Method for manufacturing shoes, system for carrying out said method, and shoes

Abstract

To provide a method for manufacturing a shoe, in particular a sports shoe.SOLUTION: There is provided a method for manufacturing a shoe, comprising the steps of: providing a plurality of individual particles for a sole element in a mold; providing an upper in the mold; and fusing the plurality of individual particles and the upper by means of an electromagnetic field to bond the plurality of individual particles with each other and with the upper.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing shoes, in particular sports shoes, a system for implementing this method, and the shoes. [Background technology]

[0002] Conventional methods for manufacturing shoes generally employ an assembly-based approach (i.e., a stock fit of parts) that requires the processing of various individual components, such as pre-fabricated soles and uppers, at different processing stations, which are then joined together at yet another location. Such manufacturing methods are typically highly complex and labor-intensive, as well as requiring the chemical use of hazardous materials to bond the stock-fitted parts together.

[0003] To overcome these disadvantages, the applicant has disclosed in DE 102016208998 A1, DE 102016209044 A1 and DE 102016209045 A1 sole forms, methods and systems for producing a plurality of finished shoes. However, these methods still leave room for improvement.

[0004] The use of particulate foam materials, i.e., materials made from individual particles of expanded plastic material (also called expanded foam beads and bead foam), has also been incorporated into the manufacture of cushioning elements for producing soles for sports shoes. In particular, the use of expanded thermoplastic polyurethane (eTPU) particles, which are fused at their surfaces by exposing the particles to pressurized steam in a mold (often referred to in the art as "steam chest molding"), has been explored for producing shoe soles.

[0005] However, conventional molds for steam-chest molding shoe soles are not optimally adapted to the unique requirements of shoe production processes. For example, steam-chest molding processes for shoe soles made from particles using conventional molds require a large amount of energy to heat the molds because conventional molds are generally large in mass. Furthermore, the cooling process of such molds is slow, thus leading to long cycle times. Finally, steam-chest molding shoe soles from particles requires a uniform supply of pressurized steam to the particles to achieve homogeneous interconnection of the particles. Due to their structure, conventional molds are not optimally adapted to such a uniform supply of media.

[0006] Energy carriers other than pressurized steam are also considered. In particular, the applicant has described in DE 10 2016 223 980 A1 a method for producing a sole element, in which a first material comprising particles of a foam material is filled into a mold, and the particles are preheated during filling of the mold by supplying energy in the form of at least one electromagnetic field.

[0007] A common disadvantage of these disclosed methods is that they still do not fully take into account the entire production of the finished shoe, which remains very complex and labor-intensive, especially for the production of modern high performance footwear such as sports shoes that require specific material properties.

[0008] It is therefore an object of the present invention to overcome the above-mentioned disadvantages of the prior art and to provide an improved method for manufacturing shoes, which method optimizes the production efforts and which method is also as energy-efficient as possible, while avoiding the use of environmentally harmful or hazardous substances. Summary of the Invention

[0009] This object is achieved by the teaching of the independent claims. Advantageous embodiments are contained in the dependent claims.

[0010] According to one aspect of the invention, a method for manufacturing a shoe, particularly a sports shoe, includes the steps of providing a plurality of individual particles for a sole element in a mold, providing an upper in the mold, and fusing the plurality of individual particles and the upper using an electromagnetic field to bond the plurality of individual particles to each other and to the upper.

[0011] By fusing a plurality of individual particles and an upper with electromagnetic energy from an electromagnetic field, the present invention provides an improved method for the overall manufacture of a shoe. Individual foam particles may be fused together to bond with one another so that they form a sole element, and the upper may be fused and bonded (or joined) to this manufactured sole element in a durable and permanent manner. In other words, the two main components of a shoe, the sole element and the upper, may be joined together in the same mold. For example, the softened (or partially melted) surface area of the particles present on the top surface of the sole element may be used as a bonding / connecting agent to connect the upper to the top of the sole element. In this way, one or more of the amount of energy, the number of process steps, the number of additional or intermediate parts, processing time, and assembly steps (and associated labor hours) may be reduced. It should be noted that in the context of the present application, fusion and bonding may occur at different processing times and / or temperatures, e.g., the plurality of individual particles may be fused at a lower temperature than the bonding of the plurality of individual particles to the upper, or may occur simultaneously due to different local energy amounts of the electromagnetic field and / or different mold temperatures. Furthermore, different processing times for fusion and bonding may also be considered when a connecting layer, such as an adhesive layer, is used.

