Patent Publication Number: US-2021161252-A1

Title: Article with at least two layers

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/164,466, filed Oct. 18, 2018, which claims the benefit of U.S. Provisional Patent Application No. 62/574,510, filed Oct. 19, 2017. All applications listed in this paragraph are hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     A variety of articles are formed with textiles. As examples, articles of apparel (e.g., shirts, pants, socks, footwear, jackets and other outerwear, briefs and other undergarments, hats and other headwear), containers (e.g., backpacks, bags), and upholstery for furniture (e.g., chairs, couches, car seats) are often at least partially formed with textiles. These textiles are often formed by weaving or interlooping (e.g., knitting) a yarn or a plurality of yarns, usually through a mechanical process involving looms or knitting machines. One particular object that may be formed from a textile is an upper for an article of footwear. 
     Conventional articles of footwear generally include two primary elements: an upper and a sole structure. The upper is typically secured to the sole structure and forms a void within the article of footwear for comfortably and securely receiving a foot. The sole structure is typically secured to a lower surface of the upper so as to be positioned between the upper and the ground. In some articles of athletic footwear, for example, the sole structure may include a midsole and an outsole. The midsole may be formed from a polymer foam material that attenuates ground reaction forces to lessen stresses upon the foot and leg during walking, running, and other ambulatory activities. The outsole may be secured to a lower surface of the midsole and forms a ground-engaging portion of the sole structure that is formed from a durable and wear-resistant material. 
     The upper of the article of footwear generally extends over the instep and toe areas of the foot, along the medial and lateral sides of the foot, and around the heel area of the foot. Access to the void on the interior of the upper is generally provided by an ankle opening in a heel area of the footwear. A lacing system is often incorporated into the upper to adjust the fit of the upper, thereby facilitating entry and removal of the foot from the void within the upper. In addition, the upper may include a tongue that extends under the lacing system to enhance adjustability of the footwear. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an article of footwear with an upper formed with a first knit layer, a second knit layer, and a third layer therebetween in accordance with the present disclosure. 
         FIG. 2  shows a first knit layer of the upper shown in  FIG. 1  when located on a jig, where the first knit layer is formed of a knitted component in accordance with the present disclosure. 
         FIG. 3  shows the first knit layer of  FIG. 2  when engaged with a support member. 
         FIG. 4  shows the first knit layer and the support member of  FIG. 3 , where the support member is secured on a lateral side and a medial side of the inner layer in accordance with the present disclosure. 
         FIG. 5  shows the first knit layer and the support member of  FIGS. 3-4 , where the support member is additionally secured in a toe area of the upper in accordance with the present disclosure. 
         FIG. 6  shows the upper of  FIGS. 1-5  further including a third layer formed of a non-knit material in accordance with the present disclosure. 
         FIG. 7  shows the upper of  FIGS. 1-6  further including an auxiliary component and a set of tensile strands in accordance with the present disclosure. 
         FIG. 8  shows the upper of  FIGS. 1-7 , further including a second knit layer formed of a knitted component in accordance with the present disclosure. 
         FIG. 9  shows the upper of  FIGS. 1-8 , where the second knit layer substantially covers the other layers and components from an outside perspective in accordance with the present disclosure. 
         FIG. 10  shows the upper of  FIGS. 1-9  as it may appear when being removed from a jig in accordance with the present disclosure. 
         FIG. 11  shows several auxiliary components that may be included in an upper in accordance with the present disclosure. 
         FIG. 12  shows the several auxiliary components of  FIG. 11  included in an upper in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Various aspects are described below with reference to the drawings in which like elements generally are identified by like numerals. The relationship and functioning of the various elements of the aspects may better be understood by reference to the following detailed description. However, aspects are not limited to those illustrated in the drawings or explicitly described below. It also should be understood that the drawings are not necessarily to scale, and in certain instances details may have been omitted that are not necessary for an understanding of aspects disclosed herein, such as conventional fabrication and assembly. 
