Shoes, shoe manufacturing systems, and methods for manufacturing shoes

Abstract

Disclosed herein is a method for manufacturing a shoe, comprising the steps of: a. providing an upper assembly (2), the upper assembly comprising an upper (3) mounted on a carrier (4), the upper (3) comprising a bottom section (5) made of a thermoplastic polymer upper material; b. providing a sole molding unit (6), the sole molding unit comprising defining a cavity; c. inserting the upper assembly (2) at least partially into the cavity; introducing a midsole polymer composition comprising a molten thermoplastic polymer midsole material having a melting temperature equal to or greater than the melting temperature of the thermoplastic polymer upper material into the cavity, foaming the molten thermoplastic polymer midsole material in the cavity to provide a foamed midsole, and forming a material bonding connection between the upper (3) and the foamed midsole (8). Furthermore, a shoe and a shoe manufacturing system are disclosed.

Description

Technical Field

[0001] The present invention is in the field of shoe manufacturing technology, and specifically relates to a method for manufacturing shoes, a shoe, and a shoe manufacturing system.

Background Art

[0002] Sports shoes, specifically running shoes, typically consist of a sole and an upper. The upper is usually a textile such as a knitted fabric or a woven fabric. Generally, the upper is manufactured as a flat textile material, for example a flat knitted fabric or a flat woven fabric. Such flat textile materials are sometimes referred to as two-dimensional structures. Flat textile materials are typically manufactured using a knitting machine or a weaving machine, and then mounted on a last. Alternatively, circular knitted fabrics are commonly used. A sole of a conventional running shoe typically comprises a foamed midsole for providing cushioning properties and a wear-resistant outsole for protecting the midsole. Furthermore, the sole may comprise an insole that comes into contact with the foot of a wearer. In the prior art, the sole, and often additionally the midsole and the outsole, and the upper are manufactured separately on different machines. Depending on the manufacturing method, it may even be necessary to use a plurality of machines only for manufacturing the sole. During manufacturing, the lasted upper is typically connected to the sole by using an adhesive to form a material-bonded connection between the upper and the sole. In addition, stitching can be used to support the connection between the upper and the sole. Such a process requires human labor, and manufactured intermediate components must be transported from one machine to another. For example, midsole foam molding is typically performed by manually inserting granular polymer into a mold, closing the mold to allow foaming, manually removing the midsole, and manually removing scrap material. The manufactured sole is then transported to another work station where it is bonded to the lasted upper. This separation of steps and the relatively large requirement for human labor make the manufacturing process cumbersome and inefficient.

[0003] Traditional foam molding has several further drawbacks. For example, the soles often expand after deformation, making precise size control difficult. Furthermore, the molds must be heated, which increases the energy consumption of the process. From an environmental perspective, traditional foam molding emits large amounts of volatile organic compounds (VOCs). [Overview of the project]

[0004] A general objective of the present invention is to advance the current state of technology in shoes and shoemaking, preferably by completely or partially overcoming the shortcomings of the prior art. In preferred embodiments, methods and shoemaking systems are provided that are more efficient, and / or reduce the required human labor, and / or reduce the need for resources and / or waste, and / or are less harmful to the environment. In further preferred embodiments, shoes produced by such methods or such shoemaking systems are provided. Such shoes have a smaller ecological footprint and are less expensive to manufacture.

[0005] This general objective is achieved by the subject matter of the independent claims. Further preferred embodiments follow from the dependent claims and the overall disclosure.

[0006] A first aspect of the present invention relates to a method for manufacturing shoes. The method comprises steps a. to d., as will be further discussed below. However, it should be noted that, as used herein, the designations of steps such as a., b., or d. should not be understood as defining a particular order of steps, but rather as serving to clearly identify a particular step. Thus, in some embodiments, step a. may be followed by step b., which in turn is followed by step c., which in turn is followed by step d., while in some other embodiments, for example, step b. may be performed before and / or during step a.

[0007] Step a includes providing an upper assembly. The upper assembly comprises an upper mounted on a carrier. The upper comprises a bottom section made of a thermoplastic polymer upper material. It should be noted that the rest of the upper or another part may be made of the same thermoplastic polymer upper material or a different material. However, typically, at least the bottom section is made of a thermoplastic polymer upper material. Preferably, the majority of the upper (i.e., more than 50% by weight) or even the entire upper may be made of the same thermoplastic polymer upper material.

[0008] Step b includes providing a sole molding unit that defines a cavity. The cavity is typically configured to produce a shoe sole, particularly a midsole. In a preferred embodiment, the cavity is bounded by one or more side walls surrounding the cavity circumferentially and a bottom wall that defines the boundary of the bottom of the cavity. However, in some embodiments, the cavity is open at the top, i.e., the portion located opposite the bottom. This opening and upper assembly may preferably be configured such that when the upper assembly is at least partially inserted into the cavity, the top of the cavity is closed by the upper assembly, specifically airtightly.

[0009] Step c includes inserting the upper assembly provided in step a into the cavity defined by the sole molding unit, at least partially or completely. Typically, step c is performed such that at least part or all of the bottom section of the upper is inserted into the cavity of the sole molding unit. By inserting the upper assembly into the cavity, at least partially or completely, a sole molding compartment is preferably formed. This sole molding compartment may be bounded by the sole molding unit and the inserted upper assembly, or more specifically, by the sole molding unit and the inserted upper assembly alone. It is understood that the sole molding compartment is configured such that a midsole can be formed therein by introducing and foaming a midsole polymer composition. The sole molding compartment may typically be part of the cavity or located inside the cavity.

[0010] Step d includes introducing, specifically injecting, a midsole polymer composition containing a molten thermoplastic polymer midsole material into a cavity, and foaming the molten thermoplastic polymer midsole material within the cavity. By introducing and foaming the molten thermoplastic polymer midsole material, a foamed midsole is provided, forming a material bonding connection, specifically a direct material bonding connection, more specifically a fused connection, between the upper, specifically the bottom section of the upper, and the foamed midsole. The molten thermoplastic polymer midsole material has a melting temperature higher than that of the thermoplastic polymer upper material. This has the effect that, upon introduction of the molten thermoplastic polymer midsole material into the cavity and during its foaming within the cavity, the molten thermoplastic polymer midsole material comes into contact with and melts the bottom section of the upper inserted into the cavity. In other words, upon introduction of the midsole polymer composition into the cavity, particularly during injection, the thermoplastic polymer midsole material comes into contact with and melts at least part or all of the bottom section of the upper. Therefore, a direct material bonding connection is formed between the upper and the midsole, which does not involve any additional external adhesives but can be considered a fusion bond between the upper and the foamed midsole. This not only allows for the avoidance of additional process steps or materials but also forms a much stronger and more reliable connection between the upper and the midsole. The midsole polymer composition can be introduced, for example, into a sole molding compartment bounded by the upper assembly and the sole molding unit. In such embodiments, the shape of the sole molding compartment defines the shape of the foamed midsole. Typically, the molten thermoplastic polymer upper material is introduced into the cavity and foamed directly within the cavity.

