Patent Publication Number: US-11659892-B2

Title: Lightweight knitted upper and methods of manufacture

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/716,128, filed Aug. 8, 2018, which is hereby incorporated by reference in its entirety. This application also claims the benefit of U.S. Provisional Application No. 62/767,818, filed Nov. 15, 2018, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     A variety of articles are formed from 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 from 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 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 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. The upper may include a tongue that extends under the lacing system to enhance adjustability of the footwear, and the upper may incorporate a heel counter to limit movement of the heel. 
     For certain activities, purposes and/or applications, it may be advantageous to provide an upper for an article of footwear that has certain desirable characteristics and properties. In order to impart the different properties to different areas, one or more yarns and/or material elements may be selected for forming the upper. In one example, it may be desirable to provide a knitted upper that is lightweight, while also breathable, durable, at least partially translucent and of high strength and containment. The upper may further include one or more additional optional elements or components that provide other desirable characteristics, including, but not limited to an inlaid component that may enhance comfort and fit, as well as provide enhanced gripping surfaces for certain activities including but not limited to skateboarding, soccer, climbing and the like where traction on at least a portion of the exterior surface of the footwear is desirable. It may also be advantageous to remove at least a portion of the mechanical stretch from a knitted component before forming the knitted component into an upper for an article of footwear. Thus, stretching the knitted component and subjecting it to a pre-determined post-processing method to retain the knitted component in a stretched condition for forming into an upper may also be desirable. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The embodiments will be further described in connection with the attached drawings. It is intended that the drawings included as a part of this specification be illustrative of the exemplary embodiments and should in no way be considered as a limitation on the scope of the present disclosure. Indeed, the present disclosure specifically contemplates other embodiments not illustrated but intended to be included in the claims. 
         FIG.  1    is an illustration showing a side view of one embodiment of an article of footwear in accordance with certain aspects of the present disclosure. 
         FIG.  2    is an illustration showing a perspective view of another embodiment of an article of footwear in accordance with certain aspects of the present disclosure. 
         FIG.  3    is an illustration showing an enlarged view of a toe region of the article of footwear of  FIG.  1   . 
         FIG.  4    is an illustration showing a side view of an embodiment of a heel element in accordance with certain aspects of the present disclosure. 
         FIG.  5    is an illustration showing a view of an inner surface of the heel element of  FIG.  4   . 
         FIG.  6    is an enlarged view of a portion of an outer surface of the heel element of  FIG.  4   . 
         FIG.  7    is a program view of a knitting sequence for forming a knitted component in accordance with certain aspects of the present disclosure. 
         FIG.  8    illustrates one example of a knitted component in an unstretched condition in accordance with certain aspects of the present disclosure. 
         FIG.  9    illustrates one example of a knitted component in a stretched condition mounted on a jig in accordance with certain aspects of the present disclosure. 
         FIG.  10    is an illustration showing a side view of one embodiment of an article of footwear in accordance with certain aspects of the present disclosure. 
         FIG.  11    is an illustration showing one example of a knitted component having an inlaid component in accordance with certain aspects of the present disclosure. 
         FIG.  12    is an illustration showing an enlarged view of a portion of the knitted component of  FIG.  2   . 
         FIG.  13    is an illustration showing two examples of an article of footwear, each having a different combination of colors, each having a knit upper with an inlaid component in accordance with certain aspects of 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 skateboarding shoe, a climbing shoe, 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. 
     Referring to  FIG.  1   , an article of footwear  100  may include 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, and a sockliner may or may not be used. In some embodiments, the sole structure  104  may include 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 lead to a void  118 . The void  118  of the article of footwear  100  may be configured to accommodate a foot of a person. The throat area  112  may be generally disposed in a midfoot area  120  of the upper  102 . The midfoot area  120  is generally an area of the upper  102  located between a heel area  122  and a toe area  124 . In some embodiments, a tongue may be disposed in the throat area  112 , but a tongue is an optional component. The tongue may be any type of tongue, such as a gusseted tongue or a burrito tongue. The article of footwear shown in  FIGS.  1  and  2    preferably includes a tongue that is integrally formed with the upper, such that the upper and the tongue are one piece and no separate attachment of a tongue component is necessary. However, in an embodiment where a tongue is not included, a tongue may be separately formed and later joined to the upper such as by adhesives, bonding and/or stitching, or, in yet another embodiment where no tongue is included, the lateral and medial sides of the throat area  112  may be joined together. As shown, in some embodiments, the article of footwear  100  may include an optional fastening element, such as a lace (which may be associated with a plurality of lace apertures  126 ). The apertures may extend from a forefoot region, through a midfoot region and toward the throat area  112 . 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 , and in still further embodiments the entire upper, may be formed of at least one knitted component  132 , such as a weft-knitting process on a flat knitting machine, for example. The knitted component  132  may additionally or alternatively form another element of the article of footwear, such as an underfoot portion, for example, and/or a heel element  134  as will be described in further detail below. Alternatively, a second or additional knitted component  136 , separately formed from knitted component  132 , may form another element of the article of footwear, such as an underfoot portion, for example, and/or a heel element  134 . In other words, additional elements such as an underfoot portion and/or a heel element  134  (or other elements or components) may be integrally formed with the upper  102  as a one-piece structure, or, alternatively, one or more such additional elements may be formed separately from the upper  102  and then later attached, secured or otherwise assembled as necessary. 
     The knitted component  132  may have a first side  130  forming an inner surface of the upper  102  (e.g., facing the void  118  of the article of footwear) and a second side  138  forming an outer surface of the upper  102  (e.g. facing generally opposite the first side  130 ). The first side  130  and the second side  138  of the knitted component  132  may exhibit different characteristics (e.g., breathability, gripping ability, abrasion resistance, strength, structure and comfort, among other advantageous characteristics mentioned herein). As previously mentioned, the knitted component  132  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 on the knitting machine may substantially form the knit structure of the knitted component  132  without the need for significant post-knitting processes or steps. Alternatively, two or more portions of the knitted component  132  may be formed separately as distinct integral one-piece elements and then the respective elements attached. For example, the heel element  134  can be knitted separately from the upper  102  and then attached or secured to the upper  102  by adhesives, stitching, bonding or other mechanisms or a combination thereof. Additional portions or details may also be secured or attached to the upper for structural or aesthetic purposes, including heel reinforcements, lace aperture reinforcements, to reinforcements and the like. These additional portions may be formed of a separate knitted component that is later attached or by other textiles or materials including, but not limited to leather, suede, rubber, plastic and others. 
     Forming the upper  102  with the knitted component  132  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), grip, breathability, bendability, strength, moisture absorption, weight, abrasion resistance, and/or a combination thereof. These characteristics may be accomplished by selecting a particular single layer or multi-layer knit structure (e.g., a ribbed knit structure, a single jersey knit structure, or a double jersey knit structure), by varying the size and tension of the knit structure, by using one or more yarns formed of a particular material (e.g., a polyester material, a relatively inelastic material, or a relatively elastic material such as spandex), by selecting yarns of a particular size (e.g., denier), and/or a combination thereof. The knitted component  132  may also provide desirable aesthetic characteristics by incorporating yarns having different colors, reflectivity, textures, various degrees of transparency or translucency or other visual properties arranged in a particular pattern. In addition to incorporating different yarns, other materials may be incorporated into the knitted component including but not limited to leather, suede, rubber, plastic or other materials. 
     The yarns themselves and/or the knit structure formed by one or more of the yarns or other materials of the knitted component  132  may be varied at different locations such that the knitted component  132  has two or more portions with different properties. In one non-limiting example, at least a portion of the knitted component  132  may be formed by one or more yarns and/or knitting techniques to provide an upper  102  that is lightweight, having relatively high strength and containment and also breathable. Other areas of the upper  102  formed by the knitted component  132  may be formed by one or more different yarns and/or formed by different knitting techniques and/or other materials that result in a portion of the upper  102  that has different characteristics. For example, the yarn(s) and/or the knitting techniques used to form the throat area  112  and/or the ankle opening  114  may be selected to provide relatively greater elasticity, soft hand, cushioning, enhanced comfort and moisture wicking properties to those regions. In some embodiments, the knitted component  132  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). In still other embodiments, the knitted component  132  may incorporate one or more materials that provide other desirable characteristics including but not limited to enhanced gripping surfaces. 