[0012] Furthermore, using electromagnetic energy from an electromagnetic field for the production of sole elements and the entire shoe can shorten molding time, save energy by, for example, avoiding excessive energy absorption by the mold, and can also help promote cooling and stabilization of the molded sole element, for example, because energy supply is not coupled to any kind of material transfer, as is the case with the injection of an energy flow. In addition, the electromagnetic field can be selected so that it penetrates the mold filled with the multiple individual particles for the sole element and the upper, achieving improved fusion / molding and bonding throughout the entire shoe and at all depths of the shoe. In this way, the entire shoe production can be greatly simplified, as the shoe can be produced in one process step by bonding the compact material of the upper with the foam material of the sole element.

[0013] The individual particles in this application may also be referred to as "foam material," "foam particles," "foam pellets," "foam beads," "foam particles," "foam-like particles," "foam-like pellets," or "foam-like beads," and the sole elements produced may therefore be referred to as "particle foam," "bead foam," or "pellet foam" parts or elements. Other terms by which such foam-like particles may be referred to in the particle foam field may also be used.

[0014] The upper material and the upper itself may be made using various techniques known in the art. In one embodiment, the upper material may be a textile upper. Generally, the textile may be a flexible material produced by creating yarns of the material. The yarns may be monofilament or multifilament yarns, which are intertwined bundles of fibers or threads produced by spinning raw fibers (either natural or synthetic) into long twisted lengths, and the textile may be formed into an upper component by weaving, knitting, crocheting, knotting, tatting, felting, bonding, or by twisting such yarns together. Furthermore, the term "textile" may be used synonymously with the textile herein. It is also contemplated that the upper may be made of leather, particularly synthetic leather materials using thermoplastic polyurethane, or a composite material of one of the textiles mentioned above and a non-textile material.

[0015] It should be noted that in the context of this application, the term "bond" may be used synonymously with the terms "attach," "firmly couple," "fix," "interconnect," or "connect" to refer to the fabric upper being joined to the sole element from individual particles in a durable, strong, and permanent manner.

[0016] The method may further include providing a support element for the sole element in the mold and / or providing an outsole element for the sole element in the mold, and the aforementioned fusing step may further include fusing the support element and the outsole element using an electromagnetic field to bond the plurality of individual particles to each other, the support element, the outsole element, and the upper. It is also conceivable that only at least two of the plurality of individual particles, the support element, the outsole element, or the upper are fused and bonded to each other using an electromagnetic field. The support element may be at least one of a reinforcing element, a fabric sheet such as a knitted fabric, a woven fabric, or a nonwoven fabric, a molded part, a heel counter, a sole plate, a medial support element, a lateral support element, a toe support element, a bonding layer, a composite element, for example, an element made of leather or synthetic leather, and other commonly used elements in the state of the art. It should be noted that in the context of this application, the term "element" may be used synonymously with the term "component."

[0017] By providing one or both of these two main components of the sole element, i.e., the support element and the outsole element, the overall manufacturing of the entire shoe may be further improved by reducing the processing time of the sole element, since pre- or post-production steps for one or both of these two elements may not be necessary. There is also no need for multiple automated production stations for the two elements, which reduces the required footprint of the manufacturing system within a facility. Furthermore, these described embodiments may help provide improved shoes, particularly sports shoes, with the mentioned enhanced material properties, since the support element may provide special sole properties, such as selective support to prevent pronation and supination.

[0018] One or more of the above-described fusing steps may be performed in a single step. This enhances the above-described advantages of the claimed method for simplifying and optimizing the overall manufacturing of the shoe through a single process step in the mold. It should be noted that the expression "one or more of the above-described fusing steps" as used herein refers to a step of fusing a plurality of individual particles and the upper using an electromagnetic field to bond the plurality of individual particles to each other and to the upper, a step of fusing a support element and an outsole element to bond the plurality of individual particles to each other, the support element, the outsole element, and the upper, as well as a step in which only two of the plurality of individual particles, the support element, the outsole element, or the upper are fused and bonded to each other using an electromagnetic field.

