Method for producing article of footwear, such as shoe, sandal, boot or like, and in particular at least portion of article of footwear for participating in sports

Abstract

A method (100) for producing at least a portion of an article of footwear (10), the method comprising the steps of:-providing (103) a mold (1) defining an open cavity (2), at least a portion of the cavity (2) having a shape corresponding to a shape of a sole (3) of the article of footwear (10), the cavity (2) being configured to be injected into a sole (3) of the article of footwear (10) via at least one injection channel (4, 5) leading to the cavity (2); 4 ', 4' ', 4 ''') to receive a mixture comprising a melt and a supercritical fluid; placing (105) the open rim (5) of the open cavity (2) in contact with a contact area (6) where at least a portion of the surface (7) of the upper portion (9) of the article of footwear (10) and the sole come into contact, such that the surface (7) of the at least a portion of the upper portion (9) closes the cavity at the contact area between the contact area (6) and the rim (5); -pressurizing (105 bis) the cavity (2); injecting (107) the mixture into the cavity (2); -decompressing (108) the cavity (2) of the mould in order to trigger the expansion of the mixture in the cavity (2) and to form the sole (3) by means of the foamed material resulting from the expansion of the mixture, at least part of the surface (7) of the at least part (9) of the upper part being captured in said foamed material of the sole (3).

Description

[0001] The present invention relates to the field of manufacturing footwear, such as shoes, and in particular to the manufacturing of footwear comprising a lightweight and shock-absorbing sole, and in particular to the manufacturing of footwear for practicing sports.

[0002] It is known to manufacture the sole in a first step and then to attach the sole to the shaft, in particular the shaft at least partially made of textile, in a second step. The manufacture of footwear with a lightweight and shock-absorbing sole requires many steps, since the sole is manufactured separately - most often from cross-linked ethylene-vinyl acetate (EVA) - and then assembled by gluing to the shaft.

[0003] A disadvantage of this known method is that it requires a number of energy-intensive manual gluing operations.

[0004] Furthermore, the following two methods are known for injecting directly into the shoe body:

[0005] - Injection of thermoplastics, PVC or other elastomers. With this method, the material can be foamed due to chemical or physical foaming agents; however, this method has the disadvantage that the sole material of the shoe obtained does not have the expected properties of a lightweight and shock-absorbing sole. The lowest sole density that can be achieved with this method is greater than 0.5 g / cm3.

[0006] In addition, the desired shock absorption and comfort performance of, for example, the sole of a running shoe cannot be achieved through this manufacturing method.

[0007] - Injection of polyurethane directly on the sole. In this case, foaming is obtained by chemical reaction of 2 compounds (polyol and isocyanate). The disadvantage of this method is that the density of the sole is still high (> 0.35 g / cm3 in the best case).

[0008] Furthermore, the non-thermoplastic nature of polyurethane makes recyclability extremely difficult to achieve.

[0009] Therefore, the present invention aims to provide a solution to all or part of these problems.

[0010] To this end, the present invention relates to a method for manufacturing at least a portion of footwear, such as a shoe, and in particular footwear for practicing sports, comprising the following steps:

[0011] - providing a mold defining an open cavity, at least a portion of the cavity having a shape corresponding to the shape of a sole of the footwear, the cavity being configured to receive a mixture comprising a molten material and a supercritical fluid via at least one injection channel leading to the cavity;

[0012] - placing the edge of the opening of the open cavity in contact with the abutment area of ​​the surface of at least a portion of the shaft of the footwear, such that the surface of at least a portion of the shaft ensures the closure of the cavity at the level of the contact between the abutment area and the edge;

[0013] - pressurizing the cavity;

[0014] - Injecting the mixture into the cavity;

[0015] - depressurizing the cavity of the mould to trigger expansion of the mixture in the cavity and to form the sole in the foamed material resulting from the expansion of the mixture, in which at least part of the surface of at least part of the shaft is embedded.

[0016] According to these arrangements, the method makes it possible to obtain, in one single injection step, a lightweight and shock-absorbing sole for footwear, which sole is joined to a portion of a shaft of footwear, wherein the sole and the shaft have good resistance to delamination.

[0017] According to one implementation, the dimensions of the shape of at least a portion of the cavity and the shape of the sole of the footwear have a ratio comprised between 1:0.98 and 1:1.02, advantageously 1:1.

[0018] According to one implementation, the pressurization of the cavity is accompanied by the simultaneous generation of a counterpressure in a region of at least a portion of the shaft situated on the other side of the closure relative to the cavity, said counterpressure advantageously having substantially the same value.

[0019] According to these arrangements, the counterpressure, which advantageously has substantially the same value, allows avoiding leakage of the pressurized gas of the cavity at the level of the contact between the abutment area and the rim.

[0020] Advantageously, during the progress of the method according to the invention, a region of at least a portion of the shaft located on the other side of the closure relative to the cavity can be depressurized simultaneously with the depressurization of the cavity of the mold to trigger expansion of the mixture in the cavity and form the sole.

[0021] According to these arrangements, the pressure increase in the cavity followed by the pressure reduction in the cavity enables the mixture to expand and a lightweight and shock-absorbing foamed material of the sole to be obtained.

[0022] According to these arrangements, the density of the sole is comprised between 0.1 g / cm3 and 0.4 g / cm3, preferably between 0.15 g / cm3 and 0.25 g / cm3.

[0023] According to one implementation, the invention comprises one or more of the following features considered alone or in any technically feasible combination.

[0024] According to one implementation, the pressurization pressure of the chamber is comprised between 3 and 50 bars, preferably comprised between 10 and 30 bars, preferably equal to 15 bars.

[0025] According to one implementation, before the step of pressurizing the cavity, the method further comprises the following steps:

[0026] - Placing the cover on the mould so that it forms, together with the mould, a closed volume comprising a cavity and its complementary parts within said closed volume, at least a portion of the shaft being located inside said closed volume, the complementary parts and the cavity being located on either side of the closed part of the cavity at the level of the contact of the abutment area with the edge.

[0027] The pressurization pressure in the complementary portion of the closed volume, advantageously identical to that of the cavity, allows the generation of a counterpressure in order to avoid leakage of the pressurized gas of the cavity at the level of the contact between the abutment area and the rim.

[0028] According to one embodiment, the cover is configured to form, together with the mold, a sealed closed volume, in particular an airtight closed volume, around at least a portion of the shoe body so that the counterpressure can be generated inside the sealed closed volume, in particular by receiving the pressurized gas of the cavity in the sealed volume to avoid leakage of the pressurized gas of the cavity at the level of the contact between the docking area and the edge.

[0029] According to one implementation, the method comprises the step of assembling together the portion of the shaft that is connected to the sole with another portion of the shaft, this assembly forming the footwear.

[0030] According to one implementation, the assembling step includes knitting together another portion of the shaft and the portion of the shaft that is connected to the sole.

[0031] According to one implementation, the method further comprises the following steps, which are performed before the step of placing the edge of the opening of the open cavity in contact with the abutment area of ​​the surface of at least a portion of the shoe body:

[0032] - providing a support having a shape corresponding to the shape of the foot,

[0033] - at least partially covering the outer surface of the support with at least a portion of a shaft of the footwear, at least a portion of the surface of at least a portion of the shaft covering a portion of the outer surface of the support corresponding to the sole of the foot,

[0034] Such that, after placing the cover on the mould, the closed volume also comprises a support with at least a portion of the shaft.

[0035] According to one implementation, at least a portion of the shoe body is a complete shoe body.

[0036] According to one implementation, the support is made of aluminum, steel or plastic.

[0037] According to these arrangements, the method allows obtaining, in a single injection step and using a single mould, a complete footwear comprising its sole joined to the complete shaft of the shoe.

[0038] According to one implementation, the mold is made in one piece.

[0039] According to one implementation, the mould comprises at least two parts, and the providing step comprises a step of assembling the at least two parts to form the mould.

[0040] According to one implementation, the mold includes an annular portion, which includes a first annular half and a second annular half, the first half being movable relative to the second annular half according to a sliding direction, so that the sliding displacement of the first half toward the second half according to the sliding direction closes the annular portion of the mold, while the sliding displacement of the first half and the second half in opposite ways opens the annular portion of the mold and separates the two halves of the annular portion.

[0041] According to one implementation, the mold further comprises a mold bottom comprising a cover and a bell-shaped member configured to wrap around the cover and the first and second annular halves of the mold when the annular portion and the mold are closed.

[0042] According to one implementation, the bell-shaped piece at the bottom of the mold includes a contact joint between the bell-shaped piece at the bottom of the mold and the annular part, the contact joint includes a first inclined plane, the first inclined plane is configured to slide on a first contact surface of the wall of the first annular half, the contact joint includes a second inclined plane, the second inclined plane is configured to slide on a second contact surface of the wall of the second annular half, the first inclination angle of the first inclined plane and the second inclination angle of the second inclined plane are configured so that the steps of assembling and closing the mold include shifting the bell-shaped piece at the bottom of the mold toward the two halves in a direction approaching the two halves of the annular part so as to close the annular part when the bottom of the mold contacts.

[0043] According to one implementation, the mold comprises elastic means configured to separate the first annular half and the second annular half.

[0044] According to one implementation, the contact engagement between the bell of the mold bottom and the annular portion comprises at least one guide configured to accompany the sliding displacement of the two portions of the annular portion when the bell of the mold bottom is displaced in a direction transverse to the sliding direction.

[0045] According to these arrangements, the mould is actuated alternately closed or open by displacement of the mould bottom towards the two halves of the annular portion or vice versa.

[0046] According to one implementation, the cavity is configured to receive the mixture via at least two injection channels leading to the cavity.

[0047] According to one implementation, the method allows obtaining a sole of an article of footwear joined to a portion of a shaft of the article of footwear by filling the cavity of the mold more quickly and more evenly.

[0048] According to one implementation, the mold comprises at least one injection channel.

[0049] According to one implementation, the support comprises at least one injection channel.

[0050] According to one implementation, the method comprises a step of gluing at least a portion of the surface of at least a portion of the shoe body, said gluing step being performed before the injection step.

[0051] According to one implementation, at least a portion of a surface of at least a portion of the upper includes a hot-melt wire material configured to melt at an injection temperature of the mixture.

[0052] According to these arrangements, the delamination resistance of the sole and the upper is enhanced.

[0053] According to one implementation, the method further comprises the following steps:

[0054] - providing an insert configured to be positioned in a cavity of a mold;

[0055] - Positioning the insert in the cavity of the mold.

[0056] According to one implementation, the insert is positioned so as to be inserted at the level of the outer surface of the sole, or to be buried inside the sole.

[0057] According to these arrangements, the delamination resistance of the sole is enhanced or the dynamics of the sole are improved, depending on whether the insert is inserted towards the outer part of the sole, for example in the case of one or more inserts made of rubber or thermoplastic material, or whether the insert is buried inside the sole, for example in the case of one or more inserts made of carbon plate or thermoplastic material.

[0058] According to one implementation, the contact surface between the insert and the sole comprises a texture.

[0059] According to one implementation, the texture comprises a plurality of patterns distributed over a portion of the contact surface according to a density that depends on the mechanical load of said portion of the contact surface.

[0060] According to one implementation, the density is determined so that on a portion of the contact surface, the plurality of patterns occupies a portion of this portion of the contact surface comprised between 1% and 15%, advantageously 6%, of this portion of the contact surface.

[0061] According to one implementation, the pattern is tubular and / or linear.

[0062] According to one implementation, the height of the pattern according to a direction transverse to the contact surface is comprised between 1 mm and 10 mm, preferably equal to 1.6 mm.

[0063] According to one implementation, the thickness of the pattern according to a direction transverse to the height direction is comprised between 1 mm and 2 mm, preferably equal to 1.6 mm.

[0064] According to these arrangements, the adhesion between the insert and the sole is enhanced by mechanical hooking, thereby eliminating a gluing step or a surface preparation step.

[0065] According to one implementation, the insert positioned to be inserted at the level of the outer surface of the sole comprises at least one through hole matching the pressurized channel so that the pressurized gas can pass through the insert.

[0066] According to one implementation, at least a portion of the surface of at least a portion of the upper is at least partially perforated or open.

[0067] According to these arrangements, the delamination resistance of the sole and the upper is enhanced.

[0068] According to one implementation, at least a portion of the surface of at least a portion of the upper is textured or perforated at a contact portion with the docking area.

[0069] According to these arrangements, the delamination resistance of the sole and the shoe body is further enhanced.

[0070] According to these settings, a delamination resistance measured according to standard ISO NF EN 1392 of higher than 2.5 N / mm is obtained.

[0071] According to one implementation, the molten material is an elastomeric thermoplastic polymer.

[0072] According to one implementation, the thermoplastic polymer is a thermoplastic polyurethane (TPU), or an ether-amide block copolymer (PEBA), or ethylene-vinyl acetate (EVA), or a polyolefin, or an ether-ester block copolymer, or a styrene-based elastomer, or a mixture of these different components.

[0073] According to one implementation, the supercritical fluid is nitrogen in a supercritical state, or a carbon-containing gas in a supercritical state, or a mixture of nitrogen and carbon-containing gas in a supercritical state.

[0074] According to one implementation:

[0075] - Most of the mass of the shoe body is formed by the main shoe body material and possibly one or more auxiliary shoe body materials;

[0076] - the majority of the mass of the sole is made of a main sole material and possibly one or more auxiliary sole materials, the foamed material resulting from the expansion of the mixture comprising said main sole material and said auxiliary sole materials;

[0077] The main material of the shoe body and possible auxiliary materials of the shoe body are selected from the following materials: polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters, and wherein the main material of the sole and possible auxiliary materials of the sole have the same chemical family as the main material of the shoe body, and may have the same chemical family as the auxiliary materials of the shoe body, or wherein the main material of the sole and possible auxiliary materials of the sole are chemically compatible with the auxiliary materials of the shoe body and possible auxiliary materials of the shoe body.

[0078] Thus, the sole main material may have the same chemical family as the body main material. Thus, for example, if the body main material is a polyolefin, the sole main material is also a polyolefin. If the body main material is a polyamide, the sole main material is also a polyamide.

[0079] In the context of the present invention, it is understood that two polymers are "chemically compatible" when they form a homogeneous medium at the microscopic level and no distinct phases are observed.

[0080] Thus, a lightweight, shock-absorbing and recyclable shoe is obtained, preferably without the need to apply glue or bonding agents between the shoe body and the sole.

[0081] In one embodiment, the sole primary material and possibly the sole secondary material are the same as the upper primary material and possibly the upper secondary material.

[0082] Since the main material of the body and possible auxiliary materials of the body as well as the main material of the sole and possible auxiliary materials of the sole are selected from the same material, or are chemically compatible with each other, their adhesion, as well as the manufacture of footwear and the recycling of footwear are facilitated. In fact, it is not necessary to separate all the parts of the parts of the footwear in order to recycle them. The footwear can be recycled in a single step by cutting it into pieces and then forming granules from the cut pieces. The applicant surprisingly found that the main materials of the sole and the main materials of the body listed above have the following advantages: they can be in very different forms in footwear applications and can be recycled many times.

[0083] Advantageously, the main material of the body and the main material of the sole and possible auxiliary materials of the body and the auxiliary materials of the sole are selected so that the at least partially recovered granules can be transformed by any plastic forming technology (especially at high temperature), for example by injection molding, injection foaming, extrusion molding, blow extrusion, thermoforming or thermomolding. Granules originating from the recycled footwear according to the invention can be used in the manufacture of soles or shoe parts (such as rear supports, front stiffeners or lateral reinforcements), or in the manufacture of wires (for example, by extrusion-spinning) or parts made of foam for the manufacture of textile parts (for example, the manufacture of body parts, or the manufacture of the entire body of the shoe by knitting or weaving). Granules originating from footwear can also be used in the manufacture of boots.

[0084] The granules can also be converted into a mat, for example by means of so-called meltblown or spunbond technology or by a combination thereof, such as, for example, into a so-called SMS (spunbond / meltblown / spunbond) mat.

[0085] The main material of the shoe body can be selected from polyester, thermoplastic polyurethane (TPU), polyolefin, and a block copolymer composed of a rigid polyamide block and a flexible polyether block.

[0086] The main material of the sole can be selected from polyester, thermoplastic polyurethane (TPU), polyolefin, and a block copolymer composed of a rigid polyamide block and a flexible polyether block.

[0087] The shoe body may include a wire comprising a material selected from the following: polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), ether-amide block copolymers (PEBA), ethylene vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0088] The shoe body may include a textile component, and wherein the textile component includes a thread material comprising a main material of the shoe body.

[0089] The shaft may comprise a textile portion with an outer face forming an area for receiving a foot, and at least one portion, in particular a strip, comprising an olefinic thermoplastic elastomer, secured to the outer face of the textile portion and to the sole.

[0090] The sole may include a porous component and / or beads made of foam, wherein the porous component and / or the beads contain a material selected from the group consisting of polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, thermoplastic polyurethanes (TPU), ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0091] The shoe body may include a front stiff tip portion comprising a main material of the shoe body or an auxiliary material of the shoe body, and / or a rear support member comprising a main material of the shoe body or an auxiliary material of the shoe body.

[0092] The shaft may comprise at least one loop for passing at least one lacing element, the at least one passing loop comprising a textile strip comprising at least one thread comprising a main material of the shaft, in particular a polyolefin.

[0093] The body may comprise a part made of a foam comprising a main body material, in particular a polyolefin.

[0094] In one embodiment, the shaft and / or the sole comprises / each comprises material recycled from the sole and / or the shaft of another shoe and / or material recycled from the sole and / or the shaft of a boot.