     For example, the knitted component  132  may include one or more 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  132  to thereby form an area of fused or bonded or continuous material that exhibits certain advantageous properties including a relatively high degree of rigidity, strength, and water resistance, for example. Other advantages of providing one or more yarns comprising a thermoplastic polymer material may include, for example, locking or securing the yarns of the knitted component into a particular position or configuration upon cooling, such that the knitted component  132  may be retained in that particular configuration. In one non-limiting example, this may include stretching the knitted component to a predetermined degree and then heating the knitted component  132  during a post processing method, such as steaming. Upon cooling, the fusible yarns may lock the adjacent and/or surrounding yarns in the stretched configuration to retain the knitted component  132  in this stretched condition. The knitted component  132  may also include one or more yarns having a relatively high degree of tenacity relative to the other yarns used to form the upper. 
     As used herein, “tenacity” is understood to refer to the amount of force (expressed in units of weight, for example: pounds, grams, centinewtons or other units) needed to rupture a yarn (i.e., the breaking force or breaking point of the yarn), divided by the linear mass density of the yarn expressed, for example, in (unstrained) denier, decitex, or some other measure of weight per unit length. The amount of force needed to break a yarn (the “breaking force” of the yarn) is determined by subjecting a sample of the yarn to a known amount of force by stretching the sample until it breaks, for example, by inserting each end of a sample of the yarn into the grips on the measuring arms of an extensometer, subjecting the sample to a stretching force, and measuring the force required to break the sample using a strain gauge load cell. Suitable testing systems can be obtained from Instron (Norwood, Mass., USA). Yarn tenacity and yarn breaking force are distinct from burst strength or bursting strength of a textile, which is a measure of the maximum force that can be applied to the surface of a textile before the surface bursts. 
     Generally, in order for a yarn to withstand the forces applied in an industrial knitting machine, the minimum tenacity required is approximately 1.5 grams per denier (g/D). Most synthetic polymer continuous filament yarns formed from commodity polymeric materials generally have tenacities in the range of about 1.5 g/D to about 4 g/D. For example, polyester filament yarns that may be used in the manufacture of knit uppers for article of footwear have tenacities in the range of about 2.5 g/D to about 4 g/D. Filament yarns formed from commodity synthetic polymeric materials which are considered to have high tenacities generally have tenacities in the range of about 5 g/D to about 10 g/D. For example, commercially available package dyed polyethylene terephthalate filament yarn from National Spinning (Washington, N.C., USA) has a tenacity of about 6 g/D, and commercially available solution dyed polyethylene terephthalate filament yarn from Far Eastern New Century (Taipei, Taiwan) has a tenacity of about 7 g/D. Filament yarns formed from high performance synthetic polymer materials generally have tenacities of about 11 g/D or greater. For example, filament yarns formed of aramid typically have tenacities of about 20 g/D, and filament yarns formed of ultra-high molecular weight polyethylene (UHMWPE) having tenacities greater than 30 g/D are available from Dyneema (Stanley, N.C., USA) and Spectra (Honeywell-Spectra, Colonial Heights, Va., USA). 
     It is also contemplated that the knitted component may also include one or more yarns having relatively high elasticity. Suitable elasticated yarns may incorporate elastane fiber(s), such as those available from Invista Company under the LYCRA trademark. Such yarns may have the configuration of covered LYCRA, for example yarns having a LYCRA core that is surrounded by a nylon sheath. Other fibers or filaments exhibiting elastic properties may also be utilized. 
     The knitted component  132  may also incorporate additional materials or components. In some non-limiting examples (such as the examples of  FIGS.  10 - 13   ), the knitted component  132  may incorporate an inlaid component  152 . The inlaid component  152  may comprise one or more yarns, rubbers, plastics, leathers and/or other natural or synthetic components. As shown generally in  FIG.  11   , the knitted component  132  (which may be incorporated into an article of footwear  204 ) may include an inlaid component  152  that extends generally in a heel to toe direction when the knitted component  132  is incorporated into an article of footwear. In another example (also shown in  FIG.  11    along with  FIG.  12   ), the inlaid component  152  may extend generally in a lateral to medial direction, and/or vertically when an associated article of footwear  206  is sitting on horizontal ground in a wearable state. In still another example, the inlaid component  152  may extend in multiple directions and/or may be located in certain portions of the upper  102  and be absent from other areas of the upper  102 . Such an arrangement may provide regional properties to certain portions of the upper, such that certain advantageous properties may deliberately be provided to certain parts of the upper while deliberately omitting certain properties from other parts of the upper  102 . 
     The knitted component  132  may include a seamless portion extending from the toe area  124 , through a midfoot area  120 , and to a heel area  122  on at least one of a lateral side  106  and a medial side  108  of the upper. In some embodiments, the knitted component  132  may include a first edge and a second edge, which may be terminal ends of the knitted component  132  after the knitting process when the knitted component  132  is removed from the knitting machine. After the knitting process, the knitted component  132  may be folded or otherwise manipulated such that a first edge and the second edge are secured together at a seam  140  during formation of the upper  102 . The seam  140  may be located on the lateral side  106  of the upper  102 , on the medial side  108  of the upper  102 , and/or in another location (e.g., at the back of the heel area  122  of the upper as shown in  FIG.  1   ). Forming the upper  102  such that it is in an appropriate shape for inclusion in an article of footwear  100  may further include lasting the upper  102 . An example of a lasting process is described in U.S. patent application Ser. No. 12/848,352, filed Aug. 2, 2010, and issued as U.S. Pat. No. 8,595,878, which is herein incorporated by reference in its entirety. 
     When forming the knitted component  132 , the knitted component  132  may be oriented with respect to a needle bed of a knitting machine such that a feeder of the knitting machine is capable of moving in a single pass (i.e., without changing its feed direction) to knit a first course from the lateral side  106  to the medial side  108  of the knitted component. As such, as subsequent courses are formed that are parallel to the first course, the toe area  124  of the knitted component  132  will be formed first, followed by the midfoot area  120  of the knitted component  132 , and then the heel area  122  of the knitted component  132  (and/or vice versa, such that the knitted component is formed along a y-axis, in a heel-to-toe direction). Alternatively, the knitted component  132  may be oriented with respect to a needle bed of a knitting machine such that a first course is knit in a direction from heel to toe (or toe to heel). As such, when additional courses are formed parallel to the first course, one of the lateral or medial side is formed first, followed by a central portion such as the throat followed by the other of the lateral or medial side. As such, the knitted component is formed along an x-axis, in a side-to-side, or lateral-to-medial direction. 
     In one embodiment, the inlaid component  152  may be generally parallel to the course-wise direction of the knitted component  132 . In an alternative embodiment, the inlaid component  152  may be generally perpendicular to the course-wise direction of the knitted component  132 . It is also contemplated that the inlaid component  152  may be oriented in a particular direction in a forefoot and/or midfoot area of the upper  102  and be oriented in a different direction in a heel area of the upper  102 , for example. 
     As shown in  FIGS.  1 - 4   , at least a portion of the upper  102  may comprise a single layer  142 . As such, an outer surface (the second side  138 ) of the single layer  142  may form an external surface of an upper  102  and the inner surface (the first side  130 ) of the single layer  142  may form an inner surface of the upper  102 , facing the void  118  of the upper configured to receive the foot of a wearer. 
     In an alternative embodiment, one or more portions of the upper  102  may comprise more than a single layer  142 , such as a first layer and a second layer that are coextensive and/or overlapping, which may form a pocket therebetween. The pocket may be filled with another element (e.g., a filler material, such as foam, down, or another suitable material or object), but this is not required, and in exemplary embodiments, the pocket may be empty and/or filled with just air. 
     As mentioned above, the upper  102  may comprise an ankle opening  114 , which leads to the void  118 , configured to accommodate a foot of a wearer. The ankle opening  114  may be formed of one or more collars. The collar  116  of the upper  102  may be referred to herein as a “first collar” which forms a “first collar opening.” The one or more of the yarns and/or knitting techniques used to form the collar  116  may be the same as the yarns and/or knitting techniques used to form other portions of the upper  102  or they may be different. 
     For example, as shown in  FIGS.  1 - 3   , the one or more yarn(s), as well as the one or more knitting technique(s) used to form the collar  116 , the throat area  112  and the remainder of the upper  102 , respectively, may differ in order to impart desired properties and characteristics to different regions of the upper  102  as described below. 