[0019] The electromagnetic field may be in the radio frequency range of 30 kHz to 300 MHz, preferably in the range of 1 MHz to 200 MHz, more preferably in the range of 1 MHz to 50 MHz, and most preferably in the range of 25 to 30 MHz, or in the microwave range of 300 MHz to 300 GHz. In a preferred embodiment, the electromagnetic field may have a frequency in the radio frequency range around 27.12 MHz. It is also contemplated that one or more radio frequencies or ranges of radio frequencies may be used.

[0020] Also, radio frequency generators are commercially available and can be easily implemented in a system for manufacturing shoes. Furthermore, the radio frequency radiation can be focused on each part of the system and its intensity and frequency can be adapted to the requirements.

[0021] Microwave generators are commercially available and can be implemented into a shoe manufacturing system to use the method of the present invention with relatively little effort. In addition, it may be possible to essentially focus the microwave radiation on the mold cavity in which the plurality of individual particles and textile upper are provided, allowing for improved energy efficiency. Furthermore, the intensity and frequency of the microwave radiation can be easily varied and adapted to the requirements of each shoe component, such as the sole element and textile upper.

[0022] It is further possible that the electromagnetic field, in particular the electromagnetic radiation, is provided in a frequency range different from the frequency ranges mentioned above.

[0023] One or more of the fusing steps described above may be performed without adhesives, which can help reduce the amount of toxic or hazardous substances, such as glue, during the manufacture of the sole and the shoe as a whole, and avoid causing harm to the manufacturing facility and its environment.

[0024] One or more of the above-described welding steps may be performed without the use of infrared radiation. This may help avoid undesired destruction of individual particles, support or outsole elements, and sole elements, such as the upper. Of course, further hardening the shoe by providing heat energy from infrared radiation is contemplated and should not be excluded from the claimed invention. The above-described welding steps may also be performed without at least one other joining technique, such as gluing, welding, radio frequency welding, ultrasonic welding, laser welding, crimping, sewing, screwing, riveting, fusing, clipping, sealing, applying heat and pressure, or exposing to steam treatment.

[0025] The method may further include locally adjusting the electromagnetic field strength distribution of the electromagnetic field within the mold. This may allow for consistent energy application to elements within the mold that have varying thicknesses, such as sole elements (or midsole) or shoe uppers, or to varying thicknesses of the mold itself. For example, higher density materials within shoe elements may heat up faster for fusing, and therefore the electromagnetic field strength distribution of the electromagnetic field may be locally adjusted so that more energy can be absorbed by those elements to balance the energy absorption of lower density areas. In this way, the properties of individual shoe elements may be influenced in a simpler manner than by applying different, varying electromagnetic fields, for example, with different, varying frequencies.

[0026] The energy supplied using the electromagnetic fields may be varied over time. For example, the energy supplied using at least one electromagnetic field may be gradually increased over time. In this manner, the time-varying magnetic flux from the electromagnetic induction of the varying electromagnetic fields may create eddy currents in the conductive material of the particle and upper, which heat the material and thus contribute to fusing the surface of the particle and the upper.

[0027] A plurality of individual particles and / or uppers in a first subregion of the mold may be supplied with more energy from the electromagnetic field than in a second subregion of the mold. This may apply to both preheating the particles and / or uppers in the mold and fusing the particles and uppers together. In this way, a plurality of different subregions may be created in the shoe, each differing in thickness, hardness, breathability, flexibility, elasticity, feel, appearance, or other properties to facilitate manufacturing.

[0028] One or more of the above-described fusing steps may further include fusing the surfaces of a plurality of individual particles and / or the surface of the upper. This may enable the production of sole elements and / or entire shoes with various thicknesses and complex shapes, since the supply of energy does not result in any kind of material transfer of the sole elements and / or upper, such as the introduction of a binder or steam. As described above, the electromagnetic field may be selected so that it penetrates the mold filled with the individual particles and upper for the sole element essentially uniformly and supplies an essentially constant amount of energy to all particles and the upper, thereby achieving uniform and consistent fusing of the particle surfaces and / or upper throughout the entire shoe and at all depths of the individual shoe components. Alternatively, the electromagnetic field may be selected so that the supply of energy to the particles and upper arranged in the mold is locally varied, as described above. In this way, the nature and degree of fusing of the particle surfaces and / or upper can be locally influenced. In particular, the fusion of particle surfaces within the sole element may be controlled independently from the fusion of particle surfaces on the surface of the sole element. In summary, these embodiments may help provide a better bond between the sole element and the textile upper.

