Liquid thermoplastic polymer application for shoe uppers

Abstract

This invention relates to a method for manufacturing an upper for footwear articles. The method includes the steps of: providing a polymer; providing a solvent; and mixing the polymer and the solvent to produce a liquefied polymer. The method further includes the steps of: providing a substrate; distributing strands of the liquefied polymer onto the substrate such that the strands form the shape of at least a portion of the upper; curing the strands; and removing the cured strands from the substrate. The invention also relates to an upper for a corresponding footwear article.

Description

Technical Field

[0001] This invention relates to a method for manufacturing the upper of footwear articles by distributing strands of a liquefied polymer onto a substrate. The invention also relates to a corresponding upper. Background Technology

[0002] Footwear typically comprises a sole and an upper. In traditional upper manufacturing, a flat, two-dimensional upper blank is usually transformed into the desired three-dimensional shape of the final footwear by placing the upper blank, or multiple components thereof, onto a last and sewing them together through one or more seams. This process primarily results in poor fit in areas where a surface needs to have two directions of curvature, such as the forefoot vamp or the quarter area on the sides of the foot. In recent years, footwear manufacturers have developed a new technique in which portions of the footwear are formed from extruded components.

[0003] For example, document WO 2016 / 077221 A1 relates to the production of footwear and its components by jet extrusion. The disclosed process uses a jet or stream of material that solidifies into fibers, which form a two-dimensional or three-dimensional web upon collection. The fibers can be produced by forcing a selected starting fiber-forming fluid material through an outlet port. The web can be a film, membrane, or pad. For example, this document discloses that it is possible to manufacture individual sole units and insoles using forcespinning or other jet extrusion methods.

[0004] Similarly, document US 2015 / 0040428 A1 relates to portions of footwear articles formed by extrusion members. The extrusion member can be a single, continuous solid material. For example, the sole of a footwear article can be made from an extrusion member, wherein the extrusion member is formed with a controlled geometric pattern. The sole may include one or more layers. Other portions of the footwear article, and the entire footwear article, can be made using one or more extrusion members. The extrusion member can be made of rubber, foam, silicone, plastic, or thermoplastic.

[0005] However, while existing jet extrusion methods produce randomly distributed fine fiber mats, the predefined arrangement of the fibers and therefore the predefined adjustment of the properties of the manufactured fiber mats are not applicable. On the other hand, although known extrusion extrusion processes can be used to generate controlled geometric patterns, these patterns are generally coarser than those of conventional knitted or woven fabrics, thus lacking the ability to create fine mesh structures.

[0006] Therefore, the problem to be solved by the present invention is to improve the method of manufacturing the upper of footwear products, so as to at least partially overcome the disadvantages of the prior art. Summary of the Invention

[0007] The problems mentioned above are solved by embodiments of the present invention. Various exemplary embodiments of the present invention are provided below.

[0008] In one embodiment, the present invention provides a method for manufacturing an upper of a footwear article. The method may include the steps of: providing a substrate; dispensing strands of a liquefied polymer onto the substrate such that the strands form the shape of at least a portion of the upper; curing the strands; and removing the cured strands from the substrate.

[0009] In this way, the present invention enables a highly flexible method for manufacturing parts or even the entire upper, while allowing for highly controlled distribution of strands onto the substrate. This allows for the provision of uppers with predefined characteristics and improved shapes. The term "distribution" as used in this invention should be understood as the controlled extrusion or output of strands. The strands are arranged or laid onto the substrate. Specifically, this distribution differs from the simple force spinning or jet extrusion of fibers disclosed in the prior art, which merely provides a random distribution of fibers as a pad or web.

[0010] The method may further include the steps of: providing a polymer; providing a solvent; and mixing the polymer with the solvent to produce a liquefied polymer. In the prior art mentioned above, the extrusion of extruded components (e.g., soles of footwear) is typically carried out by, for example, extruding a preheated thermoplastic polymer material, which can be cured by lowering its temperature. The present invention is based on a different method, namely, producing a liquefied polymer by mixing a polymer and a solvent. The mixture can then be applied to a substrate and cured thereon. In this way, the liquefied polymer can be applied to the substrate more precisely and efficiently because heating the liquefied polymer is not required.

[0011] According to this disclosure, a "polymer" is, but is not limited to, a macromolecule based on repeating subunits (monomers) that combine together to form a network structure. Polymers can be classified into the following categories: synthetic polymers, natural polymers, biodegradable polymers, and composite polymers.

[0012] According to this disclosure, a "solvent" is, but is not limited to, a compound capable of dissolving, dispersing, or extracting other compounds. Solvents can be polar or nonpolar. Common solvents are in liquid form, but can also be gases or solids.

[0013] According to this disclosure, "mixing" should be understood as, but not limited to, the process of combining two or more substances to obtain a mixture of the substances.

[0014] According to this disclosure, "curing" should be understood as, but not limited to, a chemical and / or physical process of a substance that generally promotes the hardening, shaping, and / or solidification of the substance. Curing is based on chemical reactions, thermal effects, and / or other external or internal factors.

[0015] The substrate may include the three-dimensional shape of at least a portion of a shoe last. The substrate can even be a shoe last itself. By dispensing liquefied polymer directly onto a three-dimensional substrate or even a shoe last, the upper or a portion thereof can be formed—in its desired shape—before the threads have cured. Therefore, the additional step required in the prior art—transforming a two-dimensional upper portion into a three-dimensional shape through stitching or gluing—can be omitted. This results in a more efficient manufacturing technique for parts or the entire upper. Uppers manufactured in this way also offer greater wearing comfort because fewer or no seams are required.