     Certain aspects of the present disclosure relate to articles at least partially formed from textiles. One example of an article is an article of apparel (e.g., shirts, pants, socks, footwear, jackets and other outerwear, briefs and other undergarments, hats and other headwear, or the like). The article may be an upper configured for use in an article of footwear. The upper may be used in connection with any type of footwear. Illustrative, non-limiting examples of articles of footwear include a basketball shoe, a biking shoe, a cross-training shoe, a global football (soccer) shoe, an American football shoe, a bowling shoe, a golf shoe, a hiking shoe, a ski or snowboarding boot, a tennis shoe, a running shoe, and a walking shoe. The upper may also be incorporated into a non-athletic shoe, such as a dress shoe, a loafer, and a sandal. 
     In one aspect, an upper for an article of footwear may include a first knit layer, a second knit layer, and a third layer located between the first knit layer and the second knit layer, the third layer including a material with a melting point of 150° C. or less, where the first knit layer and the second knit layer are secured via the material of the third layer. A first zone may be included, where the first knit layer, the second knit layer, and the third layer are coextensive in the first zone. A second zone may be included, where the first knit layer, the second knit layer, and the third layer are coextensive in the second zone, and where less of the material of the third layer, by mass per unit surface area, is located in the second zone than in the first zone. The first zone may have a first stretch resistance and the second zone may have a second stretch resistance, where the first stretch resistance is greater than the second stretch resistance. 
     In this and/or another aspect, an upper for an article of footwear may include a first knit layer, a second knit layer, and a third layer located between the first knit layer and the second knit layer, the third layer including a material with a melting point of 150° C. or less. A support member may be located between the first knit layer and the second knit layer, where the first knit layer, the second knit layer, the third layer, and the support member are coextensive at least in a first zone of the upper, where at least one of the first knit layer and the second knit layer are secured to the support member via the material of the third layer, and where the support member extends across a throat area of the upper. 
     In this and/or another aspect, an upper for an article of footwear may include a first knit layer, a second knit layer, and a third layer located between the first knit layer and the second knit layer. The third layer may have a first porous structure in at least a first zone with a first set of apertures for providing the first zone with a first stretch resistance, where the third layer includes a second porous structure in at least a second zone with a second set of apertures for providing the second zone with a second stretch resistance, and where the first stretch resistance is at least 10% greater than the second stretch resistance. 
     In this and/or another aspect, a method for forming an upper for an article of footwear may include one or more of the following steps: forming a first knit layer, forming a second knit layer, placing a third layer in contact with the first knit layer, where the third layer includes a material with a melting point of 150° C. or less, placing the second knit layer in contact with the third layer such that the third layer is located between the first knit layer and the second knit layer, and heat-processing the material of the third layer to secure the third layer to the first knit layer via the material of the third layer. 
     Referring to  FIG. 1 , an article of footwear  100  is generally depicted as including an upper  102  secured to a sole structure  104 . The upper  102  may include a lateral side  106  and a medial side  108 . The area of the shoe where the sole structure  104  joins the upper  102  may be referred to as the biteline  110 . The upper  102  may be joined to the sole structure  104  in a fixed manner using any suitable technique, such as through the use of an adhesive, by sewing, etc. It is contemplated that the upper  102  may extend partially or completely around the foot of a wearer and/or may be integral with the sole. 
     In some embodiments, the sole structure  104  includes a midsole (not shown) and an outsole. The article of footwear  100  may additionally include a throat area  112  and an ankle opening  114 , which may be surrounded by a collar  116  and may lead to a void (not shown). The void of the article of footwear  100  may be configured to accommodate a foot of a person. The throat area  112  is generally disposed in the mid-foot area  118  of the upper  102 . The mid-foot area  118  is generally an area of the upper  102  located between a heel area  120  and a toe area  122 . 
     A tongue may be disposed in the throat area  112  of the shoe, but a tongue is an optional component. The tongue may be any type of tongue, such as a gusseted tongue or a burrito tongue. If a tongue is not included, the lateral and medial sides of the throat area  112  may be joined together. In some embodiments, the article of footwear  100  may include an optional fastening element, such as a lace (which may be associated with lace apertures). Any suitable type of fastening element may be used. 