[0029] The method may further include disposing a connecting layer between the plurality of individual particles for the sole element and the textile upper prior to one or more of the above-described fusing steps. Such an embodiment may provide a kind of protective layer for the particles to avoid an uneven surface of the manufactured sole element, which may penetrate into the textile upper and cause an uncomfortable wearing experience for the shoe wearer. Protection of the textile upper by such a connecting layer is also contemplated.

[0030] One or more of the above-described fusing steps may further include molding a sole element from a plurality of individual particles. Molding a sole element from a plurality of individual particles is a particularly efficient method for manufacturing shoes. Additionally, molding the particles into a sole element as a type of particle foam component does not require toxic or hazardous materials.

[0031] The plurality of individual particles and / or the upper may be preheated in the mold prior to one or more of the above-described fusing steps. Preheating may be achieved by an electromagnetic field. The type / nature of the electromagnetic field used for preheating may be different from the type / nature of the electromagnetic field used to fuse the particles and the upper. However, it is also possible for the type / nature of the electromagnetic field used for preheating to be the same as the type / nature of the electromagnetic field used to fuse the particles and the upper. Preheating the particles and / or the upper can reduce the amount of energy that must be supplied to the particles and / or the upper in the mold, which may further shorten processing time, conserve energy by, for example, avoiding excessive energy absorption by the mold, and may also help facilitate cooling and stabilization of the manufactured shoe, as described above. Preheating the particles and / or the upper may also generally allow for more finely tuned control of the manufacturing process, for example, because different subsets of particles used to manufacture the sole element may be preheated to different degrees.

[0032] The mold used in the above-described method may comprise a polymeric material, preferably a thermoplastic material, more preferably one or more of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyoxymethylene (POM), polyamideimide (PAI), polycarbonate (PC), polyketone (PK), polyetheretherketone (PEEK), polyvinylidene fluoride or polyvinylidene difluoride (PVDF), thermoplastic polyurethane (TPU), or polyethylene (PE). Furthermore, the polymeric material of the mold may consist of a foam-like material. These materials have been found to be advantageous and may therefore be used in the context of the present invention. For example, POM has a dielectric loss factor D of approximately 0.008 for radio frequency radiation. Therefore, this material is essentially transparent to radio frequency radiation, since it absorbs only a portion of the electromagnetic field, and due to its relatively low loss factor, it can be formed to a certain thickness. The polymeric material may be adapted to increase the dielectric constant of the mold compared to the shoe or element thereof being manufactured. The polymer material may be adapted to increase the dielectric loss factor of the mold.

[0033] The plurality of individual particles used in the above-described method may comprise a foam material, preferably based on one or more of expanded thermoplastic polyurethane (eTPU), expanded polyamide (ePA), expanded polyether block amide (ePEBA), polylactide (PLA), polyether block amide (PEBA), expanded polyethylene terephthalate (ePET), expanded polybutylene terephthalate (ePBT), expanded thermoplastic polyester ether elastomer (eTPEE), and expanded polystyrene (ePS). For example, for use in the manufacture of shoe soles, particles of eTPU, ePEBA, and / or ePA have proven advantageous and may therefore be used in the context of the present invention. The use of foam material on both the particle and the mold surface may result in similar loss rates, thereby providing substantially uniform heating of both the particle and the mold, and the mold may be prepared for better fusion of the sole elements.

[0034] The upper used in the above-described method may be a textile upper and may include one or more of a knitted structure, a woven structure, a nonwoven structure, randomly deposited fibers, a multidirectional layered material, and a mesh structure. Some of these textile structures may be beneficially used in portions of the upper requiring good breathability or breathability. Furthermore, a knitted structure may provide much greater stretch due to the intertwined mesh of the textile structure. Furthermore, a nonwoven structure may provide a suitable feel on the inner surface of the upper and may provide adequate stability in desired portions of the textile upper.

