ARTICLE OF FOOTWEAR WITH ENHANCED DURABILITY FEATURES

Abstract

Aspects herein are directed to, among other things, a knitted upper for an article of footwear. The knitted upper includes different knit zones including a first knit zone which may be located in a toe and forefoot region of the article of footwear. The first knit zone includes a first knit layer forming an outer-facing surface of the knitted upper, a second knit layer forming an inner-facing surface of the knitted upper, and a third thermoformed layer substantially contained between the first knit layer and the second knit layer. The third thermoformed layer acts as a barrier, reducing the likelihood of abrasion forces that may occur from contact between the knitted upper and a ground or other surface from contacting yarns that form the second knit layer, thereby increasing the structural integrity of the knitted upper.

Description

TECHNICAL FIELD

Aspects herein are directed to an article of footwear comprising a knitted upper that has enhanced durability features.

BACKGROUND

Some uppers used in articles of footwear may experience high rates of abrasion due to dragging portions of the upper against a ground surface or other types of surfaces. Some example activities where this may occur include skateboarding, tennis, soccer, and the like. The high rates of abrasion may cause tearing, holes, or a weakening in the structural integrity of the upper, which decreases the useable life of the article of footwear. This may be especially true with knitted uppers, as the yarns may fray or break under the repeated stress of the activity. Traditional articles of footwear may layer multiple materials on top of each other in an effort to better withstand the abrasion forces. Layering multiple materials may not only increase the overall weight of the article of footwear, but it may also increase manufacturing time and expense.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of aspects herein are described in detail below with reference to the attached drawing figures, wherein:

FIG. 1A illustrates a medial view of an example article of footwear in accordance with aspects herein;

FIG. 1B illustrates a lateral view of the example article of footwear of FIG. 1 in accordance with aspects herein;

FIG. 2 illustrates a top view of a knitted upper of the article of footwear of FIG. 1 in accordance with aspects herein;

FIG. 3 illustrates a perspective view of a portion of the knitted upper of FIG. 2 used in a first knit zone of the knitted upper in accordance with aspects herein;

FIG. 4 illustrates the portion of the knitted upper of FIG. 3 with a first knit layer lifted away to illustrate inlaid yarns in accordance with aspects herein;

FIG. 5 illustrates a perspective view of a portion of the knitted upper of FIG. 2 used in a second knit zone and a third knit zone of the knitted upper in accordance with aspects herein;

FIG. 6 illustrates the portion of the knitted upper of FIG. 5 with the first knit layer lifted away to illustrate inlaid yarns in accordance with aspects herein;

FIG. 7 illustrates a schematic depiction of a possible knit structure having an inlaid yarn substantially contained between a first knit layer and a second knit layer in accordance with aspects herein;

FIG. 8 illustrates a schematic depiction of an example mold press that may be used to create a thermoformed layer in the knitted upper in accordance with aspects herein;

FIG. 9 illustrates a schematic depiction of a portion of the knitted upper placed on the mold press of FIG. 8 in accordance with aspects herein;

FIG. 10 illustrates a cross-section of the mold press of FIG. 8 and the knitted upper when heat and/or pressure is applied to the knitted upper in accordance with aspects herein;

FIG. 11 illustrates a cross-section of the knitted upper depicting the thermoformed layer of the first knit zone and the inlaid yarns of the second knit zone in accordance with aspects herein;

FIG. 12 illustrates a cross-section of the first knit zone of the knitted upper before heat and/or pressure are applied to the first knit zone of the knitted upper in accordance with aspects herein;

FIG. 13 illustrates a cross-section of the first knit zone of the knitted upper after heat and/or pressure are applied to the first knit zone of the knitted upper in accordance with aspects herein; and

FIG. 14 illustrates a flow diagram of an example method of manufacturing a knitted upper in accordance with aspects herein.

DETAILED DESCRIPTION

Aspects herein are directed to an article of footwear having a knitted upper, a knitted upper for an article of footwear, and methods of manufacturing a knitted upper for an article of footwear, The knitted upper may include yarns and knit structures that enhance the knitted upper's ability to withstand abrasion forces while providing a pleasing aesthetic to the knitted upper. In example aspects, the knitted upper may include a first knit zone. In some example aspects, the knitted upper may include the first knit zone, a second knit zone, or a third knit zone, or any combination of thereof. In some aspects, the knitted upper may include both the first knit zone and the second knit zone, both the first knit zone and the third knit zone, both the second knit zone and the third knit zone, or each of the first knit zone, the second knit zone, and the third knit zone.

In aspects, the first knit zone may be located in one or more of a toe area of the knitted upper, a lateral side, and a medial side of a forefoot region of the knitted upper. The second knit zone may be located on the lateral side and/or the medial side of a midfoot region of the knitted upper. In some example aspects, the second knit zone seamlessly extends from the first knit zone. The third knit zone may be located on the lateral side and/or the medial side of a heel region of the knitted upper and may also be located in a rear-most heel area of the knitted upper. In some example aspects, the third knit zone seamlessly extends from the second knit zone. In some aspects, the first knit zone, the second knit zone, and the third knit zone may be integrally knitted with each other during a single knitting process such as to form an integrally-coextensive knitted component. In other aspects, the knit zones may be knitted at least in part separately and then combined to form a composite knitted structure.

In example aspects, each of the first knit zone, the second knit zone, and/or the third knit zone may include yarns and/or knit structures that impart one or more functional characteristics to the corresponding knit zones. In some example aspects, functional characteristics, such as elasticity or strength, may be provided by selecting particular knit structures in the different knit zones, and/or by incorporating one or more yarns formed of a particular material in the different knit zones. For example, in certain sports such as skateboarding, the toe area and the forefoot region of the knitted upper may experience greater amounts of contact with a ground surface and/or other surface (e.g., skateboard surface) compared to the midfoot and heel regions of the knitted upper, although these regions may also make contact with the ground surface and/or the skateboard surface. By extension, due to the greater amount of contact with the ground surface and/or the skateboard surface, the toe area and the forefoot region of the knitted upper may experience higher rates of abrasion and may wear out quicker than other regions of the upper.

In some aspects, to impart durability features to one or more knit zones (e.g., a first knit zone, a second knit zone, and/or a third knit zone, or another zone, as described herein) of a knitted component forming a knitted upper, knit zones may include a first knit layer located on an outer-facing surface of the knitted upper, a second knit layer located on an inner-facing surface of the knitted upper, and a third thermoformed layer that is substantially contained between the first knit layer and the second knit layer. When a knitted upper repeatedly contacts a ground surface and/or a skateboard surface during use (e.g., in the toe area and/or in the forefoot region), yarns forming the first knit layer can be degraded, e.g., may wear, fray and/or eventually break. However, having a third thermoformed layer that acts as a barrier helps the knitted upper better withstand abrasion forces (compared to, for example, yarns not forming a thermoformed structure) thus limiting or inhibiting abrasion forces from fraying or breaking yarns forming the second knit layer. Incorporation of the aforementioned aspects and others allows a knitted upper to be less prone to developing areas of degradation, structural weakness, and/or holes, which increases the useable life of the knitted upper and thus contributes to more sustainable use of footwear. Further, the third thermoformed layer may also comprise a water-resistant and/or water-proof barrier that helps limit, inhibit, or even substantially prevent moisture contacting the outer-facing surface of the knitted upper in the first knit zone from contacting the wearer.

In example aspects, to form the first knit zone of the knitted upper, one or more yarns are used to knit the first knit layer and the second knit layer. The one or more yarns have a first melting point. A plurality of inlaid yarns may be inlayed between the first knit layer and the second knit layer such that the plurality of inlaid yarns are at least partially positioned between the first knit layer and the second knit layer. In example aspects, the plurality of inlaid yarns may comprise a thermoplastic material having a second melting point such as thermoplastic polyurethane (TPU) and/or thermoplastic elastomer (TPE). In example aspects, the second melting point of the plurality of inlaid yarns is less than the first melting point of the one or more yarns used to knit the first knit layer and the second knit layer.

To form the third thermoformed layer, heat is applied to the knitted upper in the first knit zone. The heat is sufficient to melt the thermoplastic material of the inlaid yarns but is not high enough to melt and/or burn the yarns used to form the first and second knit layers. A small amount of pressure is also applied to the first knit zone, where the pressure is sufficient to cause some flow of the melted thermoplastic material in order to form the third thermoformed layer. The amount of applied pressure is calibrated such that the melted thermoplastic material generally does not migrate to the surfaces of the first knit layer and the second knit layer and is substantially contained between the first knit layer and the second knit layer. This helps to preserve the handfeel and pliability of the knitted upper. For example, when too much pressure is applied, the melted thermoplastic material may migrate to the surfaces of the first and second knit layers resulting in a stiff, inflexible knitted upper, which reduces wearer comfort. Once the knitted upper is cooled, the melted thermoplastic material hardens and forms the third thermoformed layer.

The second knit zone and the third knit zone of the knitted upper may have a similar knit construction including the first and second knit layers and one or more inlaid yarns at least partially positioned between the first and second knit layers. However, unlike the first knit zone of the knitted upper, heat may not be applied to the second knit zone and the third knit zone such that the inlaid yarn(s) may remain in their native, un-melted yarn state.

