, 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 71, the present disclosure is directed to the method of aspect 70, wherein the barrier material is an additional material according to any one of aspects 37-67. 
     In accordance with Aspect 72, 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 73, the present disclosure is directed to the method of aspect 72, wherein the structural material is an additional material according to any one of aspects 37-67, 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 74, 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 1-73, optionally wherein the solid foamable material is a recycled material. 
     In accordance with Aspect 75, 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 aspects 1-73, optionally wherein the solid foamable material is a recycled material. 
     In accordance with Aspect 76, the present disclosure is directed to the method of any of aspects 34-36, wherein the steps of maintaining and expanding comprise nucleating foaming at the one or more interfaces in the foamable material. 
     In accordance with Aspect 77, the present disclosure is directed to the method of any 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 2000 pounds per square inch (13,790 kilopascals), optionally from about 15 pounds per square inch (103.4 kilopascals) to about 1500 pounds per square inch (10,342 kilopascals), or from about 100 pounds per square inch (689.5 kilopascals) to about 1200 pounds per square inch (8,274 kilopascals). 
     In accordance with Aspect 78, the present disclosure is directed to the method of any 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 79, the present disclosure is directed to the method of any 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 80, the present disclosure is directed to the method of any 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 81, the present disclosure is directed to the method of any 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 82, the present disclosure is directed to the method of any 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 83, 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 84, 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 85, 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 86, 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 87, 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 88, 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 89, the present disclosure is directed to the method of any one of aspects 2-88, 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 90, the present disclosure is directed to the method of any one of aspects 2-88, 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 91, 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 0.1 gram per cubic centimeter, optionally wherein, in the stabilized foamed article, the foamed material has a density of from about 0.01 gram per cubic centimeter to about 0.1 gram per cubic centimeter. 
     In accordance with Aspect 92, 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 93, the present disclosure is directed to the method of any one of aspects 1-91, 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 94, 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 0.1 gram per cubic centimeter. 
     In accordance with Aspect 95, 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 96, 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 97, 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 98, 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 99, 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 100, 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 101, 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 102, 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 103, the present disclosure is directed to the method of any of the preceding aspects, wherein the steps of subjecting and expanding occur in the vessel. 
     In accordance with Aspect 104, the present disclosure is directed to the method of any one of aspects 1-103, 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 105, the present disclosure is directed to the method of any one of aspects 1-103, 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 106, the present disclosure is directed to the method of aspect 105, 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 107, the present disclosure is directed to the method of aspect 106, 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 108, the present disclosure is directed to the method of any one of aspects 105-107, 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 109, the present disclosure is directed to the method of aspect 108, 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 110, the present disclosure is directed to the method of any 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 111, the present disclosure is directed to the method of aspect 110, wherein the fluid bath has a temperature of from about 20 degrees Celsius to about 90 degrees Celsius. 
     In accordance with Aspect 112, the present disclosure is directed to the method of aspect 110 or 111, 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 113, the present disclosure is directed to the method of any one of aspects 1-109, 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 114, the present disclosure is directed to the method of aspect 113, 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 115, the present disclosure is directed to the method of any one of aspects 3-114, 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 116, the present disclosure is directed to the method of any one of aspects 3-115, wherein the optional step of stabilizing comprises stabilizing at the fifth pressure of about atmospheric pressure. 
     In accordance with Aspect 117, the present disclosure is directed to the method of any one of aspects 3-116, 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 118, the present disclosure is directed to the method of any one of aspects 3-117, 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 119, the present disclosure is directed to the method of any one of aspects 3-118, 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 120, the present disclosure is directed to the method of any 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 121, the present disclosure is directed to the method of aspect 120, 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 122, 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 123, the present disclosure is directed to the method of aspect 122, wherein, 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 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 124, the present disclosure is directed to the method of aspects 122 or 123, wherein the article is a layered sheet, the steps of subjecting and expanding foam at least one layer of the sheet, and following the subjecting and expanding, a thickness of the foamed layered sheet is at least 5 percent greater, or at least 10 percent greater, or at least 15 percent greater, or at least 20 percent greater than a thickness of the layered sheet in its unfoamed state. 