[0035] For reinforcement and to reduce elongation, fusible yarns with added thermoplastic material may be used in the textile upper, which secure the knitted structure after fusion. It is conceivable to use thermoplastic yarns surrounded by non-thermoplastic yarns, non-thermoplastic yarns surrounded by thermoplastic yarns, or pure fusible yarns of thermoplastic material. Such fusible yarns may be knitted into the knitted structure of the textile upper.

[0036] The strength of the bond in the above-described method may be higher than the strength of the weakest fused material. In other words, the weakest fused material yields to the strength of the bond between the plurality of individual particles and the upper. In the context of this application, the term "strength" refers to a mechanical property that allows a material to resist deformation load, which means that the strength of a material is the material's ability to withstand fracture under the action of an external load. The stronger the material, the greater the load it can withstand. Furthermore, the expression "weakest fused" corresponds to a certain degree of fusion between different materials.

[0037] The invention also relates to a system comprising means for carrying out the above-described method so that a shoe is manufactured in one step by joining the compact material of the upper with the particulate material of the sole element.

[0038] The invention also relates to a shoe, in particular a sports shoe, manufactured by one of the methods described above, which may, for the reasons explained above, be free of adhesive.

[0039] The present invention includes the following embodiments. 1. A method for manufacturing shoes, in particular sports shoes, comprising: a. providing a plurality of individual particles for a sole element in a mold; b. providing an upper in a mold; c. fusing the plurality of individual particles and the upper utilizing an electromagnetic field to bond the plurality of individual particles to each other and to the upper. 2.d. Providing a support element for the sole element within the mold; e. Providing an outsole element for a sole element in a mold; and further comprising one or more of: f. The method of the above embodiment, wherein step c further comprises fusing the support element and the outsole element utilizing an electromagnetic field to join the plurality of individual particles to each other, to the support element, to the outsole element, and to the upper. 3. The method of one of the above embodiments, wherein step c is performed in a single step. 4. The method of one of the above embodiments, wherein the electromagnetic field is in the radio frequency range of 30 kHz to 300 MHz, preferably in the range of 1 MHz to 200 MHz, more preferably in the range of 1 MHz to 50 MHz, and most preferably in the range of 25 to 30 MHz, or in the microwave range of 300 MHz to 300 GHz. 5. The method of one of the above embodiments, wherein step c is performed without adhesive. 6. The method of one of the above embodiments, further comprising the step of locally adjusting the electromagnetic field strength distribution of the electromagnetic field within the mold. 7. The method of one of the above embodiments, wherein an electromagnetic field is utilized to vary the delivered energy over time. 8. The method of one of the above embodiments, wherein the plurality of individual particles and / or uppers in the first sub-region of the mold are supplied with more energy by the electromagnetic field than in the second sub-region of the mold. 9. The method of one of the above embodiments, wherein step c further comprises fusing the surfaces of the plurality of individual particles and / or the surface of the upper. 10. The method of one of the above embodiments, further comprising, before step c, a step of disposing a connecting layer between the plurality of individual particles for the sole element and the upper. 11. The method of one of the above embodiments, wherein step c further comprises molding a sole element from a plurality of individual particles. 12. The method of one of the above embodiments, wherein the plurality of individual particles and / or uppers are preheated in the mold prior to step c. 13. The method of one of the above embodiments, wherein the mold comprises a polymeric material, preferably a thermoplastic material, more preferably one or more of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyoxymethylene (POM), polyamideimide (PAI), polycarbonate (PC), polyketone (PK), polyetheretherketone (PEEK), polyvinylidene fluoride or polyvinylidene difluoride (PVDF), thermoplastic polyurethane (TPU), or polyethylene (PE). 14. The method of one of the above embodiments, wherein the plurality of individual particles comprises a foam-like material, preferably based on one or more of expanded thermoplastic polyurethane (eTPU), expanded polyamide (ePA), expanded polyether block amide (ePEBA), polylactide (PLA), polyether block amide (PEBA), expanded polyethylene terephthalate (ePET), expanded polybutylene terephthalate (ePBT), expanded thermoplastic polyester ether elastomer (eTPEE), expanded polystyrene (ePS). 15. The method of one of the above embodiments, wherein the upper is a textile upper and includes one or more of a knitted structure, a woven structure, a nonwoven structure, randomly deposited fibers, a multi-directional layered material, and a mesh structure. 16. A system comprising means for implementing the method of one of the above embodiments. 17. Shoes, in particular sports shoes, manufactured by a method according to one of the above embodiments. 18. The shoe of any of the above embodiments, wherein the shoe does not contain adhesive.