Aspects herein contemplate that the first knit layer in each of the second knit zone and the third knit zone may be knit to include engineered openings having a predefined size. The inlaid yarn(s) are exposed and/or visible through the openings in the first knit layer. In example aspects, the yarns used to form the first knit layer may have a different or contrasting color compared to the plurality of inlaid yarns. In this aspect, a pleasing aesthetic may be produced. In further example aspects, the thermoplastic material used to form the inlaid yarns may have a coefficient of friction that is higher compared to the coefficient of friction of the yarns used to form, for example, the first knit layer, such that the inlaid yarns may have a noticeable tackiness or grip Thus, because the inlaid yarn(s) are exposed by way of the openings in the first knit layer, aspects herein contemplate that the second knit zone and the third knit zone may have a coefficient of friction higher than regions without engineered openings or without the inlaid yarn(s) being exposed on an outer-facing surface. This may be useful in providing tactile feedback to a wearer of the article of footwear when regions of the knitted upper having the engineered openings make contact with, for example, a skateboard or a ground surface. Stated differently, when portions of the knitted upper that include the second knit zone and the third knit zone contact a ground surface and/or a skateboard surface, the inlaid yarns may momentarily “grip” a contacting surface through the engineered openings, which provides a tactile sensation that may be used by the wearer to understand the positioning of the article of footwear in relation to the surface.

As used herein, an article of footwear generally includes a sole structure secured to an upper. The article of footwear described herein may comprise a running shoe, a baseball shoe, a basketball shoe, a skateboarding shoe, a cycling shoe, an American football shoe, a tennis shoe, a global football shoe, a training shoe, a walking shoe, a hiking shoe, and the like. The concepts described herein may also be applied to other footwear types that are considered non-athletic such as dress shoes, loafers, sandals, and work boots. As used herein, the article of footwear may be divided into different general regions. A forefoot region generally includes portions of the article of footwear that correspond to the toes and joints connecting the metatarsals with the phalanges. A midfoot region generally includes portions of the article of footwear corresponding with an arch area and an instep area of the foot. A heel region generally corresponds with rear portions of the foot including the calcaneus bone. The article of footwear described herein may include a lateral side which corresponds with an outside area of the foot (i.e., the surface that faces away from the other foot) and a medial side which corresponds with an inside area of the foot (i.e., the surface that faces toward the other foot). The different regions and sides described above are intended to represent general areas of footwear to aid in the following discussion and are not intended to demarcate precise areas. The different regions and sides may be applied to the article of footwear as a whole, to the knitted upper, and to the sole structure.

The term “outer-facing surface” as used herein means a surface of the knitted upper or article of footwear that faces the external environment. In some aspects, the outer-facing surface may mean the outermost-facing surface of the knitted upper or article of footwear. The term “inner-facing surface” as used herein means a surface of the knitted upper or article of footwear that faces a void for receiving the wearer's foot. In some aspects, the inner-facing surface may mean the innermost-facing surface of the knitted upper or article of footwear.

The term “knit” is used herein to describe the knitted upper refers to a textile piece that is formed from at least one yarn that is manipulated (e.g., with a knitting machine) to form a plurality of intermeshed loops (also known as interlooping) that define courses and wales. The term “course,” as used herein, refers to a predominantly horizontal row of knit loops (in an upright textile as it is knit on the knitting machine) that is produced by adjacent needles during the same knitting cycle. The course may comprise one or more stitch types, such as a knit stitch, a missed stitch, a tuck stitch, a transfer stitch, a rib stitch, and the like as these terms are known in the art of knitting. The term “coursewise direction” refers to a direction that is parallel to the knit courses of the textile piece. The term “wale,” as used herein, is a predominantly vertical column of intermeshed or interlooped knit loops, generally produced by the same needle at successive (but not necessarily all) courses or knitting cycles. The term “walewise direction” refers to a direction that is parallel to the knit wales of the textile piece.

The term “double knit construction” as used herein refers to a knit construction that is generally formed on at least two needle beds of a knitting machine (i.e., a multi-bed construction). Such multi-bed knit constructions may be characterized by two opposing faces of knit loops and/or tucks, e.g., one face of loops formed on a first needle bed, and a second face of loops formed on a second needle bed. In example aspects, the two faces may be joined by yarns that interloop with yarns in both the first face and the second face of the double knit construction. Common double knit constructions include double jersey, rib, interlock, cardigan, other “double bed” knit structures initially formed on at least two needle beds, and other knit structures having two opposing faces of knit loops or tucks, including full-gauge and less-than full gauge variations of those structures. The term “single knit construction” as used herein refers to a knit construction generally formed on a single needle bed (i.e., a single-bed construction). Common single knit constructions include single jersey.

The term “integrally knit,” as used herein, may mean a knit textile having a yarn from one or more knit courses in a first area or zone being interlooped with one or more knit courses of another area or zone. The interlooping may be through a simple knit stitch, a tuck stitch, a held stitch, a float or miss stitch, and the like. In this way, areas or zones that are integrally knit together have a seamless transition such that they seamlessly extend from one another.

The term “opening” when used with respect to the first knit layer in the second knit zone and the third knit zone refers to openings formed through an intentional knitting action (known as “engineered openings”) as opposed to the inherent spacing between yarns in a knit structure. For example, the openings may be created through transfer stitches as is known in the art of knitting. The transfer process may include a two-needle transfer which would result in an opening that generally extends the distance of two knit wales, a one-needle transfer which would result in an opening that generally extends the distance of one knit wale, and the like. By way of this knitting sequence, the openings in accordance with aspects herein may comprise a rectangular shape or oval shape corresponding generally to a two-needle transfer, or square shape corresponding generally to a one-needle transfer, with the openings having a length dimension in a coursewise direction and a width direction in a walewise direction. Moreover, based on the knitting sequence, the openings may form a regular and repeating pattern with each opening having a generally uniform size.

Forming the knitted upper using a knit construction may provide advantages including, but not limited to, a particular degree of elasticity (for example, as expressed in terms of Young's modulus), breathability, bendability, strength, moisture absorption, weight, abrasion resistance, and/or a combination thereof. These characteristics may be accomplished by selecting a particular 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 elasticated yarns, a thermoplastic material), by selecting yarns of a particular size (e.g., denier), and/or a combination thereof. Using a knit construction may also provide desirable aesthetic characteristics by incorporating yarns having different colors, textures or other visual properties arranged in a particular pattern. The yarns themselves and/or the knit structure formed by one or more of the yarns may be varied at different locations such that the knitted upper may have different properties, as described herein.

The yarns in accordance with aspects herein may include monofilament yarns and/or multifilament yarns formed from, for example, synthetic materials. In example aspects, yarns used to knit the first knit layer and the second knit layer may include high-melting polymer yarns (e.g., yarns that melt at about 175 degrees Celsius or higher) including polyethylene terephthalate (PET) yarns (commonly known as polyester), recycled PET yarns, polyamide yarns (commonly known as nylon), elastane yarns, and other high-melting synthetic yarns. In other examples, yarns used to knit the first knit layer and the second knit layer may include natural fibers with a higher decomposition temperature (e.g., above 200 degrees Celsius).

In example aspects, the inlaid yarns that form the third layer of the knitted upper may include yarns with a lower melting temperature than the melting or decomposition temperature of at least some yarns in the first and second knit layers. For example, the inlaid yarns that form the third layer may include low-melting thermoplastic yarns (e.g., yarns that melt at about 170 degrees Celsius or less). The low-melting thermoplastic yarns comprise a synthetic polymeric material formed from a polymer that melts at relatively low temperatures. In example aspects, the inlaid yarns may include a thermoplastic elastomer, such as thermoplastic polyurethane (TPU) yarns, thermoplastic polyethylene (TPE) yarns, and other synthetic polymeric materials having a low melting point. In some examples, the inlaid yarns include a thermoplastic elastomer that is either TPU or a styrene ethylene/butylene styrene (SEBS). In some example aspects, the inlaid yarns may comprise a core-sheath configuration in which the low-melting thermoplastic material (e.g., thermoplastic elastomer such as TPU or SEBS) surrounds a core of a high-melting material such as, for example, high-melting PET. In other example aspects, the inlaid yarns may be entirely formed from the thermoplastic material. In example aspects, the melting temperature of the thermoplastic material of the inlaid yarns may be sufficiently different from the melting temperature of the yarns used to form the first and second knit layers that the thermoplastic material of the inlaid yarns may be essentially completely melted without melting or adversely affecting (e.g., burning, charring, or singeing) the characteristics of the yarns used to knit the first and second knit layers. In some aspects, the melting temperature of the low-melt polymer of the inlaid yarns is no greater than 180 degrees Celsius and, in some aspects, at least 120 degrees Celsius. In one example, the melting temperature is between approximately 160 degrees Celsius and 170 degrees Celsius. Additionally, in some aspects, the low-melt thermoplastic polymer of the inlaid yarns is a composition of one or more thermoplastic elastomers with a glass transition temperature(s) below minus 20 degrees Celsius, which allows the thermoplastic elastomer(s) present in the polymeric composition to be in their “rubbery” state, even when the knitted component used in cold environments.

The term “thermoformed” when used to refer to the third layer in the first knit zone, refers to a generally unitary or continuous structure formed after pressure is applied to the melted thermoplastic material of the inlaid yarns and after the melted thermoplastic material has hardened upon cooling. As such, the thermoformed layer may comprise the same polymeric material as the thermoplastic material used to form the inlaid yarns (e.g., TPU, TPE, and the like). When the inlaid yarns are entirely formed from the low-melting thermoplastic material, the thermoformed layer may comprise only the cooled thermoplastic material and, if present, any yarns forming the first and/or second layers crossing to the opposite layer. When the inlaid yarns comprise a core-sheath configuration, the thermoformed layer may comprise the cooled thermoplastic material and the sheath portion of the inlaid yarns (as well as any yarns forming the first and/or second layers crossing to the opposite layer if present). Any and all aspects, and any variation thereof, are contemplated as being within the scope herein.

The static or dynamic coefficient of friction (COF) of a textile or plaque sample can be determined using test method ASTM D1894. In this method, a sample is cut to size and mounted on the sled, and a 100 gram weight plate is placed on the sled. During the test, the weighted sled is pulled across a test surface of the material being tested. For example, static and dynamic or wet and dry COF may be determined by pulling the sled across a concrete surface to determine the COF of the sample and concrete. The coefficient of friction of the sample against that surface is captured by recording the normal force (100 grams plus sled weight) and measuring the applied force required to drag the sled across the test surface. The coefficient of friction (COF) is then calculated from the ratio of the two forces. Dry COF is determined by testing a dry sample against a dry testing surface, and wet COF is determined by testing a sample wetted with water by soaking it in room temperature water for ten minutes against a test surface wetted with room temperature water.