     At least a portion of the upper  102 , and in some embodiments substantially the entirety of the upper  102 , may be formed of a knitted component  124 . The knitted component  124  may additionally or alternatively form another element of the article of footwear  100 , such as an underfoot portion, for example. The knitted component  124  may have a first side facing the void of the article of footwear  100  and a second opposite facing side, which may form an outer surface  128 . The first side and the second side of the knitted component  124  may exhibit different characteristics (e.g., the first side may provide abrasion resistance and comfort while the second side may be relatively rigid and provide water resistance). The knitted component  124  may be formed as an integral one-piece element during a knitting process, such as a weft knitting process (e.g., with a flat knitting machine or circular knitting machine), a warp knitting process, or any other suitable knitting process. That is, the knitting process may substantially form the knit structure of the knitted component  124  without the need for significant post-knitting processes or steps. Alternatively, two or more portions of the knitted component  124  may be formed separately as distinct integral one-piece elements and then the respective elements attached. In some embodiments, the knitted component  124  may be shaped after the knitting process to form and retain the desired shape of the upper  102  (for example, by using a foot-shaped last or jig). The shaping process may include attaching the knitted component  124  to another object (e.g., a strobel) prior to lasting. However, the present embodiments may advantageously eliminate the necessity of using a strobel. 
     Forming the upper  102  with the knitted component  124  may provide the upper  102  with advantageous characteristics including, but not limited to, a particular degree of elasticity (for example, as expressed in terms of Young&#39;s modulus), breathability, bendability, strength, moisture absorption, weight, and abrasion resistance. These characteristics may be accomplished by selecting a particular single layer or multi-layer knit structure, by varying the size and tension of the knit structure, by using one or more yarns formed of a particular of different materials (e.g., a polyester material, a relatively inelastic material, and/or a relatively elastic material such as spandex), by selecting yarns of particular sizes (e.g., denier), or a combination thereof. The knitted component  124  may also provide desirable aesthetic characteristics by incorporating yarns having different colors, textures or other visual properties arranged in a particular pattern. The yarns themselves and/or the knit structure formed by one or more of the yarns of the knitted component  124  may be varied at different locations such that the knitted component  124  has two or more portions with different properties (e.g., a portion forming the throat area of the upper  102  may be relatively elastic while another portion may be relatively inelastic). In some embodiments, the knitted component  124  may incorporate one or more materials with properties that change in response to a stimulus (e.g., temperature, moisture, electrical current, magnetic field, or light). For example, the knitted component  124  may include yarns formed of a thermoplastic polymer material (e.g., polyurethanes, polyamides, polyolefins, and nylons) that transitions from a solid state to a softened or liquid state when subjected to certain temperatures at or above its melting point and then transitions back to the solid state when cooled. The thermoplastic polymer material may provide the ability to heat and then cool a portion of the knitted component  124  to thereby form an area of bonded or continuous material that exhibits certain advantageous properties including a relatively high degree of rigidity, strength, and/or water resistance, for example. 
     As shown in  FIG. 1 , at least a portion of the external surface of the upper  102  may be formed with the knitted component  124 , which may define an outer knit layer (herein referred to as a first knit layer  130 ) with an outer surface  128  at least partially forming the external surface of the upper  102 . As described in more detail below (but not depicted in  FIG. 1 ), a second knit layer  132  may form an inner surface facing the void of the article of footwear and a third layer  134  (which may be non-knit) may be located between the first knit layer  130  and the second knit layer  132 . 
     More or less than three layers may be included. For example, another layer may be provided by the depicted surface element  126 , which may cover a portion of the knitted component  124  such that it forms at least a portion of the external surface of the upper. The surface element  126  may be formed of any suitable material. For example, the surface element  126  may be formed of a water resistant (e.g., waterproof) material to enhance the overall water resistance of the upper at least at some locations (but while also allowing sufficient breathability certain locations, for example). The surface element  126  may also advantageously cover the knitted component  124  at locations that typically experience contact with external elements during normal use. This may protect the knitted component  124  from damage due to abrasion, which may increase the overall durability of the article of footwear. Thus, when included, the surface element  126  may be formed with a material that is relatively durable with respect to the knitted component  124 . In one non-limiting exemplary embodiment, the surface element may be a skin or film formed of a thermoplastic polyurethane, which may be applied to the knitted component  124  after formation of the knitted component  124  on a knitting machine. 