[0016] The base can include a metallic surface, a textured surface, or a combination thereof. Depending on the desired characteristics of the upper, the surface roughness of the base can be adjusted to affect the tactile perception of the upper—the side facing the base. This side may correspond to the inner surface of the finished upper—facing the wearer's foot. For example, a recess in the base can result in a protrusion on the inner side of the upper. Conversely, a protrusion on the base can result in a recess on the inner side of the upper. Thus, a structured inner side of the upper can be provided. This structuring can be used, for example, to reduce direct skin contact, mimic a more woven feel, improve wearing comfort, and reduce foot slippage within the upper.

[0017] The dispensing may include dispensing liquefied polymer through a nozzle. This can be achieved, for example, by moving the nozzle relative to a substrate. Pre-programmed strand dispensing can be achieved by moving the substrate around a fixed nozzle, or by moving the nozzle around a fixed substrate, or by moving the nozzle around a moving substrate, thereby producing a desired upper shape.

[0018] The distribution may include strands with a width of 1-10 mm, preferably 2-4 mm, and most preferably 3 mm. The inventors have discovered that liquefied polymers make it possible to distribute strands with a specified (small) width. The term "width" as used in this invention should be understood as the diameter in the case of circular strands, or the maximum diameter in the case of oval or other shaped strands. Based on the specified fine width, uppers can be manufactured that have similar properties to conventional fabric uppers while being more easily adaptable to specific needs. This is because the distribution pattern can be configured and optimized more efficiently, rather than developing complex knitted or woven patterns.

[0019] After curing, the width of the strands is 0.3 mm to 0.7 mm, preferably 0.5 mm. Therefore, this invention provides a manufacturing technique for shoe uppers that have a fabric-like feel without the drawbacks and limitations of traditional fabric patterns—such as knitted or woven patterns. The fabric-like feel can be achieved based on the fine dimensions of individual strands used to manufacture part or all of the shoe upper.

[0020] The dispensing may include dispensing strands in a first region and a second region of the substrate, such that the mechanical properties of the cured strands in the first region differ from those in the second region. Due to the high degree of freedom of movement during the dispensing of the liquefied polymer on the substrate, regions with different mechanical properties can be effectively created.

[0021] The magnitude of the mechanical property of the cured strand in the third region may differ from the magnitude of the same mechanical property of the cured strand in the fourth region. Therefore, the disclosed method can not only achieve different mechanical properties, but also adjust the magnitude of the same mechanical property.

[0022] The mechanical properties of the cured strands can be at least one of the following: density, width, strand diameter, elasticity, breathability, water resistance, tensile strength, Shore hardness, adhesion friction, or a combination thereof. Each of these properties can be optimized individually or in combination—by adjusting the distribution of the liquefied polymer accordingly.

[0023] The allocation may include: allocating strands in a strand pattern. Specifically, the allocation may include: allocating strands in a strand pattern by arranging individual strands on a substrate and / or previously allocated strands to form a strand pattern. The degree of fabric feel can be adjusted according to the strand pattern. The strand pattern may further define one or more of the mechanical properties described above.

[0024] In some embodiments, the method may further include the steps of: heat-curing at least a portion of the yarn strands; and attaching that portion of the yarn strands to a first component of the footwear article. This may eliminate the need for stitching or gluing to attach portions of the upper to the first component. The first component may include, or even be, a sole component. This makes it possible to weld the upper to the sole component without seams or gluing. The first component may be a midsole. In this way, the use of a strobel board and / or stitching the upper to a strobel board can be avoided, resulting in a smooth and non-irritating transition from the upper to the midsole. Therefore, wearing comfort can be improved.

[0025] The method may further include: arranging a second component on a substrate prior to dispensing, wherein the dispensing may further include: dispensing strands of the liquefied polymer at least partially onto the substrate and at least partially onto the second component. Thus, gluing or even heat treatment may not be necessary to attach the upper to the second component. Due to the high adhesion coefficient of the liquefied polymer, the second component can adhere to the liquefied polymer and remain firmly attached after the curing step. The second component may include at least one of a reinforcing component, a padding component, a foil component, a mesh component, or a foam component.

[0026] The polymer can be selected from the group consisting of polyurethane (PU), thermoplastic polyamide (TPA), thermoplastic polyester (TPE), thermoplastic styrene block copolymer (TPS), thermoplastic polyurethane (TPU), thermoplastic vulcanizate (TPV), rubber, or ethylene-vinyl acetate copolymer (EVA), preferably thermoplastic polyurethane (TPU), and / or combinations thereof. The inventors have found that using these polymers enables time-efficient and sustainable processes in the production of parts. Suitable polymer materials can be elastic foam materials, such as thermoplastic elastomers and / or elastomers. Preferred materials used in this disclosure are thermoplastic elastomers. More preferred materials used in this disclosure are urethane-based thermoplastic elastomers (TPU), polyester-based thermoplastic elastomers (TPE), and / or polyamide-based thermoplastic elastomers (TPA).

[0027] The solvent may be a mixture selected from the group consisting of solvent-based solvents and / or water-based solvents, preferably selected from the group consisting of solvent-based solvents, and more preferably selected from the group consisting of: C1-C6 ethers, ... 10 Esters, C1-C8 ketones, C1-C8 alkanes, and / or combinations thereof. These solvents have shown optimal compatibility with shoe upper manufacturing methods, while allowing for flexible adaptation of the polymer's mechanical properties to product and process requirements.

[0028] The solvent can be one or a mixture of the following: tetrahydrofuran (THF), methyl ethyl ketone (MEK), cyclohexane (CYC), ethyl acetate, butyl acetate, preferably THF and / or CYC. These solvents have the advantage that they can be removed in a time-efficient manner during the curing process and allow for production processes that can accommodate a wide range of mechanical properties of the liquid polymer.