     One or more yarns may be used when knitting the knitted component  132  that is formed into an upper  102 . In one non-limiting example, a first yarn  144  may include a high tenacity polyester yarn. In one non-limiting example, the high-tenacity polyester yarn may be formed from polyethylene terephthalate (PET). The first yarn  144  may have a tenacity of at least 5 grams per denier, and more preferably higher than 6 grams per denier and even more preferably from 6.5-7 grams per denier. In one example, three ends of 300 denier high tenacity polyester yarn may be used. The high tenacity polyester may be translucent or at least partially transparent in some embodiments. This may allow one or more images, elements, symbols, logos or other objects that are behind portions of the knitted component  132  formed from the first yarn  144 , (such as images or elements that are adjacent to the inner surface or first side  130  of the upper  102  and/or within the void  118  formed by the upper  102 , to be visible from the second side  138  or exterior of the upper  102 . This may enhance the visual properties and/or aesthetic appearance of the upper  102 , for example. It will be recognized that more or fewer ends of the first yarn  144 , having lower or higher tenacity and/or lower or higher denier, may be used as one of skill in the art would recognize to achieve the desired and necessary properties. 
     A second yarn  146  may be used to form at least a portion of the first knitted component  132 , alone or in combination with the first yarn  144 . The second yarn  146  may be the same as the first yarn  144  or it may be different. In one example, the second yarn  146  may have one or more thermoplastic polymers (collectively “the thermoplastic polymer material”), and in some embodiments, substantially the entirety of the second yarn  146  may be formed of the thermoplastic polymer material. The thermoplastic polymer material of the second yarn may have a melting temperature of between about 80-100 degrees C. and more preferably 85-90 degrees C. based on atmospheric pressure at sea level, though any other suitable melting temperatures is contemplated. In a non-limiting example, the second yarn  146  may be referred to as a “fusible yarn” sold under the trade name Grilon K-85 by EMS-Griltech. The K-85 yarn is a multifilament yarn where the polymer basis is a copolyamide. It should also be noted that a yarn with a melting temperature below 140 degrees C. that can be melted/post processed by steaming, heat and/or pressing to bind or fuse with the surrounding (non-low melt) yarns and hold them in place may be referred to as a ‘fusible’ or ‘low melt’ yarn herein. In one example, two ends of 235 denier of the second yarn  146  may be used. Alternately, fewer ends of a higher denier second yarn  146  may be used, such as one end of a 500 denier yarn. More or fewer ends of the second yarn  146  having lower or higher denier or lower or higher melting temperature may be used as one of skill in the art would recognize to achieve the desired and necessary properties. 
     A third yarn  148  may be used to form at least a portion of the knitted component  132 , alone or in combination with the first yarn  144  and/or the second yarn  146 . In one example, the third yarn  148  may also be a high tenacity polyester yarn formed from polyethylene terephthalate (PET). The third yarn  148  may sometimes be referred to herein as a high tenacity sewing thread or “M-60” and/or sold under the trade name “Gral” by Coats Group PLC. The term “thread” in reference to the third yarn  148  may infer to one of skill that this yarn has an increased amount of twist to keep the filaments tighter/more compact, often useful for going smoothly and efficiently through sewing or knitting needles. In the present case, the third yarn  148  (e.g. high tenacity polyester sewing thread) may provide a different aesthetic as compared to the first yarn  144  (e.g. also a high tenacity polyester yarn). The third yarn  148  may have a tenacity of at least 5 grams per denier, and in some examples approximately 6-8 grams per denier and more preferably approximately 7.5 grams per denier. In one example, one end of the third yarn  148  may be used, but it will be recognized that more or fewer ends of the third yarn  148 , having lower or higher tenacity and/or lower or higher denier, may be used as one of skill in the art would recognize to achieve the desired and necessary properties. 
     The high tenacity yarns, including the first yarn  144  (i.e. the high tenacity polyester yarn) and/or the third yarn  148  (i.e. the high tenacity polyester sewing thread) may be knit alone or in combination with other yarns, such as the second yarn  146  (the fusible yarn). For example, the high tenacity polyester yarns  144 ,  148  may be knit in combination with the fusible yarn  146  mentioned above. The combination of yarns as well as the knitting technique used to form the upper  102  is described in further detail below. 
     In addition to the first, second and third yarns  144 ,  146 ,  148 , a fourth yarn  150  may be used to form the knitted component  132 . The fourth yarn  150  may be the same as the first, second and/or the third yarn  144 ,  146 ,  148 , or it may be different. In one example, the fourth yarn  150  used to form at least a portion of the knitted component  132  comprises a yarn that is different than the first, second and third yarns  144 ,  146 ,  148  and comprises a relatively more elastic yarn than the aforementioned first, second and third yarns. In one example, the fourth yarn  150  may comprise a combination of a polyester yarn with an elastic core. In some embodiments, the fourth yarn  150  may be referred to as “E08” which may be two strands of a textured polyester yarn wrapped about an elastic (i.e. a 420D Spandex) core. Other suitable elastic yarns may also include “E06” which may be two strands of textured polyester wrapped around a 140D Spandex core or “E04” which may be two strands of textured polyester wrapped around a 210D Spandex core, although other suitable elastane yarns may be used to achieve the necessary properties and characteristics. The combination of materials, such as the polyester yarn and the elastic yarn that together form the fourth yarn  150  may be achieved by twisting, winding, braiding, and/or wrapping on about the other and the like, and/or the yarns may be a core/sheath configuration, and/or the yarns may be tacked along their length at a plurality of points. 
     During the knitting process, another yarn and/or material may be inlaid within the knitted component  132 . This inlaid component  152  ( FIGS.  10 - 13   ) may be the same as one or more of the first, second, third or fourth yarns. Alternatively, the inlaid component  152  may be another material including leathers, rubbers, plastics, nylon and/or other natural and/or synthetic materials or combinations thereof. The material of the inlaid component  152  may be selected depending on the structural or aesthetic or advantageous characteristic that is desired. In one non-limiting example, the inlaid component  152  may include a natural material such as leather, or a synthetic material such as synthetic leather. The inlaid component  152  may be in the form of a strip or cord or other type of elongated structure. 
     During or after the knitting process, a stimulus, such as heat, may be applied to at least a portion of, or to the entirety of the upper  102 . This heat may be in the form of steam, such as by a steam-providing device, for example. One or more effects may result from the exposure of the knitted component  132  to steam. 
     In one example, the steam may cause one or more of the yarns used to form the knitted component  132  to melt into a softened or liquid state. For example, the steam may cause the second yarn  146  (the thermoplastic yarn, or “fusible yarn,” for example) having a melting temperature of 85 degrees C., to soften or become molten or enter into a relatively liquid state when the temperature reaches or exceeds the designated melting temperature of the yarn. When subjected to a stimulus, such as steam heat and/or pressure, the thermoplastic polymer material included with the second yarn  146  described above, may at least partially melt. 
     In one example, the steam may activate thermoplastic polymer materials in the second yarn  146 . Once this heat is removed and the article cools, the thermoplastic material present in the second yarn  146  may at least partially fuse together with adjacent or surrounding yarns in its proximity within the knitted component  132 . In other words, the second yarn  146  may infiltrate and/or permeate any of the adjacent or surrounding knit loops and/or courses of the knitted component  132  formed from any of the other yarns used to form the knitted component  132  and/or the inlaid component  152 . As a result, the at least a portion of one or more of the separate yarns originally forming the knitted component  132  (and/or the inlaid component  152 ) may become bonded and/or continuous with the second yarn  146  to form a “fused” area. There may be fewer and relatively large fused areas in one or more portions of the upper, or there may be a plurality of relatively small fused areas throughout the upper. In some instances, the fused area may be small enough or they may be at least partially translucent or transparent such that they are not readily visible. When the thermoplastic material transitions back to a solid state upon cooling, this may cause the fused yarns to remain fixed in (or at least have a tendency to remain fixed in) a desirable position and orientation. Heat-processing the fusible material of the fusible yarn may also enhance the rigidity, strength, and other mechanical properties of the knitted component at least in select locations and/or have the effect of securing or locking the relative positions of the yarns within the knitted component  132 . 
     As shown in  FIG.  1   , at least a portion of the knitted component  132  forming the upper  102 , and more preferably, a majority of (i.e. greater than 50%) or even more preferably a substantial majority (i.e. greater than 75% or more) of the knitted component is formed from the first, second and third yarns  144 ,  146 ,  148 . The inlaid component  152  ( FIGS.  10 - 13   ) may be incorporated into the portion of the knitted component  132  formed from the first, second and third yarns  144 ,  146 ,  148 . Hereinafter, the portion of the upper  102  formed from the first, second and third yarns  144 ,  146 ,  148 , which, in one example, is the upper excluding the throat area  112  and/or the first collar  116 , will be referred to as the “body”  154  of the upper  102 . Stated differently, the body  154  of the upper  102 , with the exception of the throat area  112  and/or the collar  116 , is formed from the first, second and third yarns,  144 ,  146 ,  148  and/or the inlaid component  152 , while the throat area  112  and/or the collar  116  are formed at least in part from the fourth yarn  150 . It is also contemplated, however, that one or more of the first, second and/or third yarns  144 ,  146 ,  148  may be present in lieu of, or in combination with, the fourth yarn  150  in the throat area  112  and/or the collar  116 . The inlaid component  152  may also be incorporated into the throat area  112  and/or the collar  116 . 