     In accordance with Aspect 125, the present disclosure is directed to the method of any one of aspects 122-124, wherein the method includes the step of stabilizing, and, following the stabilizing, the stabilized foam 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 126, the present disclosure is directed to the method of any one of the preceding aspects, further comprising thermoforming the foamed article, optionally wherein the foamed article is a stabilized foamed article. 
     In accordance with Aspect 127, 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 128, the present disclosure is directed to the method of any one of the preceding aspects, wherein the foamed article is a component of an article of apparel, footwear, or sporting equipment. 
     In accordance with Aspect 129, 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 a foamed article made by the method of any one of aspects 1-128. 
     In accordance with Aspect 130, the present disclosure is directed to the method of aspect 129, 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 131, the present disclosure is directed to the method of aspect 129, 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 132, the present disclosure is directed to the method of aspect 131, wherein the first component is a cushioning element, and the second element is a sole component or an upper component. 
     In accordance with Aspect 133, the present disclosure is directed to the method of aspect 129, 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 134, the present disclosure is directed to a foamed article made by the method of any of aspects 1-133. 
     In accordance with Aspect 135, the present disclosure is directed to 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 accordance with Aspect 136, the present disclosure is directed to the foamed article of aspect 135, wherein 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 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 foamed article. 
     In accordance with Aspect 137, the present disclosure is directed to the foamed article of aspect 135 or 136, wherein the foamed article is a stabilized 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 138, the present disclosure is directed to the foamed article of any one of aspects 135-137, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 2000 pounds per square inch (13,790 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 139, the present disclosure is directed to the foamed article of any one of aspects 135-138, wherein the foamed material of the foamed article is substantially opaque. 
     In accordance with Aspect 140, the present disclosure is directed to the foamed article of any one of aspects 135-139, 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 141, the present disclosure is directed to the foamed article of any one of aspects 135-140, wherein the foamed material has an Asker C hardness of from about 40 to about 50. 
     In accordance with Aspect 142, the present disclosure is directed to the foamed article of any one of aspects 135-141, 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 143, the present disclosure is directed to the foamed article of any one of aspects 135-142, 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 144, the present disclosure is directed to the foamed article of any one of aspects 135-143, 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 145, the present disclosure is directed to the foamed article of any one of aspects 135-144, wherein the one or more first thermoplastic elastomers comprise or consist essentially of polyether block polyamide (PEBA) copolymer elastomers. 
     In accordance with Aspect 146, the present disclosure is directed to the foamed article of any one of aspects 135-145, 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 147, the present disclosure is directed to the foamed article of any one of aspects 135-146, 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 148, the present disclosure is directed to the foamed article of any one of aspects 135-147, 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 149, the present disclosure is directed to the foamed article of any one of aspects 135-148, 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 150, the present disclosure is directed to the foamed article of any one of aspects 135-149, wherein the one or more first thermoplastic elastomers comprises or consists essentially of one or more thermoplastic polyester-polyurethane elastomers. 
     In accordance with Aspect 151, the present disclosure is directed to the foamed article of any one of aspects 135-150, wherein the polymeric component of the thermoplastic elastomeric material consists of one or more thermoplastic polyester-polyurethane elastomers. 
     In accordance with Aspect 152, the present disclosure is directed to the foamed article of any one of aspects 135-141, 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 153, the present disclosure is directed to the foamed article of any one of aspects 135-152, 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 154, the present disclosure is directed to the foamed article of any one of aspects 135-153, wherein the one or more first thermoplastic elastomers comprises or consists essentially of thermoplastic elastomeric ethylene-vinyl acetate copolymers. 
     In accordance with Aspect 155, the present disclosure is directed to the foamed article of aspect 154, wherein the thermoplastic elastomeric ethylene-vinyl acetate copolymers include from about 25 to about 50 weight percent vinyl acetate content. 
     In accordance with Aspect 156, the present disclosure is directed to the foamed article of any one of aspects 135-155, 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 157, the present disclosure is directed to the foamed article of any one of aspects 135-156, wherein the one or more first thermoplastic elastomers comprises or consists essentially of one or more recycled first thermoplastic elastomers. 
     In accordance with Aspect 158, the present disclosure is directed to the foamed article of any one of aspects 135-157, 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 159, the present disclosure is directed to the foamed article of aspect 158, 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 160, the present disclosure is directed to the foamed article of aspect 158 or 159, 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 161, the present disclosure is directed to the foamed article of any one of aspects 158-160, 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 162, the present disclosure is directed to the foamed article of any one of aspects 158-161, wherein the one or more second thermoplastics comprise or consist essentially of one or more thermoplastic polyethylene copolymers. 
     In accordance with Aspect 163, the present disclosure is directed to the foamed article of any one of aspects 158-162, wherein the one or more second thermoplastics comprise or consist essentially of one or more thermoplastic ethylene-vinyl alcohol copolymers. 
     In accordance with Aspect 164, the present disclosure is directed to the foamed article of any one of aspects 158-163, 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 165, the present disclosure is directed to the foamed article of any one of aspects 158-164, 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 166, the present disclosure is directed to the foamed article of any one of aspects 158-165 wherein the blend comprises one or more recycled first thermoplastic elastomers, or one or more recycled second thermoplastics, or both. 