[0011] As used herein, the term “melting temperature” may refer to a specific melting point, for example, when a single or pure material is used as a thermoplastic polymer upper material or thermoplastic polymer midsole material, or it may also refer to a range of melting temperatures, for example, when a mixture of different substrates is used as a thermoplastic polymer upper material or thermoplastic polymer midsole material.

[0012] The bottom section of the upper is typically located at the bottom of the carrier and may preferably be the section that forms the periphery lower boundary of the upper at the transition to the foam midsole in the manufactured shoe. The bottom section may typically surround the wearer's foot circumferentially. The bottom section may also be the region of the upper between the carrier and the foam midsole, correspondingly during manufacturing, when the shoe is worn and positioned beneath the wearer's foot. For example, the bottom section may extend up to 3 cm vertically in the upper.

[0013] As used herein, the term “thermoplastic polymer upper material” is used to indicate that the material is a thermoplastic polymer material present in the upper of a formed shoe. Similarly, the term “thermoplastic polymer midsole material” is used to indicate that the material is a thermoplastic polymer material present in the midsole of a formed shoe. In some embodiments, the thermoplastic polymer upper material and the thermoplastic polymer midsole material may be the same material or different materials. Similarly, the term “thermoplastic polymer outsole material” is used to indicate that the material is a thermoplastic polymer material present in the outsole of a formed shoe. In some embodiments, the thermoplastic polymer upper material, the thermoplastic polymer midsole material, and the thermoplastic polymer outsole material may be the same material or different materials.

[0014] As used herein, a direct material bonding connection between two elements means that the two elements are connected to each other without additional adhesive. For example, a direct material bonding connection may also be a fusion connection where the two elements are fused together.

[0015] It is generally understood herein that the term “comprising” means including the feature that follows it, but without excluding the presence of other features, as long as it does not render the claims non-functional. On the other hand, when the expression “consisting of” is used, there are no further features in the corresponding element other than those that follow the expression.

[0016] The abbreviation "SCIF," as used herein, stands for supercritical injection foaming.

[0017] Generally, molten thermoplastic polymer midsole materials can be provided by melting the thermoplastic polymer midsole material inside a melting unit or extruder, such as a screw and barrel extruder. For example, the thermoplastic polymer midsole material can be provided as molten granules.

[0018] In some embodiments, the carrier is removed from the upper after step d.

[0019] The carrier may preferably be a shoe last, for example, a shoe last, or at least a part of a shoe last. Such a shoe last may be, for example, a standardized shoe last for a particular shoe size, or a customized shoe last, for example, a shoe last manufactured based on a prior scan of the wearer's foot. The shoe last may be provided by molding, additive manufacturing, or subtractive manufacturing such as milling.

[0020] In some embodiments, the foam midsole is cooled after step d. This can be done either within the cavity or after the foam midsole and the upper material-bonded to the foam midsole, specifically the fused upper, have been removed from the cavity.

[0021] The sole molding unit is typically understood to have one or more injection openings configured to introduce the midsole polymer composition into the cavity, correspondingly into the sole molding compartment, and correspondingly defined.

[0022] In some embodiments, step d. is performed by supercritical injection foaming (SCIF), or correspondingly includes or consists of supercritical injection foaming. SCIF has the advantage of significantly reducing the emission of volatile organic compounds compared to conventional foaming. Furthermore, in contrast to other foaming techniques, it does not require the use of nucleating agents to facilitate mold release and / or coating of the mold with chemical agents. Thus, SCIF is more environmentally friendly and easier to implement.

[0023] SCIF, as used in some embodiments of the present invention, may preferably involve injection of a midsole polymer composition into a cavity by an extruder, such as a screw and barrel extruder, in an injection unit. In such embodiments, the midsole polymer composition may include, or consist of, a molten thermoplastic polymer midsole material and a supercritical fluid, such as N2 or CO2.

[0024] In some embodiments of the present invention, the midsole polymer composition used in SCIF may be injected into the cavity as a single phase, i.e., a homogeneous single phase, in step d.

[0025] In some embodiments using SCIF, the midsole polymer composition is injected into a cavity, and the pressure in the cavity is lower than the pressure in the injection unit, specifically in the barrel of the extruder. This has the effect that foaming occurs directly during injection and stops when the cavity, specifically the sole molding compartment, is filled to its maximum filling capacity under the applied conditions. These conditions may specifically include the pressure in the cavity and the injection unit. Due to the low pressure in the cavity, and generally in the SCIF method, the foamed midsole does not expand after deformation. Therefore, the cavity directly and accurately determines the size of the foamed midsole. For example, the pressure in the cavity may be lower than the pressure in the injection unit, such as 800 to 1200 bar, specifically 900 to 1000 bar.

[0026] In some embodiments, the cavity is pressurized to a first cavity pressure above atmospheric pressure before and / or during injection of the midsole polymer composition. The first cavity pressure may be provided as a gas counterpressure against the cavity.

[0027] In some embodiments, foaming of the molten thermoplastic polymer midsole material can generally be achieved by reducing the first cavity pressure to a second cavity pressure lower than the first cavity pressure. This results in the formation of bubbles of a physical foaming agent that leads to the foaming of the molten thermoplastic polymer midsole material. In some embodiments, the second cavity pressure may be atmospheric pressure.

[0028] Reducing the pressure within the cavity from the first cavity pressure to the second cavity pressure can be achieved by ventilation of the cavity, a continuous pressure reduction at a predetermined rate (e.g., by a valve or by reducing the counter-gas pressure applied to the cavity), or a stepwise reduction. The predetermined rate may be, for example, 0.5 bar / sec to 50 bar / sec, more specifically 1 bar / sec to 20 bar / sec, and more specifically 1 bar / sec to 10 bar / sec.