[0029] The proportion of the mixture can be in the range of 10 vol% to 90 vol% (vol%, volume percentage), preferably 20 vol% to 80 vol%, more preferably 30 vol% to 70 vol%. Alternatively, the proportion of the mixture can be in the range of 10 wt% to 90 wt% (wt%, mass percentage), preferably 20 wt% to 80 wt%, more preferably 30 wt% to 70 wt%. The inventors have discovered that the proportion of solvent mixtures exhibits optimal compatibility in mixing polymers and in modifying / adapting the mechanical properties of liquefied polymers to the specific requirements of products and processes.

[0030] The liquefied polymer may contain a dynamic viscosity of 10,000 to 50,000 mPa·s, preferably 20,000 to 40,000 mPa·s. Liquid polymers containing specific dynamic viscosities allow for their use in automated and / or manual deposition processes.

[0031] In the mixing step, the ratio of polymer to solvent can range from 2:98 to 40:60 (vol%), preferably from 5:95 to 30:70 (vol%), and more preferably from 10:90 to 20:80 (vol%). The inventors have discovered that a specific ratio of solvent to polymer allows for convenient use during the dispensing process and flexibility to adapt to product and / or process requirements.

[0032] Liquefied polymers may also contain pigments. This allows for preferred color selection of the liquefied polymer. For example, some liquefied polymers, such as liquefied thermoplastic polyurethanes, may have glassy transparency without the presence of color pigments. The desired color effect can be achieved by adding up to 1 vol% of pigment to the liquefied polymer without negatively impacting the mechanical properties of the cured strands.

[0033] The liquefied polymer may also contain fibers. This allows for increased stiffness and durability in selected application areas. "Fibers" should be understood as, but not limited to, threads or filaments based on natural and / or synthetic materials. For example, the inventors have found that adding 2.5 wt% to 5 wt% of glass fiber to a liquefied polymer improves the durability of the shoe upper, particularly its abrasion resistance.

[0034] The liquefied polymer may also contain granules. These granules may comprise various materials, such as finely ground rubber granules in the range of 0.1-0.3 mm. In this way, based on the use of granules, adhesion and grip properties are enhanced in selected areas of the shoe upper. Furthermore, the visual appearance of the shoe upper can be enhanced. "Particle" should be understood as, but is not limited to, particles of different sizes and shapes, based on natural and / or synthetic materials, and may possess specific mechanical properties.

[0035] The liquefied polymer may also contain a foaming agent. A foaming agent should be understood as a substance that expands during the curing step, thereby creating a porous structure in the upper through a foaming process. The porous structure in the matrix reduces its density and increases the relative stiffness of the original polymer. Thus, the surface roughness of the upper can be increased depending on the amount of foaming agent used. Surface roughness increases the fabric feel of the upper, resulting in greater wearing comfort.

[0036] Curing may include curing under the following conditions: a curing temperature between 20°C and 150°C, preferably between 30°C and 100°C, more preferably between 40°C and 50°C, and a curing duration between 2 minutes and 750 minutes, preferably between 5 minutes and 390 minutes, more preferably between 10 minutes and 30 minutes. The inventors have discovered that these curing conditions allow for a cost-effective and energy-efficient process—for use in shoe upper production.

[0037] The dispensing may include dispensing a liquefied polymer at a temperature ranging from 10°C to 40°C, preferably from 15°C to 30°C, and most preferably ambient temperature. The inventors have recognized that known methods for manufacturing shoe uppers—based on the softening of thermoplastic polymers (by raising the temperature above their glass transition temperature)—are mostly complex, time-consuming, and inefficient. In contrast, this disclosure focuses on an alternative method: polymer liquefaction. Based on the mixing of polymer and solvent, the method disclosed herein does not require elevated temperatures. This provides an improved and more flexible manufacturing method compared to known techniques.

[0038] In another aspect, the present invention provides an upper for a footwear article, which is made by a method comprising one or more steps as described above. Attached Figure Description

[0039] Possible embodiments of the present invention will be further described in the following detailed description with reference to the accompanying drawings.

[0040] Figure 1 : A flowchart illustrating an embodiment of the manufacturing method.

[0041] Figure 2 : A schematic diagram of an embodiment of a footwear product, wherein the footwear product includes a plurality of thread patterns.

[0042] Figure 3 : Schematic diagram of another embodiment of the substrate.

[0043] Figure 4A : Schematic diagram of an embodiment of liquefied polymer strands distributed on a substrate.

[0044] Figure 4B : Figure 4A A schematic diagram of polymer strands after curing and removal from the substrate.

[0045] Figure 5A : Schematic diagram of an embodiment of a liquefied polymer strand before activation by a foaming agent.

[0046] Figure 5B Schematic diagram of polymer strands after curing and activation by foaming agent.

[0047] Figure 6 : A schematic diagram of another embodiment of a footwear article, wherein the footwear article includes a plurality of mechanical characteristic areas.

[0048] Figure 7A : A schematic diagram of another embodiment of a footwear article, wherein the footwear article includes a low-density thread pattern.

[0049] Figure 7B : A schematic diagram of another embodiment of footwear, wherein the footwear includes a high-density thread pattern.

[0050] Figure 8 : A schematic diagram of an embodiment of the shoe upper, wherein the shoe upper includes components attached to the shoe upper.

[0051] Figure 9 : A schematic diagram of another embodiment of a footwear article, wherein the footwear article includes regions with different mechanical stiffness. Detailed Implementation

[0052] Exemplary embodiments of the invention will be described in more detail below with reference to the uppers of footwear articles. Although specific combinations of features are described below with respect to exemplary embodiments of the invention, it should be understood that this disclosure is not limited to such embodiments. In particular, not all features are required to implement the invention, and embodiments can be modified by combining certain features of one embodiment with one or more features of another embodiment.