[0095] Advantageously, the ratio of the mass of the main material of the shoe body and the mass of possible auxiliary materials of the shoe body to the total mass of the shoe body is greater than or equal to 40%.

[0096] Advantageously, the ratio of the mass of the main material of the shoe body and the mass of the auxiliary material of the shoe body to the total mass of the shoe body is greater than or equal to 50%.

[0097] Advantageously, the ratio of the mass of the main sole material and of any auxiliary sole material to the total mass of the sole is greater than or equal to 40%.

[0098] Advantageously, the ratio of the mass of the main sole material and the mass of the auxiliary sole material to the total mass of the sole is greater than or equal to 50%.

[0099] The footwear may contain up to 10% by weight of one or more contaminant materials, in particular up to 10% by weight of one or more thermoplastic contaminant materials and / or up to 5% by weight of one or more thermosetting contaminant materials, wherein the one or more contaminant materials are not selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0100] Advantageously, the sole main material and possibly the sole auxiliary material originate at least partially from recycling of at least one other type of footwear.

[0101] The method may further include collecting the footwear, and the method may include converting the footwear into thermoplastic granules.

[0102] Advantageously, the converting step comprises:

[0103] - a step of shredding the at least one shoe to obtain shredded particles;

[0104] - a step of compacting the chopped particles to obtain chopped and compacted particles, in particular, the compacting being cold compaction or hot compaction,

[0105] - a step of extrusion-granulation of the shredded and compacted particles to obtain granules that can be transformed by a plastic thermal transformation process.

[0106] The method may comprise the step of thermally transforming at least a portion of the thermoplastic granules for producing a plastic part, in particular partially forming a plastic part for practicing a sport.

[0107] The invention also relates to a plastic part, in particular a plastic part at least partially forming an article for practicing sports, which is obtainable by said method, in particular said part is a swimming flipper.

[0108] According to an aspect, the invention also relates to a footwear, such as a shoe, and in particular a footwear for practicing sports, obtained by a method according to one of the aforementioned implementations.

[0109] The main material of the body and the main material of the sole selected from the present invention and possible auxiliary materials of the body and / or the auxiliary materials of the sole can be thermoplastic materials with the advantage of being derived from olefins. Therefore, these materials can advantageously be transformed multiple times at high temperatures without their performance being significantly reduced, in particular not significantly reduced due to oxidation caused by air and / or humidity. Compared with some polymer materials, such as polyurethane in particular, which oxidize over time, this ability enables the above materials to increase their life of recyclable cycles. Therefore, advantageously, footwear can be recycled multiple times.

[0110] The auxiliary material of the shoe body can be different from the main material of the shoe body and / or the main material of the sole.

[0111] The auxiliary materials of the shoe body can be different from each other.

[0112] The auxiliary material of the sole may be different from the main material of the sole and / or the main material of the upper.

[0113] The sole auxiliary materials may be different from each other.

[0114] Regarding “the main material of the upper body or the auxiliary material of the upper body is the same as the main material of the sole or the auxiliary material of the sole”, it should be understood that the main / auxiliary material of the upper body is the same base polymer material as the main / auxiliary material of the sole.

[0115] The same reasoning applies to combining two identical or different body auxiliary materials or sole auxiliary materials.

[0116] With respect to “the main material of the upper body or the auxiliary material of the upper body is different from the main material of the sole or the auxiliary material of the sole”, it should be understood that the main / auxiliary material of the upper body is not the same base polymer material as the main / auxiliary material of the sole.

[0117] Preferably, the main material of the shoe body and / or the main material of the sole are selected from polyolefins and / or olefin-based thermoplastic elastomers and / or styrene-based thermoplastic elastomers and / or vulcanized thermoplastic elastomers.

[0118] In one embodiment, the main material of the shoe body is thermoplastic polyurethane (TPU), or ether-amide block copolymer (PEBA), or ethylene-vinyl acetate (EVA), or polyolefin, or ether-ester block copolymer, or styrene-based thermoplastic elastomer, or olefin-based thermoplastic elastomer, or vulcanized thermoplastic elastomer, or styrene-based elastomer, or polyester, or a mixture of these different components.

[0119] In one embodiment, the main material of the sole is thermoplastic polyurethane (TPU), or ether-amide block copolymer (PEBA), or ethylene-vinyl acetate (EVA), or polyolefin, or ether-ester block copolymer, or styrene-based thermoplastic elastomer, or olefin-based thermoplastic elastomer, or vulcanized thermoplastic elastomer, or styrene-based elastomer, or polyester, or a mixture of these different components.

[0120] Preferably, the vulcanized thermoplastic elastomer is used only in the outsole and not in the midsole. Thus, in one embodiment, the outsole is the only part of the sole that may contain thermoplastic vulcanizate (TPV).

[0121] Preferably, the auxiliary material of the shoe body is selected from polyolefins and / or styrene-based thermoplastic elastomers and / or olefin-based thermoplastic elastomers and / or vulcanized thermoplastic elastomers.

[0122] Preferably, the auxiliary sole material is selected from polyolefins and / or styrene-based thermoplastic elastomers and / or olefin-based thermoplastic elastomers and / or vulcanized thermoplastic elastomers.

[0123] Shoe body

[0124] Preferably, the shoe body includes a forefoot area configured to cover all or part of the forefoot, and a rearfoot area configured to cover all or part of the rearfoot, and / or a medial area configured to cover all or part of the medial part of the foot, and / or a lateral area configured to cover all or part of the lateral part of the foot, and / or an insole area configured to cover all or part of the insole, and / or a leg area configured to cover all or part of the leg.

[0125] Advantageously, the shoe body comprises (may consist of) a main shoe body material and possibly one or more auxiliary shoe body materials, in particular, the auxiliary shoe body materials are different from the main shoe body material and possibly different from each other.

[0126] For example, the main material of the shoe body can be thermoplastic polyurethane (TPU), or ether-amide block copolymer (PEBA), or ethylene-vinyl acetate (EVA), or polyolefin, or ether-ester block copolymer, or styrene-based thermoplastic elastomer, or olefin-based thermoplastic elastomer, or vulcanized thermoplastic elastomer, or styrene-based elastomer, or polyester, or a mixture of these different components, and the first shoe body auxiliary material can be an olefin-based thermoplastic elastomer or a vulcanized thermoplastic elastomer.

[0127] For example, the main material of the shoe body can be polypropylene or polyethylene, and the shoe body includes a first shoe body auxiliary material selected from polypropylene and polyethylene different from the main material of the shoe body. Therefore, the main material of the shoe body can be polypropylene, and the first shoe body auxiliary material can be polyethylene.

[0128] In one embodiment, the footwear is a shoe, and the main material of the shoe body is thermoplastic polyurethane (TPU), or ether-amide block copolymer (PEBA), or ethylene-vinyl acetate (EVA), or polyolefin, or ether-ester block copolymer, or styrene-based thermoplastic elastomer, or olefin-based thermoplastic elastomer, or vulcanized thermoplastic elastomer, or styrene-based elastomer, or polyester, or a mixture of these different components, and is preferably a polyolefin, preferably polypropylene or polyethylene.

[0129] In one embodiment, the main material of the shoe body is different from the main material of the sole, and the sole further comprises a first auxiliary sole material that is the same as the main material of the shoe body (particularly, the auxiliary sole material does not dominate the quality of the sole). Preferably, the main material of the shoe body is polyolefin, the main material of the sole is a styrene-based thermoplastic elastomer, and the first auxiliary sole material is polyolefin.

[0130] The shaft main material and / or sole main material and / or shaft auxiliary material and / or sole auxiliary material may be one or more materials recycled from the sole and / or shaft and / or plastic of another shoe or boot and / or may be derived from biomass.

[0131] The shoe body may include one or more shoe body parts (in particular, may be composed of one or more shoe body parts), which contain the main shoe body material and / or one or more shoe body auxiliary materials (in particular, may be composed of the main shoe body material and / or one or more shoe body auxiliary materials).

[0132] The body part can be a textile part, or a reinforcing part, or a part for lacing, or a shock-absorbing part, or a porous part such as foam, or a lace, or a ring, or a front stiff tip, or a rear support or a lateral support, or a combination thereof.

[0133] The textile component can be a tissue, a knit, a mat, a braid, a cable, a fiber-spun wire, a multi-filament wire, a monofilament wire, a group of fibers, or a combination thereof.

[0134] The textile component may be a three-dimensional textile (eg a knit or a fabric), ie comprising an upper textile panel and a lower textile panel connected by an intermediate thread extending between the textile panels.

[0135] The textile component can be a knitted component which is knitted, for example, on a linear knitting machine, or on a warp knitting machine, or on a warp knitting or weft knitting circular knitting machine, in particular on a small-diameter knitting machine.

[0136] The textile component may be a knitted tubular element, in particular a knitted sock including a knitted sole portion;

[0137] Preferably, the shaft comprises one or more shaft parts assembled by gluing, knitting, or by welding (for example by ultrasonic welding or by high-frequency welding).

[0138] Preferably, the shoe body comprises a textile component with a one-piece textile construction, in particular with a one-piece knitted or woven construction, which component comprises the forefoot area and / or the rearfoot area and / or the lateral area and / or the medial area and / or the instep area.

[0139] By "one-piece textile construction" it is understood that the textile component does not include knitted portions or welds, for example to join edges, other than those that may be necessary to give it its shape.

[0140] In one embodiment, the shoe body comprises a porous part, in particular a foam and / or a bead made of a foam, comprising a material selected from the following: polyolefin, styrene thermoplastic elastomer, olefin thermoplastic elastomer, vulcanized thermoplastic elastomer, thermoplastic polyurethane (TPU), polyamide, ether-amide block copolymer (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymer, styrene-based elastomer and polyester, preferably olefin thermoplastic elastomer or polyolefin, more preferably polyolefin. The material can be the main material of the shoe body or the auxiliary material of the shoe body.

[0141] Preferably, the body comprises a porous component comprising a main material of the body, in particular foam and / or beads made of foam.

[0142] In one embodiment, the mass fraction of the main material of the shoe body in the shoe body is greater than or equal to 20%, preferably greater than or equal to 30%, and more preferably greater than or equal to 40%.

[0143] Preferably, the mass fraction of the main material of the shoe body in the shoe body is less than or equal to 90%, particularly less than or equal to 80%, more particularly less than or equal to 70%, particularly less than or equal to 60%.

[0144] Alternatively, the mass fraction of the main material of the shoe body in the shoe body may be greater than or equal to 60%, preferably greater than or equal to 70%, more preferably greater than or equal to 80%, preferably greater than or equal to 90%.

[0145] In one embodiment, the surface fraction of the shoe body occupied by the main material of the shoe body is greater than or equal to 30%, preferably greater than or equal to 40%, more preferably greater than or equal to 50%.

[0146] Preferably, the surface fraction of the shoe shaft occupied by the main material of the shoe shaft is less than or equal to 90%, in particular less than or equal to 80%, more particularly less than or equal to 70%.

[0147] Alternatively, the surface fraction of the shoe body occupied by the main material of the shoe body may be greater than or equal to 60%, preferably greater than or equal to 80%, more preferably greater than or equal to 90%.

[0148] Preferably, the surface fraction occupied by the main material of the shoe body and one or more auxiliary materials of the shoe body in the shoe body is greater than or equal to 60%, more preferably greater than or equal to 70%, preferably greater than or equal to 80%.

[0149] In one embodiment, the shoe body includes a main shoe body material and a first shoe body auxiliary material, and the mass fraction of the first shoe body auxiliary material in the shoe body is greater than or equal to 5%, preferably greater than or equal to 20%.

[0150] The mass fraction of the first shoe shaft auxiliary material in the shoe shaft is preferably less than or equal to 60%, preferably less than or equal to 50%, and more preferably less than or equal to 40%.

[0151] In one embodiment, the shoe body includes a main shoe body material and one or more auxiliary shoe body materials, in particular, a first auxiliary shoe body material and / or a second auxiliary shoe body material; the ratio of the mass of the main shoe body material and the mass of the auxiliary shoe body materials to the total mass of the shoe body is greater than or equal to 50%, preferably greater than or equal to 60%, more preferably greater than or equal to 70%, preferably greater than or equal to 80%, and in particular greater than or equal to 90%.

[0152] Optionally, the ratio of the mass of the main material of the shoe body and the mass of the auxiliary material of the shoe body to the total mass of the shoe body is less than or equal to 90% or 80%.

[0153] Advantageously, the shoe body comprises a first shoe body auxiliary material, which is selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; preferably polyolefins or olefin-based thermoplastic elastomers or vulcanized thermoplastic elastomers; more preferably polyolefins.

[0154] Advantageously, the shoe body comprises a first shoe body auxiliary material and a second shoe body auxiliary material, and the first shoe body auxiliary material and the second shoe body auxiliary material are selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; preferably polyolefins or olefin-based thermoplastic elastomers or vulcanized thermoplastic elastomers; more preferably polyolefins.

[0155] Preferably, the first shoe shaft auxiliary material is different from the second shoe shaft auxiliary material.

[0156] In one embodiment, the footwear is a shoe, and the main material of the shoe body is selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0157] Preferably, the mass fraction of the main material of the shoe body in the shoe body is greater than or equal to 40% and less than or equal to 80%, more preferably less than or equal to 60%.

[0158] Preferably, the mass fraction of the first shoe shaft auxiliary material in the shoe shaft is greater than or equal to 5%, more preferably less than or equal to 40%, more preferably less than or equal to 30%; for example included between 25% and 40%.

[0159] Preferably, the surface fraction of the main material of the body of the shoe body that is a polyolefin, in particular polypropylene, is greater than or equal to 45%. More preferably, the surface fraction of the main material of the body of the shoe body and the first auxiliary material of the body of the shoe body that is a polyolefin, in particular polyethylene, is greater than or equal to 70%. In particular, the surface fraction of the second auxiliary material of the body of the shoe body that is an olefinic thermoplastic elastomer or a styrenic thermoplastic elastomer or a vulcanized thermoplastic element is greater than or equal to 15%, in particular less than or equal to 30%.

[0160] In one embodiment, the footwear is a shoe, and the main material of the shoe body is an olefin thermoplastic elastomer or a vulcanized thermoplastic elastomer. Optionally, the shoe body further includes a first shoe body auxiliary material, in particular, the first shoe body auxiliary material is a polyolefin, such as polypropylene or polyethylene.

[0161] Preferably, the mass fraction of the main material of the shoe body in the shoe body is greater than or equal to 40% and less than or equal to 80%, more preferably less than or equal to 60%.

[0162] Preferably, the mass fraction of the first shoe body auxiliary material in the shoe body is greater than or equal to 5%, more preferably greater than or equal to 20%, particularly greater than or equal to 30% and less than or equal to 50%, more particularly greater than or equal to 35% and less than or equal to 45%.

[0163] Sole

[0164] The sole comprises (in particular consists of) a main sole material and possibly one or more auxiliary sole materials, in particular one or more auxiliary sole materials different from the main sole material.

[0165] Preferably, the main material of the sole is selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0166] For example, the sole main material may be a styrene-based thermoplastic elastomer, and the sole comprises a first sole auxiliary material, which is a polyolefin, such as polypropylene or polyethylene.

[0167] Advantageously, the sole comprises a first sole auxiliary material, which is selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; preferably polyolefins or styrene-based thermoplastic elastomers or vulcanized thermoplastic elastomers.

[0168] Preferably, the mass fraction of the main sole material in the sole is greater than or equal to 25%, more preferably greater than or equal to 40%, preferably greater than or equal to 50%, more preferably greater than or equal to 60%.

[0169] Preferably, the mass fraction of the main sole material in the sole is less than or equal to 80%.

[0170] Preferably, the mass fraction of the first sole auxiliary material in the sole is greater than or equal to 10%, more preferably less than or equal to 40%, preferably less than or equal to 30%, for example comprised between 15% and 25% (inclusive).

[0171] In one embodiment, the sole comprises a sole main material and possibly one or more sole auxiliary materials, in particular a first sole auxiliary material and / or a second sole auxiliary material, and the ratio of the mass of the sole main material and the mass of the possible sole auxiliary materials to the total mass of the sole is greater than or equal to 30%, preferably greater than or equal to 40%, more preferably greater than or equal to 50%, preferably greater than or equal to 60%, more preferably greater than or equal to 70%, preferably greater than or equal to 80%, and in particular greater than or equal to 90%.

[0172] Optionally, the ratio of the mass of the sole main material and possible sole auxiliary materials to the total mass of the sole is less than or equal to 90%, in particular less than or equal to 80%, more particularly less than or equal to 70%.

[0173] In one embodiment, the footwear is a shoe and the sole main material is selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0174] Preferably, the mass fraction of the main material of the sole is greater than or equal to 55% and less than or equal to 70%.

[0175] Preferably, the mass fraction of the first auxiliary sole material is greater than or equal to 5% and less than or equal to 35%, in particular greater than or equal to 10% and less than or equal to 30%.

[0176] In one embodiment, the main material of the sole is selected from polyolefins, styrene thermoplastic elastomers, olefin thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; preferably styrene thermoplastic elastomers, preferably SEBS or SBS, and the sole comprises a first sole auxiliary material, the first sole auxiliary material is selected from polyolefins, styrene thermoplastic elastomers, olefin thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; preferably styrene thermoplastic elastomers (different from the main material of the sole), preferably SEBS or SBS. The sole may comprise a second sole auxiliary material, the second sole auxiliary material being a polyolefin such as PP or PE.