[0029] In some embodiments, the pressure within the cavity, i.e., the first cavity pressure, may be from 10 bar to 200 bar, specifically from 40 bar to 100 bar. In some embodiments, the pressure within the injection unit, for example within the barrel of an extruder, may be from 900 bar to 1200 bar, specifically from 1000 bar to 1100 bar.

[0030] In some embodiments, the polymer composition in step d. comprises a physical blowing agent. Typically, the physical blowing agent may be mixed together with the thermoplastic polymer midsole material before introducing the midsole polymer composition into the cavity. In certain specific embodiments, it may be possible to mix the physical blowing agent with the thermoplastic polymer midsole material, for example within the injection unit, for example within the barrel of a screw and barrel extruder. It may also be possible to inject the physical blowing agent into the thermoplastic polymer midsole material before or during melting of the thermoplastic polymer midsole material.

[0031] The blowing agent may preferably be a physical blowing agent such as N2 or CO2. As will be appreciated by those skilled in the art, a physical blowing agent is a blowing agent that can induce foaming when the physical state of the blowing agent or physical conditions such as pressure and / or temperature are changed to induce foaming. In contrast, a chemical blowing agent is a blowing agent that releases gas upon a chemical reaction, for example the release of N2 from a diazo moiety. In some embodiments, although it is possible to use chemical blowing agents, physical blowing agents are generally preferred. In certain embodiments, the physical blowing agent is in a supercritical state, for example in the injection unit, correspondingly in the screw and barrel extruder. This may be the case, for example, for embodiments where step d. is performed by SCIF.

[0032] In some embodiments, the bottom section of the upper is at least partially or completely melted during step d. In certain embodiments, the bottom section is at least partially or completely melted by the thermal energy of the molten thermoplastic polymer midsole material. This means that the thermal energy provided by the molten thermoplastic polymer midsole material is transferred to the bottom section upper, at which point the bottom section upper melts. In certain embodiments, the bottom section is at least partially or completely melted solely by the thermal energy of the molten thermoplastic polymer midsole material. This means that no additional thermal energy needs to be supplied.

[0033] In a particular embodiment, the bottom section of the upper is covered before step d, specifically before step c, with a thermoplastic film preferably made from a thermoplastic polymer midsole material.

[0034] In some embodiments, the sole molding unit does not include heating and / or cooling elements. This not only reduces the complexity of the sole molding unit but also improves manufacturing efficiency and the ecological footprint of the manufacturing process. In some embodiments, the sole molding unit is not heated or cooled during step d. and / or any of steps a. to d.

[0035] In some embodiments, the upper assembly is inserted into the sole molding unit in step c. such that a closed sole molding compartment is formed by the sole molding unit and the upper assembly, specifically defined solely by the sole molding unit and the upper assembly. In such embodiments, it is understood that the sole molding unit may preferably have one or more injection ports for introducing the midsole polymer composition into the cavity, correspondingly into the sole molding compartment. The formed sole molding compartment is typically located within the cavity of the sole molding unit. When the upper assembly is inserted into the cavity, the upper, specifically the bottom section of the upper, is inserted into the cavity of the sole molding unit.

[0036] In certain embodiments, the upper assembly is inserted into the sole molding unit in step c. such that a closed and sealed sole molding compartment is formed defined by the sole molding unit and the upper assembly. In certain embodiments, the upper assembly is configured to form a sealing element, such as a sealing lip, which provides a fluid-tight connection between the sole molding unit and the upper assembly. The sealing element may be, for example, a part of the upper, particularly a whole part of the upper. Alternatively, the sealing element may be releasably connected to the upper and / or carrier. As will be understood by those skilled in the art, a releasable connection, as used herein, is a connection that can be released without destroying the structural integrity of the connected elements. Optionally, a releasable connection can be released and reconnected multiple times. Thus, shape-locking and / or force-locking connections can be considered releasable connections, but material-bonding connections cannot.

[0037] In some embodiments, an outsole polymer composition, specifically a molten polymer outsole material, and more specifically a molten thermoplastic outsole material, is introduced into the cavity after step d. to provide an outsole material-bonded to a foam midsole. Preferably, the provided outsole is material-bonded directly to the foam midsole. As used herein, a direct material-bonded connection between two elements means that the two elements are connected to each other without additional adhesive. For example, a direct material-bonded connection may be a fused connection where the two elements are fused together. In some embodiments, the outsole polymer material may be the same material as the thermoplastic polymer upper material and / or the molten thermoplastic polymer midsole material. Providing an outsole in this manner makes it possible to produce a foam midsole material-bonded to an upper and an outsole material-bonded to a foam midsole in a single unit without the need to move parts and intermediate products between different locations.

[0038] In some embodiments, the upper assembly is held by a movable robotic arm, specifically between steps c. and d., and / or during step a. For example, step c., i.e., insertion of the upper assembly into the cavity, may be performed by the robotic arm. The robotic arm may be, for example, a cantilever. Preferably, the robotic arm is movable in three-dimensional space. The robotic arm may comprise, for example, one or more beams connected to each other via joints, thereby enabling the movement of the arm in three-dimensional space. In some embodiments, the movement of the robotic arm, in particular its movement in three-dimensional space, may be controlled by a control unit. The control unit may preferably comprise a circuit, for example, a microprocessor. For example, a movement path may be stored in a memory unit that can be accessed by the control unit to move the robotic arm along this movement path. For step c., it may be possible that the robotic arm already holds the carrier of the upper assembly before step c., or that the robotic arm first grasps the carrier and then inserts its upper assembly at least partially into the cavity of the sole molding unit.

[0039] In some embodiments, a robotic arm can be used to remove the carrier after step d., thereby separating the manufactured shoes from the carrier.

[0040] In certain embodiments, the robot arm may hold the upper assembly by holding the carrier. Specifically, the robot arm holds the upper assembly in a shape-lock or force-lock manner. For example, the robot arm and the carrier may be connected by a snap-fit ​​engagement, or the robot arm may have a gripping element that can grasp the carrier of the upper assembly.

[0041] In some embodiments, the upper assembly is provided by manufacturing the upper on a carrier in step a. This can be done by dispensing the thermoplastic molten upper material, which is included in at least the bottom section of the upper or on which the upper is made, onto the carrier by a nozzle in the form of at least one filament, particularly at least one continuous filament, to provide the upper mounted on the carrier. Specifically, the nozzle dispenses only one filament onto the carrier at a time; that is, if two or more filaments are to be dispensed, the filaments are dispensed sequentially onto the carrier.