[0053] Figure 1 A flowchart illustrating exemplary method steps of method 100 according to the present invention is presented, wherein the method is used to manufacture uppers 210, 610, 710, 760, 800, and 950 of footwear articles 200, 600, 700, 750, and 900. Method 100 includes step 140: providing a substrate 300 or 400. The substrates 300 or 400 may have a three-dimensional shape—at least a portion of a shoe last 300. In some embodiments, a shoe last 300 may be used as the substrate 300 or 400. The substrates 300 or 400 may include: metal surfaces 310, 410, and 420, a textured surface 420, or a combination thereof. Further details of embodiments of the substrates 300 or 400 are referenced below. Figure 3 As shown in Figure 4.

[0054] Method 100 further includes step 150: dispensing liquefied polymer strands 430, 500 onto substrates 300, 400 such that the strands 430, 500 form a shape representing at least a portion of the uppers 210, 610, 710, 760, 800, 950. Thus, after dispensing, the liquefied polymer may be substantially in its final shape, as desired or intended for use in the uppers 210, 610, 710, 760, 800, 950. The term "substantially" refers to minute changes in the liquefied polymer strands 430, 500 that occur during the curing step (see below). Therefore, based on advantageous dispensing, for the uppers 210, 610, 710, 760, 800, 950 according to the invention, a further step of transforming a two-dimensional portion of the upper into a three-dimensional shape may not be necessary. The dispensing in step 150 may include dispensing the liquefied polymer through a nozzle. The nozzle may be movable relative to the substrates 300, 400. Therefore, either the nozzle can move while the bases 300 and 400 are fixed, or the bases 300 and 400 can move while the nozzle is fixed. It may also be advantageous if the bases 300 and 400 and the nozzle move simultaneously during dispensing. In this way, there are practically no limitations, and various shapes of shoe uppers 210, 610, 710, 760, 800, and 950 can be manufactured based on this invention.

[0055] Additionally or alternatively, step 150 may include dispensing strands 430, 500 having widths of 1-10 mm, preferably 2-4 mm, and most preferably 3 mm. It should be noted that, based on the invention, varying widths within the same strand 430, 500 are also possible. For example, varying widths of individual strands 430, 500 can be achieved by varying the pressure applied to the liquefied polymer during dispensing—to expel it from the nozzle. Such adaptable widths within individual strands 430, 500 are not possible in known technologies (such as those discussed in the Background section)—e.g., jet extrusion or force spinning.

[0056] The width of the cured strands 440 and 510 can range from 0.3 mm to 0.7 mm, preferably 0.5 mm. Such a small diameter is impossible using known extrusion techniques. This is likely primarily due to the lower viscosity of the liquefied polymer compared to the heated polymers mostly used in jet extrusion or force spinning techniques. The dynamic viscosity of the liquefied polymer can range from 10,000 to 50,000 mPa·s, preferably 20,000 to 40,000 mPa·s. Method 100 makes it possible to dispense the liquefied polymer, wherein the liquefied polymer has an advantageous small width. The described fine strands 430, 440, 500, and 510 provide uppers 210, 610, 710, 760, 800, and 950—with properties similar to or improved upon those of conventional woven uppers. Simultaneously, the limitations of conventional woven uppers, such as knitting or weaving requirements, or the disadvantages arising from transforming two-dimensional fabrics into three-dimensional upper shapes, are no longer limitations.

[0057] Alternatively or additionally, step 150 may include distributing strands 430 and 500 in at least two regions 310, 410, and 420 of the substrates 300 and 400 such that the mechanical properties of the cured strands 440 and 510 differ in these regions 310, 410, and 420. Alternatively or additionally, the distribution may also result in the same mechanical properties having different values. The mechanical properties of the cured strands 440 and 510 may be at least one of the following: density, width, strand diameter, elasticity, breathability, water resistance, tensile strength, Shore hardness, adhesion friction, or a combination thereof.

[0058] Additionally or alternatively, step 150 may include: distributing strands 430, 500 in strand patterns 230, 240, 250, 260. This can be achieved by arranging individual strands 430, 500 on bases 300, 400 and / or previously distributed strands in strand patterns 230, 240, 250, 260. The degree of fabric feel can be adjusted according to the strand patterns 230, 240, 250, 260. The strand patterns 230, 240, 250, 260 may further be at least partially decisive for the mechanical properties of the uppers 210, 610, 710, 760, 800, 950. For example, denser strand patterns 230, 240, 260 may result in higher tensile strength compared to a looser or less dense strand pattern 250.

[0059] In addition to the mechanical properties provided by the strand patterns 230, 240, 250, and 260, the softness / stiffness of the polymer used to liquefy the polymer also affects the mechanical properties. In this case, the mechanical properties are based on the softness / stiffness of individual strands. The Shore A value of the polymer used can range from less than 50 Shore A (resulting in soft and comfortable strands) to greater than 90 Shore A (for highly stiff strands 430, 440, 500, and 510).

[0060] Method 100 may further include the step of arranging a second component on substrates 300, 400 prior to dispensing, wherein the dispensing may further include: dispensing at least partially strands 430, 500 of the liquefied polymer onto substrates 300, 400 and onto the second component. Thus, gluing or even heat treatment may be unnecessary to attach the uppers 210, 610, 710, 760, 800, 950 to the second component. The second component may include at least one of a reinforcing component 810, padding components 270, 820, 821, a foil component, a mesh component, and a foam component.

[0061] Method 100 further includes step 160: curing strands 430 and 500. In this manner, the liquefied polymer having the substrate shapes 300 and 400 is cured, while the solvent present in the liquefied polymer is removed. The solvent can be removed by condensation, and the condensate can be recovered. The curing temperature in curing step 160 can be between 20°C and 150°C, preferably 30°C to 100°C, more preferably 40°C to 50°C, and the curing time is between 2 minutes and 750 minutes, preferably 5 minutes to 390 minutes, more preferably 10 minutes to 30 minutes. In some embodiments, curing step 160 can be performed using radiation. Curing 160 is preferably performed using infrared radiation (IR). However, other types of radiation are also applicable. After curing step 160, the width of strands 440 and 510 is 0.3 mm to 0.7 mm, preferably 0.5 mm.