       FIG. 2  illustrates an example of a last or jig  136 , which may be used during the manufacturing of the upper  102 . The jig  136  may have a foot-shaped profile and may be substantially flat with two opposite-facing parallel surfaces. In other embodiments, the jig  136  may be substantially foot-shaped in three dimensions. Some examples of suitable jigs and suitable jig characteristics are described in U.S. Patent Application Publication No. 2015/0282564 to Meschter et al., which is herein incorporated by reference in its entirety. 
     As shown in  FIG. 2 , the first knit layer  130  (which may be the outer-most knit layer of the upper  102  depicted in  FIG. 1 ) may be the first component placed on the jig  136 . The first knit layer  130  may be relatively elastic and compliant to substantially retain the shape of the jig  136 . The elasticity and compliance may be achieved by the particular knit structure used to form the first knit layer  130 , the types of yarns used, or a combination thereof. It is also contemplated that different portions of the first knit layer  130  may have different knit structures and/or different yarns such that the elasticity (and/or other characteristics) of the first knit layer  130  varies among different areas. 
     The first knit layer  130  may be inside-out when on the jig  136 . That is, with reference to  FIG. 2 , the outer surface  128  (which is configured to face externally in a completed article of footwear as shown in  FIG. 1 ) may face inward towards the jig  136 , and an opposite second surface  138 , which may face inward in a completed article of footwear, may initially face outward on the jig  136 . Advantageously, this inside-out orientation on the jig  136  may allow for efficient securement of certain elements to an inward-facing surface while preserving the aesthetics of the outer surface  128 . However, an inside-out orientation on the jig  136  is not required in all embodiments. 
     The first knit layer  130  may be manufactured by any suitable knitting process. For example, the first knit layer  130  may be formed on a flat knitting machine or a circular knitting machine. Optionally, a first end  140  forming a toe area may be closed (e.g., closed by a sewn seam), and a second end  142  forming a throat/ankle area may be open to define and ankle opening and to allow access to a void. The jig  136  may be inserted through the opening of the second end  142  after the first knit layer  130  is formed and removed from the knitting machine. 
     As shown, the first knit layer  130  may be configured to extend substantially around the entirety of the foot, and as such may include an underfoot portion  144  associated with a surface of a plantar aspect of the foot (also known as the sole or bottom of a foot). The first knit layer may also include an overfoot portion  146  associated with the remainder of the foot, including the dorsal surface (i.e., the top of the foot). The underfoot portion  144  may extend from a lateral side  106  of the upper  102  to a medial side  108  of the upper and from the heel area  120  to the toe area  122 . The underfoot portion  144  may be configured to attach to a sole structure  104  using any suitable technique, such as through the use of an adhesive, by sewing, bonding, welding, etc. 
     Referring to  FIG. 3 , in some embodiments, additional components (which may be knitted components, or not) may be engaged with the second surface  138  of the first knit layer  130  to provide the upper  102  with a suitable degree of strength, rigidity, support, and/or other characteristics. For example,  FIG. 3  depicts a support member  148  that may engage the second surface  138  of the first knit layer  130 . The support member  148  may be formed of a rubber, a plastic, a metal, and/or any other suitable material to provide suitable structural characteristics at least at select locations. As shown, the support member  148  may extend from a heel region to a throat area, and/or from the throat area to the toe area on at least one of the medial side  108  and the lateral side  106  of the upper  102 . It is also contemplated that the support member  148  may be configured to provide certain areas with increased water resistance with respect to uncovered areas. 
     The support member  148  may have different areas with different structures or constructions. For example, referring to  FIG. 3 , a first area  150  of the support member  148  may be defined by a structure that is relatively dense and/or nonporous. With respect to other areas, the first area  150  may exhibit a relatively high degree of strength, rigidity, water resistance, etc. It may be advantageous to form the support member  148  such that the first area  150  is aligned with certain areas of the upper  102  that typically experience deformation, abrasion, contact with water or another liquid, etc. 