[0177] In one embodiment, the main sole material is a vulcanized thermoplastic elastomer. Optionally, the sole further comprises a first sole auxiliary material, in particular a styrene-based thermoplastic elastomer, such as SEBS or SBS which may be grafted.

[0178] Preferably, the mass fraction of the sole main material in the sole is greater than or equal to 40% and less than or equal to 85%, more preferably greater than or equal to 30%, preferably greater than or equal to 40%, in particular greater than or equal to 55%.

[0179] Preferably, the mass fraction of the first auxiliary sole material in the sole is greater than or equal to 8%, more preferably less than or equal to 30%, for example comprised between 15% and 25%.

[0180] In one embodiment, the main material of the sole is polypropylene.

[0181] Preferably, the mass fraction of the main sole material in the sole is greater than or equal to 50%, more preferably greater than or equal to 80%, in particular greater than or equal to 90%, for example in the range of 100%.

[0182] Preferably, when the sole comprises one or more auxiliary sole materials, these auxiliary sole materials are preferably embedded in a polymer matrix, such as one or more fillers, formed by the main sole material.

[0183] The sole according to the present invention may be / may include an outsole or a midsole or a combination thereof.

[0184] In one embodiment, the footwear comprises an outer sole and a midsole, in particular the midsole is a removable sole.

[0185] The midsole may be removably disposed within a foot-receiving chamber of the footwear so as to be positioned beneath a user's foot.

[0186] The midsole can also be used as an insole.

[0187] The sole according to the present invention may include one or more sole components (in particular, consist of one or more sole components), which contain the sole main material and / or one or more sole auxiliary materials (in particular, consist of the sole main material and / or one or more sole auxiliary materials).

[0188] The sole component may be an outer sole, a midsole, a first insole, a shock-absorbing heel component (e.g. a donut), a textile component (as defined above with reference to the body), a functional device imparting stability, or a reinforcing insert or a shock-absorbing insert, or a porous component, in particular a foam or a group of foamed and possibly agglomerated and / or glued beads.

[0189] In one embodiment, the sole comprises / is a midsole comprising an outer face in direct contact with the ground.

[0190] Advantageously, the midsole is configured to ensure the functionality of an outer sole.Thus, the footwear does not comprise any outer sole.

[0191] Preferably, the midsole is a one-piece component.

[0192] Preferably, a shaped midsole will be selected which has good wear resistance.

[0193] In one embodiment, the sole comprises an outsole element, preferably an outsole (or an outsole), having a density (g / cm3) greater than or equal to 0.85; the density (g / cm3) is preferably less than or equal to 1.30.

[0194] In one embodiment, the sole comprises an intermediate sole component, preferably comprising an intermediate sole (or the intermediate sole) having a density (g / cm3) greater than or equal to 0.10; the density (g / cm3) is preferably less than or equal to 0.90; more preferably has a density less than or equal to 0.50; in particular, the density is less than or equal to 0.40.

[0195] In one embodiment, the sole comprises an intermediate sole part, preferably a midsole (or a midsole), having a density (g / cm3) greater than 0.50 and less than or equal to 0.85; in particular, said density is less than or equal to 0.75.

[0196] In one embodiment, the footwear comprises: an injected outsole, in particular, the outsole comprises a sole main material (for example, possibly grafted SEBS) and a possible first sole auxiliary material (for example, PP or PE); and an injected midsole, in particular, the midsole is located directly above the outsole which is still in a softened state.

[0197] The midsole comprises a sole main material (eg possibly grafted SEBS) and a possible first sole auxiliary material (eg PP or PE) mixed with at least one blowing agent. The outsole and the midsole are manufactured by double injection.

[0198] In one embodiment, the shoe comprises a first insole, in particular, the first insole being arranged in a foot receiving chamber of the shoe so as to be located under the foot when the shoe is worn.

[0199] Preferably, the first insole is removable.

[0200] This arrangement is advantageous when the sole is injected onto the upper. Indeed, when the first insole is already present during the injection process, the latter may be crushed and thus lose its foot-receiving properties. The use of a first removable insole allows this problem to be overcome.

[0201] Advantageously, the first insole may comprise agglomerated beads made of foam, more preferably, the beads made of foam contain (in particular consist of) a material selected from the group consisting of polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters, or a combination thereof.

[0202] In particular, the first insole may comprise a foam comprising a polyolefin, in particular polyethylene. The foam may be laminated with a textile, possibly between two textiles. The or the textile comprises threads and / or fibers made of a polyolefin.

[0203] Main material of the shoe body and / or main material of the sole and / or auxiliary material of the shoe body and / or auxiliary material of the sole

[0204] Polyolefins

[0205] The polyolefins mentioned herein, in particular the polyolefins used for the main material of the body and / or the main material of the sole and / or the auxiliary material of the body and / or the auxiliary material of the sole, are selected from homopolymers of polyolefins which may be grafted, copolymers or terpolymers of polyolefins which may be grafted.

[0206] Copolymers of polyolefins comprise two olefin repeating units which may be grafted.

[0207] Terpolymers of polyolefins comprise repeating units of three or more olefins which may be grafted.

[0208] Preferably, the olefin repeat units comprise olefin, particularly ethylene or propylene derived units.

[0209] By definition, the polyolefins embodied in the present invention are thermoplastics.

[0210] By grafting is understood one or more grafted functional groups or one or more grafted groups which may consist of one or more linear or branched alkyl groups containing 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, such as methyl, ethyl or propyl; or one or more ester functional groups, such as alkyl esters whose alkyl groups contain 1 to 5 carbon atoms; or one or more acrylate (RO-CO-CH=CH2) or acryloyl (H2C=CH-CO-R) functional groups, in particular R being an alkyl group containing 1 to 10 carbon atoms.

[0211] The polyolefins mentioned herein, in particular the polyolefins used for the main material of the upper body and / or the main material of the sole and / or the auxiliary material of the upper body and / or the auxiliary material of the sole, are preferably selected from List I comprising (in particular consisting of) the following: polypropylene; polyethylene, in particular high-density polyethylene, very high-density polyethylene, low-density polyethylene and very low-density polyethylene (LLDPE); polymethylpentene (PMP), polybutene-1 (PB-1), polyisobutylene; preferably selected from polypropylene and polyethylene, in particular, polyethylene is selected from high-density polyethylene, very high-density polyethylene, low-density polyethylene and very low-density polyethylene (LLDPE).

[0212] The polyolefins mentioned herein, in particular the polyolefins used for the main material of the upper body and / or the main material of the sole and / or the auxiliary material of the upper body and / or the auxiliary material of the sole, can also be selected from List II comprising (in particular consisting of) the following: poly(ethylene-vinyl acetate) (EVA) (in particular poly(ethylene-vinyl acetate) derived from the copolymerization of ethylene and vinyl acetate, which is composed of copolymers of olefins), in particular uncrosslinked poly(ethylene-vinyl acetate); poly(ethylene vinyl alcohol).

[0213] The polyolefin used for the sole main material and / or the sole auxiliary material mentioned herein may be selected from mineral oils based on olefins such as poly-α-olefins, in particular, the mineral oil includes a plasticizer made of styrene-based thermoplastic elastomer.

[0214] The polyolefin may be a bio-derived or petrochemical polyolefin, in particular a bio-derived polyolefin, ie derived from renewable materials, for example it may consist of bio-derived polyethylene derived from sugar cane.

[0215] By material of biogenic origin is meant any material which originates from renewable materials in contrast to fossil materials.

[0216] Bio-derived polyolefins can be of so-called direct origin, i.e. they are derived directly from renewable materials, or of indirect origin, i.e. they are derived from a mixture of renewable materials and petrochemical materials and / or recycled materials. In the latter case, the polyolefin is qualified by obtaining a certification established according to the principle of the "mass balance approach", which defines the proportion of recycled materials and / or materials of bio-derived origin used to obtain the polyolefin.

[0217] Olefin thermoplastic elastomer

[0218] The olefinic thermoplastic elastomers mentioned herein, especially the olefinic thermoplastic elastomers used for the main material of the shoe body and / or the main material of the sole and / or the auxiliary material of the shoe body and / or the auxiliary material of the sole, are selected from:

[0219] - polyisobutylene (PIB); and / or

[0220] - ethylene, propylene and diene terpolymers (EPDM); ethylene and propylene copolymers; ethylene and α-olefin copolymers, such as ethylene and butene copolymers or ethylene and octene copolymers, and mixtures thereof; preferably EPDM and ethylene and propylene copolymers; and / or

[0221] - a mixture of a polyolefin, in particular polypropylene, with one or more unvulcanized olefinic thermoplastic elastomers and possibly one or more plasticizers, the olefinic thermoplastic elastomer or the olefinic thermoplastic elastomer may consist of an ethylene and propylene copolymer, an ethylene, propylene and diene terpolymer, an ethylene and α-olefin copolymer (for example, an ethylene and butene copolymer or an ethylene and octene copolymer).

[0222] Vulcanized thermoplastic elastomer

[0223] The vulcanized thermoplastic elastomer (TPE-V) mentioned herein, in particular the vulcanized thermoplastic elastomer used for the main material of the shoe body and / or the main material of the sole and / or the auxiliary material of the shoe body and / or the auxiliary material of the sole, is preferably:

[0224] a mixture of a vulcanized olefin elastomer, in particular a vulcanized olefin elastomer forming the rubber phase, and a polyolefin, in particular a polyolefin as defined herein, more particularly a polyolefin forming the thermoplastic phase, in particular a polypropylene, or

[0225] - a mixture of a vulcanized olefin elastomer, in particular a vulcanized olefin elastomer as defined herein and vulcanized, more particularly a vulcanized olefin elastomer forming a rubber phase, and a styrenic thermoplastic elastomer, in particular a styrenic thermoplastic elastomer as defined herein, more particularly a styrenic thermoplastic elastomer forming a thermoplastic phase, in particular SEBS or SBS

[0226] Typically, vulcanization occurs during the extrusion-granulation step. Preferably, a highly vulcanized rubber phase is dispersed in the thermoplastic phase. The advantage of this elastomer is that it has good adhesion to olefin polymers such as polypropylene and polyethylene. This vulcanization is known in the prior art and is similar to dynamic vulcanization, during which the elastomer is vulcanized during mixing of the elastomer in a molten state with a suitable thermoplastic polyolefin.

[0227] Preferably, the vulcanized olefin elastomer is selected from: ethylene, propylene and diene terpolymers (EPDM); ethylene and propylene copolymers; ethylene and α-olefin copolymers, such as ethylene and butene copolymers or ethylene and octene copolymers, and mixtures thereof; preferably EPDM and ethylene and propylene copolymers.

[0228] In this context, polyurethanes are not considered to be vulcanized thermoplastic elastomers.

[0229] Styrene thermoplastic elastomer

[0230] The styrene thermoplastic elastomers mentioned herein, in particular the styrene thermoplastic elastomers used for the main material of the shoe body and / or the main material of the sole and / or the auxiliary material of the shoe body and / or the auxiliary material of the sole, are preferably selected from thermoplastic elastomers containing styrene repeating units (TPE-S) (in particular styrene groups: -CH(C6H5)-CH2), more preferably selected from thermoplastic elastomers containing one or more styrene blocks and optionally one or more olefin blocks (possibly grafted), preferably selected from: poly(styrene-ethylene-butylene-styrene) (SEBS); poly(styrene-butadiene-styrene) (SBS); poly(styrene-butadiene) (SBC); poly(styrene-isoprene-styrene) (SIS); poly(styrene-ethylene-propylene-styrene) (SEPS), for example, produced by Kuraray under the brand name Septon Or by Kraton under the brand name Kraton Commercial poly(styrene-ethylene-propylene-styrene).

[0231] The styrenic thermoplastic elastomer according to the invention may be grafted, for example SEBS may be grafted, for example with one or more anhydrides such as maleic anhydride and / or one or more carboxylic acids and / or one or more vinyl functional groups.

[0232] Grafting the styrenic thermoplastic elastomer is intended to improve the adhesion of a sole, such as an outsole, to another sole, such as a midsole, and / or to a shoe body when the sole is directly injected onto the shoe body.

[0233] Advantageously, the thermoplastic elastomers selected in the context of the present invention have better deformability and lower associated energy costs than thermosetting elastomers made by conventional thermoplastic processes, such as injection molding, extrusion, thermoforming, blow molding, and the like.

[0234] In particular, those mentioned may be made of polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0235] definition

[0236] Advantageously, the main material of the shoe body and / or the main material of the sole and possibly one or more auxiliary materials of the shoe body and / or one or more auxiliary materials of the sole have (in particular each have) a melting point (Tf) and / or a glass transition temperature (Tg), in particular, the melting point is higher than the glass transition temperature.

[0237] In this context, reference to shoes should be understood as any footwear excluding boots.

[0238] In the present context, by boots is to be understood rain or snow boots or clogs, in particular footwear comprising a shaft and a sole portion comprising a common polymer material forming the majority of the mass of the shaft and the sole, which are moulded together.

[0239] In this context, by thermoplastic material is understood any material which can be softened or melted by heating and in a sufficient manner without degradation of the material so that it can be implemented in a process for converting plastics, such as those mentioned above, and so on a multiple basis.

[0240] As far as most of the mass of the shoe body is concerned, it should be understood as follows:

[0241] - the mass fraction of the main material of the shoe body is greater than the mass fraction of any other material contained in the shoe body, measured relative to the total mass of the shoe body; or

[0242] - the mass fraction of the main material of the shaft plus the corresponding mass fraction of the auxiliary material of the shaft, measured relative to the total mass of the shaft, is greater than the mass fraction of any other material comprised by the shaft and not selected from the main list defined herein; or

[0243] - the fraction of the surface occupied by the main material of the shaft is greater than the fraction of the surface occupied by any other material comprised by the shaft, measured relative to the total surface of the shaft; or

[0244] - The surface fraction occupied by the main material of the shaft plus the corresponding surface fraction of the auxiliary material of the shaft, measured relative to the total surface of the shaft, is greater than the surface fraction occupied by any other material comprised by the shaft and not selected from the main list defined herein.

[0245] Thus, the main shaft material and possible auxiliary shaft material may correspond to, for example, 30 weight %, 40 weight % or 50 weight % or 60 weight % of the shaft or the outer surface of the shaft.

[0246] With respect to the main material of the shoe body, it should be understood that the mass fraction or surface fraction of the main material of the shoe body is greater than the mass fraction or surface fraction of any auxiliary material of the shoe body, and may be greater than the mass fraction or surface fraction of any other material contained in the shoe body that is not selected from the main list defined in this document.

[0247] When the main material of the shoe body accounts for, for example, 30% of the mass of the shoe body, the auxiliary materials (each) account for less than 30% of the mass of the shoe body.

[0248] Preferably, the outer surface of the shoe body is calculated by the shoe body projection plane. For example, the outer surface of the shoe body can be composed of the surface of the shoe body blank before it is three-dimensionally formed by sewing, but includes all the shoe body parts arranged on its outer surface.

[0249] By the total mass of the shaft it is understood the mass of the shaft on the finished shoe with all its components.

[0250] As far as most of the quality of the sole is concerned, it should be understood that:

[0251] - the mass fraction of the main material of the sole is greater than the mass fraction of any other material comprised by the sole, measured relative to the total mass of the sole; or

[0252] - The mass fraction of said sole main material plus the corresponding mass fraction of sole auxiliary material, measured relative to the total mass of the sole, is greater than the mass fraction of any other material comprised by the sole which is not selected from the main list defined herein above.

[0253] Thus, the main sole material and possible auxiliary sole materials may correspond to 40% by weight or 50% by weight or 60% by weight of the sole.

[0254] With respect to the sole primary material, it will be understood that the mass fraction of the sole primary material is greater than the mass fraction of any sole auxiliary material, and possibly greater than the mass fraction of any other sole material not selected from the main list defined herein.

[0255] For example, when the main material of the sole accounts for 30% by weight of the sole, the auxiliary materials (each) account for less than 30% by weight of the sole.

[0256] Herein, the mass fraction of the main material of the shoe body or the auxiliary material of the shoe body in the shoe body is the ratio of the mass (g) of the main material of the shoe body or the auxiliary material of the shoe body to the total mass (g) of the shoe body.

[0257] For calculating the total mass of the shaft in order to define the mass fractions of the main shaft material and / or the auxiliary shaft material, it is taken into account that all the shaft material covers the top of the foot, i.e. is arranged above the support plane of the foot. Possible materials of the sole connected to the shaft (e.g. the sole part of a knitted sock) are counted as belonging to the sole, in particular the midsole or the outsole.

[0258] In this article, the surface fraction occupied by the main material of the shoe body or the auxiliary material of the shoe body is the surface fraction occupied by the visible material (cm 2 ) and the total external surface of the shoe body projection plane (cm 2 ) ratio, the outer surface of the shoe body is the surface pointing to the outside of the shoe.

[0259] Herein, the mass fraction of the sole main material or the sole auxiliary material in the sole is the ratio of the mass of the main material or the auxiliary material to the total mass of the sole.

[0260] When the first shaft part comprises a main shaft material and the second shaft part comprises said main shaft material, each of the first part and the second part comprises the main shaft material in the same base polymer, which may be selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; and in particular polyolefins, such as PP or PE. However, the base polymer material of the first part may differ from the base polymer material of the second part in terms of hardness or its intrinsic properties (molar mass, degree of polymerization, amount of monomers) or its form (foam, textile, foamed beads, etc.).