Unless indicated otherwise, all measurements provided herein are taken when the upper and/or article of footwear is at standard ambient temperature and pressure (298.15 K and 100 kPa) and is in a resting (non-tensioned) state. As used herein, the terms “substantially” and “about” mean within +5% of an indicated value.

FIGS. 1A and 1B respectively schematically depict a medial view and a lateral view of an example article of footwear 100 having a knitted upper 110 and a sole structure 112 secured to the knitted upper 110. The knitted upper 110 includes an outer-facing surface 111 and an inner-facing surface 113. The article of footwear 100 is shown in the form of an athletic shoe, but other types of shoes (e.g., sandals, leisure shoes, and the like) are contemplated herein. The article of footwear 100 includes a forefoot region 114 having a toe area 115, midfoot region 116, and a heel region 118 having a heel area 119, a medial side 120, and a lateral side 122. The article of footwear 100 includes an ankle collar 124 having an opening 125 for receiving a wearer's foot, a throat area 126, and a tongue 128. In example aspects, the tongue 128 may be integrally formed with the knitted upper 110, or the tongue 128 may comprise a separate element that is secured to the knitted upper 110 in, for example, a post-knitting manufacturing step. Although not shown, aspects herein contemplate that the article of footwear 100 may include additional elements layered on top of the knitted upper 110 including, for example, leather materials, synthetic leather materials, knitted or woven textiles, polymer skins, and the like. The additional elements may be positioned at discrete locations of the knitted upper 110 including, for example, the toe area 115 (e.g., a toe cap), the heel area 119 (e.g., a heel counter), and the like.

In example aspects, the knitted upper 110 may comprise a unitary knit construction and may be formed in a single knitting process. The knitted upper 110 may include a first knit zone 130, a second knit zone 132, and/or a third knit zone 134. The first, second, and third knit zones 130, 132, and 134 are depicted schematically and are provided to illustrate potential locations of the knit zones on the knitted upper 110. Additional macroscopic features of the first, second, and third knit zones 130, 132, and 134 are shown in at least FIG. 2. In some example aspects, the first knit zone 130 may be located in the toe area 115 of the knitted upper 110 and may extend along each of the medial side 120 and the lateral side 122 of the knitted upper 110 in the forefoot region 114. In some aspects, the first knit zone 130 within the toe area 115 extends from a forward-most end of the knitted upper 110 to the forward portion of a throat area 126, which may be where a tongue 128 is located in aspects including a tongue. In some aspects, the first knit zone 130 within the toe area 115 extends from a forward-most end of the knitted upper 110 and into or beyond where the forward portion of the throat area 126 starts on the medial side 120 and/or the lateral side 122. While the first knit zone 130 is shown in FIGS. 1A and 1B in the forefoot region toe area 115, in other example aspects, the first knit zone 130 can be located in other regions of the knitted upper 110. For example, the first knit zone 130 may be located adjacent to, surround, and/or may include a plurality of lace apertures, or may include the throat area 126, the tongue 128, the midfoot region 116, and/or the heel region 118, or may include some combination of the same.

In example aspects, and as depicted in FIGS. 1A and 1B, the first knit zone 130 extends a greater distance toward the heel area 119 of the knitted upper 110 on the lateral side 122 compared to the medial side 120. For example, the first knit zone 130 may extend at least partially into the midfoot region 116 of the knitted upper 110 on the lateral side 122. When the article of footwear 100 is intended for use as a skateboarding shoe, the lateral side 122 of the knitted upper 110 and, particularly, the area between the forefoot region 114 and the midfoot region 116 on the lateral side 122, may come into more frequent contact with a ground surface and/or the skateboard compared to the medial side 120 of the knitted upper 110. As described below, the first knit zone 130 may include features that make it more resistant to wear-and-tear from abrasion, and extending the first knit zone 130 a greater distance toward the heel area 119 on the lateral side 122 reduces the chances of wear-and-tear in this location.

The second knit zone 132 seamlessly extends from the first knit zone 130. The second knit zone 132 is generally located in the midfoot region 116 on both the medial side 120 and the lateral side 122 of the knitted upper 110. As will be described in greater detail with respect to subsequent figures, the second knit zone 132 may include engineered openings through which inlaid yarns are visible and/or exposed. The third knit zone 134 seamlessly extends from the second knit zone 132 and is generally located in the heel region 118 on both the medial side 120 and the lateral side 122 of the knitted upper 110. The third knit zone 134 may also be located in the heel area 119 of the knitted upper 110. The third knit zone 134 may also include engineered openings (shown, for example, in FIG. 2) through which the inlaid yarns are visible and/or exposed. In example aspects, the engineered openings in the third knit zone 134 may be smaller in size than the engineered openings in the second knit zone 132.

FIG. 2 depicts the knitted upper 110 of FIG. 1 before being secured to the sole structure 112. In example aspects, the knitted upper 110 may have a generally U-shaped configuration that is outlined by an outer perimeter edge 210, a pair of heel edges 212, and an inner edge 214. The U-shaped configuration is just one example shape of the knitted upper 110, and other example shapes are contemplated herein. When incorporated into the article of footwear 100, the outer perimeter edge 210 may be positioned against the upper surface of the sole structure 112 and may be joined to a strobel in example aspects. In other aspects, the knitted upper 110 may include an underfoot portion. In this example, the article of footwear 100 may not include a strobel. In example aspects, the pair of heel edges 212 are joined to each other and extend generally vertically in the heel area 119 of the article of footwear 100. The inner edge 214 forms the ankle collar 124 and extends forward to define the throat area 126. The knitted upper 110 includes a first surface 216 that corresponds to the outer-facing surface 111 of the article of footwear 100 and an opposite second surface 217 that corresponds to the inner-facing surface 113 of the article of footwear 100. In example aspects, the first surface 216 of the knitted upper 110 is formed at least partially by a first knit layer 218, and the second surface 217 of the knitted upper 110 is formed by a second knit layer 220.

The knitted upper 110 is formed from yarns that are manipulated (e.g., with a knitting machine) to form, for example, the first knit layer 218, the second knit layer 220, and one or more inlaid yarns at least partially positioned between the first knit layer 218 and the second knit layer 220. Each of the first knit layer 218 and the second knit layer 220 includes a plurality of intermeshed loops that define a variety of courses that extend in a coursewise direction 223 and wales that extend in a walewise direction 225. Aspects herein contemplate that portions of the knitted upper 110 may be joined together (e.g., edges of the knitted upper 110 being joined together following the knitting process). In this example, the knitted upper 110 is formed such that the coursewise direction 223 corresponds to a lateral-to-medial direction and the walewise direction 225 corresponds to a heel-to-toe direction, but it should be understood that other examples of the knitted upper 110 may be knit with a different orientation on the knitting machine such that these directions may vary.

FIG. 2 depicts the first knit zone 130, the second knit zone 132, and the third knit zone 134 of the knitted upper 110, where each of the first, second, and third knit zones 130, 132, and 134 seamlessly extend from one another. As depicted, the first knit zone 130 extends a greater distance toward the heel edges 212 on the lateral side 122 compared to the medial side 120 of the knitted upper 110.

FIG. 2 is provided to illustrate some of the macroscopic features of at least the first knit layer 218 of the knitted upper 110. In the first knit zone 130, the first knit layer 218 comprises intermeshed loops that form a plurality of courses 222 extending in the coursewise direction 223 and a plurality of wales 224 extending in the walewise direction 225, as shown in the enlarged view of the first knit zone 130. In example aspects, the first knit layer 218 does not include engineered openings in the first knit zone 130. As such, the third thermoformed layer is generally not visible or exposed by way of the first knit layer 218.

The second knit zone 132 includes a first plurality of openings 226 in the first knit layer 218, as shown in the enlarged view. As will be described below, each opening within the first plurality of openings 226 is generally formed by knitting at least two consecutive knit stitches using one or more yarns, executing a two-needle transfer, and then knitting at least two consecutive knit stitches using the yarns. This pattern is just one example, and other knit patterns are contemplated herein, such as knitting more than one knit stitch and transferring the yarns for more than two consecutive needle positions or knitting more than two consecutive knit stitches and transferring the yarns for two or more consecutive needle positions. In other examples, each opening within the second knit zone 132 may be formed from a single-needle transfer.

The knit pattern is repeated within a particular knit course. The pattern is also executed when knitting the additional knit courses that form the second knit zone 132. For example, the knit pattern may be executed in every knit course of the first knit layer 218 in the second knit zone 132, every other knit course, every third knit course, every fourth knit course, and so on. The result is a repeating pattern of the first plurality of openings 226. For example, the first plurality of openings 226 may be arranged in a repeating pattern of rows extending in the coursewise direction 223 and columns extending in the walewise direction 225, where openings 226 in a particular course may be offset from openings 226 in consecutive courses to form a staggered arrangement.

Each of the first plurality of openings 226 may have a uniform size. Because of how the plurality of openings 226 are formed, each of the openings 226 may have a length 228 corresponding to a long axis of the opening 226, where the long axis of the opening 226 extends in the coursewise direction 223. Further, each of the openings 226 may have a width 230 corresponding to a short axis of the opening 226, where the short axis of the opening 226 extends in the walewise direction 225. This is shown in the additional enlarged view depicted in FIG. 2. In example aspects, the length 228 may be greater than the width 230 such that each of the first plurality of openings 226 has a generally rectangular or oval shape. In example aspects, the length 228 may be about 0.5 mm, about 1 mm, about 1.5 mm, about 2 mm, about 2.5 mm, about 3 mm, or about 3.5 mm. These are illustrative lengths and other lengths are contemplate herein dependent on the knit pattern used to create the first plurality of openings 226.