     As previously mentioned, different characteristics and advantageous properties may be imparted to different areas or regions of the upper. This may be accomplished by not only selecting a particular yarn or yarns to form different regions of the upper  102 . However, this may also be accomplished by selecting a particular knitting technique, selecting single layer or multi-layer knit structure (e.g., a ribbed knit structure, a single jersey knit structure, or a double jersey knit structure), by varying the size and tension of the knit structure, by using one or more yarns formed of a particular material (e.g., a polyester material, a thermoplastic material, a relatively inelastic material, or a relatively elastic material such as spandex, etc.), by selecting yarns of a particular size (e.g., denier), and/or a combination thereof. In one example, the first, second and third yarns  144 ,  146 ,  148  forming the body  154  of the upper  102  may be knit using a particular knitting technique to achieve a particular knit density, for example, including but not limited to a half-gauge knit (knitting on every other needle of a knitting machine). This may include a half-gauge jersey knit as shown in  FIG.  1    and  FIG.  3   , for example. It is also contemplated that the body  154  of the upper  102  may be formed from a lesser gauge knit, including but not limited to a third gauge knit (knitting on every third needle) or quarter gauge knit (knitting on every fourth needle). 
     As such, in some embodiments, the body  154  of the upper  102  may have a different stitch density than other portions, such as the throat area  112  and/or the collar  116 . For example, the body  154  may have a half gauge stitch density or less-than half gauge stitch density. As used in this application, the terms “full gauge,” “half gauge,” and “less than full gauge,” may generally refer to the stitch density of a knit component. Generally, a knit component may include an area having a “full gauge” stitch density if that area contains stitches (e.g., loops or tucks) formed on at least two consecutive needles of a needle bed (often more than two consecutive needles). Similarly, the same knit component may include an area having a “half gauge” stitch density, in which that area contains stitches formed on every other needle. Similarly, the same knit component may have “less than full gauge” areas that are neither full gauge nor half gauge, for example one-third gauge (stitches formed on every third needle) or one-quarter gauge (stitches formed on every fourth needle). 
     The relatively lower density knit structure provided by the half-gauge knitting technique may therefore provide a lightweight, breathable upper. Additionally, any one or more of the first, second, third and/or fourth yarns  144 ,  146 ,  148 ,  150  used to knit the upper  102  may be at least partially translucent and/or transparent either before and/or after any post-processing steps such as exposure to a stimulus (i.e. steam or other heat). Accordingly, the relatively low density of the knit combined with the translucency or transparency of one or more of the yarns used to form the knitted component  132  may result in the upper  102  also being at least partially translucent and/or transparent. This may reveal, display or otherwise show any auxiliary elements or components or other features (such as logos, decorative elements, colors, etc.) that may lie behind or underneath the first side  130  (the inner surface of the knitted component  132 ) and/or within the void  118 . This may also allow the inlaid component  152  to be readily apparent, this providing an additional desirable aesthetic appearance to the upper  102  in addition to other advantages that may be provided by the inlaid component  152 . 
     This is shown, for example, in  FIGS.  1  and  2   . Placement of an additional or auxiliary element  156  within the void  118 , adjacent a first side  130 , is visible from the exterior of the footwear.  FIG.  1    shows an auxiliary element  156  that extends at least partially around a lower perimeter of the article of footwear  100 , such as near the biteline  110  where the upper  102  meets and/or joins the sole structure  104 . While the auxiliary element  156  is shown generally as a band or a strip, the auxiliary element  156  may be of any shape, length, size and/or dimension. In another example shown in  FIG.  2   , the auxiliary element  156  is a band that extends generally between the lateral and medial sides  106 ,  108  of the upper  102 , over the top of the foot in the toe area  124 . The auxiliary element  156  may be formed from a knit structure or a non-knit structure, including but not limited to other textiles, rubbers, plastics, metals, cables, foams and/or padding. The auxiliary element  156  may be integrally formed with the upper  102  during the knitting process or it may be formed separately and later attached to the upper  102  such as by stitching, bonding, adhesives or other suitable attachment mechanisms. In one example, the auxiliary element  156  may provide enhanced structure, support, rigidity, water repellency, comfort, strength or other advantageous properties to the article of footwear  100 . Additionally or alternatively, the auxiliary element  156  may enhance the aesthetic visual and design properties of the upper, such as by providing additional colors, shine, reflectivity and allow the display of logos, placards, emblems and insignia as desired. 
     As described in further detail below with reference to the knit diagram shown in  FIG.  7   , the body  154  of the upper  102  may be formed by a series of courses of the first, second and third yarns  144 ,  146 ,  148 . In one non-limiting example, a first course may be knit with a combination of the first yarn  144  (e.g., the high tenacity polyester yarn) and the second yarn  146  (e.g., formed thermoplastic polymer material, the “fusible yarn”). A second consecutive course may be formed from a combination of the third yarn  148  (e.g., the high tenacity polyester “sewing thread”) and the second yarn  146  (e.g., formed thermoplastic polymer material, the “fusible yarn”). This pattern of yarn selection may be repeated, knitting on every other needle of a needle bed, to form a half-gauge knit body  154  for the upper  102 . It is noted that the use of one or more relatively high tenacity yarns, including the first yarn  144  (e.g., the high tenacity polyester yarn) and/or the third yarn  148  (e.g., the high tenacity polyester “sewing thread”) may provide the advantage of an upper  102  having relatively high strength and containment (e.g. “lock in” of a wearer&#39;s foot) even when knit as a relatively less dense, single layer, half-gauge structure using every other needle (as compared to a more densely knit structure formed as a “full gauge knit” using every needle of a knitting machine). 
     It is also contemplated that during the knitting process, the knitting machine may include an additional feeder that includes the component to be inlaid. For example, a feeder may be provided with (or connected to) a spool or other reservoir containing a leather strip or band. The leather strip may be inlaid within the knitted component  132 . Of course, materials other than leather may be inlaid within the knitted component depending on the advantageous characteristic to be achieved, including suede, faux leather, nylon, plastic, rubber and the like. One example of an inlay process that may be used to inlay the inlaid component  152  of  FIGS.  10 - 13    is described in U.S. Pat. No. 8,839,532, which is hereby incorporated by reference in its entirety. 
     In one example, the inlaid component  152  provides an additional gripping characteristic that is advantageous to the wearer when participating in certain activities, including but not limited to skateboarding, soccer, climbing and the like. More specifically, the properties of the inlaid component  152  preferably provide at least a portion of the outer surface of the upper  102  with a greater or enhanced tackiness and ability to grip or temporarily adhere to another surface, such as a board, ball, wall or other surface. The result may be a greater friction between at least a portion of the upper  102  where the inlaid component  152  is present and the additional surface, such that the user experiences less slippage and feeling of enhanced tactile quality, feedback and control (e.g., “board feel” when referring to skateboarding, for example). Thus, in one example, one or more inlaid components  152  may provide an enhanced grip between the upper  102  and a surface of a skateboard, climbing wall and/or ball. In some embodiments, for example (such as that of  FIG.  10   ), each course of the knitted component  132  may include an inlaid component  152 , but this is not required. 
     As noted above, in addition to the body  154 , the upper  102  further includes throat area  112 . The knitting technique and/or yarn(s) used to form the throat area  112  may be the same as the knitting technique and/or the yarn(s) used to form the body  154  or the yarn(s) may be different. In one example, the throat area  112  is formed by a different knitting technique than the one used to form the body  154 . In one example, the throat area  112  may be a rib structure, a rib structure with mesh, a full gauge jersey, double jersey or other suitable knit structures that may be selected to achieve a desired characteristic. As shown in  FIG.  1   , the throat area  112  may be a ribbed structure that is a relatively more dense knit structure than the body  154 . The throat area  112  may be formed at least in part from the fourth yarn  150  (e.g., the relatively elastic yarn, such as E08 described above, or other relatively elastic yarns). While the throat area  112  may be exclusively knit by the fourth yarn  150 , it is also contemplated that one or more of the first, second and/or third yarns  144 ,  146 ,  148  may be present in the throat area  112 . The relatively high degree of stretch and/or elasticity provided by the fourth yarn  150  imparts stretch to the throat area  112  that may provide ease of entry of a wearer&#39;s foot into the void while also allowing the upper to conform to the foot when worn, and enhance comfort and fit. 
     As noted above, in addition to the body  154  and the throat area  112 , the upper  102  may further include collar  116 . The knitting technique and/or yarn(s) used to form the collar  116  may be the same as the knitting technique and/or the yarn(s) used to form the body  154  or the throat area  112 , or they may be different. In one example, the collar is formed by a different knitting technique than the one used to form the body  154  and the throat area  112 . For example, the collar may be a rib structure, a tubular structure, single full gauge jersey, double jersey or other suitable knit structures that may be selected to achieve a desired characteristic in the collar  116 . As shown in  FIG.  1   , the collar  116  may be a double jersey knit structure that is a relatively more dense knit structure than the body  154  and the throat area  112 . The collar  116  may be formed from the fourth yarn  150  (e.g., the relatively elastic yarn, such as E08 described above). While the collar  116  may be exclusively knit by the fourth yarn  150 , it is also contemplated that one or more of the first, second and/or third yarns  144 ,  146 ,  148  may be present in the collar  116 . The relatively high degree of stretch and/or elasticity provided by the fourth yarn  150  imparts stretch to the collar  116  that may provide ease of entry of a wearer&#39;s foot into the void while also allowing the upper  102  to conform to the foot when worn, and enhance comfort and fit. 