[0040] Possible embodiments of the invention will now be further explained with reference to the following figures: [Brief explanation of the drawings]

[0041] [Figure 1] 1 illustrates a method of the present invention for producing a finished shoe in a former. [Figure 2a] FIG. 10 shows a manufactured sole element according to the present invention made from individual particles after fusing the particles together using an electromagnetic field. [Figure 2b] FIG. 10 illustrates a manufactured sole element according to the present invention made from individual particles after utilizing an electromagnetic field to fuse the plurality of individual particles together and bond them together. DETAILED DESCRIPTION OF THE INVENTION

[0042] Possible embodiments of various aspects of the present invention are described in the following detailed description primarily in the context of the manufacture of shoes in general, e.g., sports shoes, casual shoes, lace-up shoes, or boots, such as work boots. However, it is emphasized that the present invention is not limited to these embodiments. Rather, the present invention may be used in various sports apparel products, such as knee or elbow protectors, that utilize foam and textile materials, at least a portion of which is formed from individual particles, such as tennis rackets, golf clubs, baseball bats, badminton rackets, cricket bats, ice hockey sticks, hockey sticks, squash rackets, table tennis bats, shin guards, etc. Furthermore, the term "sports apparel" may refer to clothing worn for sports or physical activity, including shoes and accessories such as sports equipment. Sports-specific apparel or garments may be worn for most sports and physical activities for practical, comfort, or safety reasons. Typical sports-specific apparel may include tracksuits, shorts, T-shirts, and polo shirts. Specialized clothing may include swimwear (for swimming), wetsuits (for diving and surfing), ski suits (for skiing), and leotards (for gymnastics). Sports footwear may include training shoes, running shoes, soccer shoes, basketball shoes, volleyball shoes, tennis shoes, rugby shoes, golf shoes, riding boots, snowboard boots, and ice skates. Sports-specific apparel or clothing may also include bikinis, some croc tops, and underwear such as jockstraps and sports bras.

[0043] It is further noted that hereinafter, only individual embodiments of the present invention may be described in more detail. However, those skilled in the art will understand that the optional features and possible modifications described with reference to those specific embodiments may be further modified and / or combined with each other in other ways or in other subcombinations without departing from the scope of the present invention. Individual features may be omitted if they are not necessary to achieve the desired results. Therefore, to avoid redundancy, reference is made to the descriptions in the preceding paragraphs, which also apply to the following detailed description.

[0044] FIG. 1 illustrates a method of the present invention for producing a finished shoe 100, particularly a sports shoe, by providing a plurality of individual particles 105 for a sole element 110 in a mold 120 and providing an upper, such as a textile upper 130.

[0045] Providing the plurality of individual particles 105 may include filling and / or transferring the particles from a container into a mold 120, for example, via at least one feedstock line in an automated manufacturing line.

[0046] Providing the textile upper 130 may be done manually by a worker and / or automatically by a machine, such as a robot.

[0047] The plurality of individual particles 105 and the textile upper 130 are then fused together using an electromagnetic field 140 to bond the plurality of individual particles 105 to each other and to the textile upper 130. The bonding of the plurality of individual particles 105 to the textile upper 130 is indicated schematically by two double-lined arrows.

[0048] The electromagnetic field 140 may be emitted from a radiation source 145, such as two capacitor plates, where one capacitor plate is connected to a radio frequency generator and the other capacitor plate is grounded. However, multiple radiation or energy sources can be used, or a single energy source can emit radiation of different frequencies, etc., in which case multiple electromagnetic fields are referred to (in the linguistic sense). These electromagnetic fields overlap at a given point in space to form a physical electromagnetic field at this point in space.

[0049] The electromagnetic field 140 may be, for example, radiation in the microwave range, i.e., radiation with a frequency in the range of 300 MHz to 300 GHz. The electromagnetic field 140 may also be radiation in the radio frequency range, i.e., radiation with a frequency in the range of 30 kHz to 300 MHz.

[0050] It is further possible that the energy is provided in the form of radiation from the electromagnetic field 140 in a frequency range different from the frequency ranges mentioned above. As a specific example, the energy may be provided in the form of ultraviolet (UV) radiation.