[0042] In some embodiments, at least one filament is coated onto a carrier such that it forms multiple intersections with itself on the carrier and / or multiple loops on the carrier. In preferred embodiments, material bonding connections are formed at at least one intersection between different sections of at least one filament. For example, the filament can form loops, thereby laying one section of the filament onto another section of the same filament. In typical embodiments, the filament is coated so that it is still molten and / or softened compared to the aggregated state of the thermoplastic polymer upper material after storage at 23°C and atmospheric pressure for 24 hours. Thus, when two sections of the same filament form an intersection, a direct material bonding connection is formed at the intersection. This significantly improves the durability of the provided upper.

[0043] A loop, as used herein, is a section formed by a filament that begins at an intersection, extends along the thermoplastic filament, and returns to the same intersection. For example, a loop may have a round shape, specifically a circular or oval shape. A loop may also have an irregular shape.

[0044] In some embodiments, the nozzle comprises a material outlet and a plurality of air openings arranged circumferentially around the material outlet. In such embodiments, pressurized air is applied to the molten polymer upper material exiting the material outlet of the nozzle so that the molten polymer upper material is coated onto or into a carrier as a helical filament. This does not necessarily mean that the helical filament must extend completely between the nozzle and the carrier during coating, but it may be so in some embodiments. In some embodiments, the pressurized air applied to the molten polymer upper material has a temperature greater than 150°C, specifically greater than 200°C. In some embodiments, the pressurized air applied to the molten polymer upper material has a temperature of up to 600°C, specifically up to 400°C. In some embodiments, the pressurized air applied to the molten polymer upper material has a temperature of 150°C to 600°C, specifically 200°C to 400°C.

[0045] In certain embodiments, the nozzle is part of a deposition unit as described herein. In certain embodiments, the deposition unit, or at least the nozzle, can be movable in three-dimensional space. The deposition unit can be controlled, for example, in some embodiments, by a deposition unit control unit. The deposition unit control unit may preferably include a circuit, such as a microprocessor. For example, a travel path can be stored in a deposition memory unit, which can be accessed by the deposition control unit to move the nozzle along this travel path. Furthermore, the pressure of the pressurized air applied to the molten thermoplastic polymer upper material being deposited can be controlled by the control unit. The deposition rate or pressure of the molten thermoplastic polymer upper material on or into the carrier can also be controlled by the control unit.

[0046] An embodiment in which the molten thermoplastic polymer upper material is applied onto a carrier by a nozzle as at least one filament is preferred, because the entire process of manufacturing the upper on the carrier, generating the foamed midsole, connecting the foamed midsole to the upper in a direct material bonding manner, for example by fusing the upper and foamed midsole together, and optionally manufacturing the outsole connection to the foamed midsole, can be carried out in a single location and / or fully automatically. Thus, in the preferred embodiment, the method for manufacturing the shoe is fully automated.

[0047] In some embodiments, while a thermoplastic polymer upper material is being applied onto a carrier, the upper assembly and nozzle are moved relative to each other in three-dimensional space by moving a robotic arm that holds the carrier and / or by moving a deposition unit, correspondingly moving the nozzle.

[0048] In some embodiments, the thermoplastic polymer midsole material is selected from polyolefins such as polyethylene or polypropylene, polyesters such as PET or PBT, polyamides, polyether block amides (PEBAX), polyurethanes, ethylene vinyl acetate (EVA), or mixtures thereof.

[0049] In some embodiments, the thermoplastic polymer upper material is selected from polyolefins such as polyethylene or polypropylene, polyesters such as PET or PBT, polyamides, polyether block amides (PEBAX), polyurethanes, ethylene vinyl acetate (EVA), or mixtures thereof.

[0050] In some embodiments, the polymer outsole material, specifically the thermoplastic polymer outsole material, is selected from rubber, polyolefins such as polyethylene or polypropylene, polyesters such as PET or PBT, polyamides, polyether block amides (PEBAX), polyurethanes, ethylene vinyl acetate (EVA), or mixtures thereof.

[0051] A method according to any embodiment of the first aspect of the present invention can be specifically carried out by a shoe manufacturing system according to any embodiment described herein, with respect to a third aspect of the present invention.

[0052] A shoe is provided according to a second aspect of the present invention. Specifically, the shoe is obtained by a method according to any of the embodiments described with respect to the first aspect of the present invention. The shoe comprises an upper made of a thermoplastic polymer upper material or comprising a thermoplastic polymer upper material. Furthermore, the shoe comprises a foamed midsole comprising a thermoplastic polymer midsole material. The upper and the foamed midsole are directly material-bonded to each other. Specifically, the upper and the foamed midsole are fused to each other. Preferably, there is no external adhesive at the connection between the upper and the foamed midsole.

[0053] In some embodiments, the shoe further comprises an intermediate material zone, in which the upper and the foam midsole are directly material-bonded to each other, specifically fused together.

[0054] Preferably, the intermediate material zone includes a thermoplastic polymer upper material and a thermoplastic polymer midsole material. In some embodiments, the thermoplastic polymer upper material and the thermoplastic polymer midsole material may be different materials, but in some embodiments, they may be the same.

[0055] The intermediate material zone preferably has a constant thickness in the vertical direction. The vertical direction extends from the midsole towards the upper, or in the operating state from the midsole or the ground to the wearer's foot. The thickness of the intermediate material zone, where both thermoplastic polymer upper material and thermoplastic polymer midsole material are present, and / or where the upper and foamed midsole form a material bonding connection and are particularly fused together, can be 0.01 mm to 1 mm, specifically 0.05 mm to 0.5 mm. In certain embodiments, the thermoplastic polymer midsole material and thermoplastic polymer upper material are mixed together in the intermediate material zone.

[0056] Therefore, the intermediate material zone is partially composed of a thermoplastic polymer upper material and a thermoplastic polymer midsole material, and the upper and midsole are directly material-bonded to each other within the intermediate material zone. This results in a remarkably durable and robust connection, thus improving the stability of the shoe. Furthermore, the structure of the intermediate material zone may differ from the structure of the rest of the upper and / or the rest of the foam midsole. For example, the intermediate material zone may have a different density and / or hardness than the rest of the upper and / or the rest of the foam midsole. In some embodiments, the rest of the upper may have a loop structure, but preferably the intermediate material zone may be a solid material layer.