The first plurality of openings 226 in the first knit layer 218 expose or make visible portions of one or more inlaid yarns 232 that are otherwise positioned between the first knit layer 218 and the second knit layer 220. In this example, a first plurality of inlaid yarns 232 extend in the coursewise direction 223 and are positioned between the first knit layer 218 and the second knit layer 220. As will be described in greater detail with respect to FIG. 4, in example aspects, at least one inlaid yarn is inlaid within each knit course in the second knit zone 132 as shown in FIG. 2. The same end of the inlaid yarn may extend through courses to form the first plurality of inlaid yarns 232, such that the first plurality of inlaid yarns 232 may refer to a plurality of segments of a continuous yarn inlaid in multiple courses. In example aspects, two inlaid yarns are inlaid within each knit course in the second knit zone 132.

In some aspects, the surface area of the first surface 216 in the second knit zone 132 may be approximately 50% exposed inlaid yarns 232 in the area containing the first plurality of openings 226. For example, a knit pattern of a two-needle transfer and two knit stitches may result in the surface area of the first surface 216 being approximately 50% of the exposed inlaid yarns 232, but it should be understood that other patterns may achieve this result.

The third knit zone 134 includes a second plurality of openings 234 in the first knit layer 218, as shown in the enlarged view. As will be described below, the second plurality of openings 234 is generally formed by knitting a knit stitch using one or more yarns, executing a one-needle transfer, and then knitting a knit stitch using the yarns. This pattern is just one example, and other knit patterns are contemplated herein such as knitting more than one knit stitch and executing a two-needle transfer, a three-needle transfer, and so on. The knit pattern is repeated within a particular knit course. The pattern is also executed when knitting the additional knit courses that form the third knit zone 134. For example, the knit pattern may be executed in every knit course of the first knit layer 218 in the third knit zone 134, every other knit course, every third knit course, every fourth knit course, and so on. The result is a repeating pattern of the second plurality of openings 234. For example, the second plurality of openings 234 may be arranged in a repeating pattern of rows extending in the coursewise direction 223 and columns extending in the walewise direction 225, where openings 234 in a course may be offset from openings in consecutive courses to form a staggered arrangement.

Each of the second plurality of openings 234 may have a uniform size. Because of how the openings 234 are formed, each of the openings 234 may have a length 236 extending in the coursewise direction 223 and a width 238 extending in the walewise direction 225. This is shown in the additional enlarged view depicted in FIG. 2. In example aspects, the length 236 may be approximately the same as the width 238 such that each of the second plurality of openings 234 has a generally square shape. In example aspects, the length 236 may be about 0.25 mm, about 0.5, about 1 mm, about 1.5 mm, or about 2 mm. These are illustrative lengths, and other lengths are contemplated herein dependent on the knit pattern used to create the openings 234. The length 236 of each of the second plurality of openings 234 is different than the length 228 of each of the first plurality of openings 226. In example aspects, the length 236 of each of the second plurality of openings 234 is generally shorter than the width 230 of each of the first plurality of openings 226. When the knitted upper 110 does not include the third knit zone 134, the second knit zone 132 may extend to the heel edges 212.

The second plurality of openings 234 in the first knit layer 218 expose or make visible portions of a second plurality of inlaid yarns 240 otherwise positioned between the first knit layer 218 and the second knit layer 220 where the second plurality of inlaid yarns 240 extends in the coursewise direction 223. In example aspects, at least one inlaid yarn is inlaid within each knit course in the third knit zone 134 as shown in FIG. 2. The same end of the inlaid yarn may extend through courses to form the second plurality of inlaid yarns 240, such that the second plurality of inlaid yarns 240 may refer to a plurality of segments of a continuous yarn inlaid in multiple courses. Such inlaid yarn may be continuous with the first plurality of inlaid yarns 232. In example aspects, two inlaid yarns are inlaid within each knit course in the third knit zone 134.

In some aspects, the surface area of the first surface 216 in the third knit zone 134 may be approximately 50% exposed inlaid yarns 240 in the area containing the second plurality of openings 234. For example, a knit pattern of a one-needle transfer and then one knit stitch may result in the surface area of the first surface 216 being approximately 50% of the exposed inlaid yarns 240, but it should be understood that other patterns may achieve this result.

The percentage of the surface area of the first surface 216 formed by the second plurality of inlaid yarns 240 may be greater in certain regions within the knitted upper 110. For example, the first knit zone 130 may have no exposed inlaid yarns or a negligible amount forming the first surface 216. The second knit zone 132 and the third knit zone 134 may have a greater amount of the first surface 216 formed by the first and/or second pluralities of inlaid yarns 232 and/or 240 compared to the first knit zone 130. As described herein, some aspects of the first and/or second pluralities of inlaid yarns 232 and/or 240 may provide a grip (increased coefficient of friction), such that exposed portions of the first plurality of inlaid yarns 232 through the first plurality of openings 226 in the second knit zone 132 and/or the second plurality of inlaid yarns 240 through the second plurality of openings 234 in the third knit zone 134 may provide increased tactile feedback to the wearer. On the other hand, containing a thermoformed layer formed by inlaid yarns between the first knit layer 218 and the second knit layer 220 in the first knit zone 130, as described below, may be particularly advantageous when the first knit zone 130 is a “high touch” area, such as when the knitted upper 110 is used as a skateboarding shoe. The increased grip provided by exposing the first and/or second pluralities of inlaid yarns 232 and/or 240 through the openings 226 and 234 may be advantageous in areas that come into contact with a skateboard or other surface but with less frequency and/or with less applied pressure, such that a desire for tactile feedback may outweigh a need for increased abrasion resistance.

In some examples, the percentage of the surface area of the first surface 216 formed by exposed first and/or second pluralities of inlaid yarns 232 and/or 240 may be about the same in the second knit zone 132 and the third knit zone 134. In other examples, the percentage of the surface area of the first surface 216 formed by exposed first and/or second pluralities of inlaid yarns 232 and/or 240 may be different in the second and third knit zones 132 and 134. For example, the exposed first plurality of inlaid yarns 232 may form a greater percentage of the surface area of the first surface 216 in the second knit zone 132 compared to the exposed second plurality of inlaid yarns 240 in the third knit zone 134. The difference in percentages to which the exposed inlaid yarns form the surface area in each zone may be at least partially based on locations of likely touch points on the knitted upper 110. For instance, in examples in which the inlaid yarns 232 and/or 240 are formed of one of the disclosed yarns providing a grip (as a result of creating a higher coefficient of friction), the second knit zone 132 may have a greater percentage of the surface area formed by an exposed first plurality of inlaid yarns 232 due to a higher likelihood of areas within the second knit zone 132 being in contact with another surface, such as a skateboard.

FIG. 3 illustrates a perspective view of a portion of the knitted upper 110 used in the first knit zone 130 of the knitted upper 110, and FIG. 4 illustrates the portion of the knitted upper 110 in the first knit zone 130 with the first knit layer 218 lifted away to illustrate inlaid yarns 310 before the inlaid yarns 310 are processed to form the third thermoformed layer. As depicted, the first knit layer 218 and the second knit layer 220 do not include engineered openings in the first knit zone 130. In example aspects, in the first knit zone 130, the first knit layer 218 may be primarily knit with an elastane and a high-melting polymer yarn, for example, a polyethylene terephthalate yarn (PET yarn). The PET yarn may be a recycled PET yarn. The use of elastane helps to create a tighter knit structure by tensioning the knit loops together. In example aspects, the tighter knit structure may act as a physical barrier preventing the melted thermoplastic material of the inlaid yarns 310 from penetrating to the first surface 216 of the first knit layer 218. This helps to preserve the pliability and handfeel of the knitted upper 110. In example aspects, the yarn used to knit the first knit layer 218 (e.g., a PET-covered elastane yarn) may be plated with an additional yarn. The use of a plated yarn may provide additional structure to the knitted upper 110 and reduce the likelihood of knitted upper 110 from becoming misshapen in post-knitting manufacturing steps such as steaming, washing, patterning, and the like.

In some example aspects, instead of using a PET-covered elastane yarn to knit the first knit layer 218, a yarn comprising recycled leather, which may be referred to herein as scrap leather yarn (“SLY”), may be used. In some aspects, the recycled leather yarn comprises a combination of leather scraps and PET, which may be in the form of recycled PET. In one example, the recycled leather yarn is formed from about 50% leather scraps and about 50% PET (e.g., by weight). In other examples, the recycled leather yarn is formed from about 25% leather scraps and about 75% PET, about 35% leather scraps and about 65% PET, or about 70% leather scraps and about 30% PET. Other ratios of leather scraps and PET (or another material, including another recyclable material) are also contemplated. The leather scraps and the PET can be mixed together before carding and spinning into the recycled leather yarn. The leather scraps can imbue the recycled leather yarn with a soft hand feel and a relatively greater resistance to abrasion compared to a PET yarn without the recycled leather scraps. Moreover, the recycled leather yarn is sustainable since it can be formed from recycled materials (i.e., the leather scraps and, in some aspects, the recycled PET).

In example aspects, the second knit layer 220 may be primarily knit with a PET yarn (e.g., knit without elastane). The PET yarn may be a recycled PET yarn. In other examples, the second knit layer 220 is also knit with a yarn having elastane. In example aspects, the yarn used to knit the second knit layer 220 (e.g., the PET yarn) may be plated with an additional yarn. As stated, the use of a plated yarn may provide additional structure to the knitted upper 110 and reduce the likelihood of the knitted upper 110 from becoming misshapen in post-knitting manufacturing steps such as steaming, washing, patterning, and the like.