[0051] If the electromagnetic field 140 is radiation in the microwave range, water may be suitable as an energy-absorbing material in the particles 105 and / or the textile upper 130, since irradiating water with microwave radiation leads to heating of the water. Water may also be considered as an energy-absorbing material for electromagnetic fields 140 in the radio frequency range. It is also contemplated that the energy-absorbing material may consist of a metal, particularly a metal powder. For example, metal, e.g., in the form of a metal powder, may be advantageous because it can absorb particularly large amounts of energy from at least one electromagnetic field while at the same time being easy to handle and inject. Metal may also, if desired, serve the purpose of affecting the appearance of the particles 105 and / or the (textile) upper 130, e.g., to impart a metallic sheen.

[0052] The particles 105 may be randomly arranged or a combination of arranged and randomly arranged particles 105 may be used. The particles 105 may be connected to each other at their surfaces. The materials used for the particles 105 and their advantages are described above.

[0053] The mold 120 may consist of different sections (not shown), such as a bottom, a top, and sides. Other mold shapes and more or fewer sections of the mold 120 are also contemplated.

[0054] The textile upper 130 may comprise one or more of the following constructions: knitted, woven, and / or nonwoven. The textile material may comprise randomly deposited fibers, multi-directional layered materials, and / or mesh constructions.

[0055] It is also contemplated that the (textile) upper 130 may comprise at least one heat-melt layer of fusible yarns, which may act as a fusible intermediate or connecting layer for indirect fusion between the particles 105 and the (textile) upper 130. It should be noted that such a layer may be optional, and the present invention may be practiced by fusing the particles 105 and the (textile) upper 130 using an electromagnetic field to bond the particles 105 to each other and to the (textile) upper 130.

[0056] As mentioned above, it is contemplated to preheat the particles 105 and / or textile upper 130 before actually fusing the particles 105 and textile upper 130. In that way, the particles 105 and / or textile upper 130 may first be heated to a particular temperature to provide a preferred absorption range for the electromagnetic radiation from the subsequently applied electromagnetic field 140 for fusing. This preheating may occur in the mold 120 before or while the particles 105 and / or textile upper 130 are fed to / into the mold 120.

[0057] Similar to the use of energy absorbing materials as described above, pre-heating of the particles 105 and / or textile upper 130 may be used, for example, when attempting to balance the absorption of the electromagnetic field 140 of multiple materials in a shoe.

[0058] Preheating of the particles 105 and / or textile upper 130 may be advantageous prior to providing the materials for the steps described above, and may also be advantageous as the mold 120 is being closed. Such preheating may improve the throughput of the system when carrying out the methods of the present invention, as it may reduce the time required for the actual fusing step and, therefore, the time required to hold the particles 105 and textile upper 130 in the mold 120.

[0059] Additionally or alternatively, in one example, the electromagnetic field 140 can be applied at a first lower power or voltage to preheat the material to a particular temperature (e.g., while the particles 105 and textile upper 130 are being provided and / or while they are in the mold 120). The power or voltage can then be increased gradually or suddenly. After being applied at a lower value, the power or voltage can also be increased in several different sub-regions of the mold 120 (not shown). In this way, only partial preheating of the particles 105 and / or textile upper 130 can be achieved. This can be useful when using particles 105 and textile upper 130 with different properties (e.g., size or absorbent material).

[0060] In some embodiments, at least one portion of the bottom, top, or sides of the mold 120 may be preheated. These options may be performed with or without providing particles 105 and / or (fabric) upper 130 material to the mold 120.

[0061] The power or voltage of the electromagnetic field 140 may be increased gradually. For example, the increase in radiation power may be selected so that the total cycle time for producing the shoe 100 is within a desired range for production. For example, the fusion may be performed in a range of 40 to 70 seconds. In addition, the cooling time for the shoe 100 after fusion may be in a range of 10 to 20 minutes. Thus, compared to conventional methods for manufacturing shoes, the method of the present invention may be significantly faster. In general, the time for increasing the radiation power can be selected quite freely and adjusted to control the fusion process between the surface of the particles 120 and the textile upper 130, and thus the overall fusion of the shoe. For example, depending on the material of the particles 120, an excessively fast increase may damage the cellular structure of the particles. On the other hand, an excessively slow increase may be insufficient or lead to substandard fusion results.

