Method for manufacturing a shoe by spraying

Abstract

The method for producing a shoe (1) comprises the following successive steps: - a provision step (E01) of providing a foot-shaped support (5), at least one liquid composition comprising a binder and a solvent, and at least one filler; - a formation step (E02) of forming an upper (2) by a spraying sub-step (E201) of spraying a composite layer based on a liquid composition and a spraying sub-step (E202) of spraying a filler onto the support (5), a drying sub-step (E203) of drying the resulting composite layer and a repetition sub-step (E204) of repeating, at least once, the spraying sub-steps (E201, E202) and the drying sub-step (E203); - a formation step (E03) of forming an intermediate sole (3) and a positioning step (E04) of positioning the intermediate sole (3) against the upper (2) to form an assembly; - a formation step (E05) of forming an outer sole (4), an assembly step (E06) of assembling the outer sole (4) to the underside of the assembly formed by the upper (2) and the intermediate sole (3), and forming a shoe (1); and - a removal step (E08) of removing the shoe (1) from the support (5). The formation of an intermediate sole (3) or outer sole (4) can also be carried out by spraying, either directly on the shoe (1) or separately. Similarly, an intermediate sole (3) or an outer sole (4) can be assembled by spraying a liquid composition.

Description

Method for manufacturing a shoe by spraying. TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of shoe production.

[0002] The present invention relates to a method of manufacturing a shoe by spraying, as well as a shoe obtained by this method. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Nowadays, most shoes generally consist of at least two parts glued together: an upper and an outsole. They may also include a midsole, which is either housed permanently or removablely within the upper, or attached to the underside of the upper.

[0004] The upper, or shaft, is the top part of the shoe that covers the foot. There are two main types: high-top or mid-top, and low-top. Lengthwise, the shaft consists of a forefoot and a heel. It protects the foot and ensures comfort within the shoe. It is usually made of textile, leather, or plastic, starting with a flat piece of material that is cut and shaped three-dimensionally into the upper.

[0005] The outsole, also known as the outsole, is the lower part of the shoe that is in direct contact with the ground, either entirely or partially. It provides insulation from the rest of the shoe and also ensures good traction. Its surface in contact with the ground usually has anti-slip treads. Outsoles are typically made of polymer, either by injection molding or die-cutting.

[0006] The midsole is the part of the shoe that is usually located between the upper and the outsole, but it can also be housed within the upper. It allows for the natural rolling motion of the foot and plays a key role in cushioning the impact of the foot on the ground. Midsoles are typically made of polymer using injection molding.

[0007] Of course, shoes can include many other elements. Among these, we can mention, for example, the insole, which is a sole housed in the upper in the part intended to be in contact with the bottom of the foot in order to provide better hygiene, better comfort and better finish by hiding any seams present in the bottom of the upper.

[0008] Nowadays, the manufacture of such shoes generally requires many assembly steps of the aforementioned parts, usually manual, which are costly and may require a great deal of expertise when the shoe has a complex shape.

[0009] Therefore, there is a need to limit the number of assembly steps.

[0010] The main purpose of the invention is therefore to propose an alternative method of manufacturing shoes aimed at limiting the number of assembly steps.

[0011] The assembly of the different parts of a shoe is usually done by gluing, using a very strong and very toxic glue.

[0012] Furthermore, due to the presence of this glue and the multi-material nature of a shoe, current shoes are very difficult to recycle and their recycling process is very complicated and expensive.

[0013] Another aim of the invention is therefore to propose an alternative method of manufacturing shoes aimed at facilitating their subsequent recycling.

[0014] Finally, since there is also an urgent and growing need to reduce the environmental and ecological impact of industrial manufacturing processes, a secondary aim of the invention is also to improve shoe manufacturing processes so that they are more environmentally friendly. SUMMARY OF THE INVENTION

[0015] In order to limit the number of assembly steps in the manufacture of a shoe, the invention proposes to manufacture at least the upper of the shoe by spraying layers of composite material onto a foot-shaped support.

[0016] In order to facilitate the recycling of shoes and to avoid the use of toxic glue, the invention also proposes to assemble the different parts of the shoe by spraying at least one layer of composite material when one or more soles among the outsole and the midsole are not made directly by spraying layers of composite material onto the upper.

[0017] The invention offers a solution to the problem of reducing the environmental and ecological impact of shoe manufacturing processes by providing a sprayable composite material that meets, as far as possible, all of the following requirements: use environmentally friendly and ecologically sound materials; use materials derived from renewable natural raw materials; use non-toxic materials, particularly by contact and / or inhalation; use as little as possible of materials obtained from fossil resources; use recyclable and / or biodegradable materials; use recycled materials; use locally produced materials; use a production process that generates little waste, with this waste being reusable, recyclable and / or biodegradable.

[0018] To meet these requirements, following numerous studies, including feasibility studies, the applicant has chosen to primarily use bio-based fillers in powder and / or fiber form, a binder comprising one or more water-soluble polymers and / or polymers capable of dispersing in water, and a water-based solvent, and to adapt the spray manufacturing process accordingly. A bio-based material is defined as a material derived from renewable, non-fossil, natural organic raw materials of plant or animal origin.

[0019] One aspect of the invention relates to a method for producing a footwear item, in particular a shoe, and especially a sports shoe, comprising an upper, a midsole and an outsole, including the following successive steps: supply E01 of a support, at least one liquid composition and at least one charge to be sprayed onto said support, this supply step E01 comprising the following sub-steps: supply E101 of at least one liquid composition comprising at least one solvent predominantly water-based and at least one binder comprising one or more water-soluble polymers and / or polymers capable of forming a dispersion in water, mixing of said at least one solvent and said at least one binder, and obtaining at least one liquid composition comprising at least one solvent predominantly water-based in which at least one polymer is dissolved and / or in the form of a dispersion; supply E102 of at least one charge consisting of loose fibres and / or a powder; supply E103 of a volume support having a three-dimensional deposition surface having the general shape of a foot; E02 formation of the stem by spraying a composite layer, this E05 formation step comprising the following sub-steps: E201 spraying onto the deposition surface of a liquid composition resulting from the E01 supply step; and spraying E202 onto the deposition surface of a charge consisting of loose fibers and / or a powder resulting from the supply step E01; the spraying substep E201 of a charge being simultaneous with or subsequent to the spraying substep E202 of the liquid composition to form a composite layer; drying E203 of the composite layer resulting from the spraying steps E201.E202, solidification of the binder of the composite layer by evaporation of the water and fixation of the filler by the binder; repetition E204 at least once of the spraying sub-steps E201, E202 and drying E203, and formation, on the substrate deposition surface, of a rod consisting of alternating composite layers; E05 formation of the outsole, E06 assembly of the outsole on the underside of the assembly resulting from the previous steps and formation of a shoe; E08 removal of the shoe from the support.

[0020] The expression "spraying onto a layer or surface" means spraying onto the outer face of a layer or surface.

[0021] By "loose fibers" we mean loose fibers that are not bound together, or compacted, nor oriented in any way, so that when sprayed, they are randomly arranged on the surface onto which they are sprayed.

[0022] The formation of several composite layers on the substrate's deposition surface by spraying advantageously creates a composite material shaped into an upper, against which a midsole and outsole can then be added to form a shoe. The composite material of the upper is preferably a flexible material that behaves much like a conventional textile used in shoemaking, even if said composite material contains neither yarns nor fibers.

[0023] By this process, the stem is manufactured from a single three-dimensional piece in the shape of a foot.

[0024] Due to its thickness, any foot-shaped piece could be considered three-dimensional. However, by three-dimensional here we mean the overall shape of the foot-shaped piece obtained through the process. Thus, a three-dimensional piece is defined as an element with a spatial configuration in three dimensions (length, width, depth), thereby forming an autonomous volume. Unlike a two-dimensional piece created from a flat pattern, it is designed to conform to the shape of the foot and generate a structural relief. This three-dimensionality results from the morphology of the volume, the assembly techniques, and the nature of the materials used.

[0025] The three-dimensional foot-shaped part according to the invention must therefore be distinguished from a simple foot-shaped part whose intrinsic thickness does not make it a three-dimensional part. Indeed, the three-dimensional foot-shaped part according to the invention is a closed volumetric part, having a closed lower portion to receive the foot and an opening provided in the upper portion to allow the foot to be inserted into the stem.

[0026] Spraying thin layers of liquid onto or into which fibers and / or powder adhere allows each layer to dry quickly, thus enabling the rapid production of a shaft. If the sub-steps E201 (spraying the liquid composition) and E202 (spraying the filler) are performed simultaneously, this significantly reduces the process time. Spraying a filler also reduces the amount of binder required to produce a shaft and increases the mechanical strength of the resulting textile material.

[0027] If necessary, this process can be supplemented by spraying several composite layers, which can, for example, further enhance the mechanical strength of the resulting composite layer and / or make it waterproof. The composition of the outer layer of the stem can be advantageously chosen to provide good abrasion resistance.

[0028] Similarly, spray forming the upper allows for easy alternation of layers of different composition, with excellent adhesion between them, which allows for many possibilities for the shoe manufacturer, including providing a shoe with a look and / or feel that is not the same inside and outside the upper.

[0029] In addition, this process makes it possible to produce a shoe locally and on demand, without requiring many manual assembly operations or very significant know-how.

[0030] In cases where a liquid composition and a filler are sprayed simultaneously, they can each be sprayed by a separate spraying unit or by the same spraying unit. In the latter case, the liquid composition and the filler can be mixed together before being introduced into the spraying unit, or mixed within it.

[0031] If the E202 spraying substep of the filler is carried out after the E201 spraying substep of the liquid composition, this allows, in particular, better control of the composition of each composite layer.

[0032] One aspect of the invention also relates to a method for producing a footwear article further comprising an intermediate sole, which includes the following steps after the supply steps E01 and forming steps E02 of the upper (2): E03 formation of the midsole and E04 positioning of the midsole against the upper to form a unit; formation E05 of the outsole, assembly E06 of the outsole on the underside of the assembly formed by the upper and the midsole and formation of a footwear article; E08 removal of the shoe item from the support.

[0033] According to one embodiment, during the E03 formation step of the midsole and / or the E05 formation step of the outsole, said sole is obtained by one of the following techniques: spraying of a composite liquid composition comprising a binder and a filler; injection molding with a material containing a binder; or cutting with a die in a thickness of material containing a binder.

[0034] According to one embodiment, the steps E03 of forming the midsole and E04 of positioning the midsole against the upper are carried out simultaneously and include the following sub-steps: supply E301 a of a molding frame in the shape of an intermediate sole; installation E302a of the molding frame on the underside of the stem; spraying E303a of a liquid composition and a filler inside the molding frame and obtaining a composite layer, said liquid composition and filler resulting from substeps E101 of supplying at least one liquid composition and E102 of supplying at least one filler; E304a drying of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; repetition E305a at least once of the previous spraying substeps E303a and drying substeps E304a, and formation, on the underside of the stem and in the molding frame, of an intermediate sole made up of alternating composite layers; and shrinkage E306a of the molding frame.

[0035] According to this aspect of the invention, the manufacturing and assembly of the midsole are advantageously carried out in a single step, directly against the upper, thus reducing the number of operations and facilitating the subsequent recycling of the footwear. Furthermore, the manufacturing of the midsole can offer all the advantages associated with spray manufacturing mentioned above.

[0036] According to one embodiment, the E03 formation step of the midsole comprises the following sub-steps: supply E301 b of a molding cavity in the shape of an intermediate sole; spraying E303b of a liquid composition and a filler inside the molding cavity and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying E101 of at least one liquid composition and supplying E102 of at least one filler; E304b drying of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; repetition E305b at least once of the preceding spraying substeps E303b and drying substeps E304b, and formation, in the mold cavity, of an intermediate sole consisting of alternating composite layers; and E306b midsole removal from the molding impression.

[0037] According to this aspect of the invention, the manufacture of the midsole can be done separately, while offering all the advantages associated with spray manufacturing mentioned above, of assembly and facilitating the subsequent recycling of the footwear.

[0038] According to one embodiment, the steps E05 of forming the outsole and E06 of assembling the outsole onto the assembly formed by the upper and the midsole are carried out simultaneously and include the following substeps: supply E501 a of a molding frame in the shape of an outsole; E502a installation of the molding frame on the underside of the stem or on the underside of the intermediate sole if the latter is on the underside of the stem; spraying E503a of a liquid composition and a filler inside the molding frame and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying E101 of at least one liquid composition and supplying E102 of at least one filler; E504a drying of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; repetition E505a at least once of the previous spraying substeps E503a and drying substeps E504a, and formation, on the underside of the upper or on the underside of the midsole and in the molding frame, of an outsole made up of alternating composite layers; removal E506a from the molding frame.

[0039] According to this aspect of the invention, the manufacturing and assembly of the outsole are advantageously carried out in a single step, directly against the upper or the midsole, thus reducing the number of operations and facilitating the subsequent recycling of the footwear. Furthermore, the manufacturing of the outsole can offer all the advantages associated with spray manufacturing mentioned above.

[0040] According to one embodiment, the E05 outsole formation step comprises the following sub-steps: supply E501 b of an outsole molding cavity; spraying E503b of a liquid composition and a filler inside the molding cavity and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying E101 of at least one liquid composition and supplying E102 of at least one filler; E504b drying of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; repetition E505b at least once of the preceding spraying substeps E503b and drying substeps E504b, and formation, in the mold cavity, of an outsole consisting of alternating composite layers; and E506b removal of the outsole from the molding impression.

[0041] According to this aspect of the invention, the manufacture of the outsole can be done separately, while offering all the advantages associated with spray manufacturing that have been mentioned above and facilitating the subsequent recycling of the footwear.

[0042] According to one embodiment, during the positioning step E04 of the midsole against the upper, the midsole is positioned inside the upper and the assembly step E06 of the outsole on the underside of the assembly formed by the upper and the midsole comprises the following substeps: spraying E601 a of a liquid assembly composition on the underside of the stem and obtaining a layer of liquid assembly composition, said liquid assembly composition resulting from the supply substep E101 of at least one liquid composition; positioning E602a and pressure E603a of the outsole on the liquid assembly composition layer; and E604a drying of the liquid assembly composition layer and solidification of the binder of the liquid assembly composition layer by evaporation of water.

[0043] This method of assembling the outsole advantageously limits the number of assembly steps and facilitates the subsequent recycling of the footwear.

[0044] According to one embodiment, during the positioning step E04 of the midsole against the upper, the midsole is assembled on the underside of the upper by the following sub-steps: spraying E401 of a liquid assembly composition onto the underside of the stem and obtaining a layer of liquid assembly composition, said liquid assembly composition resulting from the supply substep E101 of at least one liquid composition; E402 positioning and E403 pressure of the midsole on the liquid assembly composition layer; and E404 drying of the liquid assembly composition layer and solidification of the binder of the liquid assembly composition layer by evaporation of water.

[0045] This method of assembling the midsole advantageously limits the number of assembly steps and facilitates the subsequent recycling of the footwear.

[0046] According to one embodiment, during the positioning step E04 of the midsole against the upper, the midsole is assembled on the underside of the upper, and the assembly step E06 of the outsole on the underside of the assembly formed by the upper and the midsole comprises the following substeps: spraying E601 b of a layer of liquid assembly composition on the underside of the intermediate sole and obtaining a layer of liquid assembly composition, said liquid assembly composition resulting from the supply substep E101 of at least one liquid composition; E602b positioning and E603b pressure of the outsole on the liquid assembly composition layer; and E604b drying of the liquid assembly composition layer and solidification of the binder of the liquid assembly composition layer by evaporation of water.

[0047] This method of assembling the outsole advantageously limits the number of assembly steps and facilitates the subsequent recycling of the footwear.

[0048] According to one embodiment, a binder of the liquid assembly composition is chemically compatible with a binder of each of the two composite layers assembled by said liquid assembly composition, which advantageously prevents delamination of the different layers and parts of the footwear article, and facilitates its subsequent recycling.

[0049] According to one embodiment, after the step E08 of removing the footwear from the support, it includes a finalization step E09 of the footwear, this finalization step E09 comprising at least one of the following substeps: rectification of the edges surrounding the opening of the stem; cutting out lace passages in the upper and inserting an eyelet in each lace passage; decoration of footwear by printing, spraying or hot stamping; functionalization of the footwear item by gluing elements onto it; cutting of the instep of the footwear item.

[0050] According to one embodiment, before the removal step E08 of the footwear from the support, it includes a formation step E07 of a finishing layer on an external face of the footwear, this formation step E07 of a finishing layer comprising the following successive substeps: spraying E701 of a liquid finishing composition onto an external face of the footwear article and obtaining a layer of liquid finishing composition, said liquid finishing composition resulting from sub-step E101 of supplying at least one liquid composition; and drying E702 of the liquid finishing composition sprayed during the previous spraying substep E701 and solidification of the binder of the liquid finishing composition layer by evaporation of water.

[0051] This E07 formation step of a finishing layer allows in particular to cover the external face of the footwear item with binder in order to give it a smooth and uniform aesthetic appearance, to protect the lower layers and / or to provide it with good resistance to abrasion.

[0052] According to one embodiment, during a drying substep E203, E304, E404, E504, E604, the support is subjected to vibrations, which notably improves the mechanical properties of the resulting rod and accelerates drying.

[0053] According to one embodiment, if the binder includes latex, a drying substep E203, E304, E404, E504, E604 further includes a hardening substep, which notably allows the latex, which remains liquid or at best pasty without hardening treatment, to harden. This hardening step notably improves the strength, durability, and stability of the latex without necessarily introducing specific crosslinking agents such as sulfur, which is used in the vulcanization hardening process.