[0062] In some embodiments, prior to step 140, method 100 may include an optional step 110: providing a polymer. The polymer is selected from the group consisting of elastomers and / or thermoplastic elastomers. Preferred materials from the group consisting of elastomers are bulk foams, such as ethylene vinyl acetate (EVA), polyurethane (PU), and / or rubber. Thermoplastic elastomers (TPEs) are beaded or bulk foams, crosslinked and / or uncrosslinked, and can be classified using the following groups: TPE-O or TPO; TPE-V or TPV; TPE-U or TPU; TPE-E or TPE or TPC; TPE-S or TPS; TPE-A or TPA. Polymer materials from the TPE-O or TPO group are polypropylene (PP), ethylene propylene diene monomer (EPDM) rubber, or ethylene propylene diene monomer (EPDM) rubber. Preferred polymer materials from the TPE-V or TPV group are thermoplastic vulcanizates, such as Sarlink®. Polymer materials from the TPE-U or TPU group are further classified as ester-based, ether-based, or linear UP materials. For example, preferred ester-based TPU materials include Huntsman-H Foam®, such as Huntsman A6055Ag®. Preferred ether-based TPU materials include Elastollan® 11XX (BASF), such as Elastollan® 1170A. Preferred polymer materials from the TPE-E or TPC group are, for example, Hytrel® (DuPont), Keyflex® (LG), and / or Arnitel® (DSM). Preferred polymer materials from the TPE-S or TPS group are, for example, Styroflex® (BASF). Preferred polymer materials from the TPE-A or TPA group are from the polyether block amide group, such as PEBAX®, and / or Vestamid®.

[0063] In an embodiment of method 100 including step 110, the method may further include an optional step 120: providing a solvent. A suitable solvent is a solvent selected from the group consisting of solvent-based solvents and / or water-based solvents, preferably from the group consisting of solvent-based solvents, and more preferably from the group consisting of C1-C6 ethers, ... 10 Esters, C1-C8 ketones, C1-C8 alkanes, and / or combinations thereof. The solvent is preferably one or a mixture of tetrahydrofuran (THF), methyl ethyl ketone (MEK), cyclohexane (CYC), ethyl acetate, and butyl acetate, more preferably THF and / or CYC. The mixture of said solvents is in the range of 10 vol% to 90 vol%, preferably 20 vol% to 80 vol%, more preferably 30 vol% to 70 vol%.

[0064] In embodiments of method 100 including steps 110 and 120, method 100 may further include an optional step 130: mixing the polymer and solvent to produce a liquefied polymer. In the mixing step, the polymer-to-solvent ratio is in the range of 2:98 to 40:60 (vol%), preferably 5:95 to 30:70 (vol%), more preferably 10:90 to 20:80 (vol%). In the mixing step, the polymer-to-solvent ratio is in the range of 10 wt% to 90 wt%, preferably 20 wt% to 80 wt%, more preferably 30 wt% to 70 wt%.

[0065] Method 100 may further include the steps of: heat-curing at least a portion of the strands 440, 510, and attaching said portions of the strands 440, 510 to a first component of the footwear article. The first component may include or even be sole components 220, 620, 625, 720, 770, 960, such as midsoles 220, 620, 720.

[0066] The liquefied polymer used in method 100 may contain pigments, fibers, particles, and / or foaming agents. The effect of the foaming agent will be described in more detail below with reference to Figure 5.

[0067] Figure 2 An embodiment of footwear article 200 is depicted, which is manufactured according to the methods described herein. For example, the upper 210 of footwear article 200 may be manufactured with reference to method 100 as described above. Footwear article 200 further includes a sole 220 attached to the upper 210. For example, a portion of the cured strands of the upper 210 may be heated and attached to a sole component of the sole 220. The sole component may be the midsole of the sole 220. Based on the heated strands, stitching or gluing may not be necessary to attach the sole 220 to the upper 210.

[0068] The upper 210 comprises various layers of cured yarn strands and different patterns 230, 240, 250, and 260. The base layer comprises a mesh pattern 230 similar to that of a conventional knitted fabric. This base layer is manufactured by depositing liquefied yarn strands onto a substrate as described above. On the base layer, a second layer is deposited in the heel area in the form of a second pattern 240. The second pattern 240 is a regular pattern of substantially parallel yarn strands. The yarn strands of the second pattern 240 have a greater width than those of the base layer. The second pattern 240 is adapted to provide stability in the heel area of ​​the upper 210.

[0069] The upper 210 further includes a third pattern 250 arranged on the base layer in the area from the forefoot to the midfoot. The third pattern 250 is a regular pattern of strands arranged in a basic diamond pattern 250 or a rhomboid pattern 250. The third pattern 250 is adapted to provide improved stretch in the forefoot area.

[0070] The upper 210 further includes a fourth pattern 260, which is arranged on the third pattern 250, located in the toe box area, and near the mid-side of the upper 210 (not on the third pattern 250). Figure 2 (As shown in the diagram) and on the sides of the body. The strands of the fourth pattern 260 are irregularly distributed, with a higher density in areas requiring higher adhesion friction or abrasion resistance. The fourth pattern 260 may be advantageous for, for example, the upper of a football boot, because the cured strands provide high friction or tack, which is beneficial for areas used for ball control. Based on various layers of cured strands directly applied to the base during manufacturing, the upper 210 includes a surface close to the wearer's foot, while providing, for example, excellent adhesion friction and grip to the ball.