     Referring now to  FIGS.  1  and  3   , the article of footwear  100  may include one or more additional components or elements. The additional components or elements may provide additional advantageous characteristics or properties. In one embodiment, the additional knitted component  136  may be knitted to form a heel element  134 . While the heel element  134  may be formed from the first knitted component  132  that forms the upper  102 , the heel element  134  may be formed separately from the upper  102 , such as from the second or additional knitted component  136 , for example, and then secured to the knitted component  132  that forms the upper  102 . The heel element  134  may be a single, unitary, one-piece structure formed by the additional knitted component  136  or it may be formed from multiple pieces that are attached together to form the heel element  134 . The heel element  134  may be secured to the upper  102  by stitching, bonding, adhesives or other suitable mechanisms of coupling or attachment. 
     It is also contemplated that the heel element  134  may be removable, such that attachment to the upper  102  may not necessarily be permanent or irreversible in some embodiments. In a non-limiting example, the heel element  134  may have one or more holes or apertures  158  formed therein which may generally align with one or more of the lace apertures  126  formed in the throat area of the upper  102 . When a shoelace or other similar securing mechanism is threaded through the one or more apertures  158  formed in the heel element  134  as well as the lace apertures  126  formed in the upper  102 , the lace may secure the heel element  134  in place, snugly against the first side  130  or inner surface of the upper  102  within the void  118  in the heel area  122  of the article of footwear. Heel element  134  may provide additional structure, support and form to the heel area  122  of the upper, as well as soft hand, breathability, cushioning, comfort and enhanced fit, for example. 
     One example of a heel element  134  is shown in  FIGS.  4 ,  5  and  6   . As shown there, the heel element  134  generally comprises a central body portion  160  with a first arm  162  and a second arm  164  extending outwardly away from the central body portion  160 . The heel element  134  has an inner surface  166  and an outer surface  168 . When properly placed in its intended position within the void  118  of the article of footwear  100 , the outer surface  168  of the heel element  134  would be adjacent to and/or abut the first side  130  of the upper  102 . The inner surface  166  of the heel element  134  would generally face the void  118 . The first arm  162  would extend towards at least one of the lateral and medial side  106 ,  108  of the upper  102 , while the second arm  164  would extend towards the other of the lateral and medial side. The central body portion  160  of the heel element  134  may generally align with a center portion or “spine” of the heel area  122  of the upper  102 . 
     As shown in  FIGS.  4  and  5   , the heel element  134  may have an upper or top edge  170  extending along the top of the first arm  162 , across and along the top of the central body portion  160  and along the top of the second arm  164 . In one embodiment, when the heel element  134  is positioned within the void  118  of the article of footwear  100 , at least a portion of the top edge  170  may extend above the first collar  116  formed by the upper  102 . As such, the top edge  170  of the heel element  134  may form a second collar  172  for receiving the foot of wearer as shown in  FIG.  1   . The central portion of the body portion  160  may extend upwards, such that the top edge  170  of the body portion  160  extends above the top edge  170  of the first arm  162  and second arm  164 . Thus, when the heel element  134  is properly placed in its intended position within the void  118  of the article of footwear  100 , the central portion of the body portion  160  of the heel element  134  may extend higher upon a wearer&#39;s ankle to cover at least a portion of the Achilles tendon, for example. 
     Furthermore, the heel element  134  may comprise a generally consistent knit density throughout, but in other embodiments, the heel element  134  may have different knit densities in different regions. For example, the portion of the heel element  134  that extends above the first collar  116  of the upper  102  may be less densely knit than other portions of the heel element  134 . As such, the portions of the heel element  134  that lie behind the upper  102  and which may be adjacent the first side  130  of the upper  102  may have a relatively more densely knit structure. 
     The first arm  162  and the second arm  164  each have a forward edge  174 . A bottom edge  176  of the heel element  134  extends along the bottom of the first arm  162 , across and along the bottom of the central body portion  160  and along the bottom of the second arm  164 . The heel element  134  may be knitted in a generally flat or two-dimensional configuration as it comes off the knitting machine. However, it may be shaped into a three-dimensional configuration before it is placed in its desired location within the void  118  of the article of footwear  100 . For example, the heel element  134  may be shaped on a last to form a gently curved or concaved structure that generally corresponds to the shape of the heel area of the upper  102 , such that it is configured to receive the foot of a wearer, for example. 
     When formed into a three dimensional configuration, such as that shown in one exemplary embodiment of  FIGS.  4 - 6   , the first arm  162  and second arm  164  extend generally forward in a direction towards the throat area  112  and/or the toe area  124  of the article of footwear  100 . Thus, it can be seen that the forward edges  174  also face in a generally forward direction within the void  118 . As previously mentioned, one or both of the first arm  162  and the second arm  164  may include one or more apertures, openings or holes  158  formed therein. In one example, the one or more holes  158  formed in either or both of the first arm  162  and/or the second arm  164  may generally align with one or more of the lace apertures  126  formed in the throat area  112  of the upper  102 . As shown in  FIGS.  4  and  5   , the first arm  162  and the second arm  164  each include at least one opening or aperture or hole  158  which generally aligns with the top-most lace aperture  126  formed in the upper  102 . When a lace element is threaded through the lace aperture  126  formed in the upper  102 , the lace may also extend through the holes  158  formed in the first arm  162  and the second arm  164  formed in the heel element  134 . 
     The heel element  134  may include an underfoot portion  178  that is configured to extend at least partially under the foot of a wearer. In one example, the underfoot portion  178  may be integrally formed with the knitted component  136  that forms the heel element  134 , such that the heel element  134  and the underfoot portion  178  are a unitary one-piece structure. In another embodiment, as shown in  FIG.  5   , the underfoot portion  178  is a separately formed knitted structure that is attached to the heel element  134 . While the underfoot portion  178  of  FIGS.  4 - 6    is a knitted component, it is contemplated that the underfoot portion  178  can be formed from other non-knitted textiles or materials. 
     In one embodiment, the underfoot portion  178  may extend only a small distance under the foot of a wearer, such that the underfoot portion  178  extends to approximately the biteline  110  where the upper  102  meets the sole structure  104 . In other embodiments, the underfoot portion  178  may extend a farther distance underfoot, such as under the ball of the heel of the foot of a wearer. In still further embodiments, the underfoot portion  178  may extend still a further distance underfoot, such as far forward as the midfoot region  120  of the article of footwear  100 . The underfoot portion  178  may extend the entire distance between the lateral and medial side  106 ,  108  of the upper  102  or the underfoot portion  178  may extend only a portion of the distance between the lateral and medial sides. A strobel, insert, liner or midsole structure (not shown) may extend over the top of the underfoot portion  178  (sandwiching the underfoot portion  178  between the strobel and the upper surface of a sole structure  104 , for example) or alternatively, the foot of a wearer may directly contact the underfoot portion  178  of the heel element  134 . 
     The heel element  134  may be formed by one or more yarns and knitting techniques to impart certain advantageous properties and characteristics. The heel element  134  may be formed from a full-gauge knit, half-gauge knit or lesser gauge, and may be a single layer or a double layer structure. In the case of a double-layer structure, a pocket may be formed between the layers which may be configured to receive one or more additional structures or elements, including but not limited to padding and the like. In one example, the heel element  134  is formed from a double jersey knit, although it shall be appreciated that other types of knit structures could be used including a single jersey, a ribbed structure, a mesh structure, a jacquard knit structure and combinations thereof. 
     The heel element  134  may be formed of one or more of the same yarns of the first knitted component  132  that forms the upper  102 , or the yarns may be different. In one non-limiting example, the heel element  134  comprises the first yarn, second yarn, and third yarn  144 ,  146 ,  148  used to form the body  154  of the upper  102  as well as the fourth yarn  150  used to form the throat area  112  and the first collar  116  of the upper  102 . In addition to the first, second, third and fourth yarns  144 ,  146 ,  148 ,  150 , the heel element  134  may further include a fifth yarn  151 . The fifth yarn  151  may be the same as the other yarns or it may be different. In one embodiment, the fifth yarn  151  may comprise thermoplastic polymer materials. More specifically, the fifth yarn  151  may comprise a thermoplastic polyurethane, or TPU. The TPU may be a coated yarn consisting of a multifilament polyester core yarn (150D) that is coated with a TPU resin sheath with a melting temperature of about 115-120 degrees C. (having a 750D total yarn size). In one non-limiting example, two ends of 550 denier TPU yarn may be used, which may be sold under the trade name Dream-Sil®, a thermoplastic polyurethane coated yarn manufactured by Sambu Fine Chemical Co., LTD. 