[0261] Footwear, in particular the body and / or the sole, may contain up to about 20% by weight, in particular up to 15% by weight, more particularly up to 10% by weight, in particular up to 5% by weight, relative to its total mass, of one or more contaminant materials, that is to say not selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers and vulcanized thermoplastic elastomers. These contaminant materials or the contaminant materials may be selected from polyurethanes, polyamides or polyesters (e.g. polyethylene terephthalate (PET) or polybutylene terephthalate (PBT)). For example, these contaminant materials may originate from recycled materials.

[0262] In a sub-variant, the footwear is a boot. The boot comprises an outer sole and a shaft. The shaft comprises a lower shaft portion covering the foot, in particular the forefoot, the instep, the medial region, the lateral region and the rear foot. The shaft also comprises an upper shaft portion at least partially covering the leg.

[0263] Preferably, the shaft lower portion and the outsole are co-injected.

[0264] In two of the above sub-variants, preferably, the main material of the sole is a styrene-based thermoplastic elastomer, in particular SEBS, and the main material of the body is a styrene-based thermoplastic elastomer.

[0265] The upper part of the ...

[0266] Preferably, the mass fraction of the main sole material in the sole is greater than or equal to 45%, more preferably greater than or equal to 50%, in particular less than or equal to 70%.

[0267] The outsole may also include a first auxiliary sole material, which may be selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; and for example, polyolefins, especially polypropylene.

[0268] The mass fraction of the first auxiliary sole material in the shoe sole is greater than or equal to 5% and less than or equal to 40%, in particular less than or equal to 30%.

[0269] Preferably, the mass fraction of the main material of the shoe body is greater than or equal to 40%, more preferably less than or equal to 60%.

[0270] The shoe body may include a first shoe body auxiliary material, wherein the first shoe body auxiliary material is a polyolefin, in particular a polypropylene, and the mass fraction of the first shoe body auxiliary material in the shoe body is greater than or equal to 10%, preferably less than or equal to 35%.

[0271] Preferably, the ratio of the mass of the main material of the shoe shaft and the mass of the first auxiliary material of the shoe shaft to the total mass of the shoe shaft is greater than or equal to 60%, more preferably greater than or equal to 70%.

[0272] In one variation, the main material of the shoe body is selected from one of the following materials: polyolefin, olefinic thermoplastic elastomer or vulcanized thermoplastic elastomer, preferably selected from polyolefin or olefinic thermoplastic elastomer, more preferably selected from polyolefin.

[0273] In a variant, the main material of the sole is selected from one of the following materials: styrene thermoplastic elastomer, polyolefin or vulcanized thermoplastic elastomer.

[0274] In one variant, the main material of the sole is a styrene-based thermoplastic elastomer.

[0275] In a variant, the main material of the sole is a polyolefin, in particular polypropylene.

[0276] In one embodiment, the shoe body includes a wire comprising a material selected from the group consisting of: polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0277] Preferably, the polyolefin is polypropylene or polyethylene.

[0278] Preferably, the wire material comprises a main material of the shoe body.

[0279] In one embodiment, the shoe body includes a textile component, and the textile component includes a wire comprising a main material of the shoe body, in particular, the main material of the shoe body is selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0280] Preferably, the main material of the body is propylene or polyethylene. In a variant, the body comprises a textile part forming an area for receiving the foot and having an outer face, and at least one part, in particular a strip, comprising an olefinic thermoplastic elastomer, which is fixed to the outer face of the textile part and to the sole.

[0281] Advantageously, the textile portion forming the area for receiving the foot comprises a textile component, in particular, the textile component comprises a thread comprising a main material of the shoe body selected from the following: polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; more particularly, the main material of the shoe body is a polyolefin or an olefin-based thermoplastic elastomer or a vulcanized thermoplastic elastomer.

[0282] Advantageously, the textile component may be as described herein.Preferably, the portion is a portion made of artificial leather.

[0283] Advantageously, the portion comprises a textile support and a polymer layer comprising, in particular essentially consisting of, more in particular consisting of a material chosen from the following: polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; and in particular the olefinic thermoplastic elastomer, the polymer layer being fixed to the textile support.

[0284] More advantageously, the face of the portion comprising the textile support is oriented opposite to the outer face of the textile portion.

[0285] Preferably, the shoe body comprises one or more strips, more preferably, the strips are arranged to extend at least partially along at least one of the following edges of the shoe: the front edge, the medial edge, the lateral edge and the rear edge.

[0286] Preferably, these parts or said parts, in particular strips, are fixed to the outer face of the textile part forming the area for receiving the foot and to the sole.

[0287] Preferably, the or the portions, in particular the strips, have (in particular each have) a thickness greater than or equal to 0.5 mm and less than or equal to 3 mm.

[0288] Preferably, the at least one portion, in particular the strip, is fixed to the outer face of the textile portion and possibly to the sole by melting at least a part of its structure.

[0289] Preferably, the at least one portion, in particular at least a portion of the strip, is arranged between the sole and an outer face of the textile portion for receiving a foot.

[0290] Advantageously, olefinic thermoplastic elastomers allow forming reinforcement parts, in particular reinforcement strips, with an artificial leather appearance, which are compatible with the polymer materials of the textile part and the sole, making it possible to glue them by melting.

[0291] In one embodiment, the portion is arranged to form a portion that overlaps all or part of the front foot portion, in particular comprising an opening for inserting the foot into the overlapping portion.

[0292] In one variant, the sole comprises a porous component, in particular a foam, comprising a material selected from the group consisting of polyolefins, styrene thermoplastic elastomers, olefin thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; and in particular a styrene thermoplastic elastomer, an olefin thermoplastic elastomer or a polyolefin, preferably a material selected from the group consisting of an olefin thermoplastic elastomer, more preferably an olefin thermoplastic elastomer.

[0293] Preferably, the beads made of foam are agglomerated into one piece, in particular glued together at their surface by melting.

[0294] Preferably, the bulk density of the porous part is comprised between 0.1 g / cm3 and 0.4 g / cm3, preferably between 0.15 g / cm3 and 0.25 g / cm3.

[0295] Preferably, the porous component is a midsole.

[0296] In one variation, the shoe body includes a front stiff tip portion comprising a main material of the shoe body or an auxiliary material of the shoe body, and / or a rear support member comprising a main material of the shoe body or an auxiliary material of the shoe body.

[0297] The shoe body may include a rear support member or a front stiffener comprising or consisting of a material selected from the following: polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0298] Thus, the shoe body may include a rear support or a front stiffener comprising or consisting of a styrenic thermoplastic elastomer, such as SEBS, possibly mixed with at least one polyolefin.

[0299] The shoe body may include a rear support member or a front stiffener that includes or consists of a vulcanized thermoplastic elastomer.

[0300] In one embodiment, the body comprises at least one loop for passing at least one lacing element, the at least one passing loop comprising a textile strip comprising at least one thread comprising a main body material or an auxiliary body material, in particular, the main body material being polyolefin.

[0301] In one embodiment, the body comprises a component made of a foam comprising a main body material, in particular, the main body material is selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0302] The shoe body may include one or more composites, the composite including a textile fixed together with the part made of foam, preferably, the textile and the part made of foam contain (especially consist of) a main material of the shoe body selected from the following: polyolefins, styrene thermoplastic elastomers, olefin thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; preferably made of polyolefins such as PP or PE.

[0303] Said component made of foam, possibly assembled with textiles, can be arranged in the region of the rear heel of the shaft and / or in the region of the medial side of the shaft and / or in the region of the lateral side of the shaft in order to impart comfort.

[0304] In a variant, the shaft and / or the sole contain / each contain recycled material of the sole and / or the shaft of another shoe and / or the sole of a boot and / or recycled material of said shaft.

[0305] Preferably, the recycled material includes main material of the shoe body and / or main material of the sole and / or auxiliary material of the shoe body and / or auxiliary material of the sole.

[0306] The other shoe may be a shoe according to the invention.

[0307] In one variant, the ratio of the mass of the main material of the shoe body and the mass of the possible auxiliary materials of the shoe body to the total mass of the shoe body is greater than or equal to 40%, preferably greater than or equal to 50%. In one variant, the ratio of the mass of the main material of the shoe body and the mass of the auxiliary materials of the shoe body to the total mass of the shoe body is greater than or equal to 50%, and the main material of the shoe body and the auxiliary materials of the shoe body are selected from polyolefins and olefin thermoplastic elastomers. In one variant, the main material of the sole at least partially covers the shoe body, in particular the main material of the shoe body.

[0308] Preferably, the sole main material rises substantially in the forefoot region and / or the rearfoot region and / or the medial region and / or the lateral region of the shaft.

[0309] In one variant, the sole main material is fixed to the body, in particular to the body main material, without any intermediate bonding agent, such as any glue or any stitching. In one variant, the ratio of the mass of the sole main material and the mass of possible sole auxiliary materials to the total mass of the sole is greater than or equal to 40%, preferably greater than or equal to 50%.

[0310] In one embodiment, the ratio of the mass of the sole main material and the mass of the sole auxiliary material to the total mass of the sole is greater than or equal to 50%, and the sole main material and the sole auxiliary material are selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0311] In a variant, the footwear, in particular the shoe, in particular the sports shoe, or the footwear, in particular the shaft and / or the sole of the shoe, comprises (in particular each comprises):

[0312] - up to 10% by weight of one or more contaminant materials not selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters,

[0313] - in particular up to 10% by weight of one or more thermoplastic contaminant materials and / or up to 5% by weight of one or more thermosetting contaminant materials.

[0314] For example, if the contaminant material consists of a thermoplastic contaminant material, the mass fraction of the contaminant in the shoe amounts to at most 10%.

[0315] For example, if a shoe contains 5 weight percent of one or more thermoset contaminant materials, the shoe may also contain at least 5 weight percent of one or more thermoplastic contaminant materials.

[0316] In one variant, the footwear, in particular a shoe, in particular a sports shoe, or the body and / or the sole of the footwear, in particular a shoe, comprises (in particular each comprises):

[0317] - One or more contaminant materials.

[0318] In one variant, a footwear, in particular a shoe, in particular a sports shoe, or a footwear, in particular a shoe body and / or a sole (each) comprises:

[0319] - up to 10% by weight of one or more contaminant materials,

[0320] - in particular up to 10% by weight of one or more thermoplastic contaminants and / or up to 5% by weight of one or more thermosetting contaminants.

[0321] In this context, thermosetting materials, in particular contaminant thermosetting materials, are understood to be any materials that do not have a temperature that can be thermally transformed by a plastic forming process, such as by extrusion-injection, extrusion-blow molding, hot pressing (thermocompression), extrusion-spinning.

[0322] In this context, by thermoplastic material, in particular thermoplastic plastic material, is understood any material having a temperature which can be thermally transformed by a plastic forming process, for example by extrusion-injection, extrusion-blow moulding, hot pressing, extrusion-spinning.

[0323] Advantageously, the inventors have determined that, depending on whether they are thermoplastic or thermoset, the levels of contaminants in footwear should not exceed certain proportions for the footwear to be recyclable without separating its different components and for the resulting recycled material to have satisfactory mechanical properties for many new applications.

[0324] A non-exhaustive explanation in particular regarding thermosetting contaminants is that the contaminant material is arranged like a granular structure in a thermoplastic matrix derived from the main material of the shaft and the main material of the sole and possibly from auxiliary materials of the shaft and the sole.

[0325] Additionally, the inventors have determined that the properties of polymer mixtures derived from footwear can be surprisingly improved by contaminant materials.

[0326] In particular, the wear resistance of the mixture is surprisingly improved when the shoe contains one or more contaminant materials made of polyurethane or polyamide, in particular the mass fraction of said contaminant materials in the shoe is at most 10% (see attachedFigure 5 Above 10%, a reduction in wear resistance has been observed.

[0327] Preferably, the mass fraction of contaminant material in the footwear is greater than or equal to 0.5%, more preferably greater than or equal to 1%.

[0328] In a variant, the footwear, in particular a shoe, in particular a sports shoe, or the shaft and / or the sole of the footwear, in particular a shoe, contains (in particular each contains) a foam in the pollutant material.

[0329] In one embodiment, the sole or the body comprises foam in the contaminant material, which corresponds to at least 30% by volume of the sole or the body, preferably at least 40% by volume, more preferably at least 50% by volume, preferably at least 60% by volume or 70% by volume.

[0330] In one embodiment, when the contaminant material is thermoplastic, the foam in the contaminant material is equivalent to at most 10 weight % of the footwear, in particular a shoe, and / or when the contaminant material is thermosetting, the foam in the contaminant material is equivalent to at most 5 weight % of the footwear, in particular a shoe.

[0331] The foam may be a foamed block or comprise agglomerated expanded particles.

[0332] For example, the density of foams made of polyurethane is in the range of 0.040 kg / l to 0.4 kg / l, for example in the range of 0.055 kg / l, while the density of styrenic thermoplastic elastomers such as SEBS is greater than or equal to 0.80 kg / l.

[0333] In one embodiment dedicated to polyester, the present invention relates to a footwear, in particular a shoe, more particularly a sports shoe, which advantageously comprises, more advantageously consists essentially of, even more advantageously consists of:

[0334] - a body, the majority of the body's mass or the majority of the body's surface being formed by a body main material, the body possibly also comprising one or more body auxiliary materials;

[0335] - a sole, the majority of the mass of which is formed by a sole main material, said sole possibly also comprising one or more sole auxiliary materials;

[0336] And it is characterized in that the main material of the shoe body and the possible auxiliary materials of the shoe body are selected from polyester and materials chemically compatible with polyester;

[0337] And the main material of the sole and possible auxiliary materials of the sole are selected from polyester and materials chemically compatible with polyester.

[0338] The main material of the shoe body may include at least one of the following materials: thermoplastic copolyester and polyethylene terephthalate.

[0339] The thermoplastic copolyester may be a block copolymer comprising rigid segments of polyester and soft segments of polyether and / or polyester, and in particular TPEE or TPC-ET.

[0340] The shoe body may include a lower portion comprising a thermoplastic copolyester, which is a block copolymer comprising rigid segments of polyester and soft segments of polyether and / or polyester, and in particular TPEE or TPC-ET.

[0341] The shaft may include an upper portion comprising polyethylene terephthalate or a thermoplastic copolyester, which is a block copolymer comprising a rigid segment of polyester and a soft segment of polyether and / or polyester, such as TPEE.

[0342] The upper part may include an upper layer made of polyethylene terephthalate, a lower layer made of polyethylene terephthalate, a central layer made of a thermoplastic copolymer and surrounded by an adhesive intermediate layer at the top and bottom, the upper intermediate layer of the upper part being arranged between the central layer and the upper layer, and the lower intermediate layer of the upper part being arranged between the central layer and the lower layer. The adhesive intermediate layer allows the different layers to be bonded together. The adhesive intermediate layer may be made of polyethylene terephthalate.

[0343] The upper may include a lace-up made from polyethylene terephthalate.

[0344] The shoe body may include a lacing loop, for example a lacing loop made in the form of a thread embroidered on the shoe body. The lacing loop may be made of polyethylene terephthalate.

[0345] The upper may include an upper reinforcement made of nonwoven polyethylene terephthalate.

[0346] The upper may include tabs made from nonwoven polyethylene terephthalate.

[0347] The footwear may include a reinforcement ring made of a thermoplastic copolyester at the rear of the footwear and over the midsole.

[0348] The sole main material may include at least one of the following materials: a thermoplastic copolyester, a thermoplastic vulcanizate (TPV) type thermoplastic elastomer including a soft phase and a thermoplastic phase made of the thermoplastic copolyester.

[0349] Thermoplastic vulcanizates (TPV) type thermoplastic elastomers may comprise a soft phase made of poly(styrene / butadiene) and a thermoplastic phase made of a block copolymer comprising a hard segment of polyester and a soft segment of polyether and / or polyester. Thus, the thermoplastic phase may be TPEE.

[0350] The sole may comprise a midsole comprising a block copolymer comprising hard segments of polyester and soft segments of polyether and / or polyester, and in particular TPEE or TPC-ET.

[0351] The sole may include an outsole comprising a thermoplastic vulcanizate (TPV) comprising a soft phase made of poly(styrene / butadiene) and a thermoplastic phase made of a block copolymer comprising a rigid segment of a polyester and a soft segment of a polyether, and in particular a thermoplastic phase made of TPEE.

[0352] Alternatively, the sole may comprise an outsole comprising rubber. In this case, the outsole is advantageously fastened to the midsole using a specific adhesive primer which, when subjected to heat, allows the outsole to be easily removed in preparation for recycling the shoe.

[0353] Finally, with regard to this embodiment dedicated to polyester as main material, the footwear may comprise a first insole comprising a block copolymer comprising rigid segments of polyester and soft segments of polyether and / or polyester, and in particular TPEE or TPC-ET.

[0354] Sometimes, it is necessary to use some materials to give specific functions to footwear, especially when it consists of sports shoes.Variations and embodiments according to the first aspect of the invention can be combined independently of each other.

[0355] The injected sole may be an outsole or a midsole, or a combination thereof.

[0356] In a first embodiment, the sole is injected directly onto the upper. Preferably, the upper is arranged on a preform of a foot-like shape and the sole is then injected onto the lower portion of the upper. The lower portion of the upper may be a first mounting piece connected to the lower edge of the upper (e.g. when the upper is three-dimensionally formed using welding and / or stitching to cover the foot) and / or to a textile sole portion of the upper textile component. The upper textile component may be a planar textile component that is three-dimensionally formed, e.g. by stitching / welding, to form a shoe for receiving a foot.

[0357] The shoe body textile component may be a knitted sock, which comprises an integral knitted sole portion, in particular a knitted sole portion that has been heat-fused or heat-compressed.

[0358] Preferably, fixing the shoe body and the shoe sole together is performed without any adhesive.