Because the first knit layer 218 and the second knit layer 220 are knit on a multi-bed knitting machine, yarns from the second knit layer 220 may intermittently be transferred to the first knit layer 218 and knitted in one or more loops before being transferred back to the second knit layer 220. Similarly, yarns used to knit the first knit layer 218 may be intermittently transferred to the second knit layer 220 and knitted in one or more loops before being transferred back to the first knit layer 218. This helps to secure the first knit layer 218 to the second knit layer 220 and to maintain the inlaid yarns 310 in a relatively fixed position. In example aspects, tuck stitches may be used to help further secure together the first knit layer 218 and the second knit layer 220, thereby reducing the likelihood of shifting between the two layers. This inclusion of tuck stitches may create an overall better fit of the knitted upper 110 on a wearer's foot. The tuck stitches may include yarns from the first knit layer 218 (e.g., the PET-covered elastane yarn and the plated yarn), and the tuck stitches may include yarns from the second knit layer 220 (e.g., the PET yarn and the plated yarn). The tuck stitches may be uniformly distributed throughout the knitted upper 110 in one aspect. In another aspect, the tuck stitches may be selectively positioned. For example, tuck stitches may be used in the second knit zone 132 and the third knit zone 134 and be omitted from the first knit zone 130.

In example aspects, the inlaid yarns 310 comprise a thermoplastic material, such as TPU and/or TPE, and are inlaid along the knit courses that form the first knit zone 130. In example aspects, the inlaid yarns 310 may be inlaid along each knit course, along every other knit course, along every third knit course, and the like. To ensure that there is enough thermoplastic material to form a unitary thermoformed layer, at least three inlaid yarn ends 310a, 310b, and 310c are inlaid along each knit course. In FIG. 3, the inlaid yarns 310 are shown in dashed line to indicate they are generally hidden from view by at least the first knit layer 218. In FIG. 4, in which the first knit layer 218 is at least partially lifted away, the inlaid yarns 310 are shown as being substantially contained between the first knit layer 218 and the second knit layer 220. As will be described, pressure and heat are used to melt the inlaid yarns 310 in the first knit zone 130 to form a thermoformed layer.

FIG. 5 illustrates a perspective view of a portion of the knitted upper 110 used in the second knit zone 132 and/or the third knit zone 134 of the knitted upper 110, and FIG. 6 illustrates the portion of the knitted upper 110 in the second knit zone 132 and/or the third knit zone 134 with the first knit layer 218 lifted away to illustrate inlaid yarns 510. The inlaid yarns 510 may comprise the first plurality of inlaid yarns 232 and/or the second plurality of inlaid yarns 240. In general, the description of the yarns used to form the first knit layer 218 and the second knit layer 220 provided with respect to FIGS. 3 and 4 also applies to FIGS. 5 and 6. In an alternative example aspect, however, a yarn (e.g., PET yarn) without elastane may be used to form the first knit layer 218 in the second knit zone 132 and the third knit zone 134, while a yarn with elastane (e.g., a PET-covered elastane yarn) may be used to form at least the first knit layer 218 in the first knit zone 130. This may be done to reduce or remove the likelihood of an elastane yarn from tensioning the first and/or second plurality of openings 226 and/or 234 to a generally closed or narrowed shape. As depicted, the first knit layer 218 includes the first plurality of openings 226 when the first knit layer 218 is located in the second knit zone 132, and the second plurality of openings 234 when the first knit layer 218 is located in the third knit zone 134. As depicted in FIG. 6, the openings 226/234 extend through the thickness of the first knit layer 218. In example aspects, the second knit layer 220 does not include engineered openings. The first and/or second plurality of openings 226 and 234 may increase the breathability/permeability of the knitted upper 110 in the second knit zone 132 and the third knit zone 134. For simplicity, the first plurality of openings 226 and the second plurality of openings 234 are illustrated in FIGS. 5 and 6 as being generally the same size; however, it should be understood that the first plurality of openings 226 and the second plurality of openings 234 may be different sizes in example aspects, as illustrated and described with respect to FIG. 2.

In example aspects, the inlaid yarns 510 comprise a thermoplastic material, such as TPU and/or SEBS, and are inlaid along the knit courses that form the second knit zone 132 and the third knit zone 134. The inlaid yarns 510 may comprise the same material as the inlaid yarns 310 in some aspects. In other aspects, the inlaid yarns 510 may comprise a different material than the inlaid yarns 310. For example, the inlaid yarns 510 in some example aspects may comprise a high-melting point synthetic material such as PET. In example aspects, the inlaid yarns 510 may be inlaid along each knit course, along every other knit course, along every third knit course, and the like. Because the inlaid yarns 510 in the second knit zone 132 and the third knit zone 134 are not thermoformed in some aspects, less yarns may be inlaid along each course. For example, the inlaid yarns 510 may comprise two inlaid yarns 510a and 510b in each knit course, as shown in FIGS. 5 and 6. In some aspects, the inlaid yarns 510 may comprise a single inlaid yarn, such as inlaid yarn 510a.

In FIG. 5, the inlaid yarns 510 are shown in dashed lines between the openings 226/234 in the first knit layer 218 to indicate they are generally hidden from view by the first knit layer 218. The inlaid yarns 510 are visible and/or exposed by way of the openings 226/234 and are thus indicated in solid lines. In FIG. 6, in which the first knit layer 218 is at least partially lifted away, the inlaid yarns 510 are shown as being substantially contained between the first knit layer 218 and the second knit layer 220. In example aspects, the yarns used to knit the first knit layer 218 may comprise a first color, and the inlaid yarns 510 may comprise a second color different from the first color. Because the inlaid yarns 510 are visible by way of the openings 226/234, an interesting visual aesthetic may be achieved.

In some example aspects, the inlaid yarns 510 may have a greater coefficient of friction or “grippiness” relative to the yarns used to form the first knit layer 218. Thus, because the inlaid yarns 510 are exposed by way of the openings 226/234, the second knit zone 132 and the third knit zone 134 may have a higher coefficient of friction compared to the first knit zone 130 that does not include openings 226/234. When portions of the knitted upper 110 that include the second knit zone 132 and the third knit zone 134 contact a ground surface and/or a skateboard surface, the inlaid yarns 510 may momentarily “grip” the surface through the openings 226/234, which provides a tactile sensation that may be used by the wearer to understand the positioning of the article of footwear 100 in relation to the surface.

FIG. 7 depicts a schematic of a double knit construction used in the knitted upper 110 and is provided to illustrate how the inlaid yarns 310/510 are substantially contained between the first knit layer 218 and the second knit layer 220. The schematic in FIG. 7 is depicted without any engineered openings in the first knit layer 218. A yarn 710 is used to knit the first knit layer 218. Although shown as a single yarn, aspects herein contemplate that the yarn 710 may be plated with another yarn. A yarn 712 is used to knit the second knit layer 220. Although shown as a single yarn, aspects herein contemplate that the yarn 712 used to knit the second knit layer 220 may be plated with another yarn. The inlaid yarns 310/510 are inlaid along each knit course, and the inlaid yarns 310/510 are substantially contained between the first knit layer 218 and the second knit layer 220. For this schematic representation, the knitted loops forming the first knit layer 218 and the second knit layer 220 are stretched to show the looped configuration, but it should be understood that, in practice, adjacent courses and wales may be compressed such that yarns 710 and 712 form the entire outer-facing surface of the first knit layer 218 and the entire inner-facing surface of the second knit layer 220. Although the inlaid yarns 310/510 are depicted as being inlaid along each knit course, aspects herein contemplate that the inlaid yarns 310/510 may be inlaid along every other knit course, every third knit course, and the like.

FIG. 8 depicts an example mold press 800 that may be used to form the third thermoformed layer in the first knit zone 130 of the knitted upper 110. The mold press 800 has a top portion 810 having a bottom surface 811 (a mold-facing surface) and a bottom portion 812 having a top surface 813 (a mold-facing surface). The bottom surface 811 and the top surface 813 may each have a planar surface as shown in FIG. 8, but aspects herein contemplate that one or more of the bottom surface 811 and the top surface 813 may have a three-dimensional texture or pattern. The rectangular shape of the top portion 810 and the bottom portion 812 is illustrative, and other shapes are contemplated herein. For example, the top portion 810 and/or the bottom portion 812 may have a shape corresponding generally to the shape of the first knit zone 130 of the knitted upper 110. The mold press 800 may be a clamshell design, where the top portion 810 and the bottom portion 812 are hinged along one edge so that the first knit zone 130 of the knitted upper 110 may be inserted between the top portion 810 and the bottom portion 812 and the mold press 800 closed down on the knitted upper 110. Alternatively, the top portion 810 and the bottom portion 812 of the mold press 800 may be two independent plates that are not otherwise connected. In this alternative configuration, the first knit zone 130 of the knitted upper 110 is positioned on the top surface 813 of the bottom portion 812, and the bottom surface 811 of the top portion 810 is then positioned on top of the knitted upper 110. The top portion 810 may be of similar size as the bottom portion 812, or it may be larger or smaller. Other mold configurations known in the art may be used herein. Additionally, other ways of forming the first knit zone 130 are contemplated herein including, for example, vacuum presses.