     In accordance with Aspect 167, the present disclosure is directed to the foamed article of any one of aspects 158-166, 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 168, the present disclosure is directed to the foamed article of aspect 167, 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 169, the present disclosure is directed to the foamed article of any one of aspects 158-168, 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 170, the present disclosure is directed to the foamed article of any of aspects 158-169, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 2000 pounds per square inch (13,790 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 171, the present disclosure is directed to the foamed article of any one of aspects 135-170, 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 172, the present disclosure is directed to the foamed article of any one of aspects 135-171, 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 173, the present disclosure is directed to the foamed article of aspect 171 or 172, 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 174, the present disclosure is directed to the foamed article of any of aspects 171-173, wherein the additional material comprises a plasticizer. 
     In accordance with Aspect 175, the present disclosure is directed to the foamed article of aspect 173 or 174, wherein, in the foamed article, the additional material is substantially unfoamed. 
     In accordance with Aspect 176, the present disclosure is directed to the foamed article of any of aspects 173-175, 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 177, the present disclosure is directed to the foamed article of any one of aspects 173-176, 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 178, the present disclosure is directed to the foamed article of any one of aspects 173-177, 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 179, the present disclosure is directed to the foamed article of any one of aspects 173-178, 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 180, the present disclosure is directed to the foamed article of any one of aspects 173-179, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 2000 pounds per square inch (13,790 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 181, the present disclosure is directed to the foamed article of aspect 180, 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 2000 pounds per square inch (13,790 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 182, the present disclosure is directed to the foamed article of any one of aspects 173-181, 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 183, the present disclosure is directed to the foamed article of any one of aspects 174-182, wherein the additional material is a thermoplastic material, optionally wherein the additional material is an additional thermoplastic elastomeric material. 
     In accordance with Aspect 184, the present disclosure is directed to the foamed article of any one of aspects 174-183, 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 185, the present disclosure is directed to the foamed article of aspect 184, 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 186, the present disclosure is directed to the foamed article of any one of aspects 184 or 185, wherein the second foamed material is a second physically-expanded foam. 
     In accordance with Aspect 187, the present disclosure is directed to the foamed article of any one of aspects 184-186, 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 188, the present disclosure is directed to the foamed article of any one of aspects 174-187, 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 189, the present disclosure is directed to the foamed article of aspect 188, 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 135-188. 
     In accordance with Aspect 190, the present disclosure is directed to the foamed article of aspect 188 or 189, 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 135-189. 
     In accordance with Aspect 191, the present disclosure is directed to the foamed article of aspect 190, 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 192, the present disclosure is directed to the foamed article of aspect 190 or 191, 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 193, the present disclosure is directed to the foamed article of any of aspects 190-192, 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 194, the present disclosure is directed to the foamed article of any one of aspects 188-193, 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 195, the present disclosure is directed to the foamed article of any one of aspects 188-194, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 2000 pounds per square inch (13,790 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 196, the present disclosure is directed to the foamed article of any of aspects 188-195, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 2000 pounds per square inch (13,790 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 197, the present disclosure is directed to the foamed article of any of aspects 188-196, wherein, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 2000 pounds per square inch (13,790 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 198, the present disclosure is directed to the foamed article of any one of aspects 188-197, 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 according to any one of aspects 135-197. 
     In accordance with Aspect 199, the present disclosure is directed to the foamed article of any one of aspects 188-197, wherein the recycled material comprises a solid material, wherein the solid material is a thermoplastic elastomeric material. 
     In accordance with Aspect 200, the present disclosure is directed to the foamed article of any of aspects 188-199, 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 201, the present disclosure is directed to the foamed article of any of aspects 192-200, wherein the recycled material includes one or more nucleating agents or one or more interfaces between phase-separated polymers. 
     In accordance with Aspect 202, the present disclosure is directed to the foamed article of any one of aspects 188-201, 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 203, the present disclosure is directed to the foamed article of any one of aspects 188-201, 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 204, the present disclosure is directed to the foamed article of any one of aspects 135-203, 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 205, the present disclosure is directed to the foamed article of aspect 204, wherein the barrier material is an additional material according to any one of aspects 171-201. 
     In accordance with Aspect 206, the present disclosure is directed to the foamed article of any one of aspects 135-205, 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 207, the present disclosure is directed to the foamed article of aspect 206, wherein the structural material is an additional material according to any one of aspects 171-201, 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 208, the present disclosure is directed to the foamed article of any one of aspects 135-207, 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 the aspects 135-207, optionally wherein the thermoplastic elastomeric material is a recycled material. 