[0062] After pre-heating, electromagnetic radiation 140 may then be applied to achieve optimal transfer of power. This approach may also be useful when materials with temperature-dependent dielectric loss factors are used.

[0063] It is emphasized here again that an advantage of the present method may be that the mold 120 absorbs only a limited amount of energy compared to the materials of the particles 105 and the textile upper 130. For example, it has been found to be advantageous to use epoxy resin for the manufacture of the mold 120. Epoxy resin can be processed to fit molds 120 with complex shaped cavities and may have low absorption capacity for electromagnetic fields. Other methods known in the art for manufacturing molds with low absorption capacity may also be used.

[0064] 2a and 2b show a manufactured sole element 110 according to the present invention made from a plurality of individual particles 105 after an electromagnetic field has been utilized to fuse the individual particles 105 together and bond them together.

[0065] FIG. 2a shows the bottom surface of a sole element 110 in which an outsole element 115 has been provided and fused to a plurality of individual particles 105 using an electromagnetic field.

[0066] Such an outsole element 115 may protect multiple individual particles 105 of the sole element 110 .

[0067] FIG. 2b shows the top surface of the sole element 110, along with a portion of the textile upper 130 (for better understanding), after the plurality of individual particles 105 have been joined to each other and to the textile upper 130 by fusing the plurality of individual particles 105 to the textile upper 130 using an electromagnetic field. [Explanation of symbols]

[0068] 100 shoes 105 particles 110 Shoe sole elements 115 Outer sole element 120 type 130 Upper 140 Electromagnetic Radiation, Electromagnetic Fields 145 Radiation Source

Claims

1. 1. A method for manufacturing a shoe, comprising: a. providing a plurality of individual particles for a sole element in a mold; b. providing an upper in a mold; c. fusing the plurality of individual particles and the upper utilizing an electromagnetic field to bond the plurality of individual particles to each other and to the upper; disposing a connecting layer between the plurality of individual particles and the upper; Including, The method wherein the upper comprises a heat-fusible layer of fusible yarn that can act as a fusible intermediate layer or as the connecting layer.

2. The method of claim 1 , wherein the connecting layer comprises at least one hot melt layer.

3. d. Providing a support element for the sole element in the former; e. Providing an outsole element for the sole element in the former; and further comprising one or more of: f. The method of claim 1, wherein step c) further comprises fusing the support element and the outsole element using an electromagnetic field to join the plurality of individual particles to each other, to the support element, to the outsole element, and to the upper.

4. The method of claim 1 , wherein step c is performed in a single step.

5. The method of claim 1, wherein the electromagnetic field is in the radio frequency range of 30 kHz to 300 MHz.

6. The method of claim 1 , wherein step c is performed without an adhesive.

7. The method of claim 1 , further comprising the step of locally adjusting the electromagnetic field strength distribution of the electromagnetic field within the mold.

8. 10. The method of claim 1, wherein the energy delivered is varied over time using an electromagnetic field.

9. The method of claim 1 , wherein the plurality of individual particles and / or uppers in a first partial region of the mold are supplied with more energy by the electromagnetic field than in a second partial region of the mold.

10. The method of claim 1 , wherein step c further comprises fusing together the surfaces of the plurality of individual particles and / or the surface of the upper.

11. The method of claim 1 , further comprising, before step c, disposing a connecting layer between the plurality of individual particles for the sole element and the upper.

12. The method of claim 1 , wherein step c further comprises molding the sole element from a plurality of individual particles.

13. The method of claim 1 , wherein the plurality of individual particles and / or uppers are preheated in the mold prior to step c.

14. The method of claim 1 , wherein the mold comprises a polymeric material.

15. The method of claim 1 , wherein the plurality of individual particles comprises a foam-like material.

16. The method of claim 1 , wherein the upper is a textile upper and includes one or more of a knitted structure, a woven structure, a nonwoven structure, randomly laid fibers, a multi-directional layered material, and a mesh structure.

17. A system comprising means for carrying out the method according to any one of claims 1 to 16.

18. A shoe manufactured by the method according to any one of claims 1 to 16.

19. 20. The shoe of claim 18, wherein the shoe is adhesive-free.

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