In example aspects, one or more of the top portion 810 and the bottom portion 812 may include a bumper 814 that extends around a perimeter of the mold press 800 and extends away from the bottom surface 811 of the top portion 810 and/or the top surface 813 of the bottom portion 812 (shown in FIG. 8) in a z-direction. The bumper 814 may be used to create a gap between the bottom surface 811 of the top portion 810 and the top surface 813 of the bottom portion 812, where the gap helps to decrease the amount of pressure applied to the first knit zone 130 of the knitted upper 110. Decreasing the amount of pressure applied to the knitted upper 110 in the first knit zone 130 achieves several purposes. For example, it helps to maintain the loft from the yarns of the knitted upper 110 in the first knit zone 130. Decreasing the amount of pressure applied to the knitted upper 110 in the first knit zone 130 also helps to ensure that the melted thermoplastic material does not migrate to the surfaces of the first knit layer 218 and/or the second knit layer 220. This, in turn, helps to preserve the flexibility/pliability of the knitted upper 110. Decreasing the amount of pressure applied to the knitted upper 110 also helps to reduce the chances of the yarns forming the first knit layer 218 and/or the second knit layer 220 from burning and reduces the chances of color migration from the yarns used to form the first and/or second knit layers 218 and 220. In example aspects, the bumper 814 may have a height such that the thickness of the knitted upper 110 is compressed between about 20% to about 45%, or between about 25% to about 40%. In example aspects, this compression may correspond to a gap between the bottom surface 811 and the top surface 813 of about 1 mm, about 1.5 mm, or about 2 mm. To describe this differently, in example aspects, a height of the bumper 814 may be approximately 50% of a thickness of the knitted upper 110 in the first knit zone 130 before pressure is applied to the first knit zone 130.

As schematically depicted in FIG. 9, after the first knit zone 130 of the knitted upper 110 is knit to include the first knit layer 218, the second knit layer 220, and the plurality of inlaid yarns 310 comprising a low-melting point thermoplastic material, the first knit zone 130 of the knitted upper 110 is positioned into the mold press 800, and the mold press 800 is engaged. The mold press 800 may be heated to a temperature approximately 10 degrees Celsius higher than the melting point of the thermoplastic material of the inlaid yarns 310. In example aspects, the temperature to which the mold press 800 is heated may be greater than the melting point of the thermoplastic material of the inlaid yarns 310 but less than the melting point of the high-melt yarns used to form the first knit layer 218 and the second knit layer 220. Sufficient pressure is applied to the first knit zone 130 of the knitted upper 110 as described above such that the melted and/or softened thermoplastic material of the inlaid yarns 310 deforms, and the first knit zone 130 of the knitted upper 110 conforms to the shape of the top surface 813 and/or the bottom surface 811 of the mold press 800. In example aspects, the pressure may be applied for about 45 seconds to about 60 seconds. After the temperature and pressure have been applied by the mold press 800, the first knit zone 130 of the knitted upper 110 is cooled. The melted and/or softened thermoplastic material of the inlaid yarns 310 hardens to form a thermoformed layer that is substantially contained between the first knit layer 218 and the second knit layer 220.

In some aspects, the second knit zone 132 and the third knit zone 134 are not heated within the mold press 800. As such, these second and third knit zones 132 and 134 may be a portion of the knitted upper 110 extending away from the mold press 800. In some aspects, at least one side of the bumper 814 is omitted so that a portion of the knitted upper 110 may extend out of the mold press 800 without being subjected to pressure.

FIG. 10 depicts a schematic cross-section of the mold press 800 with the first knit zone 130 of the knitted upper 110 positioned between the top portion 810 and the bottom portion 812 of the mold press 800. The first knit zone 130 includes the first knit layer 218, the second knit layer 220, and the inlaid yarns 310 (schematically depicted as an undulating line) prior to the thermoplastic material of the inlaid yarns 310 melting (i.e., prior to the mold press 800 applying heat to the first knit zone 130). The bumper 814 is shown extending upward from the top surface 813 of the bottom portion 812 of the mold press 800. The bumper 814 creates a gap, such as gap 1000, between the bottom surface 811 of the top portion 810 and the top surface 813 of the bottom portion 812, where the gap 1000 decreases the amount of pressure applied to the first knit zone 130 of the knitted upper 110, as described above.

The thermoplastic material of the inlaid yarns 310 may be softened by the mold press 800 applying heat to the first knit zone 130 of the knitted upper 110. The first knit zone 130 is heated to soften the low-melting thermoplastic material of the inlaid yarns 310. The heat may be applied via omnidirectional means, such as the use of steam, an oven, or equivalent, or by directional means, such as a hot surface, heat gun, or equivalent. Depending on the crystallinity or general characteristics of the thermoplastic material of the inlaid yarns 310, to soften the thermoplastic material, the first knit zone 130 may be heated to or above the melting point of the thermoplastic material, above the glass transition temperature of the thermoplastic material, or to or above the thermoplastic material's softening point for a given processing pressure. In one example aspect, the first knit zone 130 may be heated to approximately 10 degrees Celsius higher than the melting point of the thermoplastic material. When the softened or melted thermoplastic material of the inlaid yarns 310 is cooled to a temperature below its softening point, the thermoplastic material becomes firm and forms a thermoformed layer.

FIG. 11 schematically depicts the transition between, for example, the first knit zone 130 and the second knit zone 132 of the knitted upper 110 after heat and pressure have been applied to the first knit zone 130 and the knitted upper 110 has been cooled. In the first knit zone 130, a third thermoformed layer 1100 is substantially contained between the first knit layer 218 and the second knit layer 220. The third thermoformed layer 1100 acts as a barrier protecting the yarns that form the second knit layer 220 from abrasion and, in some aspects, water or other moisture. For example, if portions of the first knit layer 218 are abraded through a thickness of the first knit layer 218, the third thermoformed layer 1100 helps to prevent the abrasion forces, which may occur from contact between the first knit zone 130 and a surface, from reaching the yarns that form the second knit layer 220. This protects the overall integrity of the knitted upper 110 by lessening the chances for holes or structural weakness to occur. Additionally, the third thermoformed layer 1100 may also act as a water-resistant or water-proof barrier preventing water or moisture from reaching an interior of the knitted upper 110, which improves overall wearer comfort.

As previously described, in some example aspects, the first knit zone 130 may form a toe area 115 of the knitted upper 110 such that the third thermoformed layer 1100 of the first knit zone 130 may provide increased durability (due to abrasion resistance) in the toe area 115. When the article of footwear 100 is intended for a particular sporting use, e.g., use as a skateboarding shoe, the area formed by the first knit zone 130 may come into more frequent contact and/or higher pressure contact with a ground surface and/or the skateboard compared to other portions of the knitted upper 110 such that increased durability may be particularly useful in the first knit zone 130. In other example aspects, as described above, the first knit zone 130 may be located adjacent to, surround, and/or include the plurality of lace apertures, the throat area 126, the tongue 128, the midfoot region 116, and/or the heel region 118.

Because heat and pressure are not applied to the second knit zone 132 (and/or the third knit zone 134), the inlaid yarns 510 (shown schematically as an undulating line) are maintained in their native, non-melted state. FIG. 11 further depicts the first plurality of opening 226 in the first knit layer 218 within the second knit zone 132. As described, the inlaid yarns 510 are visible and/or exposed by way of the openings 226.

FIG. 12 illustrates a schematic cross-section of the first knit zone 130 of the knitted upper 110 before heat and/or pressure are applied to the first knit zone 130 of the knitted upper 110. As depicted, the inlaid yarn 310 is positioned between the first knit layer 218 and the second knit layer 220 and is substantially contained between the two layers. The term “substantially contained” means, as used herein, that the inlaid yarn 310 generally does not extend to the first surface 216 of the first knit layer 218 (the outer-facing surface of the knitted upper 110) or the second surface 217 of the second knit layer 220 (the inner-facing surface of the knitted upper 110). A similar definition of the term may be applied where the term is used in other examples described herein.

FIG. 13 illustrates a cross-section of the first knit zone 130 of the knitted upper 110 after heat and/or pressure are applied to the first knit zone 130 and the third thermoformed layer 1100 is formed. The third thermoformed layer 1100 is substantially contained between the first knit layer 218 and the second knit layer 220. In this context, “substantially contained” means that the re-solidified thermoplastic material of the third thermoformed layer 1100 does not extend to the first surface 216 and the second surface 217, thereby helping to preserve the pliability of the knitted upper 110. As depicted, in example aspects, the third thermoformed layer 1100 may encapsulate portions of yarn loops that form the first knit layer 218 and the second knit layer 220 forming a secure attachment between the two layers, which increases the overall structural integrity of the first knit zone 130. Because the third thermoformed layer 1100 does not extend to the first surface 216 and the second surface 217, both the first and second surfaces 216 and 217 maintain a knit texture, which may be desirable in articles of footwear for its soft/comfortable surface characteristics and aesthetics. As stated, the third thermoformed layer 1100 imparts abrasion resistance to the first knit zone 130 and also forms a water-resistant and/or water-proof barrier between the first knit layer 218 and the second knit layer 220.

FIG. 14 depicts a flow diagram of an example method 1400 of manufacturing a knitted upper such as the knitted upper 110. At a step 1410, a first knit zone, such as the first knit zone 130, and a second knit zone, such as the second knit zone 132, are formed by knitting a first knit layer and a second knit layer on a knitting machine. The first knit layer may be the first knit layer 218, and the second knit layer may be the second knit layer 220. The first knit zone is further formed by inlaying one or more inlaid yarns, such as the inlaid yarns 310, between the first knit layer and the second knit layer. The one or more inlaid yarns comprise a thermoplastic material having a melting point.

At a step 1412, one or more of heat and pressure are applied to the first knit zone such that the thermoplastic material of the inlaid yarns rises to a temperature at or above the melting point of the thermoplastic material. In example aspects, the one or more of heat and pressure are not applied to the second knit zone of the knitted upper.

At a step 1414, the knitted upper is cooled such that a third thermoformed layer, such as the third thermoformed layer 1100, is formed in the first knit zone. The third thermoformed layer is substantially contained between the first knit layer and the second knit layer and acts as a physical barrier preventing or reducing the likelihood of abrasion forces contacting the yarns that form the second knit layer.

The method 1400 may comprise additional steps including knitting a third knit zone, such as the third knit zone 134, by knitting the first knit layer and the second knit layer and inlaying the inlaid yarns between the first and second knit layers. In example aspects, the heat and/or pressure applied to the first knit zone are not applied to the third knit zone. Additional manufacturing steps may include forming a first plurality of openings in the second knit zone, such as the first plurality of openings 226. This may be done by executing a two-needle transfer. The manufacturing steps may include forming a second plurality of openings in the third knit zone, such as the second plurality of openings 234. This may be done, for example, by executing a one-needle transfer.