     As such, when the heel element  134  is exposed to a stimulus, such as post-processing methods including steaming, heat pressing and the like, the resin sheath of the fifth yarn  151  may melt, whereas the polyester core, having a higher melting temperature, does not. As mentioned above, yarns that have a melting temperature below about 140 degrees C. (or, in this case a resin sheath having a melting temperature below about 140 degrees C.) may be referred to or identified as a “fusible yarn” like the second yarn  146  formed of thermoplastic polymer materials described above (i.e. the K-85). 
     The first, second, third, fourth and fifth yarns  144 ,  146 ,  148 ,  150 ,  152  may be knitted together to form the heel element  134 , or the yarns may be knitted in certain combinations or patterns. For example, one or more of the yarns may be fed together on a particular feeder of a knitting machine or, in another example, a certain course of the knitted component  136  may include one or more of the first, second, third, fourth and fifth yarns  144 ,  146 ,  148 ,  150 ,  152  or combinations thereof, while another course of the knitted component  136  may be formed from others of the aforementioned yarns or combinations thereof. 
     The fifth yarn  151 , or TPU, may preferably have a higher melting temperature than any one or more of the first, second, third and/or fourth yarns  144 ,  146 ,  148 ,  150 . The fifth yarn  151  may impart certain properties that are advantageous for including in a heel element  134 , such as, for example, stiffness, rigidity, shape, structure, durability and/or strength. When subjected to heat and/or pressure during a post-processing procedure (and, if desired, placing the heel element  134  on a last for molding and shaping) the fifth yarn  151  may allow the heel element  134  to retain its form and provide the desired rigidity shape and structure. While the fifth yarn  151  may be present in the entire heel element  134  and/or the underfoot portion  178  of the heel element  134 , the fifth yarn  151  may be present in certain areas of the heel element  134  and present in only relatively small amounts or entirely absent from the underfoot portion  178 . 
     For example, the fifth yarn  151  may be more concentrated in certain areas of the heel element  134  and less concentrated in others. This may provide more rigidity and structure to the areas where the fifth yarn  151  is more highly concentrated. As shown in  FIG.  6   , the fifth yarn  151  may be more concentrated in the central zone  180  of the central body portion  160  from an area just below the second collar  172  of the heel element  134  to an area adjacent to the bottom edge  176 . The fifth yarn  151  may also extend at least partially into the first arm  162  and the second arm  164  as necessary and desired to provide the appropriate stiffness, rigidity, shape and structure to the heel element  134 . 
     As shown in  FIGS.  4  and  5   , the top edge  170  of the heel element  134  which may form at least a portion of the second collar  172  may be formed from the fourth yarn  150  (the relatively elastic yarn, such as E08 described above, or other relatively elastic yarns). It is also contemplated that the forward edges  174  of the first arm  162  and the second arm  164 , as well as the bottom edge  176  of the heel element  134  may also be formed from the fourth yarn  150 , or other suitable elastic yarns. The underfoot portion  178  may also be formed from the fourth yarn  150 , and preferably, the underfoot portion  178  may be formed substantially or entirely of the fourth yarn  150  or other suitable elastic yarns. 
     The fourth yarn  150  may be more concentrated in certain areas of the heel element  134  and less concentrated in others. This may provide more stretch, resilience and compliance to the areas where the fourth yarn  150  is more highly concentrated. As shown in  FIGS.  4  and  6   , the fourth yarn  150  may be more concentrated in the top edge  170  and/or adjacent the top edge  170  including, in one example, the area formed by the second collar  172  of the heel element  134  that extends above the first collar  116  of the upper  102 . The fourth yarn  150  may also be more concentrated in the bottom edge  176  and/or in an area adjacent the bottom edge  176 , such as an area adjacent to the biteline  110 . The concentration of the fourth yarn  150  in an area that lies between the first area and the third area, including, for example, central zone  180 , may be less concentrated, thus providing a “high-low-high” elastic “gradient” in the heel element  134 . The fifth yarn  151  may also extend at least partially into the underfoot portion  178  of the heel element  134 . 
     Once the heel element  134  has been knitted and then lasted to form a three-dimensional structure such as that shown in  FIGS.  4 - 6   , it may be inserted through the first collar  116  of the upper  102  and into the void  118  of the article of footwear. The central body portion  160  of the heel element  134  may generally align with the center of the heel area  122  of the upper  102 . The heel element  134  may be attached to the upper  102  as already described above, and, if apertures or holes  158  are present in the first arm and/or second arm  162 ,  164 , a lace element can be fed there through. As such, when the laces are tightened by a wearer, the tension of the laces may pull the heel element  134  slightly forward to enhance fit, containment and comfort. 
     Turning now to  FIG.  7   , a knit program  182  used to form at least a portion of the knitted component  132  will be described. In other words, the knit program  182  described hereinafter forms the portion of the upper  102  formed from the first, second and third yarns  144 ,  146 ,  148 , which, in exemplary  FIG.  1   , is the majority of the upper (referred to herein as the “body”  154  of the upper) excluding the throat area  112  and/or the collar  116 . It is noted that the inlaid component  152  is not represented in the knit program  182 . Thus, the inlaid component  152  may be incorporated into the knitted component  132  during the knitting process or it may be inlaid as a separate or additional step following the knitting process. 
     First, looking to  FIG.  7   , a program view of a knit program is illustrated. As shown, the knitted component  132  is formed on a knitting machine having a single bed, although it is contemplated that two beds may be used to form at least a portion of the knitted component  132 . It can be seen that the knitting is formed on every other needle of the needle bed, thus forming the previously described half-gauge structure, resulting in a lightweight and at least partially translucent or transparent upper, yet strong and having high containment (or “lock out”) due to the use of one or more high tenacity yarns. 
     The knit diagram illustrates a first course  184  knit on a single needle bed. The first course includes a combination of the first yarn  144  (the high tenacity polyester) and the second yarn  146  (the fusible yarn). The combination of the first yarn  144  and the second yarn  146  is knit on every other needle of the needle bed. 
     A second consecutive course  186  is then knit following the first course  184 . The second course  186  includes a combination of the second yarn  146  (the fusible yarn) and the third yarn  148  (the high tenacity polyester “sewing thread”). The combination of the second and third yarn  146 ,  148  are tucked on one needle (shown as an upside-down “U” in the diagram) which tucks on top of the first and second yarns  144 ,  146  of the first course  184 . Following the tuck stitch of the second course  186 , the second and third yarns  146 ,  148  float three needles then knit on the fourth needle. As shown in the knit program  182 , this sequence can then be repeated, starting again with a tuck stitch. 
     A third consecutive course  188  is then knit following the second course  186 . The third course  188  is a repeat of the first course  184 , which includes a combination of the first yarn  144  (the high tenacity polyester) and the second yarn  146  (the fusible yarn). The combination of the first yarn and the second yarn  144 ,  146  is knit on every other needle of the needle bed. 
     A fourth consecutive course  190  is then knit following the third course  188 . The fourth course  190  includes a combination of the second yarn  146  (the fusible yarn) and the third yarn  148  (the high tenacity polyester “sewing thread”). The combination of the second and third yarns  146 ,  148  are knitted on one needle, then float three needles. Following the three needle float, the combination of the second and third yarns  146 ,  148  are then tucked (shown as an upside-down “U” in the diagram) which forms a tuck stitch on top of the first and second yarns  144 ,  146  of the first course  184 . Following the tuck stitch, the second and third yarns  146 ,  148  again float three needles then knit again on the fourth needle. As shown in the knit program  182 , this sequence can then be repeated, starting again with the knit loop on the fourth needle following the float sequence. 
     A fifth consecutive course  192  is then knit following the fourth course  190 . The fifth course  192  is a repeat of the first and third courses  184 ,  188 , which includes a combination of the first yarn  144  (the high tenacity polyester) and the second yarn  146  (the fusible yarn). The combination of the first yarn and the second yarn  144 ,  146  is knit on every other needle of the needle bed. 
     The knit sequence of  FIG.  7    may be repeated, as necessary, to form a knitted component with a suitable size. Further, it is noted that the sequence(s) may be varied to incorporate different features by changing certain knit structures, by varying yarn types, by increasing or decreasing the number of courses at each step, or by any other suitable adjustment to the knitting process or materials used. Further, other sequences may be used before, after, or between the sequences described above. 
     Referring now to  FIGS.  8  and  9   , processing of the knitted component  132  and formation of the upper  102  for an article of footwear are described. After the entirety of the upper  102  is formed, including the body  154  of the upper (using the knit sequences described above) and further including the throat area  112  and first collar  116 , the knitted component  132  may be subjected to one or more post-processing methods. In one example, it may be desirable to remove or otherwise eliminate a pre-determined amount of mechanical stretch of the knitted component  132  before it is assembled onto a sole structure  104  to form an article of footwear  100 . In one example, at least a portion of the mechanical stretch may be removed from the knitted component  132 , and in other examples, it is preferable to remove substantially all of the mechanical stretch from the knitted component  132 . 
     One non-limiting example of a test method used to illustrate the physical property measurements and stretch of a swatch or test sample of the knitted component  132  (comprising the first, second and third yarns  144 ,  146 ,  148 ) is set forth below: 
     