[0071] The upper 210 further includes a padding 270 in the heel area of ​​the footwear 200. This padding can be made of conventional fabric and attached to the upper 210—by heating the cured strands in that area. The padding 270 increases wearing comfort for the wearer of the footwear 200. The padding 270 further stabilizes the collar area of ​​the upper 210, preventing it from collapsing. This facilitates stepping into the footwear 200. In another embodiment, the padding can also be manufactured by dispensing a liquefied polymer as described above. For example, multiple layers of cured strands with a mesh pattern can provide cushioning properties similar to those of padding from conventional fabrics. It is even possible to manufacture the entire footwear upper based entirely on the disclosed liquefied polymer dispensing method.

[0072] Figure 3 An embodiment of a base 300 is depicted, which has the shape of a shoe last 300. The base 300 can even be a shoe last 300. The base 300 has a smooth and metallic surface 310. Surface 310 facilitates the removal of cured strands from the base 300 after the curing step. In the forefoot and toe regions 320 of the base 300, two distinct layers 330, 340 of liquefied polymer strands are depicted. The first layer 330 of liquefied polymer strands is distributed along the tip segment of the toe region 320, starting from the first toe side and extending to the fifth toe side. If the base 300 is placed on the ground—with the sole section facing the ground—the strands of the first layer 330 will extend substantially parallel to the ground. The density of the distributed strands in the first layer 330 is highest in the central segment 331—compared to the edge segments 332, 333. Based on this, compared to the less dense edge sections 332 and 333, the central section 331 offers a higher degree of abrasion resistance, reinforcement, and toe protection. On the other hand, compared to the denser central section 331, the edge section 333 offers a higher degree of elasticity and breathability.

[0073] A second layer 340 of liquefied polymer strands is disposed on top of the first layer 330. The strands of the second layer 340 are substantially perpendicular to the direction of the strands of the first layer 330. The strands of the second layer 340 originate below the toe area 320 on the side where the sole will be attached and extend upward toward the forefoot area 321 of the base / last 300. The strands of the second layer 340, due to their lower density compared to the strands of the first layer 330, provide less directional tensile strength along the individual strands of the first layer 330.

[0074] exist Figure 3 In this invention, a first layer 330 and a second layer 340 of distributed liquefied polymer strands are arranged in a region of the shoe last 300, which is curved in two directions. These regions are difficult to manufacture using conventional methods, in which a two-dimensional surface must be shaped into the desired three-dimensional shape without introducing kinks or creases. The present invention overcomes these difficulties of the prior art. Therefore, in some embodiments, at least a portion of the upper that is curved in two directions is manufactured according to the methods disclosed herein.

[0075] Figure 4A Another embodiment of a substrate 400 according to the present invention is depicted. The substrate 400 has two distinct surface regions 410 and 420. The first surface region 410 is smooth, while the second surface region 420 has a textured surface. Figure 4A In the second surface region 420, the textured surface consists of square protrusions 421 arranged in a regular configuration. Recesses 422 are formed between the square protrusions 421. Protrusions of other shapes and forms are also applicable.

[0076] During the dispensing of liquefied polymer strands 430 onto the substrate 400, two surface regions 410 and 420 result in cured strands 440 with different textures, such as Figure 4B As depicted. Specifically, segment 450 of the cured strand 440 corresponds to a segment of the strand 430 disposed on surface region 410, while segment 460 of the cured strand 440 corresponds to a segment of the strand 430 disposed on surface region 420. Depending on the viscosity level of the liquefied polymer, the side of the strand 430 facing the substrate 400 will at least partially flow into the recess 422 in the second surface region 420. This results in a protrusion 442 on the side of the cured strand 440 facing the substrate 400 before removal. The same side of the cured strand 440 on segment 450—due to being disposed on smooth surface region 410—has been smoothly flattened 411.

[0077] Typically, compared to segments allocated and cured on a smooth (or smoother) surface, strand segments allocated and cured on a textured surface will retain a rougher or more textured surface. In other words, cured strands can typically have a roughness corresponding to a negative shape of the surface. The term "negative" should be understood as a concave portion in the substrate being transformed into a protrusion in the cured strand, and vice versa. The different textures of the cured strands provide the wearer of the upper—manufactured according to the invention—with different haptic or tactile sensations. The textured side of the strand may correspond to the side of the upper facing the wearer's foot. Textured strands can be used to reduce the area of ​​the upper in direct contact with the skin. Additionally or alternatively, textured strands may be adapted to mimic the feel or texture of fabric for the wearer.

[0078] Figure 5A / 5B depicts a schematic diagram of strands 500, 510 according to the present invention. Strands 500, 510 contain a foaming agent. Figure 5A The image depicts the thread 500 before the curing step. Therefore, in the thread 500, the foaming agent has not yet been activated, and the thread 500 has a smooth, closed surface 501.

[0079] Figure 5B A strand 510 is depicted, corresponding to the cured strand 500. During the curing process, a foaming agent is activated and expands, thereby creating a porous structure in the strand 510 through a foaming process. This porous structure creates a surface roughness 511 in the strand 510, the degree of which depends on the amount of foaming agent used in the liquefied polymer. The surface roughness 511 increases the fabric feel—of the upper manufactured according to the invention—thus providing a more pleasant wearing comfort for the wearer. The foaming agent is adapted to not increase the width of the cured strand 510—compared to a cured strand without foaming agent—by more than 10%, preferably not more than 5%.

[0080] Figure 6 An embodiment of footwear article 600 is depicted, which is manufactured according to the methods described herein. For example, the upper 610 of footwear article 600 may be manufactured with reference to method 100 as described above. Footwear article 600 further includes a midsole 620 attached to the upper 610. For example, a portion of the cured strands of the upper 610 may be heated and attached to the midsole 620. Based on the heated strands, the midsole 620 may be attached to the upper 610 without stitching or gluing—after the strands have cooled again. On the opposite side of the midsole 620, an outsole 625 is further attached.