[0057] Typically, the remaining portion of the upper, for example, the portion that is not part of the intermediate material zone (e.g., the upper section of the shoe), preferably does not contain thermoplastic polymer midsole material. Conversely, the remaining portion of the midsole, for example, the portion that is not part of the intermediate material zone (e.g., the midsole section of the shoe), preferably does not contain thermoplastic polymer upper material.

[0058] In some embodiments, the intermediate zone extends entirely across the foam midsole and / or the upper, in a plane along the longitudinal and transverse directions. The longitudinal direction extends from the heel edge to the toe of the shoe and is perpendicular to the vertical direction. The transverse direction extends perpendicular to the longitudinal and vertical directions and extends from the outer area to the inner area of ​​the shoe.

[0059] In some embodiments, the intermediate material zone can form an insole.

[0060] When the upper and the foam midsole form a direct material bonding connection with each other, that is, when the upper and the foam midsole are fused to each other, the upper and the foam midsole are integral to each other.

[0061] In some embodiments, the intermediate material zone is located between a midsole section without thermoplastic polymer upper material and an upper section without thermoplastic polymer midsole material. In a particular embodiment, the intermediate material zone is a layer separating the midsole section without thermoplastic polymer upper material from the upper section without thermoplastic polymer midsole material.

[0062] In some embodiments, the intermediate material zone includes a gradient of thermoplastic polymer upper material. This gradient preferably extends from the upper section to the midsole section. In other words, the gradient extends against the vertical direction of the shoe. This means that the amount (by weight) of thermoplastic polymer upper material in the intermediate material zone decreases against the vertical direction, i.e., towards the foamed midsole.

[0063] In some embodiments, the intermediate material zone includes a gradient of thermoplastic polymer midsole material. This gradient preferably extends from the midsole section to the upper section. In other words, the gradient extends along the vertical direction of the shoe. This means that the amount (by weight %) of thermoplastic polymer midsole material in the intermediate material zone decreases along the vertical direction, i.e., towards the upper.

[0064] In some embodiments, the melting temperature of the thermoplastic polymer midsole material is equal to or greater than the melting temperature of the thermoplastic polymer upper material. In some embodiments, the thermoplastic polymer upper material may be the same as or different from the thermoplastic polymer midsole material.

[0065] In some embodiments, the thermoplastic polymer midsole material is selected from polyolefins such as polyethylene or polypropylene, polyesters such as PET or PBT, polyamides, polyether block amides (PEBAX), polyurethanes, ethylene vinyl acetate (EVA), or mixtures thereof.

[0066] In some embodiments, the thermoplastic polymer upper material is selected from polyolefins such as polyethylene or polypropylene, polyesters such as PET or PBT, polyamides, polyether block amides (PEBAX), polyurethanes, ethylene vinyl acetate (EVA), or mixtures thereof.

[0067] A third aspect of the present invention relates to a shoe manufacturing system, more specifically to an automated shoe manufacturing system. Such a shoe manufacturing system is preferably configured to perform the method described herein, specifically in relation to embodiments of the first aspect of the present invention. The shoe manufacturing system may also be used to manufacture shoes such as those described herein, specifically in relation to embodiments of the second aspect of the present invention.

[0068] The shoe manufacturing system comprises a sole molding unit, specifically, a sole molding unit as described herein with respect to a first aspect of the present invention. The sole molding unit defines a cavity. The shoe manufacturing system further comprises a movable robotic arm configured to hold an upper assembly, i.e., a carrier of an upper assembly as described herein.

[0069] In some embodiments, the cavity defined by the sole molding unit is bounded by one or more side walls surrounding the cavity circumferentially and by correspondingly defined bottom walls that further define the boundary of the bottom of the cavity. However, in some embodiments, the cavity is open at the top, i.e., the portion located opposite the bottom. This opening and upper assembly may preferably be configured such that when the upper assembly is at least partially inserted into the cavity, the top of the cavity is closed by the upper assembly, specifically airtightly.

[0070] The robotic arm may be, for example, a cantilever. Preferably, the robotic arm is movable in three-dimensional space. The robotic arm may include, for example, one or more beams connected to each other, preferably via joints, thereby enabling the movement of the arm in three-dimensional space.

[0071] In some embodiments, the robotic arm may be controlled by a control unit, which may be part of a shoe manufacturing system. The control unit may preferably comprise a circuit, such as a microprocessor. For example, a travel path may be stored in a memory unit, which can be accessed by the control unit to move the robotic arm along this path. The memory unit may also be part of a shoe manufacturing system.

[0072] In some embodiments, the shoe manufacturing system includes a deposition unit configured to deposit thermoplastic polymer upper material onto a carrier held by a movable robotic arm. The deposition unit may be a deposition unit as described herein with respect to the embodiments described in the first aspect of the present invention.

[0073] In some embodiments, the deposition unit comprises a nozzle. In certain embodiments, the nozzle may comprise a material outlet and a plurality of air openings arranged circumferentially around the material outlet. The air openings are further configured to apply pressure to the molten thermoplastic polymer upper material exiting the material outlet so that the exiting molten thermoplastic polymer upper material is coated onto or onto a carrier as helical filaments and deposited accordingly.

[0074] In some embodiments, the deposition unit further comprises a melting unit. The melting unit is configured to convert a thermoplastic polymer upper material, specifically in a solid form, into a molten thermoplastic polymer upper material by energy transfer, such as heating. For example, the melting unit may be an extruder, or part of an extruder, specifically one having a screw and a barrel. The melting unit is preferably in fluid communication with the material outlet of a nozzle. Thus, the thermoplastic polymer upper material can be melted in the melting unit and then transported to the nozzle and coated onto the carrier through the material outlet of the nozzle.

[0075] In a particular embodiment, the deposition unit further comprises a pump, such as a metering pump, configured to transport molten thermoplastic polymer upper material from a nozzle onto a carrier.

[0076] In some embodiments, the deposition unit can be movable in three-dimensional space. The deposition unit may be controlled, for example, by a deposition unit control unit in some embodiments. The deposition unit control unit may preferably include circuitry, such as a microprocessor. For example, a movement path may be stored in a deposition memory unit, which can be accessed by the deposition control unit to move the robot arm deposition along this movement path. In some embodiments where the deposition unit is movable in three-dimensional space and the carrier is held by a movable robot arm, the deposition unit control unit may also be part of or equivalent to a control unit that controls the robot arm holding the carrier.