       
         
           
               
               
               
               
             
               
                   
               
               
                   
                 Breaking 
                   
                 Basis 
               
               
                   
                 Strength 
                 Stiffness 
                 Weight 
               
               
                 Sample 
                 (kgf) 
                 (kgf @ 10% strain) 
                 (g/m2) 
               
               
                   
               
             
            
               
                 Machine Direction 
                 82-96 
                 10-17 
                 250-375 
               
               
                 Cross Machine Direction 
                 63-72 
                 12-19 
               
               
                   
               
            
           
         
       
     
     In the chart above, fabric breaking strength and stiffness were determined using an Instron model 5565 equipped with Bluehill 3 analysis software. Test specimens (3″×6″) were cut in both the machine and cross machine directions and tested using 1″ flat faced grips. Samples were tested using a 3″ gauge length and a crosshead speed of 4 in/min. The breaking strength of the fabric was determined at the point of the first yarn break. Stiffness of the fabric was taken as the load (kgf) at 10% elongation. 
     In the example above, the stiffness may refer to the force needed to stretch the sample a certain amount. This may provide information relating to how much lock out or containment is provided when this textile is formed into an upper  102  for an article of footwear  100 . The basis weight may refer to the grams per square meter for the specific sample size used. In other words, this measurement provides a normalized weight of a particular size sample swatch of the textile, which can then be used to calculate different sizes of the textile, such as the weight of an amount of the textile used to form an upper  102 . 
     To remove the desired amount of mechanical stretch, the knitted component  132  may first be stretched from its original first unstretched state (see  FIG.  8   ) to a second stretched state (see  FIG.  9   ). The knitted component  132  may be stretched in a cross-machine direction, which comprises stretching the knitted component in a course-wise direction, or width along the x-axis. The knitted component  132  may also be stretched in a machine direction, which comprises stretching the knitted component in a wale-wise direction, or length along the y-axis. The knitted component  132  may be stretched in only one of these directions, but preferably, the knitted component  132  is stretched along both the length and width. When an inlaid component is included (shown in  FIGS.  10 - 13   ), the knitted component  132  may be stretched in a direction that is parallel to the inlaid component  152 , in a direction that is perpendicular to the inlaid component  152 , or both. In one non-limiting example, it was determined that the upper  102  had a relatively greater ability to stretch in a direction that is perpendicular to the direction of the inlaid component  152  (e.g., since the inlaid component  152  may itself be resistant to stretching). For example, where the inlaid component extends in a heel to toe direction, there may be greater stretch in the lateral to medial direction (at least in a pre-processed state). Whereas, where the inlaid component extends generally in a lateral to medial direction, there may be greater stretch in the heel to toe direction. However, it is also contemplated that the inlaid component  152  may have little to no effect on the general stretch characteristics of the knitted component  132  into which it is inlaid. Further, in embodiments where it is desirable to stretch the knitted component  132  in a direction parallel to the lengthwise direction of at least one inlaid component  152  (e.g., to remove elasticity in that direction after “processing” as described below), the inlaid component  152  may initially include slack, and such slack may be removed during the stretching step such that the inlaid component  152  is substantially taught (and/or stretched relative to its relaxed state) after post-knit processing. 
     It is estimated that above a 12% stretch in both width and length could be a base level that may provide a desirable amount of the desired lockout benefit to a wearer when the knitted component  132  is formed into the upper  102 . However, stretching less or more than 12% is also contemplated. One example of stretch percentages is illustrated in the chart below. As shown, a 50 mm×50 mm test swatch of a knitted component  132  is stretched in both a length wise and width wise direction. “Unprocessed” refers to a sample of the knitted component  132  before stretching and steaming, while “processed” refers to the same sample after stretching and exposure to steam. The unprocessed state has a baseline of 100%, such that after processing (the “processed state”) it has been stretched 14% in the width direction and 21% in the length direction. It can be seen that the unprocessed sample weighed 1.3 grams, and, after stretching and steaming, it weighed 0.9 grams. The loss of mass may be attributable to various factors, including but not limited to stretching, where the density of the textile is reduced while the size increases. Also, reduction in mass may also be the result of any fusible material present in the yarns being lost due to the steaming process. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Unprocessed 
                 Processed 
                 Stretch % 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 W (mm) 
                 370 
                 420 
                 114% 
               
               
                   
                 H (mm) 
                 380 
                 460 
                 121% 
               
               
                   
                 50 mm × 50 mm 
                 1.3 grams 
                 0.9 grams 
               
               
                   
                   
               
            
           
         
       