     A second area  152  may have a structure or construction that is less dense and/or more porous (e.g., having larger apertures  156  (also called “pores” herein) and/or more apertures per unit area) with respect to the first area  150 . The second area  152  may be relatively light, breathable, flexible, and/or elastic with respect to the first area  150 . Thus, the second area  152  may be located in areas of the upper  102  where low weight, flexibility, and/or elasticity (or other characteristics) are desired, and/or where there is less need for strength, durability, rigidity, or other characteristics more associated with the first area  150 . 
     Similarly, a third area  154  may have a structure or construction different than the construction of the first area  150  and/or the second area  152 . In  FIG. 3 , the third area  154  has more and larger apertures  156  with respect to the second area  152 , and thus may exhibit respectively greater degrees of characteristics associated with a highly-porous and/or low-density structure. While only three areas with different structures are described, more or less than three may be included. Further, while the differences in structure between the first area  150 , the second area  152 , and the third area  154  are primarily depicted and described as differences in density or porosity, other differences may additionally or alternatively be included. For example, the first area  150  could have a first thickness and/or density of a material and the second area  152  and third area  154  may have respectively decreasing thicknesses and/or densities. As another example, the first area  150  could be constructed of a first material and the second area  152  and third area  154  may be constructed of one or more different materials. 
       FIGS. 4-5  show the support member  148  being placed on and wrapped around the second surface  138  of the first knit layer  130 . While it is contemplated that the support member  148  may remain moveable/slidable with respect to the first knit layer  130  when incorporated into an article of footwear, it may be secured in a relatively fixed manner to the second surface  138  of the first knit layer  130  in some exemplary embodiments. The support member  148  may be secured to the second surface  138  through any suitable securement device or method. For example, the support member  148  may be formed of a thermoplastic polymer material that at least partially melts when heated to a particular temperature and then hardens to a solid state when cooled. In one particular embodiment, the support member  148  may include synthetic suede along with 100 micron NASA-T hot melt material sold by Sambu Fine Chemical. While the first knit layer  130  is on the jig  136 , the heated thermoplastic polymer material of the support member  148  may be placed into contact with the first knit layer  130  such the support member  148  bonds with the yarns of the first knit layer  130  once the thermoplastic polymer material is cooled to a solid state. Any suitable heating process is contemplated. For example, heat may be applied through the jig  136  (as described in detail in U.S. Patent Application Publication No. 2015/0282564, incorporated above), and/or a heat pressing process may be used as described in U.S. patent application Ser. No. 15/443,808 to Green et al. (filed Feb. 27, 2017, and not yet published), which is herein incorporated by reference in its entirety. 
     As shown in  FIG. 6 , another non-knit element or layer may be located adjacent to the second surface  138  and coextensive with the first knit layer  130 , such as the depicted third layer  134 . The third layer  134  may be formed with a thermoplastic polymer material having a melting point between about 80° C. and about 200° C., such as about 150° C. or less, and more particularly about 120° C. in certain non-limiting exemplary embodiments. When the third layer  134  is formed of a thermoplastic polymer material, it may have a melting point different than a melting point or decomposition point of other components that are also meltable (such as the support member  148 , for example). In some embodiments, the third layer  134  may be at least partially formed with a 50 micron NASA-T hot melt material sold by Sambu Fine Chemical. The third layer  134  may be advantageous for reasons similar to those described above with respect to the support member  148 . For example, the third layer  134  may provide increased strength, durability, water resistance, etc., while also providing suitable elasticity, flexibility, breathability, etc. 