[0054] According to one embodiment, at least one drying substep E203, E304, E404, E504, E604 is carried out at room temperature. "Room temperature" refers to the temperature of the room where the process is implemented. This temperature depends on the geographical region and the season, but it is usually between 10 and 30 °C, more commonly between 15 and 25 °C, and even more commonly between 18 and 22 °C. The process of the invention is thus designed to be carried out at a temperature at which most people are accustomed to working indoors.

[0055] According to one embodiment, at least one drying substep E203, E304, E404, E504, E604 is carried out at a temperature between 50 and 90 °C, which in particular accelerates drying and, for example, promotes polymerization of polymers.

[0056] According to one embodiment, after a drying substep E203, E304, E404, E504, E604, E702 of a layer of material, it includes a stabilization step E10 of the material of said layer by one of the following techniques: heat treatment; plasma therapy; and / or cross-linking by UV irradiation.

[0057] According to one embodiment, at least part of a surface is textured in relief or intaglio, said surface being chosen from: the surface area of ​​the substrate; one side of a mold impression in the shape of an intermediate sole; one side of a mold impression in the shape of an outsole.

[0058] This raised or recessed surface allows in particular to generate a recessed or raised texture on at least part of the upper, midsole and / or outsole obtained by spraying against said textured surface.

[0059] According to one embodiment, during substep E101 of supplying at least one liquid composition, said liquid composition is such that: the water-soluble polymer(s) and / or polymer(s) capable of forming a dispersion in water represents(s) 30 to 70% by weight of the liquid composition; Water represents 30 to 70% by weight of the liquid composition.

[0060] In addition to being non-toxic, inexpensive, and abundant, water offers numerous and obvious environmental and ecological advantages compared to organic solvents. Thus, the process according to the invention has a considerably reduced environmental and ecological impact compared to previous methods of producing footwear.

[0061] According to one embodiment, during the E102 supply substep of at least one filler consisting of loose fibers and / or a powder, at least 5% by weight of said filler is of bio-based origin, which advantageously reduces the carbon footprint of the process.

[0062] According to one embodiment, before a drying substep E203, E304, E504 of a composite layer, the filler represents 30 to 60% by weight of said composite layer, which advantageously allows the quantity of binder used to be reduced and therefore reduces the environmental and ecological impact of the process.

[0063] According to one embodiment, prior to a drying substep E203, E304, E504 of a composite layer, the filler-to-binder weight ratio in said composite layer is between 2:1 and 1:2. This advantageously reduces the environmental impact of the process while providing a composite layer with characteristics suitable for its subsequent use. The choice of this ratio allows, in particular, for adjusting the flexibility and strength of the resulting composite layer for a given final thickness, with a high binder content generally favoring flexibility, while a high filler content generally favoring rigidity of the resulting rod.

[0064] According to one embodiment, before a drying substep E203, E304, E504 of a composite layer, a bio-based filler represents 5 to 50%, preferably 10 to 40% and more preferably 15 to 30% by weight of said composite layer, which advantageously reduces the environmental and ecological impact of the process.

[0065] According to one embodiment, during the E102 feedstock supply step, 5 to 70%, preferably 10 to 60% and more preferably 20 to 50% by weight of the feedstock is of bio-based origin.

[0066] According to one embodiment, during the supply substep E102 of at least one filler, 5 to 70%, preferably 30 to 65% and more preferably 40 to 60% by weight of the bio-based filler, consists of viscose fibers, cotton fibers, wool fibers, silk fibers, cashmere fibers, flax fibers, fur fibers, mammal hair, mycelium fibers, cellulose fibers, wood fibers, hemp fibers, mycelium powder, rice powder, wheat powder, wood powder, starch powder, alginate powder, carbon black powder, wheat flour, corn flour, millet flour, hemp flour, rapeseed flour, soybean hull powder, walnut hull powder, olive kernel powder, cellulose nanofiber powder, polyamide powder or fibers, of polypropylene powder or fibers,of polyethersulfone powder or fibers or polyurethane powder or fibers, used alone or in mixtures, which notably helps to reduce the carbon footprint of the process.

[0067] According to one embodiment, during the E102 feedstock supply substep, 5 to 70% preferably 30 to 65% and more preferably 40 to 60% by weight of the bio-based feedstock consists of micronized dried plant, which plant is selected from plants of the Plantain, Eclipta, Tulsi, Coleus, Bacopa, Centella families and mixtures thereof.

[0068] According to one embodiment, during the E102 supply substep of at least one filler, 5 to 70%, preferably 30 to 65% and more preferably 40 to 60% by weight of the filler, are made up of at least one bio-based material comprising at least 5% by weight of calcium, preferably at least 10% by weight of calcium, which in particular improves the tensile strength, the compressive strength and / or the water absorption capacity of the resulting composite layer.

[0069] According to one embodiment, at least one bio-based material comprising at least 5% by weight of calcium is gypsum powder, limestone powder, bone powder, calcium carbonate powder or chalk powder, which advantageously reduces the environmental and ecological impact of the process.

[0070] Indeed, calcium carbonate increases the tensile and compressive strength of the resulting composite layer. Magnesium sulfate increases both the tensile and compressive strength of the composite layer, as well as its water absorption capacity. Gypsum, on the other hand, only increases the tensile strength of the composite layer, while sodium sulfate increases its water absorption capacity.

[0071] According to one embodiment, the binder comprises at least 10%, preferably at least 30% and more preferably at least 60% by weight of bio-based and / or biodegradable polymer, which in particular helps to reduce the carbon footprint of the process.

[0072] According to one embodiment, during the E101 supply substep of at least one liquid composition, the binder comprises at least 5%, preferably at least 30% and more preferably at least 70% by weight of elastomer, which makes it possible in particular to produce a composite layer exhibiting elastic properties.

[0073] According to one embodiment, during the supply substep E101 of at least one liquid composition, the binder comprises at least 5%, preferably at least 30% and more preferably at least 70% by weight of natural latex of vegetable origin, latex of vegetable origin treated to reduce its protein content, bio-based polylactic acid, bio-based thermoplastic polyurethane, bio-based polyurethane dispersion, rosin dispersion of vegetable origin, terpene dispersion of vegetable origin, bio-based acrylic polymer or polymer matrix hydrogel, taken alone or in mixture, which advantageously reduces the environmental and ecological impact of the process.

[0074] According to one embodiment, during the supply substep E101 of at least one liquid composition, the binder comprises at least 10%, preferably at least 20% and more preferably at least 30% by weight of electrically conductive polymer, which notably enables the instrumentation of the resulting footwear article.

[0075] According to one embodiment, during the E101 supply substep of at least one liquid composition, the liquid composition comprises 1 to 30% by weight of magnesium sulfate and / or sodium sulfate, which in particular improves the tensile strength, compressive strength and / or water absorption capacity of the resulting composite layer.

[0076] According to one embodiment, during the supply substep E101 of at least one liquid composition or during the supply substep E102 of a filler consisting of loose fibers and / or a powder, the liquid composition or the filler includes a bridging agent capable of forming ionic and / or covalent bonds with the binder, which makes it possible in particular to improve or modify the physical properties of the composite layer formed from these constituents, in particular its mechanical strength and / or its elasticity.

[0077] According to one embodiment, the bridging agent mainly comprises a culture substrate containing fungal spores grown therein, fungal mycelium, silicate derivatives or magnesium chloride derivatives, taken alone or in mixture, which advantageously reduces the environmental and ecological impact of the process.

[0078] According to one embodiment, before a drying substep E203, E304, E504 of a composite layer, the weight ratio of bridging agent: binder in said composite layer is in the range between 1:100 and 1:1, preferably between 1:10 and 1:4, and more preferably between 2:10 and 3:10, which in particular allows the physical properties of the composite layer to be improved or modified satisfactorily.

[0079] According to one embodiment, during the E101 supply substep of at least one liquid composition, the feed includes a coalescing agent whose quantity represents from 0.1 to 10%, preferably 1 to 5% by weight of the liquid composition.

[0080] According to one embodiment, the coalescing agent is 2,2,4-trimethyl-1,3-pentane diol monoisobutyrate, glycol acetate, butyl glycol, fatty acid ester, propylene glycol or ethyl acetate, taken alone or in mixture.

[0081] According to one embodiment, during the supply substep E101 of at least one liquid composition, said liquid composition includes at least one pigment, which advantageously makes it possible to produce a footwear article with at least one layer dyed in the mass.

[0082] According to one embodiment, during substep E101 of supplying at least one liquid composition, said liquid composition includes a viscosity-modifying agent, preferably water-soluble, which advantageously allows the viscosity of the liquid composition to be adjusted, for example, to thicken or thin it, in particular to ensure that it adheres to the substrate without excessive dripping. Viscosity here also refers to the rheological properties of the liquid composition.

[0083] According to one embodiment, the viscosity agent is polylactic acid, sugar, polysaccharide derivative, alginate, potato dextrose, agar, glucose, malt, peptone, yeast extract or a polyacrylate-based thickener in the form of anionic acrylic polymer solution, taken alone or in mixture, which advantageously reduces the environmental and ecological impact of the process.

[0084] According to one embodiment, during the E101 supply substep of at least one liquid composition, said liquid composition has a dynamic viscosity between 0.1 and 10,000 mPa.s at 20 °C, which provides a wide viscosity range suitable for different spraying conditions and different applications envisaged.

[0085] According to one embodiment, during substep E101 of supplying at least one liquid composition, said liquid composition includes an adhesive agent, preferably water-soluble, which notably improves the bond between the different layers of the footwear article if necessary. Indeed, the bond between layers can be achieved by the binder itself present in each layer, particularly when the binders of each layer are from the same chemical family.

[0086] According to one embodiment, the adhesive agent is an aqueous dispersion of rosin and terpene, both of plant origin, which advantageously reduces the environmental and ecological impact of the process.

[0087] According to one embodiment, during a substep of spraying E201, E3013, E503 of a liquid composition, said liquid composition completely covers a filler comprising fibers, at least 80% of these fibers having a length between 3 and 7 mm, preferably between 3 and 5 mm, and more preferably between 3 and 4 mm, which notably allows the composite layer obtained to be reinforced.

[0088] According to one embodiment, during a substep of spraying E201, E3013, E503 of a liquid composition, said liquid composition does not completely cover a filler comprising fibers, at least 80% of these fibers having a length between 0.1 and 2 mm, preferably between 0.5 and 1.5 mm, and more preferably between 0.5 and 1 mm, which notably improves the feel of the resulting composite layer, with average titles of 1.7 Dtex for fibers of length 0.5 mm and 3.3 Dtex for fibers of length 1 mm.

[0089] Another aspect of the invention relates to a footwear article comprising an upper and an outsole, in which the upper comprises an alternation of layers of binder-based material comprising one or more water-soluble polymers and / or polymers capable of forming a dispersion in water, and at least one filler comprising a powder and / or fibers, said footwear article being a product resulting from the process as described above.

[0090] According to one embodiment, the footwear item is a dress shoe, a sports shoe, a moccasin, an orthopedic shoe, a flip-flop, a sandal, a clog, a walking shoe, a boot, an ankle boot, a mule, a safety shoe or a slipper.

[0091] A further aspect of the invention relates to an assembly comprising at least one liquid composition, a charge, and a spraying system for implementing the process as described above, in which: The spraying system includes the following equipment: at least one spraying unit equipped with one or more spray nozzles; at least a fluid displacement device; at least one tank; supply pipes connecting at least one reservoir to at least one fluid displacement device and to at least one spray nozzle; at least one support; A liquid composition is contained in a reservoir and comprises: a binder comprising one or more water-soluble polymers and / or polymers capable of forming a dispersion in water, and a solvent predominantly water-based, a charge is in powder form and is contained in a reservoir, a charge is in the form of loose fibers, taken alone or in mixture, and is contained in a reservoir; at least one volume support has a three-dimensional deposition surface having the general shape of a foot on which a rod can be manufactured by spraying at least one fluid contained in a reservoir and supplied by a fluid displacement device to a spraying unit.

[0092] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0093] The figures are presented for illustrative purposes only and are in no way limiting to the invention.

[0094] [Fig. 1] is a schematic representation of an example of a method according to the invention in which the upper is made first, then the midsole, then the outsole.

[0095] [Fig. 2] is a schematic representation of the substeps of the stem formation step according to an example of a process according to the invention in which a liquid composition is sprayed before a charge.

[0096] [Fig. 3] is a schematic representation of the sub-steps of the stem formation step according to an example of a process according to the invention in which a liquid composition and a filler are sprayed simultaneously.

[0097] [Fig. 4] is a schematic representation of the sub-steps of the midsole formation step according to an example of a process according to the invention in which the midsole is produced by spraying directly onto the underside of the upper.

[0098] [Fig. 5] is a schematic representation of the sub-steps of the midsole formation step according to an example of a process according to the invention in which the midsole is made separately in a molding cavity.

[0099] [Fig. 6] is a schematic representation of the sub-steps of the midsole positioning step against the upper according to an example of a method according to the invention in which the midsole is assembled on the underside of the upper.

[0100] [Fig. 7] is a schematic representation of the sub-steps of the outsole formation step according to an example of a process according to the invention in which the outsole is made by spraying directly onto the underside of the upper or onto the underside of the intermediate sole if the latter is on the underside of the upper.

[0101] [Fig. 8] is a schematic representation of the sub-steps of the outsole formation step according to an example of a process according to the invention in which the outsole is made separately in a molding cavity.

[0102] [Fig. 9] is a schematic representation of the sub-steps of the step of assembling the outsole on the underside of an assembly formed by the upper and the midsole according to an example of a method according to the invention, whether the outsole is assembled on the underside of the upper or on the underside of the midsole.

[0103] [Fig. 10] is a schematic representation of the sub-steps of the step of forming a finishing layer on an external face of the shoe according to an example of a process according to the invention.

[0104] In these figures, optional steps are represented by dashed lines.

[0105] [Fig. 11] is a schematic view of an example device comprising two spraying units each mounted on a separate robotic arm and each having a spray nozzle, enabling the implementation of the process according to the invention at least for the production of a rod.

[0106] [Fig. 12] is a schematic view of an example of a device comprising three spraying units mounted on the same robotic arm, enabling the implementation of the process according to the invention for the production of three pairs of midsoles.

[0107] [Fig. 13] is a schematic view of an example of a device comprising three spraying units mounted on the same robotic arm, enabling the implementation of the process according to the invention for the production of three pairs of outsoles.

[0108] [Fig. 14] is a schematic cross-sectional view of an example of a shoe according to the invention in which the midsole is removably housed in the bottom of the upper and the outsole is assembled on the underside of the upper.

[0109] [Fig. 15] is a schematic cross-sectional view of an example of a shoe according to the invention in which the midsole is assembled on the underside of the upper, between said upper and the outsole, said outsole being assembled on the underside of the midsole.

[0110] [Fig. 16] is a schematic perspective view illustrating a stem mounted on a foot-shaped support, with a molding frame in the shape of an intermediate sole and positioned on the underside of said stem.

[0111] [Fig. 17] is a schematic perspective view illustrating a stem mounted on a foot-shaped support and whose underside is fitted with an intermediate sole, with an outsole-shaped molding frame positioned on the underside of said intermediate sole.

[0112] [Fig. 18] is a photo illustrating a stem obtained by using an example of the process of the invention.

[0113] [Fig. 19] is a photo illustrating an intermediate sole obtained by using an example of the process of the invention.

[0114] [Fig. 20] is a photo illustrating an outsole obtained by using an example of the process of the invention.

[0115] [Fig. 21] is a photo illustrating a sports shoe obtained by using an example of the process of the invention.

[0116] [Fig. 22] is a photo illustrating a mask and midsole with reinforcements obtained from the mask. DETAILED DESCRIPTION

[0117] Unless otherwise specified, the same element appearing on different figures has a unique reference.

[0118] The process according to the invention relates to a method for manufacturing a shoe 1 comprising at least one manufacturing step by spraying a composite layer.

[0119] The term "shoe" in the remainder of this description means all footwear articles usually comprising an upper 2 and an outsole 4, and possibly an insole 3. Thus, the shoe 1 obtained by the process of the invention can be a dress shoe, a sports shoe, a moccasin, an orthopedic shoe, a flip-flop, a sandal, a clog, a walking shoe, a boot, an ankle boot, a mule, a safety shoe, a slipper, or any other footwear of this type.

[0120] Of course, an upper 2, a midsole 3 and an outsole 4 can have different dimensions and thicknesses, but within the same shoe, the underside of the upper 2, the midsole 3 and the outsole 4 have a general shape and dimensions that are close, or even similar.

[0121] The process according to the invention uses at least one liquid composition and at least one filler intended to be sprayed to form composite layers, said composite layers serving both to manufacture at least one part of the shoe 1 and to assemble at least two parts of the shoe 1. Thus, at least one liquid composition and at least one filler are intended to be sprayed onto a support 5 in order to produce the upper 2, and possibly other parts of the shoe 1. And at least one liquid composition and at least one filler are intended to be sprayed onto the outsole 4 to assemble it with the upper 2 and / or with the midsole 3.

[0122] A liquid composition according to the invention comprises a binder, preferably water-soluble and / or capable of forming a dispersion in water, and a solvent, preferably aqueous, in which the binder is dissolved and / or in the form of a dispersion.