[0081] Figure 6Three exemplary areas with different mechanical properties are further described. These mechanical properties are particularly suitable for the improved laceless footwear 600. Therefore, the upper 610 should provide sufficient locking to ensure that the footwear 600 stays on the wearer's foot—even when swinging the leg, for example, during a sprint or when hitting a ball. On the other hand, the upper 610 should also provide sufficient flexibility to ensure that the wearer can easily step into the footwear 600 when putting it on.

[0082] These various mechanical properties can be effectively provided based on the methods described herein. In the first region, omnidirectional or non-directional tensile strength of the upper 610 is provided (indicated by arrow 611). This tensile strength can be achieved based on a polymer material having one or more of the following properties: Shore A hardness below 70, high tensile strength, low stiffness, etc. In the second region, directional locking is provided, as indicated by arrow 612, while substantially perpendicular tensile strength is also provided in different directions (indicated by arrow 613). This can be achieved, for example, by using a hard polymer material, thicker strands, and / or more rigid strands for the upper distributed in a direction parallel to arrow 612. Simultaneously, strands having similar properties to those described with reference to the first region are distributed onto the substrate in the direction of arrow 613. The distribution of different strands can be separated in alternating layers (e.g., first distributing one layer of strands in the direction of arrow 612, then distributing another layer of strands in the direction of arrow 613, ...). However, the mesh pattern also applies, where a strand is assigned in direction 612, followed by a strand in direction 613, then another strand in direction 612, and so on. Although Figure 6 This should be understood as an exemplary embodiment, but other arrangements of different regions (having one or more of the mechanical characteristics described above) are also applicable based on this disclosure.

[0083] Figure 7A An embodiment of footwear article 700 is depicted, which is manufactured according to the methods described herein. For example, the upper 710 of footwear article 700 may be manufactured with reference to method 100 as described above. Footwear article 700 includes a sole 720 attached to the upper 710. Preferably, a portion of the cured strands of the upper 710 may be heated and attached to the midsole 720. Based on the heated strands, stitching or gluing may not be necessary to attach the sole 720 to the upper 710. However, alternative attachment methods, such as stitching or gluing, may also conform to this disclosure.

[0084] Figure 7AAn embodiment of an upper 710 is depicted, which—through a thread pattern with openings 711—has a high degree of breathability. The upper 710 may also have various areas—with different levels of breathability, such as breathability-sensing areas adapted to the human foot. For this purpose, the thread density is low (compared to the thread density providing a closed surface, for example, in upper 760) and arranged in a mesh pattern, thus providing multiple openings 711 in the upper 710. The upper 710 may be advantageous for footwear, for example, adapted for running.

[0085] Figure 7B An embodiment of footwear article 750 is depicted, which is manufactured according to the method described herein. For example, the upper 760 of footwear article 750 may be manufactured with reference to method 100 as described above. Footwear article 750 includes a sole 770 attached to the upper 760.

[0086] In contrast to footwear 700, footwear article 750 depicts an embodiment of an upper 760 having a high degree of adhesion friction and / or water resistance. The upper 760 may also have various areas—with different levels of adhesion friction—which can be adjusted, for example, based on the corresponding application or the type of sport for which footwear 750 is intended. For this purpose, the yarn density is high (i.e., higher than that of the upper 710) and arranged in a mesh pattern, so that the upper 760 provides a closed surface 761 instead of openings. The upper 760 may be advantageous for footwear articles, for example, adapted for playing soccer.

[0087] Figure 8 A schematic diagram of an embodiment of an upper 800 manufactured according to the method described herein is depicted. For example, the upper 800 may be manufactured with reference to method 100 as described above. The upper 800 includes a reinforcing element 810 in a toe region 815. For example, the reinforcing element 810 may have been disposed on a base prior to any dispensing. Then, liquefied polymer strands are dispensed onto the base and the reinforcing element 810. Due to the high viscosity coefficient of the liquefied polymer strands, the reinforcing element 810 and the dispensed strands adhere to each other. The level of adhesion is further increased through a curing step and may become permanent. Alternatively, the reinforcing element 810 may be attached to the upper after dispensing but before the curing step. In this way, it is possible to place the reinforcing element 810 on the exterior of the finished upper, i.e., on the side that does not contact the wearer's foot when wearing the footwear article comprising the upper 800.

[0088] Instead of or incorporating reinforcing element 810, the upper 800 further includes a lateral (outer side of the foot) padding element 820 and a medial (inner side of the foot) padding element 821 in the collar area 825. Padding elements 820 and 821 may be attached to the upper 800 in the same manner as described with reference to reinforcing element 810. Although Figure 8 Two additional elements are depicted in the toe area 815 and the collar area 825, but further elements in different areas are also applicable and well known to those skilled in the art.

[0089] Figure 9 An embodiment of footwear article 900 is depicted from a lateral viewpoint 910 and a mesial viewpoint 920. Footwear article 900 is manufactured according to the methods described herein. For example, the upper 950 of footwear article 900 may be manufactured with reference to method 100 as described above. Footwear article 900 further includes a sole 960 attached to the upper 950. For example, a portion of the cured strands of the upper 950 may be heated and attached to the sole 960. Based on the heated strands, stitching or gluing may not be necessary to attach the sole 960 to the upper 950.

[0090] exist Figure 9 The system provides various regions with different levels of mechanical stiffness. Different levels of mechanical stiffness can be achieved by correspondingly changing the strand density. Higher strand density results in higher mechanical stiffness, and lower strand density results in lower mechanical stiffness. Although... Figure 9 The areas indicated may be optimized for football boots, but other area arrangements are also applicable based on the requirements of other types of footwear. These areas are generally known to those skilled in the art.

[0091] While the above embodiments illustrate various individual examples, one or more of these examples can also be combined in a footwear article 200, 600, 700, 750, 900 according to this disclosure. For example, the textured strands 430, 440 described with reference to FIG. 4 can be combined with any embodiment describing various mechanical properties in various regions. Furthermore, reference to... Figure 7A The footwear article 700 described, having an opening 711 for improved breathability, may also have—see reference—another area of ​​the same upper 210, 610, 710, 760, 800, 950. Figure 7B The described closed surface 761 has improved water resistance and abrasion resistance.