     The third layer  134  may be engaged (e.g., secured in a fixed manner or otherwise engaged) with the second surface  138  of the first knit layer  130 . Any suitable device or method may be used to apply and engage the third layer  134  to the first knit layer  130 . For example, the third layer  134  may be laminated, sprayed, painted, etc., directly or indirectly on the second surface  138 . In some embodiments, the third layer  134  may be separately manufactured as a membrane and then placed into contact with the second surface  138  while the first knit layer  130  is on the jig  136 . The membrane may then be trimmed or otherwise treated as necessary to be properly sized with respect to the second surface  138 . A heat press may then engage the membrane to bond it to the second surface  138 . When the jig  136  is substantially flat with two opposite-facing planar surfaces, two separate membranes may be used (e.g., one on each opposite-facing planar surface corresponding respectively with the lateral and medial sides of the upper  102 ). 
     The support member  148  is not necessarily included in all embodiments. When the support member  148  is included, the third layer  134  may be located between the support member  148  and the second surface  138  of the first knit layer  130  or alternatively the support member  148  may be located between the third layer  134  and the second surface  138  of the first knit layer  130 . In one particular embodiment, the support member  148  may be placed in contact with the second surface  138  of the first knit layer  130  (but not yet permanently secured), and then a membrane forming the third layer  134  may be placed over the support member  148  and the first knit layer  130 . Then, a heat processing step may be performed to secure the three components together. For example, the membrane forming the third layer  134  may include a material with a melting point that is lower than a melting or decomposition temperature of the first knit layer  130  and the support member  148 . During the heat-processing step, certain areas may be heated to a temperature above the melting temperature of the third layer  134  (but potentially lower than a melting or decomposition temperature of the other components) such that the membrane at least partially melts to bond the first knit layer  130 , the support member  148 , and the third layer  134  together once cooled. In other embodiments, the melting point of the support member  148  may be the respective lowest. It is also contemplated that the first knit layer  130  may include yarns with a meltable material (e.g., a thermoplastic polyurethane) configured to facilitate bonding. 
     Similar to as described above with respect to the support member  148 , the third layer  134  may have different structures or constructions in different areas, which may provide the upper  102  with different properties in different zones (and herein, a “zone” refers to an area of the upper as a whole). For example, referring to  FIG. 6 , a first zone  160  may be included where the first knit layer  130  and the third layer  134  are coextensive. Similarly, a second zone  162  may be included where the first knit layer  130  and the third layer  134  are coextensive. The first zone  160  and the second zone  162  may have different properties resulting from differences in the structure or material of the third layer  134  at areas corresponding to different zones of the upper  102  (even when the structure of the first knit layer  130  is consistent). 
     To illustrate with reference to  FIG. 6 , in the first zone  160 , the third layer  134  may have a relatively low porosity (and may be substantially non-porous). The third layer  134  may be relatively porous at an area corresponding to the second zone  162 . Thus, since the third layer  134  may be relatively elastic, flexible, etc., in areas exhibiting a relatively high porosity, the first zone  160  may have a stretch resistance that is greater than a stretch resistance of the second zone  162  (e.g., such that it stretches at least 10% more, such as at least 20% more, and such as at least 30% more when subjected to the same test tensile force (e.g., on the same tensometer with a 5 pound test force)). Similarly, the first zone  160  may have a degree of rigidity, strength, etc., that is high with respect to the second zone  162 , and the second zone  162  may be relatively light, breathable, elastic, and/or flexible. Further, a third zone  164  may be included, where the third zone  164  is associated with an area of the third layer  134  having a greater porosity (e.g., with either more apertures per unit area and/or larger apertures) and thus exhibiting an even lesser degree of certain characteristics than the second zone  162 . More or less than three zones corresponding with different structures of the third layer  134  may be included. While differences of the structure of the third layer  134  are described primarily with respect to porosity, other differences may additionally or alternatively be included. For example, the third layer  134  may have different thicknesses, material densities, material properties, etc., in different respective areas. 
     A fourth zone  166  may be included where the first knit layer  130  remains uncovered by the third layer  134  and the support member  148  such that the fourth zone  166  is free of the third layer  134  and the support member  148 . At least one of the third layer  134  and the support member  148  may terminate adjacent to an edge  167  of the fourth zone. The fourth zone  166  may be relatively elastic and compliant relative to the above-described zones with the third layer  134  and/or the support member  148  since the elasticity of the first knit layer  130  alone may be greater than the elasticity of the first knit layer  130  combined (coextensively) with the above-described components. Further, when a second knit layer  132  is included (as described below), the first knit layer  130  and the second knit layer  132  may be unsecured to each other in the fourth zone  166  such that they are movable (e.g., slidable) relative to one another in that area, which may be advantageous for suitable comfort and/or for providing a pocket between the first knit layer  130  and the second knit layer  132  for receiving additional elements. 