[0123] A liquid composition according to the invention comprises at least one aqueous solvent and at least one binder comprising one or more water-soluble polymer(s) and / or polymers capable of being in the form of a dispersion in water. The liquid composition therefore comprises at least one aqueous solvent in which at least one binder is dissolved and / or in the form of a dispersion.

[0124] In this text, "aqueous solvent" or "solvent predominantly water-based" means a solvent comprising at least 50% water by weight.

[0125] By "dispersion" in water, we mean an emulsion or a suspension in water.

[0126] The aqueous solvent preferably consists of at least 90% water by weight, and more preferably consists entirely of water to which additives may be added, but in such a way as to represent less than 10% by weight of the aqueous solvent. The aqueous solvent represents 30 to 70% by weight of the liquid composition.

[0127] The binder preferably comprises at least one water-soluble polymer or one suitable for being in the form of a dispersion in water, of which at least one polymer represents 30 to 70% by weight of the liquid composition.

[0128] The percentages relating to the composition of the binder given here are in dry weight of water-soluble polymer and / or polymer suitable for being in the form of dispersion in water.

[0129] The binder preferably comprises one or more water-soluble bioplastics and / or bioplastics capable of dispersing in water, or one or more water-soluble recyclable polymers and / or bioplastics capable of dispersing in water. Bioplastics are defined as polymers derived from renewable sources (bio-based polymers) and biodegradable polymers. Thus, a bioplastic can be bio-based but not biodegradable, bio-based and biodegradable, or derived from fossil resources (often petrochemicals) and yet biodegradable. Bioplastics should not be confused with biocompatible plastics.

[0130] Thus, the binder comprises at least 10%, preferably at least 30% and more preferably at least 60% by weight of bio-based and / or biodegradable polymer.

[0131] In order to enable the production of a shoe 1 exhibiting elastic properties, the binder may comprise at least 5%, preferably at least 30% and more preferably at least 70% by weight of elastomer.

[0132] According to one embodiment, the binder comprises at least 5%, preferably at least 30% and more preferably at least 70% by weight of natural latex of vegetable origin, latex of vegetable origin treated to reduce its protein content, bio-based polylactic acid, bio-based thermoplastic polyurethane, bio-based polyurethane dispersion, rosin dispersion of vegetable origin, terpene dispersion of vegetable origin, bio-based acrylic polymer or polymer matrix hydrogel, taken alone or in mixture.

[0133] Preferably, the binder does not contain latex.

[0134] Preferably, the binder does not contain polyurethane.

[0135] Natural latex of plant origin is extracted in liquid form from several plants and trees, primarily the rubber tree (Hevea brasiliensis), and forms rubber after polymerization. It is advantageous because it is bio-based, biodegradable, compostable, recyclable, and elastic. A plant-based latex treated to reduce its protein content was Vytex® from VYSTAR, which yielded excellent results with the production process for a shoe 1 according to the invention, particularly for the manufacture of an outsole 4.

[0136] Polylactic acid (PLA) is a homopolymer of lactic acid. It is advantageous because it is biodegradable, compostable, recyclable, and can be bio-based, notably being obtained primarily from corn.

[0137] Thermoplastic polyurethanes (TPUs) are thermoplastic elastomers (TPEs) of isocyanate block polyurethane. They are advantageous because they are recyclable and can be bio-based, biodegradable, and elastic.

[0138] Highly satisfactory results were obtained with a bio-based polyurethane dispersion using one of the following products: Impranil® DL 1545, Impranil® DL 1126, Impranil® DL 2611 / 1, Impranil® DLU, Impranil® 43031, and Impranil® DL 1380 from COVESTRO. Similarly, highly satisfactory results were obtained with a polyester-polyurethane dispersion using Impranil® DLP from COVESTRO.

[0139] Very satisfactory tests were also obtained with a rosin dispersion based on Dermulsene A 7510® (Brookfield viscosity at 20 °C, 50 min-1, mPa.s: 600) and from a rosin solution based on Dermulsene TR 602® (Brookfield viscosity at 20 °C, 50 min-1, mPa.s: 800) from LES DERIVES RESINIQUES ET TERPENIQUES (DRT).

[0140] Among the water-soluble bio-based polymers and / or those capable of forming a dispersion in water that can be used, the following polymers can also be mentioned: the natural polymer, 100% bio-based and biodegradable from LACTIPS, which can provide water-soluble properties to a binder or composite layer; ethylene vinyl acetate (VAE), a water-soluble thermoplastic polymer that can be derived from bio-based sources; Polyvinyl alcohol (PVA), a water-soluble polymer that can be produced from renewable raw materials; polyethylene glycol (PEG), also known as polyethylene oxide (PEO) and poly(oxyethylene) (POE), is a water-soluble linear polyether polymer that can also be used as a thickening agent and can be derived from renewable resources; polyvinylpyrrolidone (PVP), a water-soluble polymer that can be used as an emulsifier and stabilizer and can be produced from bio-based sources; ExpertGel®, a water-soluble thermogelling polymer developed by POLYMEREXPERT, derived from natural oils; and EstoGel® Green, a bio-based rheology modifier also developed by POLYMEREXPERT, is a biodegradable, 100% origin, oily gelling and shear-thinning agent that allows for great versatility in terms of textures and visuals and flexibility in its use.

[0141] According to one embodiment, the binder comprises at least 10%, preferably at least 20% and more preferably at least 30% by weight of electrically conductive polymer.

[0142] The process according to the invention also uses a filler consisting of loose fibers and / or a powder. At least 5% by weight of the filler is bio-based. Depending on the sprayed layers and the materials chosen, 5 to 70%, preferably 10 to 60%, and more preferably 20 to 50% by weight of the filler is bio-based.

[0143] The filler improves the texture and consistency of a composite layer, increasing its durability. It can also provide additional properties, especially when it includes a bridging agent. When bio-based, it is environmentally friendly.

[0144] In addition to adding flexibility and durability to a composite layer by increasing its wear resistance, a filler made of fibers can provide a soft and pleasant texture to a composite layer.

[0145] In one embodiment, 5 to 70%, preferably 30 to 65% and more preferably 40 to 60% by weight of the bio-based filler, consists of viscose fibers, cotton fibers, wool fibers, silk fibers, cashmere fibers, flax fibers, fur fibers, mammal hair, mycelium fibers, cellulose fibers, wood fibers, hemp fibers, mycelium powder, rice powder, wheat powder, wood powder, starch powder, alginate powder, carbon black powder, wheat flour, corn flour, millet flour, hemp flour, rapeseed flour, soybean hull powder, walnut hull powder, olive kernel powder, cellulose nanofiber powder, bio-based polyamide powder or fibers, bio-based polypropylene powder or fibers, powder or bio-based polyethersulfone fibers or powder or bio-based polyurethane fibers,taken alone or in mixtures.

[0146] According to one embodiment, during the E03 feedstock supply step, 5 to 70%, preferably 30 to 65%, and more preferably 40 to 60% by weight of the bio-based feedstock, consists of micronized dried plant material, which is selected from plants of the plantain, eclipta, tulsi, coleus, bacopa, centella, and mixtures thereof. Indeed, each of these plants possesses characteristics that are of interest and are given below: Plantain: Rich in mucilage and fibers, it is already used in composites to improve strength and water retention. The publication provides information on adhesion, friction control, and durability when blended with polymers. Eclipta: Contains pigments and polyphenols with natural UV absorption. It is likely to contribute to weather resistance and opacity, while remaining micronizable to < 50 µm for spraying. Its use is interesting due to the presence of numerous fibers in its aerial parts and its very high biomass accumulation rate. Tulsi (Ocimum sanctum): The leaves and stems contain hydrophobic compounds and exhibit antimicrobial activity. It may contribute to hydrophobicity, chemical resistance (perspirant / oils), and odor / friction control. Coleus: The fibers and pigments in the roots give the plant strength, abrasion resistance, and opacity, while also ensuring lightness. A good choice for its durability and UV stability. Bacopa: Features a flexible polysaccharide matrix that provides flexibility, elasticity and transparency control to coatings or films. Centella: Comprising a lignocellulosic base reinforced with triterpenoids, known for its resistance to UV radiation and weathering, as well as its abrasion resistance. It is likely to increase the tensile strength of mixtures.

[0147] In the case of plantain, eclipta, tuslin, coleus, bacopa, and centella, their surfaces bear -OH, -COOH, and, in some cases, -NH2 groups. This means that in a PUD system, they can act as partially reactive fillers and are likely to contribute to cross-linking while preserving the stability of the formulation. Among these, plantain and eclipta stand out because both are rich in fiber and more economical once dried and micronized under optimal post-harvest and processing conditions.

[0148] In one embodiment, the liquid composition and / or filler comprises a bridging agent, preferably water-soluble, capable of forming ionic and / or covalent bonds with the binder, preferably with a water-soluble polymer, and / or capable of forming a dispersion of the binder in water. Preferably, the bridging agent mainly comprises a culture substrate containing fungal spores cultured therein, fungal mycelium, silicate derivatives, or magnesium chloride derivatives, alone or in mixtures. The bridging agent is preferably present in such a quantity that, during a step in the formation of a composite layer, before drying, the weight ratio of bridging agent to binder in said composite layer is in the range of 1:100 to 1:1, preferably between 1:10 and 1:4, and more preferably between 2:10 and 3:10.As a reminder, a bridging agent is a chemical compound designed to eliminate the effects of water at the interface of the two materials of a composite material and to improve its physical properties.

[0149] For mushroom mycelium, preferred mushroom species include: Pleurotus and subspecies ostratus and eryngii (king oyster mushroom), Ganoderma and subspecies lucidum (reishi) and resinceum, Trametes and subspecies versicolor (Turkish mushroom) and multicolor, Cordyceps, Lentinus, Lentinula, Agancus (e.g. Agaricus bisporus, known as the button mushroom), Hericium, Schizophylium commune (saw fungus), Fomes fomentarius (birch fungus) and Lentinula edodes (shiitake).

[0150] Bridging agents in powder form are preferentially present in the filler, while bridging agents in liquid form are preferentially present in the liquid composition. Of course, if a filler is mixed with a liquid composition before spraying, a bridging agent can be added to this mixture.

[0151] In one embodiment, 5 to 70%, preferably 30 to 65%, and more preferably 40 to 60% by weight of the filler, consists of at least one bio-based material containing at least 5% by weight of calcium, preferably at least 10% by weight of calcium. Such a material improves the rigidity and strength of the material, while being a natural product. This bio-based material containing at least 5% by weight of calcium is preferably gypsum powder, limestone powder, bone meal, calcium carbonate powder, or chalk powder.

[0152] When the charge includes powder, this powder preferentially exhibits a narrow particle size distribution within the range of 20 to 100 pm, with an average particle size distribution, for example, of about 50 pm.

[0153] A liquid composition according to the invention may also comprise 1 to 30% by weight of an additive suitable for improving the tensile strength, compressive strength, and / or water absorption capacity of the resulting binder or composite layer. This additive may, for example, be magnesium sulfate and / or sodium sulfate.

[0154] A liquid composition according to the invention may also include a coalescing agent, preferably water-soluble, which lowers the minimum film formation temperature (MFT) of aqueous dispersions, allowing the binder polymers to react more readily at lower temperatures. As a reminder, a coalescing agent is a chemical compound designed to lower the minimum film formation temperature (MFT) of aqueous dispersions by reducing the surface tension between particles, thereby facilitating their coalescence.

[0155] Some examples of usable coalescing agents are given in the table below, with preferred concentrations given for each as a percentage by weight relative to the total mass of the liquid composition.

[0156] [Table 1] [Ü0157] Among the preferred glycol acetates are, for example, 2-hexyl-1,3-dioxolane-4-methanol, 2-hexyl-1,3-dioxane-5-ol, 2-hexyl-2-methyl-1,3-dioxolane-4-methanol, and 2-hexyl-2-methyl-1,3-dioxane-5-ol. Ethylene glycol monoethyl ether acetate is a preferred choice due to its favorable atomizing properties and compatibility with water-based formulations.

[0158] A liquid composition according to the invention may also include at least one pigment. This pigment is preferably water-soluble. It may, for example, be an organic or inorganic pigment, for example, of chemical, mineral, or natural origin. It may also be pigments extracted from fungi or algae. Finally, it may also be disperse, azo, acid, or reactive dyes.

[0159] Some examples of usable pigments are given in the table below.

[0160] [Table 2]

[00161] It should be noted that other seaweed extracts can be used in the invention in combination with pigments: Agar: A polysaccharide extracted from certain red algae such as Gelidium and Gracilaria. It can be used as a natural mordanting agent to fix dyes to cellulosic and protein fibers. Alginates: Polysaccharides found in brown algae such as Laminaria and Macrocystis. They can be used as thickeners and binders for natural dyes in textile applications. Carrageenans: Sulfated polysaccharides extracted from red algae such as Chondrus cnspus. They improve the fixation and durability of natural dyes on fibers. Fucoidans: Sulfated polysaccharides found in brown algae. They possess properties similar to carrageenans for textile dyeing.

[0162] A liquid composition according to the invention may also include a viscosity-modifying agent, preferably water-soluble. This viscosity-modifying agent is preferably polylactic acid, sugar, a polysaccharide derivative, alginate, potato dextrose, agar, glucose, malt, peptone, yeast extract, or a polyacrylate-based thickener in the form of an anionic acrylic polymer solution, taken alone or in mixtures.

[0163] In one embodiment, the liquid composition exhibits a dynamic viscosity ranging from 0.1 mPa·s at 20 °C for highly dilute solutions to several thousand mPa·s at 20 °C, for example, 10,000 mPa·s at 20 °C for solutions with a viscosity-enhancing agent concentration of up to 20% or more, depending on the type of polymer(s) used in the binder. For example, polyacrylamides and polyethylene glycols (PEGs) can have specific viscosities of up to 10 mPa·s or more in certain formulations, such as 500 mPa·s or 10,000 mPa·s at 20 °C.

[0164] A liquid composition according to the invention may also include an adhesive agent, preferably water-soluble. The adhesive agent may be in the form of an aqueous dispersion of rosin and terpene, both of plant origin. Other examples of adhesive agents are given below. Advantageously, most of them are water-soluble and compatible with mycelium-based materials.

[0165] [Table 3]

[60166] The process according to the invention allows the production of a shoe 1 comprising several parts, including an upper 2, an intermediate sole 3 and an outsole 4.

[0167] The upper (shaft 2) is designed to conform to the shape of the foot and completely enclose it. The bottom section of the upper, which supports the foot when the shoe (shoe 1) is worn, is therefore closed, while the top section is open to allow the user to insert their foot. In the case of a boot or ankle boot, for example, the upper may also extend higher to conform to the shape of part of the calf, or even higher.

[0168] The midsole 3 can be housed inside the upper 2 (see [Fig. 14]) or located on the underside of the upper 2, between the midsole 3 and the outsole 4 (see [Fig. 15]). The outsole 4 is always the lower part of the shoe, although it may also extend at least partially over the midsole 3 and / or the upper 2.

[0169] The underside, or lower surface, refers to the surface facing downwards and therefore towards the ground when the shoe 1 is worn and resting horizontally on the ground. Similarly, the upper surface refers to the surface facing upwards when the shoe is worn and resting horizontally on the ground. Generally, when using the terms lower or upper, we are referring to the position of a shoe 1 when it is resting horizontally on the ground (see [Fig. 14] and [Fig. 15]).

[0170] The process according to the invention comprises several steps aimed in particular at spraying at least one liquid composition and at least one filler according to the invention onto a support 5, into a molding cavity 7,9 or onto a part of the shoe 1 to form a composite layer, and repeating this operation after drying of said composite layer in order to superimpose several of them, these superimposed composite layers then being able to constitute the upper 2, the midsole 3 and / or the outsole 4.

[0171] It should be noted that the liquid composition and / or the filler may be identical or different for each composite layer and for the different parts of the shoe 1.

[0172] The process according to the invention also includes several steps aimed in particular at spraying at least one liquid composition in order to assemble two parts of the shoe 1 together.

[0173] The main steps of the process according to the invention are shown in [Fig. 1],

[0174] The process according to the invention comprises a preliminary step E01 of supplying certain essential means of the invention, a step E02 of forming an upper 2 by spraying a composite layer, a step E03 of forming an intermediate sole 3, a step E04 of positioning the intermediate sole 3 against the upper 2, a step E05 of forming an outsole 4, a step E06 of assembling the outsole 4 on the underside of an assembly formed by the upper 2 and the intermediate sole 3 and a step E08 of removing the shoe 1 from the support 5. It should be noted that these different steps are not necessarily carried out in this order.

[0175] The process according to the invention therefore comprises a preliminary supply step E01 of certain essential means of the invention. This supply step E01 comprises a supply substep E101 of at least one liquid composition according to the invention comprising a binder and a solvent in which the binder is dissolved and / or in the form of a dispersion and as described above, a supply substep E102 of a filler according to the invention consisting of loose fibers and / or a powder and as described above, and a supply substep E103 of a support 5.

[0176] This support 5 is a three-dimensional component designed for manufacturing a stem 2 by spraying and having a three-dimensional deposition surface 501 with the general shape and dimensions of a human foot. This three-dimensional support 5 may be a single piece or made of several parts that may be removable or joined together. The deposition surface 501 is designed to receive composite layers that will be formed by spraying according to the process of the invention, these layers then forming a stem 2. The deposition surface 501 is preferably an external surface of the support 5, but it may also be an internal face thereof.

[0177] It should be noted that a support 5 generally rests on the ground by means of a positioning device 24, for example an articulated arm or a simple rigid foot.