[0359] The selected sole main material and shoe body main material and / or sole auxiliary material and shoe body auxiliary material in the present invention allow the sole to be manufactured by injecting the sole directly onto the shoe body without adhesion problems, thereby simplifying the process and reducing the number of different materials used.

[0360] Preferably, the main material of the shoe body is selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0361] The Applicant has observed that the sole main material has very good adhesion to the body main material, in particular when it consists of a polyolefin or an olefinic thermoplastic elastomer.

[0362] The mixture injected to make the sole may also contain the sole main material, plasticizers and / or fillers (eg calcium carbonate) and / or one or more foaming agents (eg in the case of a midsole).

[0363] The plasticizer may be selected from mineral oils and / or naphthenic or paraffinic oils.

[0364] The sole injected on the upper can be an outer sole or an intermediate sole. In the latter case, at least one foaming agent is used to mix with the sole main material.

[0365] In one embodiment, the method comprises the following steps: treating at least a portion of the surface of the sole, in particular the outsole and / or the midsole, and / or at least a portion of the surface of the upper, in particular at least a portion of the surface of one or more textile components, in order to improve the adhesion of the sole to the upper and / or the adhesion of the outsole to the midsole and / or the adhesion of functional components (for example, lateral reinforcements, front stiffeners or rear support components) to textile components of the upper.

[0366] The treatment steps include a light abrasion step (particularly referred to as a “buffing treatment”) and / or a plasma treatment step and / or a flame treatment step and / or a corona treatment step.

[0367] This step allows the two parts to be fixed together without the need for any adhesive, thus avoiding the addition of materials that could become contaminants during subsequent recycling.

[0368] In a variant, the sole main material and possibly the sole auxiliary material originate at least partly from recycling of at least one other shoe or at least one boot, in particular at least one footwear according to any of the variants or embodiments of the first aspect of the invention.

[0369] In one variant, the method comprises the step of foaming a component made of foam containing a sole main material or at least one sole auxiliary material on an injected sole in a softened state in order to at least partially fix the component made of foam to the sole, in particular without any adhesive.

[0370] Double injections can be performed as described above.

[0371] The component made of foam and the sole are fixed together while the injected sole is in the softened state, ie before it cools down to room temperature.

[0372] According to another aspect, the present invention relates to a method for recycling at least one kind of footwear, in particular a shoe, comprising: recycling at least one kind of footwear, in particular a shoe, obtained according to any one of the variants and embodiments of the first aspect of the invention or by implementing the manufacturing method according to any one of the variants and embodiments of the second aspect of the invention, and converting the at least one kind of footwear, in particular the shoe, into thermoplastic granules.

[0373] In a first step, the collected footwear, in particular shoes, are shredded to obtain shreds, in particular shreds having at least one dimension in the range of at least 1 mm to 40 mm. The shreds are conveyed to an extrusion-granulation device to obtain thermoplastic granules. Prior to this, they may undergo a washing step in order to remove dust.

[0374] In this context, by thermoplastic granules are understood any granules having a temperature which can be thermally transformed by a plastic forming process, for example by extrusion-injection, extrusion-blow moulding, hot pressing, extrusion-spinning, injection with supercritical fluids.

[0375] The thermoplastic granules thus behave like thermoplastics when they are subjected to a thermal conversion process, even if they contain one or more thermosetting materials, but in a smaller amount so as not to alter their ability to be converted like thermoplastics.

[0376] Preferably, the extrusion-granulation device is / comprises a twin-screw extruder. Advantageously, this type of extruder allows for better mixing of the chopped material.

[0377] Advantageously, there is no need to separate the different components of the footwear, in particular the shoe, since these components are compatible with one another for their implementation in the thermoplastic material conversion process.

[0378] In one variant, the conversion step comprises the following, in particular in the following order:

[0379] - a step of shredding the footwear, in particular the at least one shoe, in particular a sports shoe, to obtain shredded particles;

[0380] - a step of compacting the chopped particles to obtain chopped and compacted particles, in particular, the compacting being cold compaction or hot compaction,

[0381] - a step of extrusion-granulation of the shredded and compacted particles to obtain granules that can be transformed by a plastic thermal transformation process.

[0382] Advantageously, the compacting step allows the air to be expelled from the foamed and / or hollow recycled material.

[0383] Preferably, the compacting step is performed by heating the shredded particles at elevated temperature, in particular in a temperature range higher than or equal to 60°C and lower than or equal to 110°C, for example in a tolerance range of 70°C and + / -10°C.

[0384] In a variant, the recycling process comprises the step of converting at least a portion of said thermoplastic granules at high temperature for the manufacture of a plastic part, in particular a plastic part partially forming an article for practicing sports.

[0385] In this context, reference is made to a plastic portion at least partially forming an article for practicing a sport, it should be understood that the portion may form only a portion or substantially the entirety of the sporting article.

[0386] The plastic part comprises one or more recycled materials, in particular one or more recycled materials originating from the recycled thermoplastic granules, said recycled materials being chosen from polyolefins, olefinic thermoplastic elastomers, styrenic thermoplastic elastomers and vulcanized thermoplastic elastomers, possibly mixed with one or more other petrochemical and / or bio-sourced and / or recycled materials or not originating from the recycling method according to the invention.

[0387] Advantageously, the plastic part is a swimming fin, or a swimming fin comprising a fin and a chamber for receiving a foot.

[0388] The plastic part could be a grip, a zipper tab, a wheel, a light cover, or a euphonium mouthpiece.

[0389] The plastic portion is not limited to recycling in sporting goods, but may be implemented in any application where the composition of the recycled footwear has satisfactory mechanical properties.

[0390] In this context, by "plastic" it is understood any material based on the implementation of one or more (co)(ter)polymers transformed by thermal treatment, such as extrusion-injection, extrusion-molding, extrusion-blow molding, thermocompression or any equivalent technique.

[0391] According to a last aspect, the invention relates to a plastic part (in particular molded, more particularly a plastic part with a one-piece molded structure), in particular a plastic part forming at least a part of a footwear for practicing sports, which plastic part can be obtained by a recycling method with respect to any one of the variants according to the third aspect of the invention, in particular, the part is a swimming fin, or a swimming fin comprising a fin and a chamber for receiving a foot.

[0392] In one embodiment, the part is a swimming fin or a swimming fin comprising a fin and a chamber for receiving the foot, and the part comprises a material dominated by mass, the material being selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters, preferably selected from styrenic thermoplastic elastomers.

[0393] By mass dominant material, it is understood that the mass fraction of the material is the most abundant material contained in the composition of the part.

[0394] In one embodiment, the portion comprises a material that is predominantly selected from the group consisting of polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters, and the mass fraction of the ... and polyesters is greater than or equal to 10%, preferably greater than or equal to 25%, more preferably greater than or equal to 35%, preferably greater than or equal to 45%, and in particular greater than or equal to 55%.

[0395] In one embodiment, the mass fraction of the recycled thermoplastic granules in the plastic part is greater than or equal to 10%, preferably greater than or equal to 25%, more preferably greater than or equal to 35%, preferably greater than or equal to 45%, in particular greater than or equal to 55%, possibly greater than or equal to 80% or 90%.

[0396] In another embodiment, the part comprises a material selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters, preferably selected from styrenic thermoplastic elastomers, and the mass fraction of the recycled material in the part is less than or equal to 25%, preferably less than or equal to 20%, more preferably less than or equal to 15%. In one embodiment, the mass fraction of the recycled thermoplastic fines in the plastic part is less than or equal to 25%, preferably less than or equal to 20%, more preferably less than or equal to 15%.

[0397] According to an aspect, the invention also relates to a footwear, such as a shoe, and in particular a footwear for practicing sports, obtained by a method according to one of the aforementioned implementations.

[0398] According to another aspect, the present invention relates to a device for manufacturing at least a portion of a footwear, the device comprising a mold defining an open cavity, the shape of at least a portion of the cavity corresponding to the shape of the sole of the footwear, the cavity being configured to receive a mixture comprising a molten material and a supercritical fluid via at least one injection channel leading to the cavity, the edge of the opening of the open cavity being configured to be placed in contact with a docking area of ​​the surface of at least a portion of the body of the footwear, so that the surface of at least a portion of the body ensures that the cavity is closed at the level of the contact portion between the docking area and the edge, so that the device is thereby configured to implement a method according to one of the aforementioned implementations.

[0399] According to one embodiment, the device also includes a cover, which is configured to be placed on the mold so as to form a closed volume portion together with the mold, which closed volume portion includes a cavity and a complementary part of the cavity in the closed volume portion, at least a part of the shoe body of the footwear is located inside the closed volume portion, the complementary part and the cavity are located on both sides of the closed part of the cavity at the level of the contact between the docking area and the edge, and the device is therefore configured to implement a method according to one of the above-mentioned embodiments.

[0400] According to one embodiment, the device also includes a support having a shape corresponding to the shape of the foot, and the outer surface of the support is configured to be covered by at least a portion of the shoe body of the footwear, and at least a portion of the surface of at least a portion of the shoe body covers a portion of the outer surface of the support corresponding to the sole of the foot.

[0401] In order to better understand the present invention, embodiments and / or implementations of the present invention are described with reference to the accompanying drawings, which, as non-limiting examples, respectively represent embodiments or implementations of the device and / or method according to the present invention. The same reference numerals in the accompanying drawings refer to similar elements or elements with similar functions.

[0402] [ Figure 1 ] is a stereoscopic view of a one-piece mold, a cover corresponding to the mold, and a shoe body mounted on a support before the step of placing the shoe body on the edge of the cavity of the mold according to an implementation method of the present invention.

[0403] [ Figure 2 ] is a stereoscopic view of a mold made in three parts, a cover corresponding to the mold and a shoe body mounted on a support before the step of placing the shoe body on the edge of the cavity of the mold according to an implementation method of the present invention.

[0404] [ Figure 3 ] is a stereoscopic view of a one-piece mold, a cover corresponding to the mold, and a portion of the shoe body of a shoe before the step of placing the shoe body portion on the edge of the cavity of the mold according to an implementation method of the present invention.

[0405] [ Figure 4 ] is a stereoscopic view of a portion of the sole connected to the shoe body obtained after implementing the method according to the implementation mode of the present invention, and a shoe obtained after implementing an additional step of assembling one portion of the shoe body with another portion of the shoe body.

[0406] [ Figure 5 ] is a cross-sectional view of the shoe body with its support placed on the mold before the injection step according to an implementation of the invention; in this figure, the cover of the mold is represented before it is placed on the mold.

[0407] [ Figure 6 ] is based on Figure 5 sectional view of the shoe body with its support placed on the mold before the injection step, with the cover forming a pressurized closed space with the mold on either side of the edge of the cavity of the mold, according to an implementation of the invention.

[0408] [ Figure 7 ] is based on Figure 5 and Figure 6 A perspective view of a shoe body with its support placed on a mould before the injection step according to an embodiment of the invention; in this figure, the cover of the mould is represented before it is placed on the mould.

[0409] [ Figure 8 ] is implemented according to Figure 5 , Figure 6 and Figure 7A three-dimensional view of a shoe with a support for the shaft obtained after the method of implementation of the present invention.

[0410] [ Fig. 9 ] is based on the corresponding Figure 5 , Figure 6 , Figure 7 and Figure 8 A perspective view of a shoe shaft support of an implementation of the present invention, wherein a seal is placed on an area of ​​the support corresponding to an abutment area with a surface of a portion of the shoe shaft.

[0411] [ Fig.10 ] is a stereoscopic view of a shoe body having an open surface at the level of the portion of the shoe body intended to be embedded in the foam material of the sole, obtained according to the implementation method of the present invention.

[0412] [ Fig.11 ] is a stereoscopic view of another shoe body having a solid surface at the level of the portion of the shoe body intended to be embedded in the foaming material of the sole, obtained according to the implementation method of the present invention.

[0413] [ Fig.12 ] is a stereoscopic view of another shoe body having a solid surface at the level of the portion of the shoe body intended to be embedded in the foaming material of the sole, obtained according to the implementation method of the present invention.

[0414] [ Fig.13 ] is a stereoscopic view of another shoe body having a perforated or textured surface close to the docking area at the level of the portion of the shoe body intended to be embedded in the foam material of the sole, obtained according to the implementation method of the present invention.

[0415] [ Fig.14 ] is a cross-sectional view of a shoe body with its support placed on a mold including multiple injection channels before the injection step according to an implementation method of the present invention.

[0416] [ Fig.15 ] is a cross-sectional view of a shoe body with its support placed on a mold before the injection step according to an implementation of the present invention, wherein the injection channel passes through the support of the shoe body.

[0417] [ Fig.16 ] is a stereoscopic view of inserts according to an implementation of the invention, which are configured to be placed in the cavity of a mold so as to be associated with the sole obtained after overmolding with foamed material.

[0418] [ Fig.17 ] is a cross-sectional view of a shoe body with its support placed on a mold before the injection step according to an implementation of the invention, wherein an insert is placed in the cavity of the mold so as to combine with the foamed material forming the sole.

[0419] [ Fig.18 ] is a cross-sectional view of a shoe body with its support placed on a mold after the injection step according to an implementation of the invention, wherein the insert is placed in the cavity of the mold and combined with the foamed material forming the sole.

[0420] [ Fig.19 ] is a flow chart of the steps of the method according to the implementation mode of the present invention.

[0421] [ Fig. 20 ] A first example of a shoe obtainable by the method according to the invention is schematically illustrated in a stereoscopic view.

[0422] [ Fig.21 ] indicates that according to Fig. 20 The longitudinal section plane II-II is shown Fig. 20 shoes.

[0423] [ Fig. 22 ] A second example of a shoe obtainable by the method according to the invention is schematically illustrated in a stereoscopic view.

[0424] [ Fig.23 ] A third example of a shoe obtainable by the method according to the invention is schematically illustrated in a stereoscopic view.

[0425] [ Fig.24 ]yes Fig.23 Detailed cross-section of a shoe.

[0426] [ Fig.25 ] is a schematic diagram of a contact surface of an insert, which includes a texture having a tubular or cylindrical pattern.

[0427] [ Fig.26 ] is a schematic diagram of a contact surface of an insert, which includes a texture having a linear pattern.

[0428] [ Fig. 27 ] is a schematic diagram of a contact surface of an insert, which includes a texture having a tubular or cylindrical pattern at the center of the surface and a linear pattern on the contour of the surface.

[0429] [ Fig.28 ] is a stereoscopic view of a mold according to an embodiment.

[0430] [ Fig.29 ] is based on Fig.28 A cross-sectional view of a mold of an embodiment of the present invention.

[0431] [Figure 30] is based on Fig.28 A cross-sectional view of a closing step and an opening step of a mold according to an embodiment of the present invention.

[0432] [Figure 31] is based on Fig.28 A cross-sectional view of a closing step and an opening step of a modification of a mold of an embodiment.

[0433] [ Fig.32 ] is based on Figure 6 The illustrated embodiment of the invention is a cross-sectional view of the shoe body with its support placed on a mold with the cover forming a pressurized closed space with the mold on either side of the edge of the mold's cavity, wherein the mold has channels for pressurizing the complementary cavity.

[0434] [ Fig.33 ] is based on Figure 6 The illustrated embodiment of the invention is a cross-sectional view of a shoe body with its support placed on a mold with a cover forming a pressurized closed space with the mold on either side of the edge of the cavity of the mold, wherein the mold has channels for pressurizing the cavity and the complementary cavity.

[0435] [ Fig.34 ] is based on Figure 6 The illustrated embodiment of the invention is a cross-sectional view of a shoe body with its support placed on a mold with a cover forming a pressurized closed space with the mold on either side of the edge of the cavity of the mold, wherein the mold has a plurality of channels for pressurizing the cavity, which channels match the through holes of an insert placed at the level of the outsole.

[0436] Reference Fig.19 The present invention relates to a method for manufacturing footwear such as Figure 4 or Figure 8 The method 100 of at least a portion of the shoe 10 shown uses the following steps: injecting 107 a supercritical mixture comprising a molten thermoplastic material and a gas in a supercritical state into a cavity 2 of a mold 1 to foam the thermoplastic material in order to obtain satisfactory properties of the foamed material forming a lightweight and shock-absorbing sole 3 of the shoe 10; in particular, Figure 4 or Figure 8 A portion of a shoe 10 is shown which is obtained at the end of the method 100, wherein a portion 9 of the shaft is embedded in the foamed material of the sole 3. To achieve this result, the cavity 2 has at least partially a shape corresponding to the final shape of the sole 3 made of foam to be obtained; this is particularly the case in Figure 3 and Figure 5 For example, the size of the shape of the cavity is in a ratio of between 1:0.98 and 1:1.02 and advantageously 1:1 to the shape of the sole of the footwear.

[0437] In order to foam the molten thermoplastic material to obtain the foamed material for forming the sole 3, the method includes: pressurizing the cavity 2 of the mold 1 before injecting the supercritical mixture into the cavity 2, in particular, pressurizing the cavity 2 of the mold 1 by injecting gas into the cavity 2, and then decompressing the cavity 2 to trigger the expansion and foaming of the thermoplastic mixture in the cavity 2, thereby obtaining the foamed material of the sole 3.

[0438] In order to embed the part 9 of the shoe 10 into the foam material of the sole 3, the part 9 of the shoe is placed in the cavity 2 of the mold in a suitable manner; for this purpose, Figure 3 and Figure 5 As shown, the cavity 2 includes an opening with an edge 5, and an area 6 of the surface 7 of the portion of the shoe body 9 - area 6 is called the docking area 6 - is placed on the edge 5, so that the surface 7 of the portion of the shoe body 9 ensures that the cavity is closed at the level of the contact between the docking area 6 and the edge 5.