Clause 1. An article of footwear, comprising: a sole structure; and a knitted upper secured to the sole structure, the knitted upper comprising: a first knit zone comprising: a first knit layer located on an outer-facing surface of the knitted upper, a second knit layer located on an inner-facing surface of the knitted upper, and a third thermoformed layer substantially contained between the first knit layer and the second knit layer, and a second knit zone comprising: the first knit layer, the second knit layer, and a first plurality of inlaid yarns at least partially positioned between the first knit layer and the second knit layer.

Clause 2. The article of footwear of clause 1, wherein the first plurality of inlaid yarns comprises a thermoplastic material.

Clause 3. The article of footwear of clause 1 or 2, further comprising a third knit zone comprising: the first knit layer; the second knit layer; and a second plurality of inlaid yarns at least partially positioned between the first knit layer and the second knit layer.

Clause 4. The article of footwear of clause 3, wherein in the second knit zone, the first knit layer comprises a first plurality of openings having a first size, and wherein in the third knit zone, the first knit layer comprises a second plurality of openings having a second size smaller than the first size.

Clause 5. The article of footwear of any of clauses 1 through 4, wherein at least a portion of the first plurality of inlaid yarns is visible by way of the first plurality of openings in the first knit layer.

Clause 6. The article of footwear of any of clauses 3 through 5, wherein at least a portion of the second plurality of inlaid yarns is visible by way of the second plurality of openings in the first knit layer.

Clause 7. The article of footwear of any of clauses 1 through 6, wherein the first plurality of inlaid yarns comprises either one or two yarn ends inlaid along each of a plurality of knit courses in the second knit zone.

Clause 8. The article of footwear of any of clauses 3 through 7, wherein the second plurality of inlaid yarns comprises either one or two yarn ends inlaid along each of a plurality of knit courses in the third knit zone.

Clause 9. The article of footwear of any of clauses 1 through 8, wherein the first knit zone is located at a toe area of the knitted upper.

Clause 10. The article of footwear of any of clauses 1 through 9, wherein the second knit zone is located at one or more of a medial side and a lateral side of a midfoot region of the knitted upper.

Clause 11. The article of footwear of any of clauses 3 through 10, wherein the third knit zone is located at a heel area of the knitted upper.

Clause 12. The article of footwear of any of clauses 1 through 11, wherein the third thermoformed layer forms a substantially water-resistant or water-proof barrier.

Clause 13. An article of footwear, comprising: a sole structure; and a knitted upper secured to the sole structure, the knitted upper comprising: a first knit zone comprising: a first knit layer located on an outer-facing surface of the knitted upper, a second knit layer located on an inner-facing surface of the knitted upper, and a third layer of thermoplastic material substantially contained between the first knit layer and the second knit layer; and a second knit zone comprising the first knit layer, the first knit layer comprising a first plurality of openings, the second knit layer, and a first plurality of inlaid yarns at least partially positioned between the first knit layer and the second knit layer, at least a portion of the first plurality of inlaid yarns being visible by way of the first plurality of openings in the first knit layer.

Clause 14. The article of footwear of clause 13, wherein the third layer in the first knit zone comprises a thermoformed layer.

Clause 15. The article of footwear of clauses 13 or 14, wherein the third layer is not visible in the first knit zone.

Clause 16. The article of footwear of any of clauses 13 through 15, wherein each opening of the first plurality of openings has a length dimension and a width dimension, the length dimension being greater than the width dimension.

Clause 17. The article of footwear of any of clauses 13 through 16, wherein the first plurality of inlaid yarns comprises a thermoplastic material.

Clause 18. The article of footwear of any of clauses 13 through 17, wherein the first plurality of inlaid yarns comprises either one or two yarn ends inlaid along each of a plurality of knit courses in the second knit zone.

Clause 19. The article of footwear of any of clauses 13 through 18, wherein the first knit zone is located at a toe area of the knitted upper and along a portion of a medial side and a lateral side of a forefoot region of the knitted upper.

Clause 20. The article of footwear of any of clauses 13 through 19, wherein the first knit zone extends a greater distance toward a heel area of the knitted upper on the lateral side of the forefoot region compared to the medial side of the forefoot region.

Clause 21. The article of footwear of any of clauses 13 through 20, wherein the second knit zone is located at one or more of the medial side and the lateral side of a midfoot region of the knitted upper.

Clause 22. The article of footwear of any of clauses 13 through 21, wherein the second knit zone is integrally knit with the first knit zone such that the second knit zone seamlessly extends from the first knit zone.

Clause 23. The article of footwear of any of clauses 13 through 22, further comprising a third knit zone comprising: the first knit layer having a second plurality of openings; the second knit layer; and a second plurality of inlaid yarns at least partially positioned between the first knit layer and the second knit layer, at least a portion of the second plurality of inlaid yarns being visible by way of the second plurality of openings in the first knit layer.

Clause 24. The article of footwear of clause 23, wherein the first plurality of openings in the second knit zone comprises a first size, and wherein the second plurality of openings in the third knit zone comprises a second size smaller than the first size.

Clause 25. The article of footwear of clause 23 or 24, wherein the third knit zone is located at a heel area of the knitted upper.

Clause 26. The article of footwear of any of clauses 23 through 25, wherein the third knit zone is integrally knit with the second knit zone such that the third knit zone seamlessly extends from the second knit zone.

Clause 27. A method of manufacturing a knitted upper, the method comprising: forming at least a first knit zone and a second knit zone by knitting a first knit layer and a second knit layer on a knitting machine and inlaying one or more inlaid yarns within the first knit zone and the second knit zone, the one or more inlaid yarns inlaid between the first knit layer and the second knit layer, the one or more inlaid yarns comprising a thermoplastic material having a melting point; at the first knit zone of the knitted upper, applying one or more of heat and pressure such that the thermoplastic material of the one or more inlaid yarns rises to a temperature at or above the melting point of the thermoplastic material, wherein the one or more of heat and pressure are not applied to the second knit zone of the knitted upper; and cooling the knitted upper such that a third thermoformed layer is formed in the first knit zone, the third thermoformed layer substantially contained between the first knit layer and the second knit layer.

Clause 28. The method of manufacturing the knitted upper of clause 27, wherein in the first knit zone, at least three yarn ends are inlaid along each of a plurality of knit courses in the first knit zone.

Clause 29. The method of manufacturing the knitted upper of clause 27 or 28, wherein in the second knit zone, either one or two yarn ends are inlaid along each of a plurality of knit courses in the second knit zone.

Clause 30. The method of manufacturing the knitted upper of any of clauses 27 through 29, wherein yarns used to knit the first knit layer and the second knit layer have a melting point greater than the melting point of the thermoplastic material of the one or more inlaid yarns.

Clause 31. The method of manufacturing the knitted upper of any of clauses 27 through 30, further comprising forming at least a third knit zone by knitting the first knit layer and the second knit layer and inlaying the one or more inlaid yarns between the first knit layer and the second knit layer, wherein the one or more of heat and pressure are not applied to the third knit zone of the knitted upper.

Clause 32. The method of manufacturing the knitted upper of any of clauses 27 through 31, further comprising forming a first plurality of openings in the first knit layer in the second knit zone.

Clause 33. The method of manufacturing the knitted upper of clause 32, wherein forming the first plurality of openings in the first knit layer in the second knit zone comprises executing a two-needle transfer.

Clause 34. The method of manufacturing the knitted upper of any of clauses 31 through 33, further comprising forming a second plurality of openings in the first knit layer in the third knit zone.

Clause 35. The method of manufacturing the knitted upper of clause 34, wherein forming the second plurality of openings in the first knit layer in the third knit zone comprises executing a one-needle transfer.

Clause 36. The method of manufacturing the knitted upper of any of clauses 31 through 35, wherein in the third knit zone, either one or two yarn ends are inlaid along each of a plurality of knit courses in the third knit zone.

Clause 37. An article of footwear, comprising: a sole structure; and a knitted upper secured to the sole structure, the knitted upper comprising: a first knit zone comprising: a first knit layer located on an outer-facing surface of the knitted upper, a second knit layer located on an inner-facing structure of the knitted upper, and a third layer substantially contained between the first knit layer and the second knit layer, wherein the third layer comprises a first plurality of inlaid yarns.

Clause 38. The article of footwear of clause 37, further comprising: a second knit zone comprising: the first knit layer, the second knit layer, and a second plurality of inlaid yarns at least partially positioned between the first knit layer and the second knit layer.

Clause 39. The article of footwear of clauses 37 or 38, wherein the first plurality of inlaid yarns are formed of thermoplastic material.

Clause 40. The article of footwear of any of clauses 37 through 39, wherein one or more of heat and pressure are applied to the third layer to form a thermoformed layer.

Clause 41. The article of footwear of any of clauses 37 through 40, wherein the first plurality of inlaid yarns comprise a core-sheath configuration, wherein a low-melting thermoplastic material surrounds a core of a high-melting thermoplastic material.

Clause 42. The article of footwear of any of clauses 38 through 41, wherein the first plurality of inlaid yarns of the first knit zone extends into the second knit zone to form the second plurality of inlaid yarns.

Clause 43. The article of footwear of any of clauses 37 through 42, wherein a yarn used to form the first knit layer is an elastane and a high-melting polymer yarn.

Clause 44. The article of footwear of any of clauses 37 through 42, wherein a yarn used to form the first knit layer is a scrap leather yarn.

Clause 45. The article of footwear of any of clauses 37 through 44, wherein a yarn used to form the first knit layer is plated with an additional yarn.

Clause 46. The article of footwear of any of clauses 38 through 45, wherein a yarn used to form the second knit layer is a high-melting polymer yarn.