[0178] At least a portion of the deposition surface 501 can be textured in relief or intaglio, for example, to form a rod 2 with a textured face. Indeed, although the support 5 only serves as a temporary support, it is the shape of its deposition surface 501, onto which the liquid composition and the filler according to the invention are sprayed, that substantially determines the shape adopted by the resulting rod 2.

[0179] The support 5 is preferably rigid, but it may be at least partially flexible or elastic. It is preferably made of steel, aluminum, thermoplastic polyurethane (TPU), thermoplastic polyamide elastomer (TPA), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate (PC), polyamide (nylon), polystyrene (PS), polypropylene (PP) or acrylonitrile butadiene styrene (ABS).

[0180] According to one variant of the invention, the support 5 is in positive relief, the layers being sprayed onto the predominantly convex external shape of the support 5.

[0181] According to another variant of the invention, the support 5 is in negative relief, the layers being sprayed onto the predominantly concave internal shape of the support 5, for example by introducing a spray nozzle 26 inside the support 5. In this case, the support 5 can be divided into several removable or detachable parts.

[0182] The process according to the invention also includes a step E02 of forming a rod 2 by spraying a composite layer onto the deposition surface 501 of the support 5, this composite layer being composed of a liquid composition and a filler resulting from the supply step E01. This formation step E02 comprises the following substeps: spraying E201 onto the deposition surface 501 of a liquid composition resulting from the supply step E01; and spraying E202 onto the deposition surface 501 of a charge consisting of loose fibers and / or a powder resulting from the supply step E01; drying E203 of the composite layer resulting from the spraying steps E201.E202, solidification of the binder of the composite layer by evaporation of the water and fixation of the filler by the binder; repetition E204 at least once of the spraying substeps E201.E202 and drying substep E203, and formation, on the deposition surface 501 of the support 5, of a rod 2 made up of an alternation of composite layers.

[0183] To form a composite layer, the E201 spraying substep of a filler can be carried out at the same time as the E202 spraying substep of a liquid composition (cf. [Fig. 3]) or be carried out subsequently (see [Fig. 2]). This can be valid each time a filler and a liquid composition are sprayed to form a composite layer, which means that these process characteristics are not only limited to the substeps concerning the formation of a rod 2, but can be applied to all substeps of the process in which a filler and a liquid composition are sprayed.

[0184] If these two spraying substeps E201.E202 are carried out simultaneously, the liquid composition and the charge can be sprayed by one and the same spraying unit 19 in which they are in the state of composite mixture, or be sprayed at the same time by a spraying unit 19 which is specific to each.

[0185] It should be noted that it is technically easier to spray a composite mixture with a single spraying unit 19 when the filler preferentially comprises a powder and / or very short fibers, because it is difficult to obtain a satisfactory spray quality when spraying a composite mixture comprising both a liquid composition and a filler containing long fibers.

[0186] The two spraying sub-steps E201 and E202 can be carried out at a pressure between 0.5 and 100 bar. This can be applied whenever a charge and / or liquid composition is sprayed.

[0187] During substep E201 of spraying a liquid composition according to the invention onto the deposition surface 501, a thin layer of the liquid composition is deposited on the surface. This can be applied each time a liquid composition is sprayed onto a surface.

[0188] During the spraying substep E202 of a filler according to the invention onto the deposition surface 501, a thin layer of filler is deposited on it. This can be applied each time a filler is sprayed onto a surface.

[0189] For these E201.E202 spraying sub-steps, a thin layer is understood to mean a layer of liquid composition with an average thickness of between 0.1 and 2 mm, preferably between 0.2 mm and 1.5 mm, and more preferably between 0.2 and 0.8 mm.

[0190] If a liquid composition and a filler are sprayed simultaneously or one after the other, with the liquid composition being sprayed before the filler, the liquid composition and the filler form a composite layer.

[0191] In a composite layer, the load distribution within the liquid composition is not necessarily homogeneous and can vary throughout the thickness of said composite layer. The upper 2, or other parts of the shoe 1 produced by spraying, may therefore exhibit different physical and / or chemical characteristics in certain areas and / or within their thickness.

[0192] Masks, which can also be referred to as shields, can be used during these E201.E202 spraying substeps to control the shape and dimensions of the 501 surface. The liquid composition and the charge deposited on these masks can be recovered and used to limit waste.

[0193] Optionally, before the E02 forming step of the upper 2, it may be necessary to add a mesh or seamless textile to at least part of the support 5 to locally or completely reinforce the structure of the upper 2 and improve its mechanical performance. After spraying, this reinforcing textile is at least partially embedded in the composite layers forming the upper 2. A rigid reinforcing element, for example, metallic, can also be integrated into the upper 2 in a similar manner, for example, during the manufacture of a safety shoe.

[0194] According to one embodiment, prior to a drying substep E203 of a composite layer, during the formation of said composite layer, the filler represents 30 to 60% by weight of the composite layer. A bio-based filler represents 5 to 50%, preferably 10 to 40%, and more preferably 15 to 30% by weight of said composite layer. This can be applied each time a composite layer is formed.

[0195] According to one embodiment, the amount of filler and the amount of liquid composition sprayed into a composite layer are such that the weight ratio of filler to binder in said composite layer is in the range between 2:1 and 1:2. This can be valid each time a composite layer is formed.

[0196] During a substep E201 of spraying a liquid composition, this spraying can be designed so that the liquid composition completely covers a filler containing so-called long fibers, meaning that at least 80% of these fibers have a length between 3 and 7 mm, preferably between 3 and 5 mm, and more preferably between 3 and 4 mm. This has the effect of strengthening the resulting composite layer. This can be applied whenever a liquid composition is sprayed onto a filler containing long fibers.

[0197] During a substep E201 of spraying a liquid composition, this spraying E201 can also be designed so that said liquid composition does not completely cover a filler containing so-called short fibers, i.e., at least 80% of these fibers have a length between 0.1 and 2 mm, preferably between 0.5 and 1.5 mm, and more preferably between 0.5 and 1 mm. This has the effect of improving the feel of the resulting rod 2. This can be applied whenever a liquid composition is sprayed onto a filler containing short fibers.

[0198] Once these two spraying substeps E201 and E202 have been carried out, the process according to the invention includes a drying substep E203 during which the composite layer solidifies, notably by evaporation of water and / or by polymerization. During this drying substep E203, the binder hardens, notably by evaporation of water, preferably at atmospheric pressure.

[0199] During the drying of a composite layer, a series of physical and chemical processes influence the final structure of the polymer film. The transformation is based primarily on water evaporation, particle coalescence, and the formation of a continuous polymer network.

[0200] When water acts as a dispersing medium for polymer particles, as the composite layer is sprayed onto a substrate, during a drying substep, water begins to evaporate from the air / film interface. This process induces a concentration gradient, causing the film to progressively become enriched with polymer at the surface. As the water concentration decreases, the polymer particles come into contact and begin to deform under capillary forces. Residual water continues to migrate through interparticle channels. For example, in the case of a binder containing polyurethane, when the water content becomes very low, the polyurethane chains interdiffused between neighboring particles, leading to coalescence and the formation of a continuous, homogeneous film. This film then hardens through partial crosslinking or physical reorganization of the macromolecular segments.

[0201] It should be noted that water acts as a temporary plasticizer. Its evaporation decreases chain mobility and increases the glass transition temperature (Tg) of the material. Similarly, as intermolecular distances decrease, hydrogen bonds and dipole-dipole interactions strengthen, improving network cohesion. Finally, the disappearance of water leads to the fusion of flexible and rigid polymer domains, producing a strong, adherent, and durable film. Thus, controlling water evaporation is essential for obtaining a film with high mechanical and aesthetic performance.

[0202] Due to the thinness of the liquid composition layer, this drying can be quite rapid, for example, on the order of 1 to 10 minutes, preferably 2 to 8 minutes, and most preferably 3 to 5 minutes. Upon hardening, the binder fixes the filler, forming a rod-shaped textile material.

[0203] This applies to any sub-stage of drying a composite layer.

[0204] The term "solidification" refers to the process by which a product in a liquid or viscous state becomes solid, whether hard, flexible, or semi-rigid. During a sub-step of drying, the composite layer solidifies, preferentially becoming flexible or semi-rigid.

[0205] A drying sub-step E203 can be carried out at ambient temperature, or with heating, for example at a temperature between 50 and 90 °C. This can be applied each time a composite layer is dried.

[0206] The drying sub-steps are preferably carried out at atmospheric pressure.

[0207] According to one embodiment, during the drying substep E203, the support 5 can be subjected to vibrations, for example by means of a vibrator.

[0208] If the binder contains latex, a drying substep must also include a curing step to solidify the latex. This curing step is preferably carried out by heating. "Curing" refers to any process that hardens and stabilizes a polymer material, particularly rubber. This curing process can be achieved, for example, by heating, using chemical agents such as peroxides, or by UV irradiation. Vulcanization is a well-known example of a curing process.

[0209] This can be valid whenever a composite layer located on the support 5 or in a molding cavity 7,9 is dried, the molding cavity 7,9 being subjected to vibrations in the latter case.

[0210] The spraying substeps E201 and E202, which produce a composite layer, and the drying substep E203, which solidifies said composite layer, can be repeated at least once to increase the thickness of the rod 2 on the deposition surface 501 of the support 5. The process according to the invention thus comprises at least one repetition step E204, which includes a spraying step E201 of a liquid composition and a spraying step E202 of a filler, followed by at least one drying substep E203 of the resulting composite layer. This principle applies to each repetition step E204, E205, and E205 of the process.

[0211] The spraying substeps E201, E202, and drying substep E203 are preferably repeated one to five times, more preferably twice, so as to superimpose three composite layers in total. This can be applied to each repetition step E204, E305, E505 of the process. This makes it possible, for example, to obtain an upper 2 with an average thickness of between 0.1 and 3 mm, preferably between 0.2 and 2 mm, for the manufacture of most shoes.

[0212] During a repeating substep E204 for layering composite materials, the liquid composition and / or filler according to the invention used for each composite layer may be identical to those of the preceding composite layer or different. In the latter case, the composition of the upper 2 is not homogeneous throughout its thickness. This allows, in particular, the combination of the characteristics of several polymers and / or fillers within the same part of a shoe 1, and thus such a part of the shoe, like its upper 2, may have inner and outer surfaces with different feels and / or appearances. This can be applied to any substep during which composite materials are layered.

[0213] Similarly, during a spraying substep E201.E202, it is possible to simultaneously spray liquid compositions and / or fillers according to the invention that differ locally, in different locations, thus obtaining a rod 2 whose composition is not homogeneous over its entire surface. This can be applied to any spraying substep.

[0214] Finally, during a spraying substep E201.E202, it is possible to locally spray more liquid composition and / or more filler, for example, onto the deposition surface 501, or to repeat the spraying substeps E201.E202 in order to spray liquid composition and / or filler locally only onto a specific part of the deposition surface 501. This makes it possible, in particular, to vary the thickness of the resulting rod 2 locally. This can also be applied to any spraying substep.

[0215] After the spraying substeps E201.E202 and drying substep E203, a rod 2 consisting of an alternation of composite layers is formed on the deposition surface 501 of the support 5.

[0216] This upper 2 is preferably left in place on the support 5 for the following steps. However, if a midsole 3 is to be housed inside the upper 2, the latter will be temporarily removed from the support 5 to allow the insertion of the midsole 3, and then preferably replaced on the support 5. Removing the upper 2 from the support 5 is facilitated by the preferentially flexible nature of the composite layers constituting said upper 2. This removal can also be facilitated by cutting the upper 2 at the instep to create a space necessary for inserting the foot into the shoe 1.

[0217] The method according to the invention also includes steps of forming E03 an intermediate sole 3 and of positioning E04 said intermediate sole 3 against the upper 2 to form an assembly.

[0218] There are several variations for these steps depending on whether the midsole 3 is manufactured directly on the upper 2 or is manufactured separately, and depending on whether the midsole 3 is intended to be housed inside the upper 2 or to be assembled on the underside of it.

[0219] During the E03 formation stage of the midsole 3, said midsole 3 can be obtained by one of the following techniques: spraying of a composite liquid composition comprising a binder and a filler; injection molding with a material containing a binder; or cutting with a die in a thickness of material containing a binder.

[0220] This can also be applied to the E05 training step of outsole 4.

[0221] The binder-containing material is preferably made from a composite liquid composition comprising a binder and a filler. The composite liquid composition preferably comprises a binder and a solvent in which the binder is dissolved and / or in dispersion form, as well as a filler consisting of loose fibers and / or a powder. These constituents are preferably a liquid composition and a filler according to the invention as described above.

[0222] According to a variant of the formation steps E03 of the midsole 3 and the positioning steps E04 of the midsole 3 against the upper 2, these steps are carried out simultaneously so that the midsole 3 is directly manufactured on the underside of the upper 2. These formation steps E03 of the midsole 3 and the positioning steps E04 of the midsole 3 against the upper 2 then include the following sub-steps (see [Fig. 4]): supply E301 a of a molding frame 6 in the form of an intermediate sole; installation E302a of the molding frame 6 on the underside of the stem 2; spraying E303a of a liquid composition and a filler inside the molding frame 6 and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying E101 of at least one liquid composition and supplying E102 of at least one filler; E304a drying of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; repetition E305a at least once of the previous spraying substeps E303a and drying substeps E304a, and formation, on the underside of the stem 2 and in the molding frame, of an intermediate sole 3 made up of an alternation of composite layers; and shrinkage E306a of the molding frame.

[0223] To illustrate this variant, a molding frame 6 in the form of an intermediate sole and positioned on the underside of a rod 2 mounted on a support 5 is shown in [Fig. 16]. In this figure, the support 5 is oriented so that the underside of the rod 2 is facing upwards.

[0224] The molding frame 6 is a component that encloses a certain volume with a rim defining a surface shaped like an intermediate sole, that is, having a general arch-like shape. The molding frame 6 preferably has a height greater than or equal to the desired thickness of the intermediate sole 3. The molding frame 6 preferably conforms to the shape of the underside of the upper 2.

[0225] During the E03 formation step of the midsole 3, one or more masks can be used to spray a composite layer only in certain delimited areas of said midsole 3, thus allowing for more localized spraying of material. As an example, such a mask 11 is shown in [Fig. 22], which is intended to be positioned on the underside of a midsole 3. This mask 11 has three windows 111, 112, 113 through which a composite layer can be sprayed to form three reinforcement layers 31, 32, 33 on the underside of the midsole 3. In [Fig. 22], the mask 11 is shown at a distance from the midsole 3. It is preferably positioned in contact with the midsole 3 or in its immediate vicinity during the formation of the reinforcement layers 31, 32, 33 by spraying.

[0226] In this variant, as in the following ones, the liquid composition and the charge are preferably a liquid composition and a charge according to the invention such as those previously described.

[0227] According to another variant of the E03 formation step of the midsole 3, the latter is manufactured separately to then be introduced inside the upper 2 or to be assembled on the underside of it.

[0228] This E03 formation step of the midsole 3 then includes the following sub-steps (see [Fig. 5]): supply E301 b of a molding cavity 7 in the form of an intermediate sole; spraying E303b of a liquid composition and a filler inside the molding cavity 7 and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying E101 of at least one liquid composition and supplying E102 of at least one filler; E304b drying of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; repetition E305b at least once of the preceding spraying substeps E303b and drying substeps E304b, and formation, in the mold cavity 7, of an intermediate sole 3 consisting of alternating composite layers; and E306b midsole removal 3 out of molding impression 7.

[0229] A molding impression 7 is a negative shape, preferably formed in a hollow in a support 5b for example in the form of a plate and may include several molding impressions 7. The molding impression 7 delimits a certain volume whose general shape is that of an intermediate sole and whose depth is preferably greater than or equal to the desired thickness for the intermediate sole 3.

[0230] Figure 12 illustrates a plate-shaped support 5b with six molding impressions 7 in the shape of an insole, three impressions for the left foot and three impressions for the right foot. As in injection molding, a molding impression 7, on its face intended to receive a sprayed material, may have raised and / or recessed areas allowing for the creation of recesses and / or raised areas respectively in the insole 3, which is produced by spraying into said molding impression 7.

[0231] Similar variants can be considered for the E05 formation stage of the outsole 4 and for the E06 assembly stage with the rest of the shoe 1.

[0232] Thus, according to a variant of the outsole 4 formation step E05 and the outsole 4 assembly step E06 onto the upper 2 and midsole 3, these steps are carried out simultaneously so that the outsole 4 is directly manufactured on the underside of the upper 2 if the midsole 3 is housed inside the upper 2, or directly manufactured on the underside of the midsole 3 if the latter has been assembled onto the underside of the upper 2. These outsole 4 formation step E05 and outsole 4 assembly step E06 onto the upper 2 and midsole 3 then include the following substeps (see [Fig. 7]): supply E501 has an 8-shaped molding frame outsole; E502a installation of the molding frame 8 on the underside of the stem 2 or on the underside of the intermediate sole 3 if the latter is on the underside of the stem 2; spraying E503a of a liquid composition and a filler inside the molding frame 8 and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying E101 of at least one liquid composition and supplying E102 of at least one filler; E504a drying of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; repetition E505a at least once of the preceding spraying substeps E503a and drying substeps E504a, and formation, on the underside of the upper 2 or on the underside of the midsole 3 and within the molding frame 8, of an outsole 4 consisting of alternating composite layers; and E506a removal from molding frame 8.