[0439] In order to be able to pressurize the cavity 2 of the mold 1, in particular by injecting gas into the cavity 2, it is necessary to ensure that the cavity 2 is sufficiently sealed, in particular sufficiently airtight, at the level of the contact between the abutment area 6 and the edge 5; the thickness of the shoe body is variable, the shoe body may have a complex shape and large dimensional tolerances, which may make it difficult to obtain the desired seal. A particularly advantageous solution may be to use counterpressure in the area of ​​the shoe body 9 that is not immersed in the cavity 2, i.e. in the area of ​​the shoe body that is located on the other side of the closure relative to the cavity 2. In particular, in Figure 5 In the figure, the area of ​​the shoe body 9 immersed in the cavity 2 is located in the lower part of the figure, and the part of the shoe body 9 not immersed in the cavity is located above the line connecting the two points of the docking area 6, and these two areas are Figure 5 and Figure 6 The reference numerals 5 and 6 are provided in the figure.

[0440] Therefore, when the pressurization of cavity 2 is accompanied by the simultaneous generation of a counter-pressure that is advantageously identical to the pressurization pressure of cavity 2 in an area of ​​the shoe body 9 that is not immersed in cavity 2, i.e., in an area of ​​the shoe body that is located on the other side of the closed part relative to cavity 2, this counter-pressure makes it possible to avoid leakage of the pressurized gas in the cavity at the level of the contact between the docking area and the edge.

[0441] In order to generate a counterpressure, before the step of injecting 107 the supercritical mixture into the cavity 2 of the mold 1, the method 100 comprises, for example, a step of placing 103bis a cover 13 on the mold 1 so as to form with the mold 1 a closed volume comprising the cavity 2 and a complementary portion 14 of the cavity 2 in said closed volume, the complementary portion 14 and the cavity 2 being located on both sides of the closed portion of the cavity 2 at the level of the contact between the abutment area 6 and the rim 5. In particular, Figure 6 It is shown that the cover 13 is placed on the mold 1 so as to form a closed volume comprising the cavity 2 on the one hand and the complementary volume 14 on the other hand; the surface 7 of the part of the shaft 9 intended to be embedded in the foamed material of the sole 3 is located inside the cavity 2 of the mold 1, and the surface of another part of the shaft is located inside the complementary part 14 of the closed volume of the cavity 2 formed by the cover 13 placed on the mold 1. Figure 5 In particular, the cover 13 of the mold 1 is shown as being above the mold corresponding thereto, but a person skilled in the art will appreciate that the method also works in the case where the mold 1 is located above the cover 13, such as in Figure 1 As shown in the figure using a stereogram as an example. Figure 5 and Figure 6 As shown, a seal 15 may also be placed at the level of the contact area between the cover 13 and the mould 1 , in order to ensure proper sealing of the closed volume constituted by the cover 13 and the mould 1 .

[0442] The complementary part 14 is pressurized, for example by injecting a gas into said complementary part 14 at a pressure similar to that of the cavity 2, so that sealing defects at the level of the area 6 and the edge 5 do not generate any leakage of pressurized gas between the cavity 2 and the complementary part 14, the pressure in the complementary part 14 acting as a counterpressure relative to the pressure in the cavity 2. Then, as Figure 6 As illustrated, the supercritical mixture may be injected 107 into the cavity 2 , for example via an injection channel 4 passing through the mold 1 .

[0443] The injection of the pressurized gas is carried out via one or more pressurized channels 119, 119bis different from the injection channel 4 of the mixture, such as Fig.32 and 33 In particular, Fig.33 As illustrated, pressurization channel 119 may be used for pressurization of chamber 2 , and complementary pressurization channel 119 bis may be used for pressurization of complementary chamber 14 .

[0444] According to an exemplary implementation, the cover 13 is configured to form a sealed closed volume portion, in particular an airtight closed volume portion, around at least a portion of the shoe body 9 with the mold 1, so as to enable the said back pressure to be generated inside the sealed closed volume portion, in particular by receiving the pressurized gas of the cavity 2 in the sealed volume to generate the said back pressure inside the sealed closed volume portion, so as to avoid the pressurized gas of the cavity from leaking at the level of the contact portion between the docking area and the edge.

[0445] Advantageously, in the method 100 according to the invention, an area of ​​at least a portion of the body 9 located on the other side of the closure relative to the cavity 2 can be depressurized simultaneously with the depressurization of the cavity 2 of the mold 1 to trigger the expansion of the mixture in the cavity 2 and form the sole.

[0446] For example, the pressurization pressure of the chamber is comprised between 3 and 50 bars, preferably comprised between 10 and 30 bars, preferably equal to 15 bars.

[0447] Reference Fig.19 , describes a complete progression of steps of a method 100 for manufacturing a shoe 10 according to an embodiment, which thus comprises the following steps:

[0448] - providing 103 a mould 1 defining an open cavity 2, at least a portion of which has a shape corresponding to the shape of a sole 3 of a shoe 10, the cavity 2 being configured to receive a mixture comprising a molten material and a supercritical fluid via at least one injection channel 4 leading to the cavity 2;

[0449] - placing 105 the rim 5 of the opening of the open cavity 2 in contact with the abutment area 6 of the surface 7 of at least a portion of the shaft 9 of the shoe 10, so that the surface 7 of at least a portion of the shaft 9 ensures the closure of the cavity at the level of the contact between the abutment area 6 and the rim 5;

[0450] - pressurizing 105bis the chamber 2, in particular by injecting a gas into said chamber 2;

[0451] - injecting 107 the mixture into cavity 2;

[0452] - Depressurizing the cavity 2 of the mold 108, in particular by evacuating the gas from the cavity 2, to trigger the expansion of the mixture in the cavity 2 and to form the sole 3 in the foamed material generated by the expansion of the mixture, at least a portion of the surface 7 of at least a portion of the body 9 being embedded in the foamed material of the sole 3.

[0453] According to these arrangements, the method allows obtaining in one single injection step 107 a lightweight and shock-absorbing sole of a shoe 10 connected to a portion of a shaft 9 of the shoe 10 , wherein the sole 3 and the shaft 9 have good resistance to delamination.

[0454] After the pressurization in the chamber 2, the decompression in the chamber 2 allows the mixture to expand and a lightweight and shock-absorbing foamed material of the sole to be obtained. The pressurization pressure in the complementary portion 14 of the closed volume ensures that the chamber 2 is sealed, in particular airtight, at the level of the contact between the abutment area 6 and the rim 5.

[0455] For example, the molten material is an elastomeric thermoplastic polymer.

[0456] According to an exemplary implementation, the thermoplastic polymer is a thermoplastic polyurethane (TPU), or an ether-amide block copolymer (PEBA), or ethylene-vinyl acetate (EVA), or a polyolefin, or an ether-ester block copolymer, or a styrene-based elastomer, or a mixture of these different components.

[0457] For example, the supercritical fluid is nitrogen in a supercritical state, or a carbon-containing gas in a supercritical state, or a mixture of nitrogen and a carbon-containing gas in a supercritical state.

[0458] The density of the sole 3 obtained at the end is comprised between 0.1 g / cm3 and 0.4 g / cm3, preferably between 0.15 g / cm3 and 0.25 g / cm3.

[0459] Furthermore, the portion of the shaft 9 embedded in the foamed material of the sole 3 allows a delamination resistance measured according to the ISO NF EN 1392 standard of greater than 2.5 N / mm to be obtained.

[0460] In particular, the step 105bis of pressurizing the cavity 2 may, for example, comprise the following steps:

[0461] - Place the cover 13 103bis on the mould 1 so as to form, together with the mould 1, a closed volume comprising the cavity 2 and a complementary portion 14 of the cavity 2 in said closed volume, at least a portion of the body 9 being located inside said closed volume, the complementary portion 14 and the cavity 2 being located on either side of the closed portion of the cavity 2 at the level of the contact between the abutment area 6 and the edge 5.

[0462] The pressurization pressure in the complementary portion 14 of the closed volume makes it possible to avoid leakage of the pressurized gas of the cavity 2 at the level of the contact between the abutment area 6 and the rim 5 .

[0463] According to an exemplary implementation, Figure 3 As shown, the portion 9 of the shoe shaft is placed directly on the rim 5 of the opening of the cavity 2 of the mold 1 , without using a support 8 to hold the shoe shaft.

[0464] In particular, the method may comprise the complementary step of assembling the portion of the shaft 9 connected to the sole 3 obtained after the decompression step with another portion 9' of the shaft, this assembly forming the shoe 10, such as Figure 4 For example, the assembly step may include sewing together the other part 9 ′ of the shoe body and the part of the shoe body 9 connected to the sole 3 .

[0465] According to another exemplary implementation, Figure 5 and Figure 6As shown, firstly, a portion 9 of the shaft is placed on the support 8 so as to at least partially cover 102 the outer surface of said support 8, said support 8 having a shape corresponding to the shape of the foot; a portion of the surface 7 of the portion of the shaft 9 intended to be embedded in the foamed material of the sole 3 covers a portion of the outer surface of the support 8 corresponding to the sole of said foot. During the step of placing 105 the portion of the shaft 9 on the edge 5 of the cavity 2, the portion of the shaft 9 is thus placed together with the support 8 on the edge 5 of the cavity 2, so that after placing 103bis the cover 13 on the mould 1, the closed volume also comprises the support 8 and the portion of the shaft 9; the surface 7 of the portion of the shaft 9 intended to be embedded in the foamed material of the sole 3 is located inside the cavity 2 of the mould 1 together with the corresponding portion of the support 8, and the surface of another portion of the shaft 9 is located together with another corresponding portion of the support 8 inside the complementary portion 14 of the cavity 2 in the closed volume formed by the placement of the cover 13 on the mould 1.

[0466] For example, the shoe body 9 may be a complete shoe body, such as Figure 7 As shown in the picture.

[0467] For example, the support 8 can be made of aluminum, steel or plastic.

[0468] Thus, the method 100 allows obtaining in a single injection step 107 a complete shoe 10, including the sole 3 of the shoe connected to the complete body 9 of the shoe 10, such as Figure 8 As shown in the picture.

[0469] The mold 1 is made in one piece, or the mold 1 comprises a plurality of parts 1', 1", 1'', such as Figure 2 As shown, the step of providing 103 the mold 1 comprises the step of assembling different parts 1', 1", 1"' to form the mold 1. For example, the mold made of multiple parts 1', 1", 1"' may include a mold bottom 1"' and two halves 1', 1", of the annular part of the mold, such as Figure 2 The two halves 1 ', 1 "are configured to form an annular member when they are assembled, and the annular member is configured to form a brim 5 of the cavity 2 when it is disposed on the bottom 1 "of the mold 1, and the brim 5 is then configured to receive a portion of the shoe body 9 of the docking area 6. In addition, as Figure 5 and Figure 6 As shown, one or more seals 15 ′ may also be placed at the level of the contact areas between the different parts 1 ′, 1 ″, 1 ′″ of the mould in order to ensure a suitable sealing of the mould 1 .

[0470] according to Figure 28 to Figure 3 1 is an embodiment of the mold shown in FIG. Figure 2The mold is similar to the mold of the present invention, which includes a mold bottom 1 "' and two halves 1', 1" of the annular part of the mold; it should be noted that in Fig.28 In the embodiment, the bottom 1" of the mold is above the two halves 1' and 1" of the annular part, and Figure 2 The bottom of the mold is at the bottom; those skilled in the art will appreciate that the differences in the figures are not significant. Figure 2 As in the example, the two halves 1' and 1" of the annular portion are configured to form an annular member when they are assembled, and the annular member is configured to form an edge 5 of the cavity 2 when it is placed on the mold bottom 1"', and the edge 5 is then configured to receive a docking area 6 of a portion of the shoe body 9.

[0471] according to Fig.28 In a particular embodiment of the present invention, the mold bottom 1'' comprises two different parts, the two different parts being a cover 115 on the one hand and a bell-shaped piece 114 on the other hand, the bell-shaped piece 114 being configured to enclose all parts including the cover 115 and the two halves 1' and 1" of the annular part when the mold is closed; more specifically, the two halves 1', 1" of the annular part of the mold are configured to be mechanically actuated so as to be displaced relative to each other by sliding according to a sliding direction, the first half 1' being displaced in a manner D' according to the sliding direction, and the second half 1" being displaced in a manner D" opposite to the sliding direction, so that the two halves 1', 1" of the annular part are displaced as shown in FIG. Fig.30c or Fig.31c As shown, they are separated from each other, or as Fig.30a or Fig.31a As shown, the two halves are close to each other, which depends on the sliding displacement of the two halves. Fig.30c or Fig.31c The first method shown in the figure is still based on Fig.30a or Fig.31a The second illustrated way is accomplished; thus, when the two halves 1 ′, 1 ″ are actuated toward each other, the annulus of the mold closes, and conversely, when the two halves 1 ′, 1 ″ are actuated away from each other, the annulus of the mold opens.

[0472] Even more specifically, the contact engagement between the bell-shaped piece 114 of the mold bottom 1'' and each of the two halves 1', 1" of the ring is configured so that a sliding displacement of the two halves in such a way that the two halves 1', 1" of the ring are separated actuates a displacement of the bell-shaped piece 114 of the mold bottom 1'' in a direction D''' transverse to the sliding direction, so that the bell-shaped piece 114, which is initially in contact with the closed ring formed by the two halves 1', 1" approaching each other, moves away from the ring when the two halves 1', 1" of the ring move away from each other. Conversely, when the bell-shaped piece 114 of the mold bottom 1'' is pushed to approach the two halves 1', 1" of the ring according to the direction D''' transverse to the sliding direction, as shown in FIG. Fig.30b and Fig.31b As shown, the pressure P exerted by the bell 114 on the two halves 1 ', 1" at the level of the contact joint actuates the sliding displacement of the two halves 1', 1" of the annular element to close the annular element. An elastic member 118 may be provided so that when the bell 114 of the mold bottom 1"' moves away from the annular element in a direction D"' transverse to the sliding direction, the two halves 1', 1" of the annular element move away from each other.

[0473] For this reason, Figure 28 to Figure 3 As shown in FIG. 0, the contact joint between the bell-shaped piece 114 of the mold bottom 1″′ and each of the two halves 1′, 1″ of the ring-shaped piece includes: a first contact plane 114′ between the bell-shaped piece 114 of the mold bottom 1″′ and the first half 1′ of the ring-shaped piece, the first contact plane 114′ being inclined according to a first angle relative to the sliding direction; and a second contact plane 114″ between the bell-shaped piece 114 of the mold bottom 1″′ and the second half 1″ of the ring-shaped piece, the second contact plane 114″ being inclined according to a second angle relative to the sliding direction, the second angle having an opposite sign to the first angle. The first contact plane 114′ is configured to be in sliding contact with a corresponding first contact surface 116′ of the wall of the first half 1′ of the ring-shaped piece, and the second contact plane 114′ is configured to be in sliding contact with a corresponding second contact surface 116′ of the wall of the second half 1″ of the ring-shaped piece.

[0474] according to Figure 28 to Figure 3 31 , the contact engagement between the bell-shaped piece 114 of the mold bottom 1″′ and each of the two halves 1′, 1″ of the ring comprises at least one guide 117′, 117″ configured to accompany the sliding displacement of the two parts 1′ and 1″ of the ring when the bell-shaped piece 114 of the mold bottom 1″′ is displaced in a direction transverse to the sliding direction.

[0475] According to these arrangements, the mould can be actuated alternately so as to be closed by displacement of the mould bottom 1'" in a direction D'"' transverse to the sliding direction, and to be opened by sliding displacement of the two halves 1', 1" so as to open the annular member. The displacement of the mould bottom 1'"' for closing can be obtained, for example, by pressure exerted on the mould bottom 1'"' towards the annular member; the sliding displacement of the two halves 1', 1" for opening can be obtained, for example, by elastic means.

[0476] In order to be able to carry out the injection step 107 , the cavity 2 of the mold is configured to receive a mixture comprising molten material and a supercritical fluid via at least one injection channel 4 , 4 ′, 4 ″, 4 ′″ opening into the cavity 2 .

[0477] For example, the mold may include an injection channel 4 leading to the cavity 2, such as Figure 6 According to another example, the injection channel 4 leading to the cavity 2 can pass through the support 8 of the shoe body 9, such as Fig.15 As shown in the picture.

[0478] According to yet another example, the chamber 2 is configured to receive the mixture via at least two injection channels 4', 4", 4'" leading to the chamber 2. Fig.14 As shown, three injection channels 4 ′, 4 ″, 4 ′″ are indicated as an example. The method 100 thus allows obtaining a sole 3 of a shoe 10 joined to a portion of a shaft 9 of the shoe 10 by filling the cavity of the mold more quickly and more evenly.

[0479] In order to improve the firmness of the connection between the shoe body 9 and the sole 3, in particular a supplementary step of gluing 106 a portion of the surface 7 of the portion of the shoe body 9 can be provided, the gluing step 106 being performed before the injection step 107. Alternatively, or in combination with the gluing step 106, the portion of the surface 7 of the portion of the shoe body 9 can include a hot-melt wire configured to melt at the injection temperature of the mixture. Thus, the delamination resistance of the sole and the shoe body is enhanced.