[0077] In some embodiments, the deposition unit further comprises a motor configured to drive a pump.

[0078] The control unit of the shoe manufacturing system may be configured to control the movement path of the robotic arm holding the carrier, and / or the movement path of a deposition unit as described later, and / or the pressure of the air applied through the air opening of the nozzle onto the molten thermoplastic upper material exiting the nozzle material outlet, and / or the pump. The deposition control unit may, for example, be part of the control unit itself.

[0079] In some embodiments, the memory unit stores one or more of the movement paths of a robotic arm and / or a deposition unit configured to hold a carrier, and correspondingly its nozzle.

[0080] In some embodiments, the control unit may determine a travel path, specifically an ideal travel path, based on training data stored in a memory unit. Preferably, the determination of the travel path may be performed by machine learning.

[0081] In particular, a robotic arm can generally be configured to move the carrier and / or upper assembly along three spatial axes, such as the vertical axis, the longitudinal axis, and the transverse axis. Additionally or alternatively, a movable robotic arm can generally be configured to rotate the carrier and / or upper assembly around a rotation axis.

[0082] The inventions described herein should not be considered to limit the inventions described in the appended claims, which will be more fully understood from the detailed description and accompanying drawings provided herein below. The drawings are shown below. [Brief explanation of the drawing]

[0083] [Figure 1] This is a schematic cross-sectional view of the upper assembly inserted into the cavity of the sole molding unit as it is being operated in one embodiment of the present invention. [Figure 2] This is a schematic diagram of the heel edge of a shoe obtained by one embodiment of the present invention and / or by a method according to one embodiment of the present invention. [Figure 3] This is a schematic diagram illustrating how an upper assembly can be provided according to one embodiment of the present invention and / or a schematic diagram of a shoe manufacturing system according to one embodiment of the present invention. [Figure 4] This is a schematic top view of a nozzle that can be used in some embodiments of the present invention. [Figure 5] This is a schematic perspective view of a nozzle that can be used in some embodiments of the present invention. [Figure 6] This is a detailed diagram of a deposit unit that can be used in several embodiments of the present invention. [Modes for carrying out the invention]

[0084] Figure 1 shows an upper assembly 2 comprising a carrier 4 and an upper 3 mounted on the carrier 4. In this embodiment or any other embodiment described herein, the carrier 4 may be, for example, a shoe last, i.e., a shoe last. The upper 3 further comprises a bottom section 5 made from a thermoplastic polymer upper material. In this embodiment, the boundary of the bottom section 5 is indicated by a dashed line. However, in some embodiments, the bottom section and the rest of the upper may be identical, for example, the bottom section and the rest of the upper may be made from the same material and / or have the same structure, such as a nonwoven, knitted or woven fabric. The upper assembly 2 is partially inserted into a cavity 7 (see Figure 3) defined by a sole molding unit 6. Thereafter, the upper assembly 2 and the sole molding unit 6 define a sole molding section 9 together. The sole molding section 9 is part of the cavity defined by the sole molding unit 6. The upper assembly, specifically the upper 3, correspondingly its bottom section 5, and the sole molding unit 6, together form a fluid-tight connection. Typically, when the upper assembly 2 is inserted into the cavity 7, the cavity 7, and therefore the sole molding compartment 9, is also filled with air, such as ambient air. In this embodiment or any other embodiment as described herein, it may also be possible to apply a pressure below atmospheric pressure to the sole molding compartment 9 after the upper assembly 2 has been partially inserted into the cavity 7 of the sole molding unit 6.

[0085] As the next step, a midsole polymer composition containing molten thermoplastic polymer midsole material is introduced into the cavity and therefore into the sole molding compartment 9. This introduction may be performed, for example, through the cavity 7 and the injection port 24 which correspondingly opens into the sole molding compartment 9. Since the upper assembly 2 is partially introduced into the cavity 7 and / or the sole molding compartment 9 is defined by the upper assembly 2 and the sole molding unit 6, the introduced molten thermoplastic polymer composition is provided on the bottom section 5 of the upper 3 which is introduced into the cavity 7. Since the molten thermoplastic polymer midsole material has a melting temperature equal to or higher than that of the thermoplastic polymer upper material of the bottom section 5 (and optionally the complete upper 3), the bottom section 5 is partially or completely melted, and a material bonding joint, which is a fusion joint between the upper and the formed foamed midsole, is created without any additional adhesive. Furthermore, during introduction, foaming of the molten thermoplastic polymer midsole material is performed during step d., which provides the foamed midsole. This results in a manufactured shoe in which the foam midsole is directly material-bonded, i.e., fused, to the upper 3. Cooling and / or curing can then be performed, the manufactured shoe can be removed from the sole molding unit 6, and the carrier 4 can be removed from the manufactured shoe.

[0086] Figure 2 shows a shoe 1 that can be obtained by the method according to the present invention. The shoe 1 comprises an upper 3 and a foamed midsole 8. The upper 3 comprises a thermoplastic polymer upper material, and the foamed midsole 8 comprises a thermoplastic polymer midsole material. In addition, the shoe 1 comprises an outsole 10 material-bonded to the foamed midsole 8. The outsole 10 can be obtained, for example, after step d of the method according to the present invention, i.e., after the foamed midsole 8 has been manufactured and material-bonded to the upper 3, by introducing a molten polymer outsole material, preferably a molten thermoplastic outsole material, onto the foamed midsole 8 in a cavity 7 defined by a sole molding unit 6, correspondingly a sole molding compartment 9. The introduction of the molten polymer outsole material may be carried out, for example, through an injection port 24 or through an additional separate injection port. Only thereafter is the shoe thus manufactured typically removed from the sole molding unit 6, and the carrier 4 is removed from the upper 3.