[0233] To illustrate this variant, a molding frame 8 in the shape of an outsole and positioned on the underside of an intermediate sole 3 assembled on the underside of a stem 2 mounted on a support 5 is shown in [Fig. 17]. In this figure, the support 5 is oriented so that the underside of the stem 2 and the intermediate sole 3 are directed upwards.

[0234] In the case where the intermediate sole 3 is housed in the stem 2, the positioning of the molding frame 8 in the form of an outsole on the underside of the stem 2 would be illustrated by a figure very similar to [Fig. 16].

[0235] The molding frame 8, shaped like the outsole, is very similar to the molding frame 6, shaped like the midsole. These two frames, 6 and 8, are used in essentially the same way and can have a very similar shape. Naturally, the molding frame 8 preferably has a height greater than or equal to the desired thickness for the outsole 4, and it preferably conforms to the shape of the underside of the upper 2 or the shape of the midsole 3.

[0236] According to another variant of the E05 outsole 4 formation step, the latter is manufactured separately to then be assembled on the underside of the upper 2 if the midsole 3 is housed inside the upper 2 or to then be assembled on the underside of the midsole 3 if the latter has been assembled on the underside of the upper 2.

[0237] This E05 formation step of the outsole 4 then includes the following sub-steps (see [Fig. 8]): supply E501 b of a molding cavity 9 in the shape of an outsole; spraying E503b of a liquid composition and a filler inside the molding cavity 9 and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying E101 of at least one liquid composition and supplying E102 of at least one filler; E504b drying of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; repetition E505b at least once of the preceding spraying substeps E503b and drying substeps E504b, and formation, in the mold cavity 9, of an outsole 4 consisting of alternating composite layers; and E506b outsole removal 4 out of molding impression 9.

[0238] An outsole-shaped molding cavity 9 is very similar to the midsole-shaped molding cavity 7, and these two molding cavities 7 and 9 are used in essentially the same way and can have a very similar shape. Of course, the molding cavity 9 delimits a certain volume whose general shape is that of an outsole and whose depth is preferably greater than or equal to the desired thickness for the outsole 4.

[0239] Figure 13 illustrates a plate-shaped support 5b with six molding impressions 9 in the shape of an outsole, three impressions for the left foot and three impressions for the right foot. On its face intended to receive a sprayed material, the molding impression 9 preferentially has raised and / or recessed areas, allowing for the creation of recesses and / or raised areas respectively in the outsole 4, which is produced by spraying into said molding impression 9.

[0240] When the midsole 3 and / or the outsole 4 is manufactured separately, by spraying or another process, it must then be assembled with the rest of the shoe. This assembly can be done by any known method, for example by gluing, but it is preferably carried out by spraying.

[0241] According to one variant of the invention, the intermediate sole 3 is assembled on the underside of the upper 2 by the following sub-steps (see [Fig. 6]): spraying E401 of a liquid assembly composition onto the underside of the rod 2 and obtaining a layer of liquid assembly composition, said liquid assembly composition resulting from the supply substep E101 of at least one liquid composition; positioning E402 and pressure E403 of the intermediate sole 3 on the liquid assembly composition layer; and E404 drying of the liquid assembly composition layer and solidification of the binder of the liquid assembly composition layer by evaporation of water.

[0242] In this embodiment, as in the following ones, the liquid assembly composition is preferably such as the liquid composition according to the invention described above. The binder of a liquid assembly composition is preferably chemically compatible with a binder of each of the two composite layers bonded by said liquid assembly composition. "Chemically compatible" means the ability of different chemical substances to coexist without undesirable reaction and to form chemical bonds in such a way as to reduce the risk of delamination between two elements made with said chemical substances.Thus, when the binder of the liquid assembly composition is chemically compatible with the composition of the layers it is to assemble, not only does it not degrade said layers, but it also creates chemical bonds with these layers to avoid any phenomenon of delamination within a shoe 1.

[0243] According to a variant of the invention, when the midsole 3 is positioned inside the upper 2, the assembly step E06 of the outsole 4 on the underside of the upper 2 comprises the following sub-steps (see [Fig. 9]): spraying E601a of a liquid assembly composition onto the underside of the stem 2 and obtaining a layer of liquid assembly composition, said liquid assembly composition resulting from the supply substep E101 of at least one liquid composition; positioning E602a and pressure E603a of the outsole 4 on the liquid assembly composition layer; drying E604a of the liquid assembly composition layer and solidification of the binder of the liquid assembly composition layer by evaporation of water.

[0244] According to another embodiment of the invention, when the midsole 3 is assembled on the underside of the upper 2, the assembly step E06 of the outsole 4 on the underside of the midsole 3 comprises the following substeps: spraying E601 b of a layer of liquid assembly composition on the underside of the intermediate sole 3 and obtaining a layer of liquid assembly composition, said liquid assembly composition resulting from the supply substep E101 of at least one liquid composition; positioning E602b and pressure E603b of the outsole 4 on the liquid assembly composition layer; and E604b drying of the liquid assembly composition layer and solidification of the binder of the liquid assembly composition layer by evaporation of water.

[0245] According to one variant of the invention, a three-dimensional reinforcement 10 in the shape of a heel can be embedded in the outsole 4 (see [Fig. 4] and [Fig. 5]), for example by positioning it at the heel after spraying a composite layer of the outsole 4 and before spraying the next composite layer.

[0246] This three-dimensional reinforcement 10 is for example made of ethylene-vinyl acetate (EVA) or any bio-based foaming material, in particular by injection molding or by spraying with a process and / or composition similar to those for making an intermediate sole 3 or an outsole 4 by spraying according to the invention.

[0247] Of course, other three-dimensional reinforcements 10 such as woven or knitted textiles can also be integrated in this way into the midsole 3 or the outsole 4 of a shoe 1 according to the invention, locally or over the entire length or width of the foot.

[0248] After the step E08 of removing the shoe 1 from the support 5, the process according to the invention may include an optional finalization step E09 of the shoe, this finalization step E09 comprising at least one of the following substeps: rectification of the edges surrounding the opening of stem 2; cutting out lace passages in the upper 2 and fitting an eyelet in each lace passage; decoration of shoe 1 by printing, spraying or hot stamping; functionalization of shoe 1 by gluing elements onto it; and cutting of the instep of shoe 1.

[0249] If the upper 2 of the shoe 1 is designed to have a lace-type closure system, to ensure productivity, the lace-up can be carried out during this optional finalization step E09.

[0250] If upper 2 of shoe 1 is not designed to accommodate a lace-up closure system, a localized increase in thickness over the instep may be necessary to provide support. This increase in thickness, also known as zoning, is achieved through both design and the selection of materials specifically chosen for this functional area.

[0251] Generally, spray-coated parts may have irregular edges or edges that taper towards the outside. Therefore, it may be necessary to correct them. This edge correction can be done, for example, by simple cutting, or by creating hems when the edge thickness allows.

[0252] The application of laces, embroidery and other decorative elements by gluing can also have a local reinforcing function, for example on the side of the arch of the foot, at the back of the shoe 1 or the forefoot.

[0253] Optionally, the method according to the invention may also include a step E07 for forming a topcoat, which is performed before the step E08 for removing the shoe 1 from the support 5. This step E07 for forming a topcoat includes a substep E701 for spraying a layer of liquid finishing composition onto the last composite layer, followed by a substep E702 for drying said layer of liquid finishing composition (see [Fig. 10]). The last composite layer onto which a layer of liquid finishing composition is sprayed is preferably an outer face of the shoe 1.

[0254] The finishing liquid composition is preferably a liquid composition according to the invention as previously described.

[0255] This drying substep E12 for hardening, for example by polymerization of the binder polymer(s) by evaporation of water, has the same characteristics as the drying step E203 previously described for a composite layer resulting from the formation step E05 of a composite layer.

[0256] This E07 formation step of a topcoat allows, for example, to ensure that the last filler to have been sprayed adheres well to the polymer(s) of the binder, or even is completely embedded in it.

[0257] This E07 formation step of a topcoat can also be achieved by adding glass beads, particularly of micron dimensions, to the liquid solution in addition to the usual fillers to enhance abrasion resistance, on all or part of the external surface.

[0258] The advantages provided by adding glass beads to the liquid solution are given in the table below.

[0259] [Table 4]

[0260] The technical characteristics of the glass beads are given in the table below.

[0261] [Table 5]

[0262] The size of the beads can be adjusted according to the specific need of the final product: Microbeads (0.05 mm - 0.5 mm): For a softer finish and better integration into the material. Medium beads (0.5 mm - 1 mm): Ideal for concealing imperfections while providing texture. Large beads (1 mm - 2 mm): Used for applications requiring a rougher texture.

[0263] With spray pressures of up to 100 bar, it is essential that the beads are strong enough not to break during the application process.

[0264] Optionally, for example after a drying substep E203, E304, E404, E504, E604, E702 of a layer of material, the process according to the invention may also include an optional stabilization step E10 of said layer of material or of a part of the shoe 1. This stabilization step E10 comprises at least one of the following substeps: heat treatment; plasma therapy; and / or cross-linking by UV irradiation.

[0265] This stabilization step E10 of a part of the shoe 1 or a layer of material, preferably composite, can notably render inert the organic components of the filler that are likely to mineralize or degrade over time. This step can also be used to treat a material in order to functionalize it or modify its physicochemical properties, for example to waterproof it, activate it, clean it, improve its adhesion, control its final shrinkage, or impregnate it with a scented, coloring, antifungal, antimicrobial, or other substance.

[0266] Heat treatment, for example, involves subjecting a material to a temperature between 50 and 90 °C for a period of 5 to 30 minutes, depending on the nature and thickness of the layer being treated. This allows for control of the material's final shrinkage in order to stabilize its dimensions. Indeed, a layer or part of the shoe 1 is likely to absorb moisture after its manufacture, and this heat treatment therefore aims to achieve a short drying process to ensure that it is moisture-free before use or packaging for the manufacture of a shoe 1.

[0267] Plasma treatment can be performed using atmospheric pressure plasma or low-pressure plasma. Atmospheric pressure plasma operates at pressures close to atmospheric pressure, allowing for rapid and efficient treatment. It is preferentially used for continuous applications, while low-pressure plasma is generally operated below 0.1 to 1 Torr, offering precise control over treatment conditions. It requires longer exposure times but can utilize higher power levels.

[0268] The power used for plasma treatment varies depending on the type of plasma and the treatment objectives. It can range from a few watts to several kilowatts, depending on the equipment and application, and is adjusted according to the type of material and the desired properties. For example, it ranges from 10 to 200 watts for atmospheric pressure plasma and from 100 to 1000 watts for low-pressure plasma. High power can improve the cleaning and functionalization of the treated layer or part of the shoe, but it must be balanced to avoid damaging the material. Excessive power can lead to thermal degradation of the material.

[0269] Just like the power applied, the duration of exposure and the type of gas used (nitrogen, argon, etc.) for plasma treatment are crucial to optimizing results.

[0270] The exposure time is for example between 10 seconds and 10 minutes, while the gas used is chosen according to the desired effect and its chemical reactivity with the material of the layer or part of the shoe 1.

[0271] The gases that can be used are as follows: Oxygen (O2): used to improve the hydrophilicity of the filler fibers (e.g., polyester fibers). Argon (Ar): used to increase the hardness of the fibers in the filler. A fluorinated gas (e.g., CF4): makes surfaces hydrophobic, similar to PTFE. A mixture of ethylene and propylene: used to obtain an oleophilic material. Nitrogen (N2): used for specific treatments and to create an inert atmosphere.

[0272] Plasma treatment can be combined with the incorporation of a liquid, powder, microparticles, or nanoparticles. For example, hydrophobic treatment of a surface can be achieved by combining plasma treatment with the addition of hydrophobic agents to create a waterproof layer or section of the shoe. Similarly, plasma treatment can be combined with the incorporation of nanoparticles or antimicrobial agents to enhance the antibacterial and antifungal properties of a layer or section of the shoe.

[0273] Plasma treatment can modify the surface texture of a layer or part of the shoe 1, for example, to prepare the surface before printing or bonding. In this case, plasma treatment can be used to increase the specific surface area available for adhesion, thereby improving the performance of the applied coatings.

[0274] Plasma treatment is advantageous because it reduces the use of water and chemicals compared to traditional methods. Indeed, plasma treatment requires little or no water and reduces the use of organic solvents, thus minimizing the environmental impact of the process.

[0275] UV irradiation crosslinking involves irradiating a coating with ultraviolet rays. This crosslinking can occur, for example, through free radicals or cationic processes. In both cases, UV protection is necessary to protect the skin and eyes.

[0276] Free radical crosslinking relies on the decomposition of a photoinitiator, releasing free radicals. It allows for very rapid polymerization, on the order of a few seconds, but is sensitive to oxygen inhibition. It generally promotes good adhesion of the treated layer, but its effectiveness depends on the composition of the photoinitiator and can be limited by the layer's thickness. Therefore, longer exposure times are required for thicker materials. Free radical crosslinking uses UV radiation power preferably between 200 and 400 mW / cm². 2 , for a period preferably between 1 and 10 seconds depending on the formulation and thickness of the layer being treated.

[0277] Cationic crosslinking relies on the formation of positive ions by UV irradiation. It allows for a slightly slower polymerization rate than free radical crosslinking, on the order of a few minutes, but is less susceptible to oxygen inhibition. It generally promotes good chemical and thermal resistance of the treated layer, and its effectiveness is less affected by thickness than free radical crosslinking. Cationic crosslinking uses a UV radiation power preferably between 100 and 300 mW / cm². 2 , for a period preferably between 10 and 60 seconds depending on the formulation and thickness of the layer being treated.

[0278] In the process according to the invention, free radical crosslinking is preferred because it is faster and suitable for the small thicknesses of the layers obtained during each spraying step.

[0279] Optionally, the process according to the invention may also include a step of applying pressure to the material of a layer or part of the shoe 1, for example before the stabilization step E10, to increase the mechanical properties of the composite layers and prevent their delamination. This pressure may, for example, be applied to the material of a layer or part of the shoe 1 by means of a counter-mold that substantially conforms to its shape, while respecting the surface design of the part.

[0280] The invention also relates to the shoe 1 obtained by the process, comprising an upper 2, a midsole 3, and an outsole 4. The shoe 1 is particularly distinguished in that the upper 2 comprises alternating layers of material based on at least one binder comprising one or more water-soluble polymers or polymers capable of forming a dispersion in water, and at least one filler comprising a powder and / or fibers. It is also distinguished in that at least one sole can be assembled to the rest of the shoe 1, not by gluing, but by spraying a liquid assembly composition, which is preferably such as the liquid composition according to the invention described above.

[0281] Depending on the nature of the liquid compositions used, the different layers of material constituting the upper 2, the midsole 3 and outsole 4, or even the entire shoe 1, may be more or less bonded to each other. They may also form a virtually homogeneous whole, making it impossible to distinguish them.

[0282] The implementation of the process for producing a shoe 1 by spraying of the invention requires in particular the use of at least one spraying system 18, comprising one or more spraying units 19. Any suitable spraying system 18 can be used within the framework of the present invention.

[0283] For spraying a liquid composition and / or a charge comprising powder and / or loose fibers according to the invention onto the support 5, in a mold cavity 7,9 or in a mold frame 6,8 a suitable spraying unit 19 may include, but not limited to, an air-based, airless or electrostatic-based sprayer, and be for example in the form of a spray gun.

[0284] Besides the spraying unit 19, the spraying system 18 may also include one or more fluid displacement devices 20, tanks 21, flow and / or pressure regulators 22, supply pipes 23 and other components known in the art for spraying liquid products or bulk fibers.

[0285] A fluid handling device 20 allows a liquid, powder, fibers, or composite material to be conveyed from a reservoir 21 to a spraying unit 19. In the case of a liquid or composite material, this is preferably a pump. In the case of a powder or fibers, it is preferably a compressor.

[0286] Each spray unit 19 is preferably variable flow to allow the creation of thicker bands or layers of product in the desired locations.

[0287] A spraying system 18 comprising several spraying units 19 makes it possible in particular to spray the desired quantities of product more quickly and / or to spray different products simultaneously.

[0288] Support 5 can be fixed or mobile.

[0289] The spraying system 18 may also include one or more positioning devices 24, for example in the form of a fixed, mobile and / or articulated leg, a robotic arm, a cobot 24a, or any other known suitable device, enabling the controlled and precise movement and orientation of a spraying unit 19 and / or the support 5, 5b in space. If masks are used, each mask may also be associated with a positioning device 24.

[0290] The spraying system 18 may also include a controller 25 that adjusts, in particular, the position relationship between each spraying unit 19 and the support 5, and that adjusts in real time the flow rate of each spraying unit 19, notably in order to precisely control the position, arrangement, and thickness of the sprayed layers. An increase in thickness can be achieved by repeating the spraying on specific areas, by slowing the movement over specific areas, or by increasing the flow rate of the sprayed product over specific areas.

[0291] The controller 25 can thus control each spraying unit 19, each fluid displacement device 20, each flow and / or pressure regulator 22, each positioning device 24 by means of control lines 27. It can also be connected to a probe provided in each of the tanks 21 in order to measure the quantity of material in each tank 21, and can in particular be provided to warn the operator when this quantity becomes low.

[0292] The controller 25 can also control the mask positioning device 24 if necessary.

[0293] In general, the controller 25 can be designed to automate or assist all or part of the process of producing a shoe 1 by spraying.

[0294] The controller 25 can be a computer, terminal, control cabinet, workstation or any other electronic device, preferably programmable, capable of controlling each device of the spraying system 18, for example individually and in a particular sequence.