[0480] According to an exemplary implementation of the method, the portion of the surface 7 of the portion of the body 9 intended to be embedded in the foamed material of the sole 3 is solid, such as Fig.11 To enhance the delamination resistance, it can also be provided that part of the surface 7 of the part of the shoe body 9 intended to be embedded in the foam material of the sole 3 is open-celled, i.e. part of the surface 7 comprises Fig.12 or Figure 3 The holes shown in the figure, for example, have three holes that pass through the portion of the surface 7 of the shoe body 9; it can also be provided that Fig.10 As shown, a portion of the surface 7 is at least partially open, for example wherein the portion of the surface 7 is almost completely open except over a portion of the surface 7 near the docking area 6. Figure 3 In the case shown, in which three holes pass through the portion of the surface 7 of the portion of the shaft 9 and in which the portion of the shaft 9 intended to be embedded in the foamed material of the sole 3 is not placed on the support 8, the cover 13 should ensure that the holes or openings of the portion of the surface 7 of the portion of the shaft 9 are closed during the step 105bis of pressurizing the cavity 2 and during the injection 107 of the mixture into the cavity. To this end, for example Figure 3 As illustrated, the cover 13 can bear, for example with a substantially flat and planar inner surface, on said portion of the surface 7 of the portion of the shaft 9 so as to close a hole or opening present on this portion of the surface 7 of the portion of the shaft 9 .

[0481] Yet another way to enhance the delamination resistance includes providing that part of the surface 7 of the part of the shoe body 9 intended to be embedded in the foam material of the sole 3 is textured or perforated at the contact portion or close portion with the docking area 6, such as Fig.13 As shown in the picture.

[0482] To improve the wear resistance of the sole 3 or the rigidity of the sole 3 , the method 100 may comprise the complementary steps of providing 104 and positioning 104bis one or more inserts 12 , 12 ′, 12 ″ configured to be positioned in the cavity 2 of the mold 1 .

[0483] For example, Fig.16 The inserts 12, 12' shown in FIG. 1 are positioned to fit at the level of the outer surface of the sole, as shown in FIG. Fig.17 Before the step of injecting the mixture 107 into the cavity 2 and Fig.18 According to another example, one or more inserts 12" may be positioned to be embedded inside the sole 3, such as in Fig.17 Before the step of injecting the mixture 107 into the cavity 2 and Fig.18 As shown after the step of injecting 107 the mixture into cavity 2.

[0484] According to these settings, the wear resistance of the sole is enhanced or the rigidity of the sole is improved, depending on: for example, in the case of inserts 12, 12' made of rubber or thermoplastic material, depending on whether the inserts 12, 12' are inserted toward the outer part of the sole 3, or for example, in the case of inserts 12" made of carbon plate or thermoplastic material, depending on whether one or more inserts 12" are buried inside the sole 3.

[0485] According to one implementation, the insert 12 ″ positioned to be inserted at the level of the outer surface of the sole 3 comprises one or more through holes 120, such as Fig.34As shown, the through-holes 120 mate with one or more pressurized passages 119 so that pressurized gas may pass through the insert.

[0486] According to an exemplary implementation, the contact surface 112 between the insert and the sole has a specific geometry to enhance the adhesion between the insert and the sole by mechanical hooking without requiring a gluing step or a surface preparation step. For example, the specific geometry of the insert includes a texture of the contact surface, such as Fig.25 , Fig.26 or Fig. 27 As shown in the picture.

[0487] For example, the texture includes a plurality of patterns formed on the contact surface 112, and the plurality of patterns are distributed on the surface according to a determined density so that on a portion of the contact surface, the plurality of patterns occupy a portion of the portion of the contact surface, the portion being between 1% and 15%, advantageously 6%, of the portion of the contact surface.

[0488] Preferably, the pattern is evenly distributed on the contact surface according to a determined density. The distribution of the pattern can also be densified in some areas of the contact surface where the load is stronger. In other words, the distribution density of the pattern on an area of ​​the contact surface can depend on the load to which the area under consideration is subjected.

[0489] The pattern has a height, measured according to a height direction transverse to the contact surface, comprised between 1 mm and 10 mm, preferably equal to 1.6 mm.

[0490] The pattern has a thickness measured according to a direction transverse to the height direction; said thickness is comprised between 1 mm and 2 mm, preferably equal to 1.6 mm. Fig.25 The tubular or cylindrical shape shown in the figure, or Fig.26 The linear thickness shown in the figure is the diameter and the width respectively.

[0491] like Fig. 27 As illustrated, the texture may include a tubular or cylindrical pattern at the center of the contact surface and a linear pattern on the contour 113 of the contact surface in order to avoid delamination initiation points.

[0492] The linear pattern on the profile may be a burr obtained on the mating plane of the closing part of the mold for overmolding the insert, which allows avoiding the removal of said burr.

[0493] According to an aspect, the invention also relates to a footwear, for example a shoe 10 obtained by a method 100 according to one of the aforementioned implementations.

[0494] According to another aspect, the invention also relates to a device comprising a mould 1 and a possible cover 13 , and a possible support 8 , and configured to implement a method 100 according to one of the aforementioned implementations.

[0495] According to one embodiment, the device includes a mold 1, which defines an open cavity 2, and the shape of at least a portion of the cavity 2 corresponds to the shape of the sole 3 of the shoe 10. The cavity 2 is configured to receive a mixture containing a molten material and a supercritical fluid via at least one injection channel 4, 4', 4", 4'" leading to the cavity 2, and the edge 5 of the opening of the open cavity 2 is configured to be placed in contact with the docking area 6 of the surface 7 of at least a portion of the shoe body 9 of the shoe 10, so that the surface 7 of at least a portion of the shoe body 9 ensures that the cavity is closed at the level of the contact portion between the docking area 6 and the edge 5, so that the device is therefore configured to implement a manufacturing method 100 according to one of the aforementioned implementations.

[0496] According to a supplementary embodiment, the device also includes a cover 13, which is configured to be placed on the mold 1 to form a closed volume portion together with the mold, which closed volume portion includes a cavity 2 and a complementary portion 14 of the cavity in the closed volume portion, at least a portion of the shoe body 9 of the shoe is located inside the closed volume portion, the complementary portion 14 and the cavity 2 are located on both sides of the closed portion of the cavity 2 at the level of the contact portion between the docking area 6 and the edge 5, and the device is therefore configured to implement a method 100 according to one of the aforementioned implementations.

[0497] According to another supplementary embodiment, the device also includes a support 8, which has a shape corresponding to the shape of the foot, and the outer surface of the support 8 is configured to be covered by at least a portion of the shoe body 9 of the shoe, and at least a portion of the surface 7 of at least a portion of the shoe body 9 covers a portion of the outer surface of the support corresponding to the sole of the foot.

[0498] According to one embodiment, Fig. 20 The shoe 10 shown includes a sole obtained by the aforementioned method 100; most of the mass of the sole is formed by the main material of the sole; in other words, the foamed material produced due to the expansion of the mixture implemented in the method 100 contains the main material of the sole; the shoe 10 also includes a body 30, most of the mass of the body 30 is formed by the main material of the body.

[0499] The main material of the sole can be selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0500] For example, the main material of the sole is a styrenic thermoplastic elastomer, in particular a styrenic thermoplastic elastomer selected from SEBS (possibly grafted), SBS, SBC, SIS and SEPS, in this specific example SEBS.

[0501] Advantageously, the sole main material is chosen from polyesters, thermoplastic polyurethanes (TPU), polyolefins, and block copolymers composed of rigid polyamide blocks and soft polyether blocks (and in particular the copolymers produced by the company Arkema under the name commercially available complexes).

[0502] The sole 20 may include a first sole auxiliary material, in particular polyolefin, more specifically, polypropylene, and the foamed material generated due to the expansion of the mixture includes the sole main material and the first sole auxiliary material.

[0503] The main material of the sole can be selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; and for example, polyolefins, in particular polyethylene or polypropylene, in this specific example, polypropylene.

[0504] Advantageously, the main material of the shoe body is selected from polyester, thermoplastic polyurethane (TPU), polyolefin, and block copolymers composed of rigid polyamide blocks and soft polyether blocks (and in particular the copolymers produced by Arkema under the name commercial compounds).

[0505] Advantageously, the body 30 comprises a lace 35 made of polypropylene, in particular a lace comprising a braided wire made of polypropylene.

[0506] Advantageously, the body 30 comprises a part 40 folded on itself and comprising, on its two faces, a foam laminated with a textile, the textile being in particular selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters. Preferably, the textile is made of polypropylene and / or polyethylene, in particular a fabric or knitted fabric with a thread made of polypropylene and / or a thread made of polyethylene, preferably a thread made of polypropylene. The foam may be selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; for example, a foam made of polyethylene.

[0507] The shoe body 30 may also include a part 50 made of foam, preferably polyethylene, which improves the accommodation of the rear foot and is contained in the folded portion of the outer part 40. The foam may be selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

[0508] The edges of the part 40 folded over on itself can be fixed according to any technique known to a person skilled in the art, for example using one or more sutures, preferably made of one or more threads made of a material selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters, and in particular, one or more threads are made of polyolefins, in particular polypropylene.

[0509] Preferably, shaft member 40 is disposed in rearfoot region 12a and partially in medial region 18 and lateral region 16 of the foot.

[0510] Advantageously, the body 30 further comprises a body part 42, which is arranged in the forefoot region 14a and partially in the lateral region 16 and the medial region 18 of the foot. The body part 42 may comprise a knitted fabric or a fabric. The body 30 may comprise other body parts. Preferably, all body elements, including parts 40 and 42, are three-dimensionally formed using a first mounting member. Preferably, the first mounting member comprises a material selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; for example, comprising a lining made of polyolefins, in particular polypropylene. Advantageously, the first mounting member is hot-melt treated on all or part of its surface to improve its tear resistance.

[0511] Preferably, the shoe body 30, as well as any shoe body according to the invention, comprises a rearfoot region 12a, a forefoot region 14a, a lateral region 16, a medial region 18 and an instep region 19 comprising a raised portion.

[0512] The forming of component 40, possibly together with other shoe body components, on a preform in the shape of a foot (the so-called lasting operation) is carried out, for example, using beads comprising a material selected from the group consisting of: polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; and in particular, beads made of polypropylene (e.g., a circular braid not shown) tension the lower edge of textile component 40 and the lower edges of possible other shoe body components.

[0513] The shoe 10 may also include a lacing loop 55 made from the molded main material of the shaft, such as polypropylene.

[0514] The shoe 10 may also include a lining made of polypropylene or polyethylene that is fully or partially coated with a coating made of poly(ethylene vinyl acetate) (EVA) that, when the EVA is activated by heat, allows the lacing loop 55 to be secured to the external textile component 50 by gluing.

[0515] The shoe 10 may include textile strips 60 and 61 made of polyethylene and / or polypropylene, in particular woven textile strips 60 and 61, in particular, the textile strips 60 and 61 include threads made of polypropylene and / or threads made of polyethylene, in particular threads made of polypropylene. Each textile strip 60 and 61 includes a lacing area 62, which forms a sheath for the passage of lacing.

[0516] Preferably, each of the textile strips 60 and 61 has a width l1 and l2 greater than or equal to 5 mm, in particular greater than or equal to 10 mm, more particularly greater than or equal to 15 mm.

[0517] Preferably, textile strip 60 includes a first end 64 and a second end 66 secured to component 40. First end 64 and second end 66 are spaced apart from one another such that textile strip 60 forms an inverted V-shape.

[0518] Preferably, textile strip 61 includes a first end 65 and a second end 67 that substantially overlap and are secured to component 40 .

[0519] Preferably, the lacing area 62 comprises a portion of the textile strip 60 or 61 folded over on itself and thus forming a sheath for the passage of the lacing.

[0520] The textile strips 60 and 61 also form outer reinforcement areas.

[0521] The shoe body 30 may include a rear support 70 secured in the rear foot region 14 of the member 40. Preferably, the rear support 70 is a molded part made of polypropylene.

[0522] The shoe body 30 may further include a front stiff tip 90, which is made of a molded material, such as a main material of the shoe body, preferably polyolefin, olefinic thermoplastic elastomer or vulcanized thermoplastic elastomer or styrenic thermoplastic elastomer, such as SEBS.

[0523] Regarding this specific embodiment, the main material of the shoe body of the shoe body 30 is polyolefin, especially polypropylene. In fact, the main material of the shoe body of the shoe body includes a basic thermoplastic material, whose mass fraction is dominant, that is, the largest compared with the mass fraction of other materials.

[0524] The shoe body 30 also includes a first shoe body auxiliary material that is different from the shoe body main material, which is polyethylene in this specific example.

[0525] In this specific example, the mass fraction of polyolefin in the shoe body is within the range of 55.17%, in particular, the mass fraction of polypropylene (main material of the shoe body) in the shoe body is within the range of 44.83%, and the mass fraction of polyethylene (first auxiliary material of the shoe body) is within the range of 10.34%. The mass fraction of olefin thermoplastic elastomer (TPO) in the shoe body is within the range of 27.59% (second auxiliary material of the shoe body), and finally, the mass fraction of glue is within the range of 17.24%.

[0526] The ratio of the mass of the main material 30 of the shoe body, in this specific example, polypropylene, and the mass of the auxiliary materials 30 of the shoe body, such as PE and TPO, relative to the total mass of the shoe body 30 is greater than or equal to 80%, in particular, in the case where the glue used is EVA, the ratio is in the range of 82% or more. Preferably, the ratio tends to 100%. When the material is recycled, there may be one or more contaminant materials, the mass fraction of which is still low, for example, in the range of 5% or less.

[0527] The sole 20 can be manufactured while it is being fixed to the shoe body. In this case, the sole is injected directly onto the shoe body, i.e. onto the lower portion of the shoe body 30. Advantageously, the main material of the shoe body 30 is compatible with the main material of the sole or is made of the same basic thermoplastic material as the main material of the sole, so that the sole adheres to the shoe body, preferably without using any external bonding agent.

[0528] Preferably, the mass fraction of the main sole material in the sole, in particular SEBS, is in the range of 65%. The mass fraction of polyolefin in the sole, in particular polypropylene mixed with SEBS, is in the range of 20%. The mass fraction of filler (e.g. calcium carbonate) in the sole is in the range of 5%. Finally, the mass fraction of plasticizer in the sole is in the range of 10%.

[0529] The shoe 10 essentially comprises a material selected from polyolefins, styrenic thermoplastic elastomers, olefinic thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; and in particular polypropylene, polyethylene, TPO and SEBS, SEBS being predominant in the sole and polypropylene being predominant in the body. Thus, the recycling of the shoe is facilitated, since there is no need to separate the different components. The shoe is shredded and the shreds are then converted into thermoplastic granules, which can be converted by conventional thermoplastic forming techniques. Thus, the thermoplastic granules contain a thermoplastic mixture containing materials selected from the present invention, which are compatible with each other during their thermal conversion and have good adhesion to each other.

[0530] Thus, the thermoplastic granules can be advantageously extruded and injected to produce all or part of a shoe outsole or midsole.

[0531] Thermoplastic granules may also be converted to produce front hard tips or rear supports or lacing loops, parts made of coalesced or uncoalesced foam or foam beads.

[0532] Fig. 22 A second example of a shoe 200 mentioned but not limiting according to the present invention is shown, which comprises a sole 220 and a body 230. The body main material can be selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters; in this specific example, polyolefins, especially polypropylene, are preferred.

[0533] The shoe body 230 includes a textile portion 240 with an outer surface 245 forming a foot receiving area, and four strips 250, 251, 252 made of olefinic thermoplastic elastomer fixed to the outer surface 245 and the sole 220. A portion of each of these strips is arranged between the sole 220 and the outer surface 245 of the textile portion 240.

[0534] The strap 250 is disposed over the front edge 205 of the shoe 200 and extends from the lateral side to the medial side of the shoe 200. The strap 251 is disposed over the rear edge 206 of the shoe 200 and extends from the lateral side to the medial side of the shoe 200. The strap 252 is partially disposed along the medial side 207 of the shoe 200 and extends between the front strap 250 and the rear strap 251. Figure 4 A strip, not visible in the photograph, is arranged partially along the medial side of the shoe 200 and extends between the front strip 250 and the rear strip 251 .

[0535] Advantageously, textile portion 240 forming the foot-receiving area comprises a textile component including a thread comprising a main material of the shaft, in particular a polyolefin or an olefinic thermoplastic elastomer.

[0536] Preferably, the four strips including the strips 250 to 252 are strips of artificial leather.

[0537] Advantageously, each strip comprises a polymer layer based on an olefinic thermoplastic elastomer, which is arranged on a textile base. Thus, the strips are advantageously compatible with the polymer materials of the textile portion 240 and the sole 220, so that they can be glued to the textile portion 240 and the sole 220 by at least partially melting their structure. The strips, including the strips 250 to 252, are glued at the outer surface 245 of the textile portion 240, so that the textile base is oriented opposite to the outer surface 245.

[0538] Depending on the intended function on the shoe, the strips, such as one of the strips 250 to 252, may have a configuration different from that of the strips. Typically, the strips may be artificial leather type parts having a shape determined according to their final function. In this particular example, the outer surface of the strips 250 to 252 is substantially smooth, but they may include one or more relief patterns embossed onto the polymer layer, for example by calendaring.

[0539] Fig.23 A third example of a shoe 80 according to the present invention is shown, which is mentioned but not limited. The shoe 80 comprises a sole comprising a midsole 21 and an outer sole 22, the majority of the mass of the sole being formed by the sole main material, and the majority of the mass of the body 36 being formed by the body main material.

[0540] The main material of the sole is polyester.

[0541] The main material of the midsole 21 can be a thermoplastic copolyester of the TPEE (thermoplastic polyetherester elastomer) or TCP-ET (thermoplastic copolyester elastomer) type. These materials are block copolymers containing rigid segments of polyester and soft segments of polyether and / or polyester.