[0087] Figure 2 shows a view of shoe 1 at its heel edge, i.e., indicated by a coordinate system along the longitudinal direction L toward the toe of the sole of shoe 1. The vertical direction V extends perpendicular to the longitudinal direction from the foamed midsole 8 toward the upper 3, correspondingly from the ground to the wearer's foot in the worn or moving state. The transverse direction T is perpendicular to both the longitudinal direction L and the vertical direction V. Shoe 1 further comprises an intermediate material zone 16 indicated by two parallel dashed lines. When the molten thermoplastic polymer midsole material is introduced onto the bottom section 5 of the upper 3, for example, by injection, the bottom section 5 melts at least partially or completely, and thus, upon cooling and / or curing, forms a material-bonded, e.g., fused joint between the foamed midsole 8 and the upper 3. This allows for the formation of the intermediate material zone 16, which includes both the thermoplastic polymer upper material and the thermoplastic polymer midsole material of the upper, correspondingly the bottom section 5. In contrast, the midsole section 17, i.e., the remaining portion of the foamed midsole 8, lacks thermoplastic polymer upper material. Similarly, the upper section 18 of the upper 3, i.e., the remaining portion of the upper 18, also lacks thermoplastic polymer midsole material. Against the vertical direction V, there is a gradient of thermoplastic polymer upper material within the intermediate material zone 16 extending from the upper section 18 to the midsole section 17. This gradient is decreasing, meaning that the amount, e.g., mass percentage, of thermoplastic polymer upper material decreases from the intermediate material zone 16 extending from the upper section 18 to the midsole section 17. Furthermore, within the intermediate material zone 16, there is an opposite gradient of thermoplastic polymer midsole material along or in the vertical direction V, i.e., extending from the midsole section 17 to the upper section 18. The gradient of thermoplastic polymer midsole material decreases in the intermediate material zone 16 from the midsole section 17 to the upper section 18. In this case, the gradient can also be represented by a decrease in the amount, e.g., mass percentage, of thermoplastic polymer midsole material.In some embodiments, the intermediate material zone 16 may extend entirely along the lateral T and longitudinal L directions of the shoe 1, for example, completely separating the midsole section 17 from the upper section 18. However, generally, the intermediate material zone 16 may also extend only along certain portions of the shoe 1 in the lateral T and / or longitudinal L directions. For example, the intermediate material zone may be located only around the periphery of the shoe 1 and therefore not in the center of the shoe.

[0088] Figure 3 shows a shoe manufacturing system 100 when used to manufacture shoes, for example, in the method according to the present invention. The shoe manufacturing system 100 includes a sole molding unit 6, such as the sole molding unit 6 described with respect to Figure 1, which defines a cavity 7 configured to mold the sole of the shoe, such as a foamed midsole 8. The cavity 7 is defined by side walls surrounding the cavity circumferentially and a bottom wall (invisible) that defines the boundary of the bottom of the cavity. As can be seen, the cavity is open at the top, which allows the upper assembly 2 to be inserted directly into the cavity 7. Furthermore, the shoe manufacturing system 100 includes a movable robotic arm 11 that holds a carrier 4. For example, the robotic arm 11 may form a shape lock and / or force lock engagement with the carrier 4. For example, it may be possible for the robotic arm 11 to form a snap-fit ​​engagement with the carrier 4. The robotic arm 11 is configured to move the carrier 4 in three-dimensional space. In particular, the robot arm 11 may generally be configured to move the carrier 4 along three spatial axes, such as the vertical axis, the longitudinal axis, and the transverse axis. Additionally or alternatively, the movable robot arm 11 may generally be configured to rotate the carrier 4 around a rotation axis. The shoe manufacturing system 100 further comprises a control unit 23 configured to control the movement of the robot arm 11 relative to a nozzle 12, which may be part of a deposition unit (see Figure 6).

[0089] Figure 3 illustrates how the upper assembly 2 can be provided in step a of the method according to the present invention. In this embodiment, the molten thermoplastic polymer upper material is applied onto the carrier 4 by a nozzle 12. A robotic arm moves the carrier 4 in three-dimensional space relative to the nozzle 4. As can be seen, the molten thermoplastic polymer upper material is applied onto the carrier 4 as a helical filament. After the application of the molten thermoplastic polymer upper material is complete, an upper assembly 2 is provided, including the carrier 4 and the upper 3 mounted on the carrier 4. In the next step of the method according to the present invention, the upper assembly 2 is at least partially inserted into the cavity 7 of the sole molding unit 6 in a manner such as that shown in Figure 1. Insertion may be performed, for example, by a movable robotic arm 11, preferably controlled by a control unit 23. After the upper assembly 2 is inserted into the cavity 7, step d of the method according to the present invention is performed, namely, the midsole polymer composition is introduced into the cavity 7, and the molten thermoplastic polymer midsole material is foamed to form a direct fused joint between the upper 3, correspondingly its bottom section 5, and the foamed midsole 8, thereby manufacturing the shoe 1. Thus, a complete shoe can be manufactured completely automatically in a single location using a single system.

[0090] Figure 4 shows a top view of a nozzle 12 that can be used in several embodiments of the present invention. The nozzle 12 comprises a centrally located material outlet 13. Furthermore, the nozzle 12 comprises a plurality of air openings 14, 15 (only two openings are referred to for clarity) arranged circumferentially around the material outlet 13. As can be seen, each air opening is positioned so that the air guided through it is directed inward, i.e., in the direction of the filaments of the molten thermoplastic upper material exiting the material outlet 13. However, each air opening is also positioned so that the pressurized air guided through the air opening is applied to the molten polymer upper material (i.e., the filaments) exiting the material outlet, which is coated onto the carrier as helical filaments. This is achieved by guiding pressurized air that is perpendicular to the material outlet 13 and offset to an axis extending through its center along the coating direction in which the molten thermoplastic polymer material is coated onto the carrier (i.e., in the direction in which the observer views the nozzle in Figure 4). This allows the movement of the exiting molten thermoplastic polymer material to be coated onto the carrier as helical filaments. Figure 5 shows a perspective view of the nozzle 12 shown in Figure 4, which further clarifies the configuration of the air openings 14 and 15.