[0295] Each spraying unit 19 can include a single spray nozzle 26 (cf. [Fig. 11]) or several (see [Fig. 12] and [Fig. 13]), the latter being oriented in the same direction or in different directions, for example converging towards a point located at an ideal spraying distance. Each spray nozzle 26 can spray the same material or different materials.

[0296] Each spray nozzle 26 can be provided to spray a liquid composition, fibers, a powder or a composite mixture according to the invention, each spray nozzle 26 being in particular connected to a suitable product reservoir 21 via a supply pipe 23.

[0297] In [Fig. 11] given as an example, two spraying units 19, each comprising a single spray nozzle 26, are provided on either side of a support 5 shaped at the base for the production of a rod 2. In this example, the support 5 is mounted on a positioning device 24 articulated and rotatable about a vertical axis so that the two spraying units 19, themselves each mounted on an articulated positioning device 24, can spray their respective product over the entire deposition surface 501. In this example, having two spraying units 19 makes it possible, for example, to spray two different products, either simultaneously or one after the other, these two products each being a liquid composition, a filler, or a composite mixture of the two.

[0298] In [Fig. 12] and [Fig. 13], also given as examples, a single spraying unit 19 with three spray nozzles 26 is provided near a plate-shaped support 5b for the production of soles. In [Fig. 12], the plate-shaped support 5b has six molding cavities 7 in the shape of an insole, three for the left foot and three for the right foot, while in [Fig. 13], the plate-shaped support 5b has six molding cavities 9 in the shape of an outsole, three for the left foot and three for the right foot. The support 5b and the spraying unit 19 are each mounted on an articulated positioning device 24.

[0299] The examples illustrated on [Fig. 12] and [Fig. 13] will be described in greater detail later in an example of implementation of the method of the invention.

[0300] It should be noted that the examples illustrated in [Fig. 11] to [Fig. 13] are highly schematic and do not necessarily represent reality. In the example illustrated in [Fig. 11], each spray nozzle 26 is connected to a single, dedicated reservoir 21. It is also possible to provide several reservoirs 21, each containing, for example, a different liquid composition and / or charge(s), which can be connected as needed to the same spray nozzle 26 by means of a quick-connect system. Each spray nozzle 26 can also be connected to several reservoirs 21, for example via a multiport valve 28, as illustrated in [Fig. 12] and [Fig. 13].

[0301] In order to control the air quality, ambient temperature and humidity, the means of the invention, in particular the spraying system 18 and the support 5.5b, can be housed in an enclosure 29. Due to the possible presence of robot(s), access to this enclosure 29 can be secured. EXAMPLES OF ACHIEVEMENTS

[0302] Examples of liquid compositions

[0303] Six examples of liquid compositions according to the invention are given in the table below. The percentage of each component is given by weight relative to the total mass of the liquid composition.

[0304] [Table 6]

[0305] Examples of charges

[0306] Six examples of loads according to the invention are given in the table below. The percentage of each component is given by weight relative to the total mass of the load.

[0307] [Table 7]

[00308] Examples of composite layers

[0309] Six generic examples of composition for a composite layer according to the invention are given in the table below. The percentage of each component is given by weight relative to the total mass of the composite layer before it dries.

[0310] [Table 8]

[00311] Three specific examples of compositions for a composite layer according to the invention are given in the table below. The percentage of each component is given by weight relative to the total mass of the composite layer before drying.

[0312] [Table 9]

[00313] In this table, example CC1 relates to a composite layer intended to be the outer layer of the upper 2 within a shoe 1, not comprising fibers, but comprising both Impranil® DL 43031 and Impranil® DL 43031 in order to also provide UV and abrasion resistance to the upper 2.

[0314] Example CC2 relates to a composite layer intended to be the inner layer of the upper 2 within a shoe 1, comprising both fibers and powders for thermal comfort and moisture management, and a binder based on Impranil® DL 43031 and Impranil® DL 43031 for good mechanical strength of the fibers deposited on the surface, as well as good elasticity for the upper 2.

[0315] Example CC3 concerns a composite layer intended to be the lower layer of a midsole 3 within a shoe 1. It comprises both fibers and powders for thermal comfort and moisture management, bound in a rubber-based binder and polyester-polyurethane dispersion to ensure good mechanical strength of the surface-deposited fibers, as well as good elasticity. It contains a significant amount of Impranil® DL 2611-based binder to enhance abrasion resistance.

[0316] Example CC4 relates to a composite layer intended to be the top layer of a midsole 3 within a shoe 1. It comprises both fibers and powders for thermal comfort and moisture management, in a binder based on rubber and polyester-polyurethane dispersion to allow good mechanical strength of the fibers deposited on the surface, as well as good elasticity.

[0317] Example CC5 relates to a composite layer intended to be the outer layer of an outsole 4 within a shoe 1, i.e. the layer intended to be in contact with the ground.

[0318] Example CC6 relates to a composite layer intended to be the intermediate layer of an outsole 4 within a shoe 1.

[0319] Finally, example CC7 concerns a composite layer intended to be the inner layer of an outsole 4 within a shoe 1, that is to say the layer intended to be in contact with the upper 2. Its composition is compatible with that of layer CC1 of the upper onto which it will be assembled by spraying.

[0320] Example of implementation of the process

[0321] An example of implementing the process of the invention according to the invention is given below for the manufacture of a shoe 1 whose three main parts are produced and assembled by spraying. These three parts are: an upper 2 made by spraying on a foot-shaped support 5 and having both a volume to accommodate the foot of the shoe user 1 and a volume to accommodate an intermediate sole 3 below the volume intended for the user's foot; an intermediate sole 3 produced by spraying onto a support 5 having an imprint in the shape of an intermediate sole, said intermediate sole 3 having a face with reliefs designed to cushion the contact of the foot with the ground by mechanical deformations and being subsequently housed in a removable manner within the upper volume 2 provided for this purpose; and an outsole 4 made by spraying onto a support 5 in the shape of an outsole, said outsole 4 being then assembled onto the underside of the upper 2 by spraying.

[0322] In this example, the upper 2 is made with a lace-up opening.

[0323] During the manufacturing of the midsole 3, each composite layer is sprayed according to a pattern that evolves with each layer to build a lattice structure, similar to additive manufacturing. However, unlike a conventional additive manufacturing process in which the material composing the object remains identical throughout the entire manufacturing process, the composition of each composite layer can vary at each stage. This allows for the advantageous creation of unique properties in the final midsole 3, such as aesthetic properties (color, appearance, feel, etc.) or technical properties (variations in thickness, rigidity, shape, etc.) to improve the performance, comfort, or appearance of the shoe 1.

[0324] It should be noted that providing a removable midsole 3 further reduces environmental impact by allowing the separability of components, thus promoting their recyclability and increasing lifespan by only replacing what has reached the end of its life. This also allows for shoe customization, enabling the user to, for example, choose their midsole 3 based on their weight and intended use of the shoe 1.

[0325] In this example, the equipment used for the manufacture of a shoe 1 is housed in an enclosure 29. This equipment consists of the following (see [Fig. 11], [Fig. 12] and [Fig. 13]). Their number is also indicated in parentheses. Enclosure 29 of 4.10 x 5.40 x 2.40 m including lighting, security door and window, camera, security sensors and door closing contact (x1). Enclosure air filtration devices (x4). Enclosure air conditioning and humidity control device (x1). Spraying units 19 (x3). Spray nozzles 26 (x3) equipping the spray unit 19, comprising two nozzles 26a, 26b adapted for spraying a composite mixture and one nozzle 26c adapted for spraying loose fibers. Tanks 21 (x3), including two tanks 21a, 21b for liquid composite mixture and one tank 21c for loose fibers. Multi-way valve 28, in the form of a mixing solenoid valve, suitable for connecting each spray nozzle 26a, 26b, 26c to one of the tanks 21a, 21b, 21c. Fluid displacement device 20 (x3) each associated with one of the tanks 21 to supply the multi-way valve 28 with fluid, two fluid displacement devices 20a, 20b being pumps connected to the tanks 21a, 21b for composite mixture, while the last fluid displacement device 20c is a compressor connected to the tank 21c for fibers. Flow and / or pressure regulators 22 (x3) in the form of solenoid valves 22a, 22b, 22c each associated with one of the fluid supply lines of the multi-way valve 28 from the tanks 21a, 21b, 21c. Polymer supply pipes 23 (x3) each connecting the multi-way valve 28 to a spray nozzle. Polymer supply pipes 23 (x3) each connecting a tank 21, to the multiport valve 28, as well as to the flow and / or pressure regulator 22 and the associated fluid displacement device 20. Positioning device 24 (x1 ) for the spraying unit 19 in the form of a cobot 24a. Support 5 in volume (x1) having a three-dimensional deposition surface (501) having the general shape of a foot and whose volume corresponds to that of a foot plus the volume of the removable intermediate sole 3. Support 5b in volume (x1) in the form of a plate having impressions 7 in the form of an intermediate sole (x6) or impressions 9 in the form of an outsole (x6). Positioning device 24 (x1) for the support 5 in the form of an articulated arm 24b. Drying system (x1). Plasma processing unit (x1). Controller 25 (x1), in the form of a control cabinet for the spray units 19, the multi-way valve 28, the solenoid valves 22a, 22b, 22c, the fluid pumps 20a, 20b, the compressor 20c, the cobot 24a and the articulated arm 24b with a touch screen, synchronizing in particular the articulated arm 24b and the cobot 24a. Electrical cabinet (x1) and electrical cables to supply electricity to the various devices.

[0326] For the sake of clarity in the figures, only a portion of this equipment is illustrated schematically and in a simplified manner in [Fig. 11],

[0327] As a reminder, a cobot, or collaborative robot, is a robot designed for direct human-robot interaction within a space where humans and robots are in close proximity.

[0328] Stem manufacturing:

[0329] Some of the equipment used for the manufacture of a rod 2 is illustrated in [Fig. 11],

[0330] In this example of process implementation, the upper 2 of shoe 1 is manufactured by spraying and layering two composite layers CC1 and CC2 onto a three-dimensional form shaped like a foot, the compositions of which are given in the table below. The percentage of each component is given by weight relative to the total mass of the composite layer before it dries.

[0331] [Table 10]

[90332] In this table, layer CC1 refers to a first composite layer, as it is sprayed first. This layer is intended to be the outer layer of stem 2 after it is folded over itself. This composite layer contains a polyurethane dispersion compatible with layer CC2 and the composite layer that will later be sprayed onto the outer layer of stem 2 to prevent delamination between these layers. Layer CC1 also provides UV and abrasion resistance to stem 2.

[0333] Impranil® DL 43031 is a polyester-based polyurethane blend. It comprises approximately 25% polymers in solution in a mixture of toluene and isopropanol.

[0334] Impranil® DL 1126 is a dispersion of aliphatic polyurethane and polycarbonate.

[0335] The advantages of the different components of the CC1 layer are as follows: Impranil® DL 43031 is a bio-based binder that provides excellent adhesion and flexibility, is water-resistant and allows for a smooth and uniform finish; Impranil ® DL 1126 is a bio-based binder, with a formulation without neutralizing amine, exhibiting good resistance to hydrolysis and high durability, with high resistance against scratches and bending; Calcium carbonate powder is a bio-based filler that improves the abrasion resistance and rigidity of the material, reduces the cost of formulation by replacing part of the binder, is non-toxic and environmentally friendly; Agaricus bisporus mycelium powder is a bio-based filler, a renewable, biodegradable and lightweight material that is rapidly cultivated and requires less water than traditional materials, which has mechanical properties similar to leather, offering flexibility and durability, and contributes to a reduced carbon footprint; Ethylene glycol monoethyl ether acetate is a coalescing agent, which improves film formation during drying, promoting better cohesion between particles, and which allows for low-temperature application, improving the fluidity of the mixture; and water is an environmentally friendly solvent, which facilitates the handling and application of the other components and allows for control of the viscosity of the mixture.

[0336] This combination of bio-based and environmentally friendly components contributes not only to the technical performance of the shoe uppers, but also to their ecological sustainability. Each element plays a crucial role in the overall process, improving mechanical properties while adhering to modern environmental standards.

[0337] The CC2 layer refers to a second composite layer, sprayed second, which is intended to be the inner layer of stem 2, manufactured on the foot-shaped support 5. This layer is designed to be the inner layer of stem 2 after it is folded over. This composite layer contains both fibers and powders for thermal comfort and moisture management, bound in a bio-based polyurethane dispersion binder to ensure good mechanical strength of the surface-deposited fibers, as well as good elasticity.

[0338] The advantages of the different components of the CC2 layer are as follows: Impranil® DL 43031 provides flexibility and resistance, offering comfort in contact with the foot; Impranil® DL 1126 complements the binder with similar properties, reinforcing the structure; synthetic polyurethane fibers improve durability and wear resistance with thermal comfort and moisture management; Calcium carbonate powder and mycelium powder strengthen the structure while offering a favorable weight-to-strength ratio; and Ethylene glycol monoethyl ether acetate is used as a coalescing agent to facilitate the application of the CC2 composite layer by spraying.

[0339] The two layers CC1 and CC2 are composed of bio-based fillers and binders to reduce the environmental impact of the process, while guaranteeing the expected usage properties for the upper 2 such as thermal comfort, water repellency and flexibility.

[0340] The combination of Impranil® DL 43031 and Impranil® DL 1126 offers good adhesion and good weather resistance for the upper 2, and allows the design of a technical shoe upper 2, usable in various environments.

[0341] The parameters for the formation of the two layers CC1 and CC2 by spraying are given in the table below.

[0342] [Table 11]

[0343] The main steps in the production of the upper 1 of shoe 2 are as follows: spraying of layer CC1 onto a foot-shaped support 5; spraying of layer CC2 onto layer CC1, with the fibers being sprayed last so as to be on the external surface of the resulting layer CC1; drying of layers CC1 and CC2, and obtaining a stem 2; removal of the rod 2 from the foot-shaped support 5 (undressing), turning it over and repositioning the rod 2 on the foot-shaped support 5 (dressing) so that the pulverized fibers are located inside the rod 2, in the receiving volume of the foot.

[0344] A complete cleaning of the equipment used is carried out beforehand, including the spraying systems. The working environment must be clean to guarantee spraying quality (no fibers, clean surfaces, filtered air and controlled air quality to eliminate foreign particles).

[0345] Temperature and humidity are controlled at 20°C and 80% respectively.

[0346] To prepare a three-dimensional upper 2 for a shoe 1, two composite layers CC1 and CC2 are required, as well as a support 5 in volume to receive the prepared solutions. The composition of these two composite layers CC1 and CC2 is given in Table 11 above.

[0347] In this example, the support 5 is mounted on an articulated arm 24b, while the spray unit 19 is mounted on a cobot 24a. The cobot 24a and the articulated arm 24b are synchronized so that all movements of the support 5 and the spray nozzles 26a, 26b, 26c are perfectly coordinated.

[0348] Support 5, whether for the right or left foot, is made of TPU using 3D printing, offering versatility and responsiveness for testing numerous design and size options. This also provides control over the overall cost and weight of stem 2, which is lighter than if injection-molded. Support 5 is coated with silicone to facilitate the demolding of stem 2 after the CC1 and CC2 composite layers have cured.

[0349] In this example, we assumed that five liters of composite material (liquid composition + filler) for spraying would be required. To facilitate the initial setup of the installation and to achieve the necessary pressure and homogeneous spraying conditions, 10 liters of composite material were produced. Indeed, to ensure a constant supply pressure to the spraying units, it is important to have enough solution to prevent the pumps from cavitating.

[0350] The weight composition (kg) for each layer is given in the table below.

[0351] [Table 12]

[00352] The preparation of the mixtures for the first composite layer CC1, which is the layer that will be sprayed first, is carried out by the following steps: draining and cleaning the three tanks 21a, 21b, 21c, the pumps 20a, 20b, the compressor 20c and the spraying unit 19, in particular the three spray nozzles 26a, 26b, 26c even though only one will be used here, namely the first spray nozzle 26a adapted for spraying a composite mixture; weighing of the two binders, i.e. 3.8 kg of Impranil® DL 1126 and 1.5 kg of Impranil® DL 43031 respectively; weighing of the water, divided into two equal volumes, i.e. 1.5 kg each; weighing of the bio-based load (calcium carbonate powder) divided into two equal volumes, i.e. 0.35 kg each; weighing of the bio-based load (mycelium powder) divided into two equal volumes, i.e. 0.4 kg each; weighing of the coalescing agent (ethylene glycol monoethyl ether acetate) divided into two equal volumes, i.e. 0.1 kg each; mixture of 3.8 kg of Impranil® DL 1126 with 1.5 kg of water, 0.1 kg of coalescing agent, and 0.4 + 0.35 kg of the bio-based load in total, i.e.: 3.8 + 1.5 + 0.1 + 0.35 + 0.4 = 6.15 kg of a first mixture designated as M1; mixture of 1.5 kg of Impranil® DL 43031 with 1.5 kg of water, 0.1 kg of coalescing agent, and 0.4 + 0.35 kg of the bio-based filler in total, i.e.: 1.5 + 1.5 +0.1 + 0.35 + 0.4 = 3.85 kg of a second mixture designated as M2; filling the first tank 21a with 6.15 kg of mixture M1; and filling the second tank 21b with 3.85 kg of mixture M2.