[0542] The main material of the midsole 21 can be a thermoplastic copolyester of the TPC-EE ("TPC with soft segments with ether bonds and ester bonds"), TPC-ES ("TPC with soft segments with ester bonds") or TPC-ET ("TPC with soft segments with ether bonds") type - the so-called COPE ("copolyester thermoplastic elastomer") or TPC ("thermoplastic copolyester").

[0543] As mentioned above, the midsole 21 can be obtained by injecting a supercritical fluid.

[0544] Advantageously, the midsole 21 is co-moulded with the outsole 22 .

[0545] The outsole 22 may also be glued together with the midsole 21 .

[0546] The midsole 21 can be injected onto the shoe body, either with or without the outsole 22. Alternatively, the sole and the shoe body 36 can be manufactured separately and assembled later.

[0547] The main material of the outsole 22 may be selected from TPV type thermoplastic elastomers.

[0548] Thermoplastic vulcanizates (TPVs) belong to the class of thermoplastic elastomers and have the properties of thermoplastics and elastomers to some extent. Typically, these are systems formed by two phases, a soft, elastomeric phase (EPDM) and a hard, thermoplastic phase (PP).

[0549] Preferably, a thermoplastic vulcanizate is used, which comprises a thermoplastic phase made of a thermoplastic copolymer and particularly TPEE. The soft phase can be made of poly(styrene / butadiene) also known as SBR rubber (standing for styrene-butadiene rubber) as a copolymer of styrene and 1,3-butadiene. The thermoplastic phase can be a thermoplastic phase made of a block copolymer, and the block copolymer comprises a rigid segment of a polyester and a soft segment of a polyether and / or a polyester.

[0550] Alternatively, the outsole 22 may comprise rubber. In this case, the outsole 22 is advantageously fastened to the midsole 21 using a specific adhesive primer that allows the outsole 22 to be removed to prepare the shoe for recycling.

[0551] The shoe 80 may also include a first insole made of TPEE or TPC-ET, which may be obtained by injection foaming of a supercritical fluid as described above.

[0552] Preferably, the main material of the shoe body is also polyester.

[0553] Advantageously, the body 36 comprises a lace 23 made of polyethylene terephthalate (PET).

[0554] Shoe 80 may include lace loops 24 made from polyethylene terephthalate (PET).

[0555] The shank 36 may comprise a lower portion 25 which is a protective layer glued to the shank. Advantageously, the lower layer 25 is made of a thermoplastic copolyester, and in particular of the TPEE or TPC-ET type.

[0556] The shoe body 36 may also include an upper portion 26 that includes polyethylene terephthalate (PET) and / or a thermoplastic copolyester, such as TPEE.

[0557] Fig.21An embodiment of the upper part 26 is shown. The upper part 26 may include an upper layer 26a made of PET, such as a two-dimensional woven PET mesh, and a lower layer 26b also made of PET, such as a three-dimensional woven PET mesh. The central layer 26c is made of a thermoplastic copolymer, such as TPEE, and in particular non-woven TPEE, and is surrounded by adhesive intermediate layers 26d, 26e at the top and bottom. The upper intermediate layer 26d is arranged between the central layer 26c and the upper layer 26a, and the lower intermediate layer 26e is arranged between the central layer 26c and the lower layer 26b.

[0558] At the rear of the shoe 80, between the shaft 36 and the midsole 21, a reinforcing ring 27 is arranged, which is an injected rigid insert, positioned in the mould and assembled or not with the shaft. Advantageously, the ring 27 is made of a thermoplastic copolyester, and in particular of the TPEE or TPC-ET type. The ring 27 can be glued between the shaft 30 and the midsole 21.

[0559] The shoe body 36 may further include an upper reinforcement 51 made of foam to improve the conformity to the rear foot. The upper reinforcement 51 may be made of PET, and in particular, non-woven PET.

[0560] The upper 36 includes a rearfoot region 28 , a forefoot region 29 , a lateral region 31 , a medial region 32 , and an instep region 33 including a tab 34 .

[0561] Advantageously, the tabs 34 are made of PET, and in particular of non-woven PET.

[0562] The shoe body may include threads made of polyester, and in particular TPEE, which imparts flexibility to the shoe.

[0563] Preferably, outsole 22 is manufactured while it is fixed to the shoe body. In this case, outsole is preferably injected directly onto the shoe body, i.e., injected onto the lower part of the shoe body 36, by the process described previously.

[0564] Advantageously, the primary material of the shaft 36 is compatible with or made of the same basic thermoplastic material as the primary material of the sole, allowing the outsole to be adhered to the shaft, preferably without the use of any external bonding agent.

[0565] Alternatively, the shoe 80 can be manufactured according to a Strobel-type conventional assembly. The outsole 22 can be fixed to the shaft 36 by gluing. Thus, the outsole 22 and the shaft 36 are manufactured separately and then fixed.

[0566] The adhesive that may be used to assemble the different parts of the shoe 80, in particular for assembling the upper to the sole, may be a polyurethane or polyester based adhesive.

[0567] The table below summarizes the mechanical properties measured on examples of polymer mixtures obtained from the recycling of shoes obtained by the method according to the invention.

[0568]

[0569] The mixture of Example 1 originates from the recycling of shoes that are free of contaminant materials within the meaning of this document. Thus, the shoes that are recycled to obtain the mixture of Example 1 contain 50 g of polypropylene (PP), 12 g of polyethylene (PE), 250 g of styrene-ethylene-butadiene-styrene (SEBS) and 25 g of vulcanized thermoplastic elastomer (TPV) - in this specific example EPDM (ethylene-propylene-diene) / PP (polypropylene).

[0570] The shoes recycled to obtain the mixture of Example 2 were identical to the shoes of Example 1, except that the soles of the recycled shoes in this Example 2 contained 2% by mass of thermoplastic polyurethane.

[0571] The recycled shoes of the mixture of Example 3 were the same as the shoes of Example 2, except that the mass fraction of the thermoplastic polyurethane in the shoes was 5%.

[0572] The recycled shoes of the mixture of Example 4 were the same as the shoes of Example 2, except that the mass fraction of the thermoplastic polyurethane in the shoes was 10%.

[0573] The shoe of the mixture of Example 5 is identical to the shoe of Example 1 except that the shoe of Example 5 contains 2 weight percent of a thermoplastic polyamide derived from a hook-and-loop attachment system made of polyamide from recycled shoes.

[0574] It can be noted that the presence of polyurethane and polyamide - up to 10% by weight of the shoe - allows to increase the yield strength, but also surprisingly increases the abrasion resistance. Above 10% by weight of polyurethane, a decrease in abrasion resistance is observed.

[0575] Furthermore, the recycled mixture obtained can be completely thermally transformed (extrusion-injection or blow molding, or by hot pressing, extrusion molding, etc.) and enables the realization of many new applications thereof while maintaining the final properties.

Claims

1. A method (100) for manufacturing at least a portion of a footwear (10), the method (100) comprising the following steps: - providing (103) a mould (1), said mould (1) defining an open cavity (2), said cavity (2) having at least a portion thereof having a shape corresponding to the shape of a sole (3) of said footwear (10), said cavity (2) being configured to receive a mixture comprising a molten material and a supercritical fluid via at least one injection channel (4, 4', 4", 4'") leading to said cavity (2); - placing (105) the edge (5) of the opening of the open cavity (2) in contact with the abutment area (6) of the surface (7) of at least a portion of the shaft (9) of the footwear (10), so that the surface (7) of at least a portion of the shaft (9) ensures the closure of the cavity at the level of the contact between the abutment area (6) and the edge (5); - pressurizing (105bis) the chamber (2); - injecting (107) the mixture into the cavity (2); - Decompressing the cavity (2) of the mold (108) to trigger expansion of the mixture in the cavity (2) and forming the sole (3) in a foamed material generated by the expansion of the mixture, at least a portion of the surface (7) of at least a portion (9) of the shoe body being embedded in the foamed material of the sole (3).

2. The method (100) according to claim 1, before the step of pressurizing (105bis) the chamber (2), the method (100) further comprising the following steps: - Placing (103bis) the cover (13) on the mould (1) so that the cover (13) together with the mould (1) forms a closed volume, comprising the cavity (2) and a complementary portion (14) of the cavity (2) in the closed volume, at least a portion of the body (9) being located inside the closed volume, the complementary portion (14) and the cavity (2) being located on both sides of the closed portion of the cavity (2) at the level of the contact portion of the docking area (6) with the edge (5).

3. The method (100) according to claim 2, further comprising the following steps before the step of placing (105) the edge (5) of the opening of the open cavity (2) in contact with the abutment area (6) of the surface (7) of at least a portion of the shoe body (9): - providing (101) a support (8) having a shape corresponding to the shape of the foot, - at least partially covering (102) the outer surface of the support (8) with at least a portion of the shaft (9) of the footwear (10), at least a portion of the surface (7) of at least a portion of the shaft (9) covering a portion of the outer surface of the support (8) corresponding to the sole of the foot, Such that, after placing (103bis) the cover (13) on the mould (1), the closed volume also comprises the support (8) with at least a part of the shoe body (9).

4. The method (100) according to one of claims 1 to 3, wherein: The chamber (2) is configured to receive the mixture via at least two injection channels (4', 4", 4'") leading to the chamber (2).

5. The method (100) according to one of claims 1 to 4, wherein: The mold (1) comprises the at least one injection channel (4).

6. The method (100) according to one of claims 3 to 5, wherein: The support (8) comprises the at least one injection channel (4).

7. The method (100) according to one of claims 1 to 6, comprising a step of gluing (106) at least a portion of the surface (7) of at least a portion of the body (9), the gluing step (106) being performed before the injection step (107).

8. The method (100) according to one of claims 1 to 7, wherein: At least a portion of the surface (7) of at least a portion of the shoe body (9) includes a hot-melt wire material configured to melt at the injection temperature of the mixture.

9. The method (100) according to one of claims 1 to 8, further comprising the steps of: - providing (104) an insert (12, 12'), said insert (12, 12') being configured to be positioned in said cavity of said mould; - Positioning (104bis) the insert (12, 12') in the cavity (2) of the mould.

10. The method (100) according to one of claims 1 to 9, wherein: At least a portion of the surface (7) of at least a portion of the shoe body (9) is at least partially perforated or open.

11. The method (100) according to one of claims 1 to 10, wherein: At least a portion of the surface (7) of at least a portion of the shoe body (9) is textured or perforated at the contact portion with the docking area (6).

12. The method (100) according to one of claims 1 to 11, wherein: The molten material is an elastomeric thermoplastic polymer.

13. The method (100) according to one of claims 1 to 12, wherein: The supercritical fluid is nitrogen in a supercritical state, or a carbon-containing gas in a supercritical state, or a mixture of nitrogen and carbon-containing gas in a supercritical state.

14. The method (100) according to one of claims 1 to 13, characterized in that: - the majority of the mass of the shoe body (9, 30, 36, 230) is made of a main shoe body material and possibly one or more auxiliary shoe body materials; - the majority of the sole (3, 20, 21, 22, 220) in terms of mass is made of a main sole material and possibly one or more auxiliary sole materials, the foamed material produced due to the expansion of the mixture containing the main sole material and the auxiliary sole materials; - the main material of the shoe body and the possible auxiliary material of the shoe body are selected from the following materials: polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), polyamides, ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters, and - The sole main material and possibly the sole auxiliary material have the same chemical group as the upper main material and possibly the upper auxiliary material, or the sole main material and possibly the sole auxiliary material are chemically compatible with the upper main material and possibly the upper auxiliary material.

15. The method according to claim 14, characterized in that The sole main material and possibly the sole auxiliary material are the same as the shaft main material and possibly the same as the shaft auxiliary material.

16. The method according to claim 14 or 15, characterized in that The main material of the shoe body is selected from polyester, thermoplastic polyurethane (TPU), polyolefin, and a block copolymer composed of a rigid polyamide block and a flexible polyether block.

17. The method according to one of claims 14 to 16, characterized in that The main material of the sole is selected from polyester, thermoplastic polyurethane (TPU), polyolefin, and a block copolymer consisting of a rigid polyamide block and a flexible polyether block.

18. The method according to one of claims 14 to 17, characterized in that The shoe body includes a wire comprising a material selected from the following: polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

19. The method according to one of claims 14 to 18, characterized in that The shoe body includes a textile component, and the textile component includes a thread material comprising a main material of the shoe body.

20. The method according to one of claims 14 to 19, characterized in that The shoe body comprises a textile portion with an outer face forming a foot receiving area, and at least one portion, in particular a strip (250, 251, 252), comprising an olefinic thermoplastic elastomer, the strip (250, 251, 252) being fixed to the outer face of the textile portion and to the sole.

21. The method (100) according to one of claims 14 to 20, characterized in that The shoe body comprises a textile portion with an outer face forming a foot receiving area, and at least one portion, in particular a strip (250, 251, 252), comprising an olefinic thermoplastic elastomer, the strip (250, 251, 252) being fixed to the outer face of the textile portion and to the sole.

22. The method (100) according to one of claims 14 to 21, characterized in that The sole includes a porous component and / or foam beads, and the porous component and / or the foam beads contain a material selected from the following: polyolefin, styrene-based thermoplastic elastomer, olefin-based thermoplastic elastomer, thermoplastic polyurethane (TPU), ether-amide block copolymer (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymer, styrene-based elastomer and polyester.

23. The method (100) according to one of claims 14 to 22, characterized in that The shoe body (30) includes a front hard tip (90) containing the main material of the shoe body or the auxiliary material of the shoe body, and / or a rear support member (70) containing the main material of the shoe body or the auxiliary material of the shoe body.

24. The method (100) according to one of claims 14 to 23, characterized in that The shoe body (30) comprises at least one loop for passing at least one lacing element, the at least one passing loop comprising a textile strip, the textile strip comprising at least one thread comprising a main material of the shoe body, in particular, the main material of the shoe body is polyolefin.

25. The method (100) according to one of claims 14 to 24, characterized in that The shoe body (30) comprises a component made of foam containing a main material of the shoe body, in particular, the main material of the shoe body is polyolefin.

26. The method (100) according to one of claims 14 to 25, characterized in that The shoe body (30; 130) and / or the sole (20; 120) comprises / each comprises recycled material of a sole of another shoe and / or the shoe body, and / or a sole of a boot and / or the shoe body.

27. The method (100) according to one of claims 14 to 26, characterized in that The ratio of the mass of the main material of the shoe body and the possible mass of the auxiliary material of the shoe body to the total mass of the shoe body is greater than or equal to 40%.

28. The method (100) according to one of claims 14 to 27, characterized in that The ratio of the mass of the main material of the shoe body and the mass of the auxiliary material of the shoe body to the total mass of the shoe body is greater than or equal to 50%.

29. The method (100) according to one of claims 14 to 28, characterized in that The ratio of the mass of the main sole material and possibly the mass of the auxiliary sole material to the total mass of the sole is greater than or equal to 40%.

30. The method (100) according to one of claims 14 to 29, characterized in that The ratio of the mass of the sole main material and the mass of the sole auxiliary material to the total mass of the sole is greater than or equal to 50%.

31. The method (100) according to one of claims 14 to 30, characterized in that The footwear (10) contains up to 10% by weight of one or more contaminant materials, in particular up to 10% by weight of one or more thermoplastic contaminant materials, and / or up to 5% by weight of one or more thermosetting contaminant materials, wherein the one or more contaminant materials are not selected from polyolefins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vulcanized thermoplastic elastomers, thermoplastic polyurethanes (TPU), ether-amide block copolymers (PEBA), ethylene-vinyl acetate (EVA), ether-ester block copolymers, styrene-based elastomers and polyesters.

32. The method (100) according to one of claims 14 to 31, characterized in that The sole main material and possibly the sole auxiliary material are at least partially derived from the recycling of at least one other footwear (10).

33. The method (100) according to one of claims 14 to 32, characterized in that The method (100) further comprises collecting the footwear (10), and the method (100) comprises converting the footwear (10) into thermoplastic granules.

34. The method (100) according to claim 33, characterized in that The conversion step comprises: - a step of shredding the at least one shoe to obtain shredded particles; - a step of compacting the chopped particles to obtain chopped and compacted particles, in particular, the compacting being cold compaction or hot compaction, - a step of extrusion-granulation of said shredded and compacted particles to obtain granules capable of being transformed by a plastic thermal transformation process.

35. The method (100) according to claim 33 or 34, characterized in that The method (100) comprises the step of thermally transforming at least a portion of the thermoplastic granules for producing a plastic part, in particular a plastic part at least partially forming an article for practicing sports.

36. A plastic part, in particular a plastic part at least partially forming an article for practicing sports, obtainable by a method according to any one of claims 33 to 35, in particular the part is a swimming fin.

37. Footwear obtained by the method (100) according to one of claims 1 to 36.

38. A device for manufacturing at least a part of a footwear (10), the device comprising a mold (1), the mold (1) defining an open cavity (2), the shape of at least a part of the cavity (2) corresponding to the shape of the sole (3) of the footwear (10), the cavity (2) being configured to receive a mixture comprising a molten material and a supercritical fluid via at least one injection channel (4, 4', 4", 4"') leading to the cavity (2), the edge (5) of the opening of the open cavity (2) being configured to be placed in contact with a docking area (6) of a surface (7) of at least a part of a shoe body (9) of the footwear (10), so that the surface (7) of at least a part of the shoe body (9) ensures that the cavity is closed at the level of the contact portion between the docking area (6) and the edge (5), so that the device is thus configured to implement a method (100) according to one of claims 1 to 36.

Images