     The first zone  160  and the second zone  162  described above may exclude the support member  148 , as shown. Other zones may include the support member  148 , and the properties of those other zones may differ based on differing structures of the support member  148 . For example, a fifth zone  170  may have a greater stretch resistance (e.g., at least 10% greater, such as at least 20% greater, and such as about 40% greater in some embodiments) than the first zone  160  and/or the second zone  162  due to the presence of the support member  148 . Multiple zones with different characteristics may include the support member  148 . Additionally or alternatively, different structures (e.g., knit structures or yarn properties) of the first knit layer  130  (and/or the second knit layer  132 , described below) in certain zones of the upper  102  may also create varying zonal properties. 
     Referring to  FIG. 7 , additional elements may be secured to the second surface  138  of the first knit layer  130  while the first knit layer  130  is on the jig  136 . For example, an auxiliary component  174  (also shown in  FIG. 6 ), which in the depicted embodiment is an elongated device with lace apertures  176 , may be substantially fixed with respect to the first knit layer  130 . The auxiliary component  174  may be secured via the material of the third layer  134  due to heat processing (as described above), but any other suitable securement device or method is additionally or alternatively contemplated. For example, the auxiliary device may be secured to the first knit layer  130  via an adhesive. 
     Tensile strands  178  may also be incorporated into the upper  102 , as shown. The tensile strands  178  may be attached to and/or may extend through the apertures  176  of the auxiliary component  174 . The tensile strands  178  may have a relatively fixed length and may communicate with a shoelace or another fastening element to provide rigidity and structure in the lateral-to-medial direction and to allow a user to sufficiently control the tightness and fit the upper  102  around the foot. In some embodiments, the tensile strands  178  may form at least one loop  180  (shown in  FIG. 1 ) configured to receive the lace, and the at least one loop  180  may extend outside the external surface of the upper  102 . The tensile strands  178  may extend beneath and around the underfoot portion  144  and from the medial side to the lateral side of the upper  102  such that a single length of a tensile strand  178  communicates with both sides of the throat area. In other embodiments, at least one of the tensile strands  178  may terminate under the foot, at a location adjacent to the biteline, or at another suitable location. 
     Referring to  FIG. 8 , the second knit layer  132  may be placed over the jig  136  (also in an inside-out fashion) with an inner surface  182  of the second knit layer  132  facing outwards. All of the characteristics and advantages associated with the first knit layer  130  described above may also be applicable to the second knit layer  132 . Once placed over the jig  136 , the second knit layer  132  may be coextensive with the first knit layer  130  and/or the third layer  134 . A second surface  184  of the second knit layer  132  may face the second surface  138  of first knit layer  130 . As shown, the third layer  134 , the support member  148 , the auxiliary component  174 , the tensile strands  178 , and/or any other components (like the additional ankle cushioning element  186 ) may be located between the first knit layer  130  and the second knit layer  132  once the second knit layer  132  is placed on the jig. Advantageously, the components between the two knit layers may be protected from outside elements and/or hidden from view. 
     The second knit layer  132  may, like the first knit layer  130 , be formed on a flat or circular knitting machine, but it is also contemplated that an alternative second layer may include a non-knitted material. Since the inner surface  182  of the second knit layer  132  may eventually be flipped inside out to form an inner surface facing a void of the upper  102 , the second knit layer  132  may include properties that are advantages for contact with a foot. For example, the second knit layer  132  may include particular yarns (e.g., yarns formed substantially of polyester) that are associated with softness, anti-abrasiveness, or other comfort-related characteristics. 