[0353] The contents of the two tanks 21a and 21b are summarized in the table below:

[0354] [Table 13]

[00355] A trial adjustment of the spraying system is then carried out. For this purpose, the two pumps 20a, 20b connected to the first and second tanks 21a, 21b are started, and the spraying unit is first supplied with compressed air at 4 bar to ensure that the first spray nozzle 26a is not obstructed.

[0356] After this, the spray unit's work program is defined for the first pass. With the support 5 positioned, the cobot's collaborative work function is used. The spray unit is positioned on the cobot's arm. The operator's experience allows them to define a trajectory suitable for spraying the composite mixture over the entire deposition surface 501 of the support 5, paying particular attention to the heel and forefoot area. This area is critical because it must ensure perfect formation of the midsole 3, heel, and toe boxes.

[0357] To achieve this, the operator manually moves the spray unit 19 around the support 5 to form a rod-shaped layer. Once this step is complete, the trajectory is recorded. One step involves verifying this trajectory by running the cobot without a load until a "OK" signal is obtained. This OK is confirmed by adding compressed air to the first spray nozzle 26a to ensure its correct distance from the deposition surface 501 of the support 5. Flour, previously deposited using a fine-mesh sieve (120-mesh nylon filter), is applied to the surfaces to be sprayed. As the spray unit 19 passes over the surface with compressed air, it is observed whether the flour is properly cleaned, area by area. If this is not the case, the trajectory is optimized directly in the program.

[0358] To continue, the work program for the spray unit 19 is defined for a second pass at a 90° angle to the first pass, in order to achieve an isotropic effect. The support 5 remains in the same position as before. The spray unit 19 is positioned on the arm of the cobot 24a, oriented at 90° to its previous orientation. The operator's experience allows them to define a trajectory suitable for spraying the composite mixture. To do this, the operator manually moves the spray unit 19 within the space to cover the entire deposition surface 501 of the support 5 to be sprayed. Once this step is completed, the trajectory is recorded. One step consists of verifying this trajectory by running the cobot 24a without a load until an OK signal is obtained.This OK is confirmed by adding compressed air to the first spray nozzle 26a to ensure the correct distance between this nozzle and the deposition surface 501 of the substrate 5. Flour, previously deposited using a fine-mesh sieve (120 mesh nylon filter), is applied to the surfaces to be sprayed. When the spray unit 19 passes over the surface with compressed air, it is observed whether the flour is properly cleaned. If this is not the case, the trajectory is optimized directly in the program.

[0359] Below is a table summarizing the parameters of the experiments carried out and the results obtained:

[0360] [Table 14]

[0362] Spray nozzle diameter: a smaller diameter allows for finer spraying, while a larger diameter increases flow rate and coverage.

[0363] Spray flow rate: measured in ml / min, it indicates the amount of composite mixture sprayed per minute.

[0364] Spraying distance: distance between the spray nozzle and the deposit surfaces, usually between 10 and 30 cm depending on the type of application.

[0365] Spraying time: time required to cover the deposited surfaces, depending on the flow rate and the number of passes.

[0366] Number of passes: the number of layers required to obtain uniform coverage, often recommended between 1 and 3 depending on the type of composite mixture sprayed and the condition of the deposition surfaces.

[0367] In this example, the composite mixture is quite viscous and the parameters chosen for the two passes are as follows: Spraying power: 1200 Watts Nozzle diameter: 1 mm; Spray rate: 500 ml / min Spraying distance: 15 cm Spraying time for the composite liquid: 2 minutes per pass Number of passes for the composite liquid: 2

[0368] At this point, we therefore have two prepared composite mixtures M1 and M2, contained respectively in the first tank 21a and in the second tank 21b, the support 5 (left foot or right foot) positioned, two trajectories validated in empty and validated spraying parameters.

[0369] The pumps 20a, 20b and the solenoid valves 22a, 22b associated with them are suitable for supplying the first nozzle 26a with the two mixtures M1 and M2, the first nozzle 26a being adapted for spraying the composite liquid compositions of layer CC1, that is to say that the diameter of the first nozzle 26a as well as the pressure are chosen as specified above.

[0370] With the prepared composite mixtures M1 and M2 mixed in the multiport valve 28, spray tests are then carried out via the first nozzle 26a onto an adjacent surface to prime the pumps 20a and 20b and ensure a constant flow rate. The solenoid valves 22a and 22b and the pumps 20a and 20b are controlled to guarantee a homogeneous mixture. It is also verified that the composite mixtures M1 and M2 are available for spraying.

[0371] The spraying program is now launched with two spray passes using the M1-HM2 mixtures through the first nozzle 26a to cover the entire deposition surface 501 of the support 5, in two opposite directions. For each spray of the composite liquid for layer CC1, the spraying time is 2 minutes per pass for the first layer, then 2 minutes per pass for the second layer, for a total of 2 x 2 + 2 x 2 = 4 minutes, with a spraying pressure of 70 bar.

[0372] This spray program is followed by drying the CC1 layer at 90°C with circulating hot air for 2 minutes.

[0373] This step is completed by a stabilization treatment of the first CC1 composite layer once it is dry, using an atmospheric plasma at 200 Watts for 1 minute. The gas used is fluorine to improve the water repellency of the outer layer.

[0374] We then have the first composite layer CC1 of a rod 2.

[0375] The preparation of the mixtures for the second composite layer CC2, which is the layer that will be sprayed second, is carried out by the following steps: draining and cleaning the three tanks 21a, 21b, 21c, the pumps 20a, 20b, the compressor 20c and the spraying unit 19, in particular the three spray nozzles 26a, 26b, 26c, although only the second spray nozzle 26b suitable for spraying a composite mixture and the third spray nozzle 26c suitable for spraying loose fibers will be used here; weighing of the two binders, i.e. 1 kg of Impranil® DL 1126 and 3.3 kg of Impranil® DL 43031 respectively; weighing of the water, divided into two equal volumes, i.e. 1.5 kg each; weighing of the non-bio-based filler, i.e. 1.5 kg of synthetic polyurethane fibers; weighing of the bio-based filler (calcium carbonate powder) divided into two equal volumes, i.e. 0.1 kg each; weighing of the bio-based load (mycelium powder) divided into two equal volumes, i.e. 0.4 kg each; weighing of the coalescing agent (ethylene glycol monoethyl ether acetate) divided into two equal volumes, i.e. 0.1 kg each; mixture of 1 kg of Impranil® DL 1126 with 1.5 kg of water, 0.1 kg of coalescing agent, and 0.4 + 0.1 kg of the bio-based filler in total, i.e.: 1 + 1.5 + 0.1 + 0.1 + 0.4 = 3.1 kg of a first mixture designated as M3; mixture of 3.3 kg of Impranil® DL 43031 with 1.5 kg of water, 0.1 kg of coalescing agent and 0.4 = 0.1 kg of the bio-based filler in total, i.e.: 3.3 + 1.5 + 0.1 + 0.1 + 0.4 = 5.4 kg of a second mixture designated as M4; filling the first tank 21a with the 4 kg of mixture M3; filling the second tank 21b with the 6 kg of M4 mixture; and filling the third 21c tank with 1.5 kg of synthetic polyurethane fibers.

[0376] The contents of the three tanks 21a, 21b, 21c are summarized in the table below:

[0377] [Table 15] route the two pumps 20a, 20b and the compressor 20c respectively connected to the first, second and third tanks 21 a, 21 b, 21c and the spraying unit 19 is first supplied with compressed air at 4 bar to ensure that the second and third spray nozzles 26b, 26c are not obstructed.

[0379] Support 5 retains the position it had for the spraying of the first layer CC1.

[0380] For the first pass, the same spray unit work program is used as for the first CC1 coat.

[0381] Similarly, for the second 90° pass, the same spray unit work program is used as for the first CC1 coat.

[0382] The parameters chosen for the two passes are as follows: Spraying power: 1000 Watts Nozzle diameter: 2 mm Spray rate: 400 ml / min Spraying distance: 15 cm Spray time for the composite liquid: 1 minute for the forefoot, 2 minutes for the midfoot, and 3 minutes for the back of the foot where the heel is located. Number of passes for the composite liquid: 2 Spraying time for fibers: 2 minutes per pass, uniform spraying (no difference between front / midfoot / rear) Number of fiber optic cable passes: 2

[0383] At this point, we therefore have two prepared composite mixtures M3 and M4 and fibers contained respectively in the first tank 21a, in the second tank 21b and in the third tank 21c, the support 5 (left foot or right foot) positioned, two trajectories validated in empty and validated spraying parameters.

[0384] Pumps 20a and 20b, and their associated solenoid valves 22a and 22b, are suitable for supplying the first nozzle 26a with the two mixtures M1 and M2. The first nozzle 26a is designed for spraying the liquid composite compositions of layer CC2; that is, the diameter of the first nozzle 26a and the pressure are selected as specified above. Compressor 20c and its associated solenoid valve 22c are suitable for supplying the third nozzle 26c with the loose fibers of layer CC2.

[0385] With the prepared composite mixtures M1 and M2 mixed in the multiport valve 28, spray tests are then carried out via the first nozzle 26a onto an adjacent surface to prime the pumps 20a and 20b and ensure a constant flow rate. The solenoid valves 22a and 22b and the pumps 20a and 20b are controlled to guarantee a homogeneous mixture. It is also verified that the composite mixtures M1 and M2 are available for spraying.

[0386] With the loose fibers stored in reservoir 21c, a spray test is also performed via the third nozzle 26c on an adjacent surface to prime the compressor 20c and ensure a constant flow rate. The solenoid valve 22c and the compressor 20c are controlled to guarantee homogeneous spraying. It is also verified that the fibers stored in reservoir 21c are available for spraying.

[0387] The CC2 layer spraying program is now launched with two spray passes using mixtures M3 and M4 through the second nozzle 26b to cover the entire deposition surface 501 of the substrate 5, in two opposite directions. Each spray of the CC2 layer composite liquid lasts 2 minutes per pass, with a spray pressure of 80 bar.

[0388] Following these two passes, the fibers contained in reservoir 21c are immediately sprayed using the same spray program as for mixtures M1 and M2. The fibers are sprayed onto the previously sprayed layers of composite liquid while they are still wet, thus promoting adhesion. Each pass of the fibers onto the composite liquid layer lasts 2 minutes, with a spray pressure of 80 bar.

[0389] This spray program is followed by drying the CC2 layer at 90°C with circulating hot air for 2 minutes.

[0390] This step is completed by a stabilization treatment of the second CC2 composite layer once it is dry, using an atmospheric plasma at 200 Watts for 1 minute. The gas used is oxygen to increase the adhesion of the fibers to the binder.

[0391] We then have the first and second composite layers CC1 and CC2 of a rod 2.

[0392] Before proceeding with the following steps, the stem 2 is removed from the foot-shaped support 5 and then inverted onto it, so that the CC2 composite layer, containing the fibers, is positioned on the inside. This provides thermal and moisture-wicking properties to the inner layer of the stem 2, which will be in contact with the skin. The elasticity of the materials and the design of the foot-shaped support 5 allow for easy removal of the stem and its inverted positioning.

[0393] Manufacturing of the midsole:

[0394] Some of the equipment used for the manufacture of a midsole 3 is illustrated in [Fig. 12],

[0395] In this embodiment, the midsole 3 is removable (see [Fig. 4]) and is formed on a three-dimensional support 5b, which is itself formed into a midsole by spraying and layering two composite layers CC3 and CC4, by adding a three-dimensional heel-shaped reinforcement 10, and then again by spraying and layering two composite layers CC3' and CC4', the compositions of which are given in the table below. The percentage of each component is given by weight relative to the total mass of the composite layer before it has dried.

[0396] Among the binder options available for making a 3-layer midsole by spraying, Impranil® DLP and Impranil® DL 2611 were selected because they provide both cushioning (shock absorption capacity) and flexibility and good abrasion resistance to the sole.

[0397] [Table 16]

[0398] In this table, layer CC3 refers to a first composite layer because it is sprayed first, which is intended to be the lower layer of the midsole 3, i.e. the layer intended to be directed towards the outsole 4. The composition of this composite layer is very close to that of layer CC4, but it contains more Impranil® DL 2611 to reinforce abrasion resistance.

[0399] The advantages of the different components of the CC3 layer are as follows: Impranil® DL 2611 is present in a larger quantity to enhance abrasion resistance. Synthetic polyurethane fibers improve durability against external elements, while calcium carbonate powder and mycelium powder reinforce the structure while offering a favorable weight-to-reinforcement ratio; and Ethylene glycol monoethyl ether acetate is used as a coalescing agent to facilitate the application of the CC3 composite layer by spraying and with water it contributes to the flexibility of the material.

[0400] The CC4 layer refers to a second composite layer because it is sprayed second, which is intended to be an intermediate layer, above the CC3 layer within the midsole 3. This composite layer includes both fibers and powders for thermal comfort and moisture management, in a polyurethane dispersion-based binder to allow good mechanical strength of the fibers deposited on the surface, as well as good elasticity.

[0401] The advantages of the various components of the CC4 layer are as follows: Impranil® DLP and Impranil® DL 2611 provide flexibility and resistance, offering comfort in contact with the foot; Impranil® DL 1126 complements the binder with similar properties, reinforcing the structure; synthetic polyurethane fibers improve durability and wear resistance with thermal comfort and moisture management; Calcium carbonate powder and mycelium powder strengthen the structure while offering a favorable weight-to-strength ratio; and Ethylene glycol monoethyl ether acetate is used as a coalescing agent to facilitate the application of the CC4 composite layer by spraying.

[0402] The CC3' layer refers to a third composite layer because it is sprayed third, which is intended to be an intermediate layer, above the CC4 layer within the intermediate sole 3. This composite layer has the same composition and the same properties as the CC3 layer.

[0403] The CC4 layer refers to a fourth composite layer, sprayed last, which is intended to be the top layer of midsole 3, i.e., the layer intended to be in contact with the foot. This composite layer has the same composition and properties as the CC4 layer.

[0404] Spraying these four layers CC3,CC4,CC3',CC4' onto a three-dimensional 5b support shaped into an intermediate sole with reliefs allows for the formation of an intermediate sole 3 providing good cushioning.

[0405] The parameters for the formation of these two layers are given in the table below.

[0406] [Table 17]

[0407] The main steps in the production of the upper 1 of shoe 2 are as follows: spraying of layer CC3 onto a support 5b having imprints 7 in the shape of an intermediate sole with reliefs; spraying of layer CC4 onto layer CC3; positioning, on layer CC4, of a three-dimensional reinforcement 10 at the rear of the foot to form a heel; spraying of a layer CC3' of identical composition to that of CC3 on the layer CC4 and on the three-dimensional reinforcement 10 in the shape of a heel; spraying a CC4' layer over the previous CC3' layer; drying of the four layers CC3, CC4, CC3', CC4', and obtaining an intermediate sole 3; and removal of the midsole 3 from the footprints 7 of the support 5b.

[0408] As with the manufacture of stem 2, a complete cleaning of the equipment used is carried out beforehand, in particular the spray systems 18 and the temperature and humidity are controlled at 20 °C and 80% respectively.

[0409] Similarly, the equipment used is housed in an enclosure. Except for support 5, it is the same equipment as for the manufacture of rod 2.

[0410] To prepare a three-dimensional midsole 3 for shoe 1, four composite layers CC3, CC4, CC3', CC4' are required, as well as a support 5b with volumetric impressions 7 to receive the prepared solutions. The composition of the four composite layers CC3, CC4, CC3', CC4' is given in Table 17 above.

[0411] In this embodiment, for the manufacture of an insole 3, the support 5b is in the form of a tray with six insole impressions fixed to the tray, namely three impressions for the right foot and three impressions for the left foot. This allows for the simultaneous manufacture of three midsoles 3 for the right foot and three midsoles 3 for the left foot.

[0412] The said platform is perfectly synchronized with the 24a cobot so that all the movements of the impressions are perfectly coordinated.

[0413] The six midsole molds are 3D printed in TPU, offering versatility and responsiveness for testing numerous design and sizing options. Once 3D printed, the molds are coated with silicone to facilitate the removal of the sprayed layers.

[0414] These indentations are sized to fill the space within the upper 2, which is designed to accommodate a midsole 3. They are also deep enough to house a three-dimensional heel-shaped reinforcement 10. These indentations feature ribs, the relief of which creates grooves in the underside of the midsole 3. The resulting hollows allow the midsole 3 to deform, ensuring a smooth gait for the foot.

[0415] In this example, we assumed that five liters of composite material (liquid composition + filler) for spraying would be required. To facilitate the initial setup of the installation and to achieve the necessary pressure and homogeneous spraying conditions, 10 liters of composite material were produced. Indeed, to ensure a constant supply pressure to the spraying units, it is important to have sufficient liquid solution and fibers to prevent the pumps and compressor from cavitating.

[0416] The weight composition (kg) for each layer is given in the table below.