Clause 47. The article of footwear of any of clauses 38 through 45, wherein a yarn used to form the second knit layer is a PET yarn.

Clause 48. The article of footwear of clause 47, wherein the PET yarn is a recycled PET yarn.

Clause 49. The article of footwear of any of clauses 38 through 45, wherein a yarn used to form the second knit layer is an elastane and a high-melting polymer yarn.

Clause 50. The article of footwear of any of clauses 38 through 49, wherein a yarn used to knit the first knit layer is intermittently transferred to the second knit layer before being transferred back to the first knit layer.

Clause 51. The article of footwear of any of clauses 37 through 50, further comprising: a third knit zone comprising: the first knit layer; the second knit layer; and a third plurality of inlaid yarns at least partially positioned between the first knit layer and the second knit layer.

Clause 52. The article of footwear of any of clauses 37 through 51, wherein the first plurality of inlaid yarns includes low-melting thermoplastic yarns.

Clause 53. The article of footwear of any of clauses 37 through 52, wherein the first plurality of inlaid yarns includes TPU yarns.

Clause 54. The article of footwear of any of clauses 37 through 53, wherein the first plurality of inlaid yarns includes SEBS yarns.

Clause 55. The article of footwear of any of clauses 37 through 54, wherein one or more yarns used to knit the first knit layer and the second knit layer have a first melting point, wherein one or more yarns forming the third layer have a second melting point, and wherein the second melting point is lower than the first melting point.

Clause 56. The article of footwear of any of clauses 37 through 55, wherein in the first knit zone, at least one yarn end of the first plurality of inlaid yarns is inlaid along each of a plurality of knit courses in the first knit zone.

Clause 57. The article of footwear of any of clauses 38 through 56, wherein in the second knit zone, at least one yarn end of the second plurality of inlaid yarns are inlaid along each of a plurality of knit courses in the second knit zone.

Clause 58. The article of footwear of any of clauses 51 through 57, wherein in the third knit zone, at least one yarn end of the third plurality of inlaid yarns are inlaid along each knit course of a plurality of knit courses in the third knit zone.

Clause 59. The article of footwear of any of clauses 38 through 54, wherein in the first knit zone, at least three yarn ends of the first plurality of inlaid yarns are inlaid along each knit course of a plurality of knit courses of the first knit zone.

Clause 60. The article of footwear of any of clauses 38 through 56, wherein in the second knit zone, one or more yarn ends of the second plurality of inlaid yarns are inlaid along every other knit course of a plurality of knit courses of the second knit zone.

Clause 61. The article of footwear of any of clauses 51 through 60, wherein in the third knit zone, one or more yarn ends of the third plurality of inlaid yarns are inlaid along every other knit course of a plurality of knit courses of the third knit zone.

Aspects of the present disclosure have been described with the intent to be illustrative rather than restrictive. Alternative aspects will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present disclosure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described.

Claims

1. An article of footwear, comprising: a sole structure; anda knitted upper secured to the sole structure, the knitted upper comprising: a first knit zone comprising: a first knit layer located on an outer-facing surface of the knitted upper,a second knit layer located on an inner-facing surface of the knitted upper, anda third thermoformed layer substantially contained between the first knit layer and the second knit layer, anda second knit zone comprising: the first knit layer,the second knit layer, anda first plurality of inlaid yarns at least partially positioned between the first knit layer and the second knit layer.

2. The article of footwear of claim 1, wherein the first plurality of inlaid yarns comprises a thermoplastic material.

3. The article of footwear of claim 1, further comprising a third knit zone comprising: the first knit layer;the second knit layer; anda second plurality of inlaid yarns at least partially positioned between the first knit layer and the second knit layer.

4. The article of footwear of claim 3, wherein in the second knit zone, the first knit layer comprises a first plurality of openings having a first size, and wherein in the third knit zone, the first knit layer comprises a second plurality of openings having a second size smaller than the first size.

5. The article of footwear of claim 4, wherein at least a portion of the first plurality of inlaid yarns is visible by way of the first plurality of openings in the first knit layer.

6. The article of footwear of claim 4, wherein at least a portion of the second plurality of inlaid yarns is visible by way of the second plurality of openings in the first knit layer.

7. The article of footwear of claim 3, wherein the first plurality of inlaid yarns comprises either one or two yarn ends inlaid along each of a plurality of knit courses in the second knit zone.

8. The article of footwear of claim 3, wherein the second plurality of inlaid yarns comprises either one or two yarn ends inlaid along each of a plurality of knit courses in the third knit zone.

9. The article of footwear of claim 3, wherein the first knit zone is located at a toe area of the knitted upper.

10. The article of footwear of claim 3, wherein the second knit zone is located at one or more of a medial side and a lateral side of a midfoot region of the knitted upper.

11. The article of footwear of claim 3, wherein the third knit zone is located at a heel area of the knitted upper.

12. The article of footwear of claim 1, wherein the third thermoformed layer forms a substantially water-resistant or water-proof barrier.

13. An article of footwear, comprising: a sole structure; anda knitted upper secured to the sole structure, the knitted upper comprising: a first knit zone comprising: a first knit layer located on an outer-facing surface of the knitted upper,a second knit layer located on an inner-facing surface of the knitted upper, anda third layer of thermoplastic material substantially contained between the first knit layer and the second knit layer; anda second knit zone comprising: the first knit layer, the first knit layer comprising a first plurality of openings,the second knit layer, anda first plurality of inlaid yarns at least partially positioned between the first knit layer and the second knit layer, at least a portion of the first plurality of inlaid yarns being visible by way of the first plurality of openings in the first knit layer.

14. The article of footwear of claim 13, wherein the third layer in the first knit zone comprises a thermoformed layer.

15. The article of footwear of claim 14, wherein the third layer is not visible in the first knit zone.

16. The article of footwear of claim 13, wherein each opening of the first plurality of openings has a length dimension and a width dimension, the length dimension being greater than the width dimension.

17. The article of footwear of claim 13, wherein the first plurality of inlaid yarns comprises a thermoplastic material.

18. The article of footwear of claim 13, wherein the first plurality of inlaid yarns comprises either one or two yarn ends inlaid along each of a plurality of knit courses in the second knit zone.

19. The article of footwear of claim 13, wherein the first knit zone is located at a toe area of the knitted upper and along a portion of a medial side and a lateral side of a forefoot region of the knitted upper.

20. The article of footwear of claim 19, wherein the first knit zone extends a greater distance toward a heel area of the knitted upper on the lateral side of the forefoot region compared to the medial side of the forefoot region.

21. The article of footwear of claim 20, wherein the second knit zone is located at one or more of the medial side and the lateral side of a midfoot region of the knitted upper.

22. The article of footwear of claim 13, wherein the second knit zone is integrally knit with the first knit zone such that the second knit zone seamlessly extends from the first knit zone.

23. The article of footwear of claim 13, further comprising a third knit zone comprising: the first knit layer having a second plurality of openings;the second knit layer; anda second plurality of inlaid yarns at least partially positioned between the first knit layer and the second knit layer, at least a portion of the second plurality of inlaid yarns being visible by way of the second plurality of openings in the first knit layer.

24. The article of footwear of claim 23, wherein the first plurality of openings in the second knit zone comprises a first size, and wherein the second plurality of openings in the third knit zone comprises a second size smaller than the first size.

25. The article of footwear of claim 24, wherein the third knit zone is located at a heel area of the knitted upper.

26. The article of footwear of claim 25, wherein the third knit zone is integrally knit with the second knit zone such that the third knit zone seamlessly extends from the second knit zone.

27. A method of manufacturing a knitted upper, the method comprising: forming at least a first knit zone and a second knit zone by knitting a first knit layer and a second knit layer on a knitting machine and inlaying one or more inlaid yarns within the first knit zone and the second knit zone, the one or more inlaid yarns inlaid between the first knit layer and the second knit layer, the one or more inlaid yarns comprising a thermoplastic material having a melting point;at the first knit zone of the knitted upper, applying one or more of heat and pressure such that the thermoplastic material of the one or more inlaid yarns rises to a temperature at or above the melting point of the thermoplastic material, wherein the one or more of heat and pressure are not applied to the second knit zone of the knitted upper; andcooling the knitted upper such that a third thermoformed layer is formed in the first knit zone, the third thermoformed layer substantially contained between the first knit layer and the second knit layer.

28. The method of manufacturing the knitted upper of claim 27, wherein in the first knit zone, at least three yarn ends are inlaid along each of a plurality of knit courses in the first knit zone.

29. The method of manufacturing the knitted upper of claim 28, wherein in the second knit zone, either one or two yarn ends are inlaid along each of a plurality of knit courses in the second knit zone.

30. The method of manufacturing the knitted upper of claim 27, wherein yarns used to knit the first knit layer and the second knit layer have a melting point greater than the melting point of the thermoplastic material of the one or more inlaid yarns.

31. The method of manufacturing the knitted upper of claim 27, further comprising forming at least a third knit zone by knitting the first knit layer and the second knit layer and inlaying the one or more inlaid yarns between the first knit layer and the second knit layer, wherein the one or more of heat and pressure are not applied to the third knit zone of the knitted upper.

32. The method of manufacturing the knitted upper of claim 31, further comprising forming a first plurality of openings in the first knit layer in the second knit zone.

33. The method of manufacturing the knitted upper of claim 32, wherein forming the first plurality of openings in the first knit layer in the second knit zone comprises executing a two-needle transfer.

34. The method of manufacturing the knitted upper of claim 33, further comprising forming a second plurality of openings in the first knit layer in the third knit zone.

35. The method of manufacturing the knitted upper of claim 34, wherein forming the second plurality of openings in the first knit layer in the third knit zone comprises executing a one-needle transfer.

36. The method of manufacturing the knitted upper of claim 31, wherein in the third knit zone, either one or two yarn ends are inlaid along each of a plurality of knit courses in the third knit zone.