[0091] Figure 6 shows a detailed view of a deposition unit 19 that can be used in several embodiments of the present invention. The deposition unit 19 comprises a melting unit 20, which may be an extruder such as a screw and barrel extruder having a screw 21 and a barrel 22. The melting unit 20 comprises a material inlet 26 into which a thermoplastic polymer upper material can be inserted, for example, as solid granules. This material is then melted within the melting unit 20 and transported toward a nozzle 12, which may be a nozzle as shown in Figures 4 and 5. The molten thermoplastic polymer upper material is then applied from the nozzle 12 through a material outlet 13. By applying pressurized air through air inlet openings 14, 15 (see Figures 4 and 5), the molten thermoplastic polymer upper material is applied to the carrier 4 as a helical filament. The upper assembly 2 can be provided by moving the carrier 4 in three-dimensional space, for example by a movable robotic arm (not shown here, see Figure 3). The deposition unit may be controlled by a deposition unit control unit 25. In some embodiments, the stacking unit control unit 25 may be included in a control unit 23 that controls the movement of the movable robot arm 11 (see Figure 3). [Explanation of symbols]

[0092] 1 Shoes 2 Upper Assembly 3 Upper 4 carriers 5. Bottom section 6. Sole molding unit 7 Cavity 8. Foam midsole 9. Sole molding section 10 Outsole 11 Robot Arm 12 nozzles 13 Material outlet 14, 15 Air openings 16 Intermediate Materials Zone 17. Midsole section without thermoplastic polymer upper material 18 Upper section without thermoplastic polymer midsole material 19 Sedimentary Units 20 melting units 21 Screw 22 barrels 23 Control Unit 24 Inlet 25. Deposition Unit Control Unit 26 Material Inlet 100 shoe manufacturing systems

Claims

1. A method for manufacturing shoes (1), a. Providing an upper assembly (2), wherein the upper assembly comprises an upper (3) mounted on a carrier (4), and the upper (3) comprises a bottom section (5) made of a thermoplastic polymer upper material. b. A step of providing a sole molding unit (6), wherein the sole molding unit defines a cavity (7), c. The step of inserting the upper assembly (2) at least partially into the cavity (7), d. The steps of introducing a midsole polymer composition containing a molten thermoplastic polymer midsole material having a melting temperature equal to or greater than the melting temperature of the thermoplastic polymer upper material into the cavity (7), foaming the molten thermoplastic polymer midsole material within the cavity (7) to provide a foamed midsole (8), and forming a material bond, specifically a fused connection, between the upper (3) and the foamed midsole (8), Methods that include...

2. The method according to claim 1, wherein step d is performed by supercritical injection foaming.

3. The method according to claim 1 or 2, wherein the polymer composition in step d comprises a physical blowing agent, specifically a physical blowing agent in a supercritical state.

4. The method according to any one of claims 1 to 3, wherein during step d, the bottom section (5) of the upper (3) is at least partially melted, specifically by the thermal energy of the molten thermoplastic polymer midsole material.

5. The method according to any one of claims 1 to 4, wherein in step c, the upper assembly (2) is inserted into the sole molding unit (6) such that a closed, specifically sealed, sole molding compartment (9) is formed, defined by the sole molding unit (6) and the upper assembly (2).

6. The method according to any one of claims 1 to 5, wherein, after step d, an outsole polymer composition containing a molten polymer outsole material is introduced into the cavity (7) to materially bond to the foamed midsole (8), specifically providing a fused outsole (10).

7. The method according to any one of claims 1 to 6, wherein the upper assembly (2) provided in step a. is held by a movable robot arm (11), and step c. is performed by the robot arm (11).

8. The method according to any one of claims 1 to 7, wherein the upper assembly (2) in step a. is provided by dispensing the molten thermoplastic polymer upper material onto the carrier (4) by a nozzle (12) in the form of at least one filament, specifically at least one continuous filament, to provide the upper (3) mounted on the carrier (4).

9. The method according to claim 8, wherein the at least one filament is coated onto the carrier (4) such that it forms a plurality of intersections with itself and / or a plurality of loops on the carrier (4), and preferably a material bonding connection is formed at at least one intersection between different sections of the at least one filament.

10. The method according to claim 8 or 9, wherein the nozzle (12) comprises a material outlet (13) and a plurality of air openings (14, 15) arranged circumferentially around the material outlet (13), and pressurized air is applied to the molten polymer upper material exiting the material outlet (13) so that the molten polymer upper material is coated onto the carrier (4) as a helical filament.

11. A shoe (1) obtained by any one of claims 1 to 10, comprising an upper (3) containing a thermoplastic polymer upper material and a foamed midsole (8) containing a thermoplastic polymer midsole material, wherein the upper (3) and the foamed midsole (8) are directly materially bonded, specifically fused, to each other.

12. The shoe (1) according to claim 11, further comprising an intermediate material zone (16) in which the upper (3) and the foamed midsole (2) are directly material-bonded to each other, wherein the intermediate material zone (16) comprises the thermoplastic polymer upper material and the thermoplastic polymer midsole material.

13. The shoe (1) according to claim 12, wherein the intermediate material zone (16) is located between the midsole section (17) which lacks the thermoplastic polymer upper material and the upper section (18) which lacks the thermoplastic polymer midsole material.

14. The shoe (1) according to claim 12 or 13, wherein the intermediate material zone (16) preferably includes a gradient of the thermoplastic polymer upper material extending from the upper section (18) to the midsole section (17), and / or the intermediate material zone (16) preferably includes a gradient of the thermoplastic polymer midsole material extending from the midsole section (17) to the upper section (18).

15. The shoe (1) according to any one of claims 11 to 14, wherein the melting temperature of the thermoplastic polymer midsole material is equal to or greater than the melting temperature of the thermoplastic polymer upper material.

16. A shoe manufacturing system (100) configured to perform the method according to any one of claims 1 to 10, specifically an automated shoe manufacturing system, the shoe manufacturing system (100) comprising a sole molding unit (6) for defining a cavity (7) and a movable robot arm (11) configured to hold the carrier (4) of the upper assembly (2).

17. The shoe manufacturing system (100) according to claim 16, further comprising a deposition unit (19) configured to deposit thermoplastic polymer upper material onto the carrier (4) held by the movable robot arm (11).

18. The shoe manufacturing system (100) according to claim 17, wherein the deposition unit (19) is equipped with a nozzle (12).

19. The shoe manufacturing system (100) according to claim 18, wherein the nozzle (12) comprises a material outlet (13) and a plurality of air openings (14, 15) arranged circumferentially around the material outlet (13), and is configured to apply pressurized air to the molten thermoplastic polymer upper material exiting the material outlet (13) so that the molten thermoplastic polymer upper material is applied to the carrier (4) as a helical filament.

20. The shoe manufacturing system (100) according to claim 18 or 19, wherein the deposition unit (19) further comprises an extruder having a screw (21) and a barrel (22) that are in fluid communication with a melting unit (20), specifically the material outlet (13) of the nozzle (12).

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