     Referring to  FIGS. 8-9 , while it is contemplated that the second knit layer  132  may remain movable (e.g., slidable) with respect to the first knit layer  130  and/or the third layer  134  at some locations, the second knit layer  132  may be secured to the first knit layer  130  and/or the third layer  134  in certain locations by any suitable securement device or method. For example, the second knit layer  132  may be sewn, adhered with an adhesive, taped, etc., to an inverted portion  188  of the first knit layer  130  in the ankle area  190 . In some embodiments, the securement at the inverted portion  188  may be temporary to hold the second knit layer  132  in place until further processing, but alternatively the securement may be substantially permanent. After the second knit layer  132  is placed over the other elements on the jig  136 , the upper  102  may go through another heat-processing step such that the material of the third layer  134  and/or the support member  148  secures to the second knit layer  132  (although at least some areas of the second knit layer  132  may remain unsecured). It is also contemplated that the first heat processing step described above may be skipped when only one heat processing step is necessary for bonding the knit layers (and components located therebetween). 
     As shown in  FIG. 10 , the upper  102  may be removed from the jig  136 , for example once some or all manufacturing steps associated with the jig  136  are completed. When, as described above, the first knit layer  130  and the second knit layer  132  are placed on the jig  136  in an inside-out fashion, removing the upper  102  from the jig  136  may include inverting the upper  102  such that it obtains the outside-out orientation that it is configured to embody when incorporated into a final article of footwear. For example, as shown in  FIG. 10 , removing the upper  102  from the jig  136  may include inverting a portion  192  of the upper  102  at the ankle area  190  and then pulling the portion  192  towards the toe area  122  such that the outer surface  128  of the first knit layer  130  becomes an external surface of the upper  102  and the inner surface  182  of the second knit layer  132  flips into its final orientation to face void of the upper  102 . Advantageously, this method of removing the upper  102  from the jig  136  may prevent sliding surfaces made of knitting material against the jig, which may reduce the probability of damage due to abrasion, for example. 
     Alternative ways of removing the upper  102  from the jig  136  are also contemplated. For example, the upper  102  may be pulled from the toe area  122  such that the upper  102  does not invert (which may be advantageous in embodiments where the second knit layer  132  is placed on the jig  136  first in an outside-out orientation). Additionally or alternatively, the jig  136  may have the capability of reducing its size through mechanical means such that it can transform from its depicted state to a compacted state where it is easily removed from the void of the upper  102 . Further, the inversion process, if required by the particular embodiment, does not necessarily need to occur during the removal of the upper  102  from the jig  136  but instead may happen after (or before in some embodiments) the upper  102  is removed from the jig  136 . 
       FIGS. 11-12  show a variety of auxiliary components that may be used in accordance with the present disclosure in addition to, or as an alternative to, the components described above. For example, a large support member  194  may be used and may extend over the throat area from the lateral side  106  of the upper  102  to the medial side of the upper  102  either between the above-described knit layers or at another location (e.g., on the external surface of the outer knit layer). The support member  194  may have openings  196  to provide access to the above-described lace apertures, for example. Similarly, a support member  198  may be located in the toe area of the upper  102 . The support members  194 ,  198  may include any suitable material and may be configured for a variety of particular functions, like providing suitable friction for ball spin during a kick, grip for climbing, protection for construction work, etc. Similarly, a heel element  202  may be configured to provide additional support and protection in the heel area  120  of the upper and/or to house cushioning/protection elements  204 . The depicted auxiliary components are included as examples, and a much larger variety of auxiliary components is contemplated than those depicted. 
     All of the structures and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While this invention may be embodied in many different forms, there are described in detail herein specific aspects of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular aspects illustrated. In addition, unless expressly stated to the contrary, use of the term “a” is intended to include “at least one” or “one or more.” For example, “a yarn” is intended to include “at least one yarn” or “one or more yarns.” 
     Any ranges given either in absolute terms or in approximate terms are intended to encompass both, and any definitions used herein are intended to be clarifying and not limiting. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges (including all fractional and whole values) subsumed therein. 
     Furthermore, the invention encompasses any and all possible combinations of some or all of the various aspects described herein. It should also be understood that various changes and modifications to the aspects described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.