     In accordance with Aspect 209, the present disclosure is directed to the foamed article of any one of aspects 135-208, 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 135-207, optionally wherein the solid foamable material is a recycled material. 
     In accordance with Aspect 210, the present disclosure is directed to the foamed article of any one of aspects 135-209, wherein the foamed material has a density of from about 0.01 gram per cubic centimeter to about 0.1 gram 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 0.1 gram per cubic centimeter. 
     In accordance with Aspect 211, the present disclosure is directed to the foamed article of any one of aspects 135-210, 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 212, the present disclosure is directed to the foamed article of any one of aspects 135-210, 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 213, the present disclosure is directed to the foamed article of any one of aspects 135-212, 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 214, the present disclosure is directed to the foamed article of any one of aspects 135-213, 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 215, the present disclosure is directed to the foamed article of any one of aspects 135-214, wherein the article is a layered sheet including one or more one foamed layers. 
     Aspect 216, 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 a foamed article according to any one of aspects 135-217. 
     In accordance with Aspect 217, the present disclosure is directed to a foamed article made by the method of any one of aspects 135-215, optionally wherein the foamed article is a foamed article according to any one of aspects 135-217. 
     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. 
     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 2000 pounds per square inch (about 13,790 kilopascals). In another aspect, the first pressure is from about 15 pounds per square inch (103.4 kilopascals) to about 1500 pounds per square inch (10,342 kilopascals), optionally about 100 pounds per square inch (689.5 kilopascals) to about 1200 pounds per square inch (8274 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 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 0.1 gram per cubic centimeter, optionally of from about 0.01 gram per cubic centimeter to about 0.05 grams per cubic centimeter, of from about 0.01 gram per cubic centimeter to about 0.025 grams per cubic centimeter, or of from about 0.05 grams per cubic centimeter to about 0.1 gram 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. 
     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 2000 pounds per square inch (about 13,790 kilopascals), optionally about 15 pounds per square inch (103.4 kilopascals) to about 1500 pounds per square inch (10,342 kilopascals), or about 100 pounds per square inch (689.5 kilopascals) to about 1200 pounds per square inch (8274 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 40 to about 50, or of from about 45 to 50, from about 48 to 50, from about 40 to 45, or from about 40 to 42, as measured using the Asker C Hardness Test Protocol. 
     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 0.1 gram per cubic centimeter, optionally of from about 0.01 gram per cubic centimeter to about 0.05 grams per cubic centimeter, of from about 0.01 gram per cubic centimeter to about 0.025 grams per cubic centimeter, or of from about 0.05 grams per cubic centimeter to about 0.1 gram per cubic centimeter. Optionally, in this aspect, in the stabilized foamed article, the foamed material has a density of from about 0.01 gram per cubic centimeter to about 0.1 gram 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 a 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 a 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 40 to about 50, optionally of about 40 to about 47, about 40 to about 47, about 40 to about 43, about 43 to about 50, about 45 to about 50, or about 47 to about 50, 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, one or more thermoplastic polyolefin homopolymers or copolymers, one or more thermoplastic polyolefin copolymers, or one or more thermoplastic polyethylene copolymers, or one or more thermoplastic ethylene-vinyl alcohol copolymers, or 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, one or more thermoplastic polyolefin homopolymers or copolymers, one or more thermoplastic polyolefin copolymers, or 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 another aspect, at a first pressure of from about 0.05 pounds per square inch (0.345 kilopascals) to about 2000 pounds per square inch (13,790 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 2000 pounds per square inch (13,790 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 2000 pounds per square inch (13,790 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 2000 pounds per square inch (13,790 kilopascals), optionally about 15 pounds per square inch (103.4 kilopascals) to about 1500 pounds per square inch (10,342 kilopascals), or about 100 pounds per square inch (689.5 kilopascals) to about 1200 pounds per square inch (8274 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 2000 pounds per square inch (13,790 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 2000 pounds per square inch (about 13,790 kilopascals), optionally from about 15 pounds per square inch (103.4 kilopascals) to about 1500 pounds per square inch (10,342 kilopascals), optionally about 100 pounds per square inch (689.5 kilopascals) to about 1200 pounds per square inch (8274 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. 
     Exemplary Aspects of Articles of Footwear, Articles of Apparel, and Articles of Sporting Equipment 
       FIGS. 1A-1M  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. 1N (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. 1O (a)- 1 O(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. 1O (c) is a cross-sectional view of A-A that depicts the upper  132  and the heel component  144 . 
       FIGS. 1P (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. 1P (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. 1Q (a)- 1 Q(e) illustrate additional views of exemplary articles of athletic footwear including various configurations of upper  176 .  FIG. 1Q (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. 1Q (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. 1Q (c) is a back view of the article of footwear depicted in  FIG. 1Q (b), showing heel clip  184 .  FIG. 1Q (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. 1Q (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 2000 pounds per square inch (13,790 kilopascals), optionally about 15 pounds per square inch (103.4 kilopascals) to about 1500 pounds per square inch (10,342 kilopascals), or about 100 pounds per square inch (689.5 kilopascals) to about 1200 pounds per square inch (8274 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 
               . 
             