Claims

1. A method (100) for manufacturing the upper (210, 610, 710, 760, 800, 950) of footwear articles (200, 600, 700, 750, 900), the method comprising: Provide (110) polymer; Provide (120) solvent; The polymer (130) is mixed with the solvent to produce a liquefied polymer; Provide (140) substrates (300, 400); Distribute (150) strands (430, 500) of the liquefied polymer onto the substrate such that the strands form the shape of at least a portion of the upper; Curing (160) the strands; and Remove (170) cured line strands (440, 510) from the substrate.

2. The method according to claim 1, wherein, The base includes a three-dimensional shape of at least a portion of a shoe last (300), wherein the base is a shoe last.

3. The method according to claim 1 or 2, wherein the substrate comprises a metal surface (310), a textured surface (420), or a combination thereof.

4. The method according to any one of claims 1-3, wherein, The dispensing includes dispensing the liquefied polymer through a nozzle, particularly by moving the nozzle relative to the substrate.

5. The method according to any one of claims 1-4, wherein, The distribution includes: strands with a width of 1-10 mm, preferably 2-4 mm, and most preferably 3 mm.

6. The method according to any one of claims 1-5, wherein, After curing, the width of the strands is 0.3 mm to 0.7 mm, preferably 0.5 mm.

7. The method according to any one of claims 1-6, wherein, The allocation includes: allocating the strands in a first region and a second region of the substrate such that the mechanical properties of the strands cured in the first region are different from those of the strands cured in the second region.

8. The method according to claim 7, wherein, The mechanical properties of the cured strands in the third region differ from those of the same cured strands in the fourth region.

9. The method according to claim 7 or 8, wherein, The mechanical properties of the cured strands are at least one of the following: density, width, strand diameter, elasticity, breathability, water resistance, tensile strength, Shore hardness, adhesion friction, or a combination thereof.

10. The method according to any one of claims 1-9, wherein, The allocation includes: allocating the strands in a strand pattern (230, 240, 250, 260), in particular by arranging individual strands on the substrate and / or previously allocated strands to form the strand pattern.

11. The method according to any one of claims 1-10, wherein, The method further includes: Heating at least a portion of the cured strands; and The portion of the thread is attached to the first part of the footwear.

12. The method according to claim 11, wherein, The first component includes sole components (220, 620, 625, 720, 770, 960), particularly the midsole.

13. The method according to any one of claims 1-12, the method further comprising: Prior to the dispensing, a second component is disposed on the substrate, wherein the dispensing further comprises dispensing at least partially strands of the liquefied polymer onto the substrate and onto the second component.

14. The method according to claim 13, wherein, The second component includes at least one of a reinforcing component, a padding component, a foil component, a mesh component, and a foam component.

15. The method according to any one of claims 1-14, wherein, The polymer is selected from the group consisting of polyurethane (PU), thermoplastic polyamide (TPA), thermoplastic polyester (TPE), thermoplastic styrene block copolymer (TPS), thermoplastic polyurethane (TPU), thermoplastic vulcanizate (TPV), rubber or ethylene-vinyl acetate copolymer (EVA), preferably thermoplastic polyurethane (TPU), and / or combinations thereof.

16. The method according to any one of claims 1-15, wherein, The solvent is a mixture selected from the group consisting of solvent-based solvents and / or water-based solvents, preferably selected from the group consisting of solvent-based solvents, and more preferably selected from the group consisting of: C1-C6 ethers, ... 10 Esters, C1-C8 ketones, C1-C8 alkanes, and / or combinations thereof.

17. The method according to any one of claims 1-16, wherein, The solvent is one or a mixture of tetrahydrofuran (THF), methyl ethyl ketone (MEK), cyclohexane (CYC), ethyl acetate, and butyl acetate, preferably THF and / or CYC.

18. The method according to claim 17, wherein, The proportion of the mixture is in the range of 10 vol% to 90 vol%, preferably 20 vol% to 80 vol%, more preferably 30 vol% to 70 vol%.

19. The method according to claim 17, wherein, The proportion of the mixture is in the range of 10wt% to 90wt%, preferably 20wt% to 80wt%, and more preferably 30wt% to 70wt%.

20. The method according to any one of claims 1-19, wherein, The liquefied polymer has a dynamic viscosity of 10,000 to 50,000 mPa·s, preferably 20,000 to 40,000 mPa·s.

21. The method according to any one of claims 1-20, wherein, In the mixing step, the ratio of the polymer to the solvent is in the range of 2:98 to 40:60 vol%, preferably 5:95 to 30:70 vol%, more preferably 10:90 to 20:80 vol%.

22. The method according to any one of claims 1-21, wherein, The liquefied polymer also contains pigments and / or fibers.

23. The method according to any one of claims 1-22, wherein, The liquefied polymer also contains particles.

24. The method according to any one of claims 1-23, wherein, The liquefied polymer also contains a foaming agent.

25. The method according to any one of claims 1-24, wherein, The curing includes curing under the following conditions: a curing temperature between 20°C and 150°C, preferably between 30°C and 100°C, more preferably between 40°C and 50°C, and a curing duration between 2 minutes and 750 minutes, preferably between 5 minutes and 390 minutes, more preferably between 10 minutes and 30 minutes.

26. The method according to any one of claims 1-25, wherein, The dispensing includes dispensing the liquefied polymer at a temperature in the range of 10°C to 40°C, preferably 15°C to 30°C, and most preferably ambient temperature.

27. An upper (210, 610, 710, 760, 800, 950) of a footwear article (200, 600, 700, 750, 900), which is manufactured by the following method (100), said method comprising the steps of any one of claims 1 to 26 according to the aforementioned method.

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