     
     In order to satisfactorily stretch the upper  102  in preparation for post-processing methods such as steaming and/or heat pressing, the upper  102  may be secured to a stretching mechanism or device. This may include stretching the upper  102  in one or more directions with the inlaid component  152  present/incorporated into the upper  102 . In one example, the stretching device may be a jig  194 . As shown in  FIG.  9   , a jig  194  may be used to hold and/or position the upper  102  during the steaming (heat) process. In other processing methods, the jig  194  may be used to hold and/or position the upper  102 , or other knitted components (such as the heel element  134 ) during heating and exposure to pressure, such as by heat pressing. The jig  194  may be a separate element from the steaming device and/or, in the case of a heat press, the jig  194  may be disposed on a bottom plate of a heat press. 
     The jig  194  may have a top section (not shown) and a bottom section  196 , which may be formed using any material, such as rubber or metal or polymers or combinations thereof. If the material used to form the jig  194  has a melting temperature, the melting temperature should be above the typical temperature achieved during the steaming or heat-pressing process to ensure that the heat does not disfigure, alter, damage or otherwise negatively affect the jig  194 . The shape and configuration of the jig  194  is also not limited. In  FIG.  9   , the shape of the jig  194  is generally rectangular. Also, the jig  194  may be a solid surface or plate, or, as shown in the cut-away portion of the knitted component  132  in  FIG.  9   , the jig  194  have cut outs or openings formed therein to allow steam or heat or other forms of stimulus to pass through the jig  194  and make contact with the knitted component  132 . 
     The jig  194  may also include a positioning mechanism or device. As shown, the positioning mechanism includes a plurality of spring-loaded pins  198  that are configured to position the upper  102  on the jig  194 . Here, the shape formed by the plurality of spring-loaded pins  198  is substantially the same as the shape of the knitted component  132  being stretched and positioned on the jig  194 . It is also contemplated that the shape formed by the plurality of pins  198  generally corresponds to the shape of an upper  102  such that it corresponds with the outer perimeter of the upper  102 . The knitted component  132  or upper  102  may include a plurality of apertures configured to receive the spring-loaded pins  198 , and/or the spring-loaded pins may penetrate through the knitted component (or upper) as shown in  FIG.  9    to hold it in position upon and within the jig  194 . 
     The jig  194  may further include a pad (not shown) configured to prevent the upper  102  from sticking to the jig  194  and/or a heat press. The pad may be insulative and/or provide cooling on one or both sides of the upper  102 . In one example, the pad may generally be in the shape of the entire upper, or it may be shaped and sized to a particular area of the upper  102 . The thickness of the pad may reduce the amount of heat applied and even reduce or substantially prevent the areas of the upper  102  not corresponding to a fused area (e.g., the throat area  112 ) from being steamed and/or pressed, directly heated and/or burned. In one embodiment, the pad is formed of Teflon and is approximately 5 mm thick, though any suitable thickness may be used. The spring-loaded pins  198  are configured to compress if necessary during the heat-pressing process such that they do not inhibit the pressure applied to the knitted component  132  (e.g., if the spring-loaded pins  198  are longer than the thickness of the knitted component  132 ). In some embodiments, the jig  194  may be configured such that two or more knitted components  132  can be processed simultaneously. 
     When performing a heat pressing process (as opposed to only steaming process) a release paper (not shown) may be placed over certain areas of the knitted component  132 . The release paper is preferably constructed of a material that reduces or prevents the certain area of the upper  102  from sticking to it and therefore, the release paper may also prevent the certain areas of the knitted component from sticking to the jig  194 . The release paper may be configured to allow heat to be conducted to the knitted component  132  directly through the release paper and without interfering in the heating process. 
     For a steaming process, the jig  194 , with a knitted component  132  secured thereto, may be placed into a steaming mechanism, such as a steam chamber or unit. The knitted component  132  may then be subjected to a predetermined temperature of steam heat for a predetermined period of time. When subjected to this steam, the thermoplastic polymer material present in the knitted component  132 , such as the thermoplastic polymer material included with a yarn (i.e., the second yarn  146  described above, for example), may at least partially melt. As a result, the material originally forming separate yarns of the upper  102  may become bonded and/or continuous to form a fused area. In addition the thermoplastic polymer material may at least partially melt with one or more portions of the inlaid component  152  ( FIG.  11   ) incorporated into the knitted component  132 . Therefore, any one or more areas where the upper  102  contains thermoplastic polymer material, and where that material is subjected to a suitable process (such as the steaming process described herein), it is contemplated that at least one fused area will be formed. Once the upper  102  reaches a predetermined temperature (e.g., enough to activate the fusible yarn, for example) and/or when the upper  102  has been subjected to the steaming process for a pre-determined amount of time, the jig  194  may be removed from the steam exposure. While steaming and heat-pressing processes are described herein, any other suitable process may be used to form the fused areas. 
     In the case of a heat pressing process, such as during post-treatment of the heel element  134 , the jig  194  may be closed (the top section placed over the bottom section  196 ) and placed into the heat press. The heat press may be preheated to between about 100° C. and about 150° C. (or any other suitable temperature range). The press may then be activated. In one embodiment, the heat press may apply approximately 8 kg/cm{circumflex over ( )}2 of pressure at between about 120° C. and about 150° C. for a period of 30 seconds. When subjected to this heat and pressure, the thermoplastic polymer material of the knitted component  136  which may form the heel element  134 , such as the thermoplastic polymer material included with a yarn (i.e., the fifth yarn  151  described above), may at least partially melt. As a result, the material originally forming separate yarns of the heel element  134  may become bonded and/or continuous to form at least one, or a plurality of fused area(s). Therefore, any one or more areas where the knitted component  132  or  136  contains thermoplastic polymer material, and where that material is subjected to a suitable process (such as the heat-pressing process described herein), it is contemplated that a fused area will be formed. The melting of the thermoplastic polymer material to one or more adjacent portions of the inlaid component  152  may also serve to hold, secure or lock the inlaid component in place, once cooled. A thermocouple (not shown) may measure the temperature of the knitted component  132  or  136  during this process. Once the knitted component  132  or  136  reaches a predetermined temperature (e.g., between about 120° C. and about 132° C.), the heat press may open, and the knitted component  132  or  136  may be removed. While a heat-pressing process is described, any other suitable process may be used to form the fused areas of the heel element  134 . 
     Next, after steaming (the upper  102 ) and/or heat-pressing (the heel element  134 ), the heated knitted component  132  and/or  136  may be shaped or formed. In one example, the heel element  134  formed from the second knitted component  136  may be formed on a last or other similar device in order to shape the heel element  134  into a concave, three-dimensional structure that would preferably generally confirm to the shape of a heel of a wearer. 
     Further, after steaming and/or heating (and shaping, if desired) the knitted component  132  and/or  136  may begin to cool. During cooling, the knitted component  132  that forms the upper  102 , for example, may remain positioned on the jig  194  in its stretched condition. As it cools, the thermoplastic material present in any one of the yarns, such as the second yarn  146  present in the knitted component  132 , may at least partially fuse together with adjacent yarns in its proximity to within the knitted component  132 . Once cooled, the fusible yarn may also enhance one or more mechanical properties of the knitted component  132  and/or  136  (such as strength and/or rigidity) at least in select locations and/or have the effect of securing or locking the relative positions of the yarns within the knitted component. Because the fusible yarn cooled when the knitted component  132  (forming the body  154  of the upper  102 ) is in its stretched condition, the knitted component may therefore remain in this stretched and expanded condition. Likewise, after cooling of the fusible yarn (i.e., the fifth yarn  151 ) within the knitted component  136  (forming the heel element  134 ) the heel element may therefore have greater stiffness, durability and ability to retain shape, for example. 
     By stretching the knitted component  132  of the upper from a first unstretched condition ( FIG.  8   ) to a second stretched condition ( FIG.  9   ) and steaming it on the jig  194  in the stretched condition, the fusible yarns (such as the second yarn  146 ) may at least partially melt and infiltrate the adjacent and surrounding yarns (such as the first yarn  144  and third yarn  148 ). Upon cooling, the fusible yarns can then lock the surrounding yarns into the stretched condition such that this process provides an ability to remove at least a portion, at least half of, substantially all or all of the mechanical stretch of the knitted component  132 , as necessary or desired, before it is ultimately removed from the jig  194  and later formed into an upper  102 . 
     As an alternative to natural cooling, the knitted component  132 ,  136  may go through a cooling process, such as a cold-pressing process. The cooling process may set the fused area(s) or otherwise bring the fused area into a state other than a melted state. In one example, the knitted component  132 ,  136  may be placed in a cold press. A silicon pad (which may be any other suitable material) may be placed on one or both sides of the knitted component  132 ,  136 , and particularly over the heated and/or partially melted areas, to ensure even pressure. The cold press may include a refrigeration system, but in some embodiments the cold press is at or about at room temperature. When activated, in one non-limiting example, the cold press may apply approximately 15-18 kg/cm{circumflex over ( )}2 of pressure for about 12 seconds. During the cold-pressing process, the release paper may remain attached to the knitted component  132 ,  136  to prevent the knitted component  132 ,  136  from sticking to the cold press, though this is not required. The cold press can be used in conjunction with a jig similar to the jig  194  described with respect to the steaming and/or heat-pressing process. 
     In some embodiments, a heat pressing process may be used to attach an auxiliary component, such as the auxiliary interior element  156  described above, to the upper  102 . While not shown, the auxiliary component  156 , which may include a thermoplastic polymer material, may be placed in contact with the upper  102  such that it at least partially melts and thereby adheres to the upper  102  during a steaming and/or a heat-pressing process. Alternatively, or in addition, an auxiliary component  156  may be substantially free of a thermoplastic polymer and may be bonded to the upper  102  by placing the auxiliary component  156  in contact with the heated thermoplastic polymer of the upper  102 . This may be done in conjunction with the process of forming the fused areas or may be done at a different time. 
     While the embodiments and other features are described generally herein with reference to an upper  102  for an article of footwear, those features could additionally or alternatively be incorporated into another type of article. For example, the features described herein may be included in 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). 
     In the present disclosure, the 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 present embodiments 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 present disclosure 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 present disclosure and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.