             = 
             
               
                 Weight 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 of 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 the 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 sample 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 in 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 air 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   ( 
                   g 
                   ) 
                 
               
               
                 
                   
                     
                       
                         Weight 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         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. 
     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. 
     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. 8A-8F  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. 8A  shows an exemplary sheet prior to undergoing a foaming process as described herein, while  FIG. 8B  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. 8C  shows another exemplary sheet prior to undergoing a foaming process as described herein, while  FIG. 8D  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. 8E  shows another exemplary sheet prior to undergoing a foaming process as described herein, while  FIG. 8F  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. 8A-8F  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 
                 25 
                 25 
               
               
                 Temperature (degrees Celsius) 
               
               
                 Carbon Dioxide Infusion Pressure 
                 1500 
                 1500 
               
               
                 (pounds per square inch) 
               
               
                 Carbon Dioxide Infusion Time 
                 1 
                 1 
               
               
                 (hours) 
               
               
                 Water Bath Temperature 
                 40 
                 60 
               
               
                 (degrees Celsius) 
               
               
                 Water Bath Time (minutes) 
                 1 
                 1 
               
               
                 Oven Temperature (degrees Celsius) 
                 50 
                 50 
               
               
                 Oven Time (minutes) 
                 30 
                 30 
               
               
                 Shrinkage of EVOH Layer Due to 
                 &lt;3 
                 &lt;4 
               
               
                 Stretching (micrometers) 
               
               
                 Increase in Thickness of 
                 26 (&lt;5 percent) 
                 69 (&lt;13 percent) 
               
               
                 Thermoplastic Polyurethane 
               
               
                 Layers Due to Foaming 
               
               
                 (micrometers) 
               
               
                   
               
            
           
         
       
     
     Foaming Selected Portions of the Articles.  FIGS. 9A-9K  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. 9A-9C . In this scenario, as shown in  FIG. 9A , 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. 9B  shows a cross section of the solid foamable material  620  of foamable article  608  of  FIG. 9A  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. 9C  shows a cross section of the same region of article  608  as shown in  FIG. 9B  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. 9B )  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. 9D-9G . In this second scenario, as illustrated in in  FIG. 12D , 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. 9E .  FIG. 9F  shows a cross section of the foamable article  608  of  FIGS. 9D-9E  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. 9G  shows a cross section of the same region of article  608  from  FIGS. 9D-9F  after the step of expanding has been carried out, and the infused portion of the solid foamable material ( 620   b  in  FIG. 9F ) 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. 91I-9K . In this third scenario, as illustrated in  FIG. 91I , 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. 9I .  FIG. 9J  shows a cross section of the foamable article  608  of  FIGS. 9H-9I  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. 9K  shows a cross section of the same region of article  608  as  FIGS. 9H-9J  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. 9K . 
     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.