[0417] [Table 18]

[60418] The preparation of the mixtures for the first composite layer CC3, which is the layer that will be in contact with the bottom of the inside of the previously made stem 2, is carried out by the following steps: draining and cleaning of the three tanks 21a, 21b, 21c, the two pumps 20a, 20b, the compressor 20c and the spraying unit 19, including the three spray nozzles 26a, 26b, 26c, although only nozzle 26a suitable for spraying a composite mixture and nozzle 26c suitable for spraying loose fibers will be used here; weighing of the two binders, i.e. 1.5 kg of Impranil® DLP, and 3 kg of Impranil® DL 2611 respectively; weighing of the water, divided into two equal volumes, i.e. 1.5 kg each; weighing of the non-bio-based filler, i.e. 0.8 kg of synthetic polyurethane fibers; weighing of the bio-based filler (calcium carbonate powder) divided into two equal volumes, i.e. 0.35 kg each; weighing of the bio-based load (mycelium powder) divided into two equal volumes, i.e. 0.4 kg each; weighing of the coalescing agent (ethylene glycol monoethyl ether acetate) divided into two equal volumes of 0.1 kg each; mixture of 3 kg of Impranil® DL 2611 with 1.5 kg of water, 0.1 kg of coalescing agent, and 0.35 +0.4 kg of bio-based fillers in total, i.e.: 3 + 1.5 +0.1 +0.35 +0.4 = 5.35 kg of a first mixture designated as M5; mixture of 1.5 kg of Impranil® DLP with 1.5 kg of water, 0.1 kg of coalescing agent and 0.35 + 0.4 kg of the bio-based load in total, i.e.: 1.5 + 1.5 + 0.1 + 0.35 + 0.4 = 3.85 kg of a second mixture designated as M6; filling the first tank 21 a with 5.35 kg of M5 mixture; filling the second tank 21b with 3.85 kg of M6 mixture; and filling the third tank 21c with 0.8 kg of synthetic polyurethane fibers.

[0419] The contents of the three tanks 21a, 21b, 21c are summarized in the table below:

[0420] [Table 19]

[00421] A trial adjustment of the spraying system is then performed. For this purpose, the two pumps 20a, 20b and the compressor 20c, respectively connected to the first, second, and third tanks 21a, 21b, 21c, are started, and the spraying unit 19 is initially supplied with compressed air at 4 bar to ensure that the first and third spray nozzles 26a, 26c are not clogged. The support 5b with the three pairs of indentations is also put in place, the indentations being aligned and spaced 20 cm apart so that, with the adjustments of the spraying unit 19, there are no homogeneity impacts when the cobot 24a moves the spraying unit 19 from one indentation to another.

[0422] After this, the spray unit's work program is defined for the first pass. With the sole impressions positioned, the collaborative work function of cobot 24a is used. The spray unit 19 is positioned on the cobot 24a's arm. The operator's experience allows them to define a trajectory suitable for spraying the composite mixture.

[0423] To do this, the operator manually moves the spray unit 19 within the space in front of all the footprints, moving from one footprint to the next. Once this step is complete, the trajectory is recorded. A further step involves verifying this trajectory by running the cobot without a load until an OK signal is obtained. This OK is confirmed by adding compressed air to the first and third spray nozzles 26a and 26c to ensure the correct distance of each nozzle from the application surface. Flour, previously deposited using a fine-mesh sieve (120-mesh nylon filter), is then applied to the sole footprints to observe, as the spray unit passes over them with compressed air, whether the flour is properly cleaned, area by area. If this is not the case, the trajectory is optimized directly in the program.

[0424] To continue, the spray unit's work program is defined for a second pass at a 90° angle to the first, to ensure an isotropic effect. The spray unit is positioned on the cobot arm, oriented at 90° to its previous orientation. The operator's experience allows them to define a trajectory suitable for spraying the composite mixture. To do this, the operator manually moves the spray unit in the space in front of all the indentations, going from one indentation to the next. Once this step is complete, the trajectory is recorded. A further step involves verifying this trajectory by running the cobot without a load until a "OK" signal is obtained. This OK is confirmed by adding compressed air to the first and third spray nozzles 26a and 26c to ensure the correct distance between the spray nozzles and the deposition surface.Flour, previously deposited using a fine-mesh sieve (120-mesh nylon filter), is applied to the sole impressions in various positions to observe, when the compressed air spray unit passes over them, whether the flour is effectively cleaned. If this is not the case, the trajectory is optimized directly within the program.

[0425] Below is a table summarizing the parameters of the experiments carried out and the results obtained:

[0426] [Table 20]

[00427] In this example, the composite mixture is quite viscous and the parameters chosen for the two passes are as follows: Spraying power: 1000 Watts Nozzle diameter: 2 mm Spray rate: 400 ml / min Spraying distance: 15 cm Spray time for the composite liquid: 1 minute for the forefoot, 2 minutes for the midfoot, and 3 minutes for the back of the foot where the heel is located. Number of passes for the composite liquid: 2 Spraying time for fibers: 2 minutes per pass, uniform spraying (no difference between front / midfoot / rear) Number of fiber optic cable passes: 2

[0428] At this point, we therefore have two prepared composite mixtures M5 and M6 and fibers contained respectively in the first reservoir 21a, in the second reservoir 21b and in the third reservoir 21c, the support 5b (comprising three left foot impressions 7 and three right foot impressions 7) positioned, two trajectories validated in empty and validated spraying parameters.

[0429] Pumps 20a and 20b, and their associated solenoid valves 22a and 22b, are suitable for supplying the first nozzle 26a with the two mixtures M5 and M6. The first nozzle 26a is designed for spraying the liquid composite compositions of the CC3 layer; that is, the diameter of the first nozzle 26a and the pressure are selected as specified above. Compressor 20c and its associated solenoid valve 22c are suitable for supplying the third nozzle 26c with the loose fibers of the CC3 layer.

[0430] With the prepared composite mixtures M5 and M6 mixed in the multiport valve 28, spray tests are then carried out via the first nozzle 26a onto an adjacent surface to prime the pumps 20a and 20b and ensure a constant flow rate. The solenoid valves 22a and 22b and the pumps 20a and 20b are controlled to guarantee a homogeneous mixture. It is also verified that the composite mixtures M5 and M6 are available for spraying.

[0431] With the loose fibers stored in reservoir 21c, a spray test is also performed via the third nozzle 26c on an adjacent surface to prime the compressor 20c and ensure a constant flow rate. The solenoid valve 22c and the compressor 20c are controlled to guarantee homogeneous spraying. It is also verified that the fibers stored in reservoir 21c are available for spraying.

[0432] The spraying program is now initiated with two spray passes using the M5 and M6 mixtures through the first nozzle 26a to cover the six footprints, in two opposite directions. For each application of the CC3 layer, the spraying time is 1 minute per pass for the forefoot, 2 minutes for the midfoot, and 3 minutes for the rearfoot, with a spray pressure of 80 bar.

[0433] Following these two passes, the fibers contained in reservoir 21c are immediately sprayed using the same spray program as for the M5 and M6 mixtures. The fibers are sprayed onto the previously sprayed layers of composite liquid while they are still wet, thus promoting adhesion. Each pass of the fibers onto the composite liquid layer lasts 2 minutes, with a spray pressure of 80 bar.

[0434] This spray program is followed by drying the CC3 layer containing fibers at 90°C with circulating hot air for 2 minutes.

[0435] This step is completed by a stabilization treatment of the first CC3 composite layer once it is dry, using an atmospheric plasma at 200 Watts for 1 minute. The gas used is oxygen gas to increase the adhesion of the fibers to the binder.

[0436] We then have six impressions covered with a first composite layer CC3 of an intermediate sole 3, adapted to the variations in thickness of the intermediate sole 3. Indeed, as the thickness of the sole varies from the front to the back of the foot, the spraying of the layers is therefore carried out so that the final thickness respects local dimensions.

[0437] The preparation of the mixtures for the second CC4 composite layer, which is the layer that will be sprayed second, is carried out by the following steps: draining and cleaning of the three tanks 21a, 21b, 21c, the two pumps 20a, 20b, the compressor 20c and the spraying unit 19, in particular the three spraying nozzles 26a, 26b, 26c, although only nozzle 26b suitable for spraying a composite mixture and nozzle 26c suitable for spraying loose fibers will be used here; weighing of the two binders, i.e. 2.5 kg of Impranil® DLP, and 2 kg of Impranil® DL 2611 respectively; weighing of the water, divided into two equal volumes, i.e. 1.5 kg each; weighing of the non-bio-based filler, i.e. 1 kg of synthetic polyurethane fibers; weighing of the bio-based filler (calcium carbonate powder) divided into two equal volumes, i.e. 0.25 kg each; weighing of the bio-based load (mycelium powder) divided into two equal volumes, i.e. 0.4 kg each; weighing of the coalescing agent (ethylene glycol monoethyl ether acetate) divided into two equal volumes, i.e. 0.1 kg each; mixture of 2 kg of Impranil® DL 2611 with 1.5 kg of water, 0.1 kg of coalescing agent, and 0.25 +0.4 kg of bio-based fillers in total, i.e.: 2 + 1.5 +0.1 +0.25 +0.4 = 4.25 kg of a first mixture designated as M7; mixture of 2.5 kg of Impranil® DLP with 1.5 kg of water, 0.1 kg of coalescing agent and 0.25 + 0.4 kg of the bio-based load in total, i.e.: 2.5 + 1.5 + 0.1 + 0.25 + 0.4 = 4.75 kg of a second mixture designated as M8; filling the first tank 21a with the 4.25 kg of mixture M7; filling the second tank 21b with the 4.75 kg of M8 mixture; and filling the third tank 21c with the 1 kg of synthetic polyurethane fibers.

[0438] The contents of the three tanks 21a, 21b, 21c are summarized in the table below:

[0439] [Table 21]

[00440] A trial adjustment of the spraying system is then carried out. For this purpose, the two pumps 20a, 20b and the compressor 20c, respectively connected to the first, second and third tanks 21a, 21b, 21c, are started up and the spraying unit 19 is first supplied with compressed air at 4 bar to ensure that the second and third spray nozzles 26b, 26c are not obstructed.

[0441] The support 5b and its impressions 7 retain the position they had for the spraying of the first layer CC3.

[0442] For the first pass, the same spray unit work program is used as for the first CC3 coat.

[0443] Similarly, for the second 90° pass, the same spray unit work program is used as for the first CC3 coat.

[0444] The parameters chosen for the two passes are as follows: Spraying power: 1000 Watts Nozzle diameter: 1 mm Spray rate: 500 ml / min Spraying distance: 15 cm Spraying time: 2 minutes per pass Number of passes: 2

[0445] At that time, we therefore have two prepared composite mixtures M7 and M8, a support 5b positioned and comprising six impressions 7 covered with a first composite layer CC3 of an intermediate sole 3, two trajectories validated in a vacuum and validated spraying parameters.

[0446] With the prepared composite mixtures M7 and M8 mixed in the mixing solenoid valve 18, spray tests are then carried out via the second nozzle 26b on an adjacent surface to prime the pumps 20a and 20b and ensure a constant flow rate. The solenoid valves 22a and 22b and the pumps 20a and 20b are controlled to guarantee a homogeneous mixture. It is also verified that the composite mixtures M7 and M8 are available for spraying.

[0447] With the loose fibers stored in reservoir 21c, a spray test is also performed via the third nozzle 26c on an adjacent surface to prime the compressor 20c and ensure a constant flow rate. The solenoid valve 22c and the compressor 20c are controlled to guarantee homogeneous spraying. It is also verified that the fibers stored in reservoir 21c are available for spraying.

[0448] The CC4 layer spraying program is now launched. We begin with two spray passes using mixtures M7 and M8 through the second nozzle 26b to cover the entire deposition surface 501 of the impressions, in two opposite directions, to create the first layer of the CC4 layer. Finally, we complete two more spray passes with mixtures M7 and M8 through the second nozzle 26b to cover the first layer and form the second layer of the CC4 layer.

[0449] For each spray, the spraying time per pass is 1 minute per pass for the front of the foot, 2 minutes for the midfoot and 3 minutes for the back of the foot for the first layer, then 1 minute per pass for the front of the foot, 2 minutes for the midfoot and 3 minutes for the back of the foot for the second layer, with a spraying pressure of 80 bars.

[0450] Following these two passes, the fibers contained in reservoir 21c are immediately sprayed using the same spray program as for layer CC3. The fibers are sprayed onto the previously sprayed layers of composite liquid while they are still wet, thus promoting adhesion. Each pass of the fibers onto the composite liquid layer lasts 2 minutes, with a spray pressure of 80 bar.

[0451] The total time for spraying the M7 and M8 mixtures and the synthetic fibers is therefore 2 x (1 + 2 + 3) + 2 x 2 = 16 minutes

[0452] This spray program is followed by drying the CC4 layer at 90°C with circulating hot air for 2 minutes.

[0453] This step is completed with a stabilization treatment using an atmospheric plasma at 200 Watts for 1 minute. The gas used is oxygen to improve the hydrophilicity of the filler fibers and ensure better adhesion to the binder.

[0454] Before applying the third and fourth composite layers CC3' and CC4', a three-dimensional heel-shaped reinforcement 10 is added to the molds on top of the previously obtained CC3 and CC4 layers. This three-dimensional heel-shaped reinforcement 10 creates a localized increase in thickness to form a heel in the midsole 3. This three-dimensional reinforcement 10 is positioned on the second composite layer CC4 at the heel.

[0455] The deposition of the third CC3' composite layer is done in the same way as the first CC3 composite layer, with the same composition, but with reduced passage times of 1 minute per pass.

[0456] This third composite layer CC3' is deposited on the second composite layer CC4 and on the reinforcement positioned on it, but with passage times reduced to 1 minute per pass.

[0457] Similarly, the deposition of the fourth composite layer CC4' is done in the same way as the second composite layer CC4, with the same composition as the latter, but with passage times reduced to 1 minute per pass.

[0458] This fourth composite layer CC4' is deposited on the third composite layer CC3'.

[0459] We then have three pairs of midsole 3, each comprising a three-dimensional reinforcement 10 forming an extra thickness at the heel, the lower face of which is covered by the first and second composite layers CC3 and CC4, and the upper face of which is covered by the third and fourth composite layers CC3' and CC4'.

[0460] The three pairs of midsoles 3 are then removed from the molds and air-dried. They will later each be inserted into an upper 2 to form a complete shoe 1.

[0461] Outsole manufacturing:

[0462] Some of the equipment used for the manufacture of an outsole 4 is illustrated in [Fig. 13].

[0463] In this embodiment, the outsole 4 is manufactured on a three-dimensional support 5b shaped into an outsole by spraying and layering three composite layers CC5, CC6, and CC7, the compositions of which are given in the table below. The percentage of each component is given by weight relative to the total mass of the composite layer before it dries.

[0464] This outsole 4 will then be spray-bonded using the same binders as those used for spraying the CC1 layer of the upper. It is important to note that this assembly method is not gluing, as the same polymers are used for both. This notably facilitates the material's recyclability.

[0465] Among the binder options available for making an outsole 4 by spraying, Vytex®, Impranil® DL 1545 and Impranil® DLP were selected because they allow both flexibility and cushioning functions to be provided to the sole.

[0466] [Table 22]

[60467] In this table, layer CC5 refers to a first composite layer of rubber type (cf. Vytex®) because it is sprayed first, which is intended to be the outer layer of the outsole 4, i.e. the layer intended to be in contact with the ground.

[0468] The CC6 layer refers to a second composite layer because it is sprayed second, which is intended to be an intermediate layer of the outsole 4.

[0469] Finally, layer CC7 refers to a third composite layer because it is sprayed third, which is intended to be the inner layer of the outsole 4, i.e. the layer intended to be in contact with the upper 2. Its composition is compatible with that of layer CC1 of the upper onto which it will be assembled by spraying.

[0470] Vytex® is an innovative material derived from natural latex, which has been treated to remove allergenic proteins, making the product safer for users with latex sensitivities. Vytex represents a significant advancement in the field of rubber materials, offering a safe and sustainable alternative to natural latex while retaining the essential properties required for various applications. It is a bio-based and renewable binder, free of petroleum products, volatile organic compounds (VOCs), and harsh chemicals, which enhances performance characteristics such as color, stability, gel time, air retention, strength, and durability.

[0471] Impranil® DL 1545 is a bio-based binder with excellent adhesion and water resistance, with a formulation suitable for textile and flexible applications, and exhibiting high resistance to hydrolysis.

[0472] Impranil® DLP is a bio-based binder made from aliphatic polyurethane dispersion, offering good UV and weather resistance and smooth, uniform finish properties. It is ideal for applications requiring good flexibility.

[0473] Synthetic polyurethane fibers constitute a non-bio-based filler, which improves the mechanical strength and durability of the final product and adds rigidity and structure without adding weight to the material.

[0474] The benefits of calcium carbonate powder, Agaricus bisponis mycelium powder, ethylene glycol monoethyl ether acetate, and water have been given previously.

[0475] Spraying these four layers CC5, CC6 and CC7 onto a three-dimensional 5b support shaped into an outsole, with grooves, allows the formation of an outsole 4 providing good insulation, good grip on the ground and good abrasion resistance.

[0476] The parameters for the formation of these three layers of the outsole 4 are given in the table below.

[0477] [Table 23]

[00478] The main steps in the production of the outsole 4 of shoe 2 are as follows: spraying of layer CC5 onto a support 5b having outsole-shaped imprints 9 with grooves; spraying of layer CC6 onto layer CC5; spraying of layer CC7 on layer CC6; drying of the three layers of the layer and obtaining an outer sole 4; and removal of the outer sole 4 from the impressions 9 of the support 5b.

[0479] As with the manufacture of the upper 2 and the midsole 3, a complete cleaning of the equipment used is carried out beforehand, including the spray systems 18 and the temperature and humidity are controlled at 20 °C and 80% respectively.

[0480] Similarly, the equipment used is housed in an enclosure. Except for support 5b, it is the same equipment as for the manufacture of the upper 2 and the midsole 3.

[0481] To prepare a three-dimensional outsole 4 for shoe 1, three composite layers CC5, CC6, and CC7 are required, as well as a support 5b with volumetric impressions 9 to receive the prepared solutions. The composition of the three composite layers CC5, CC6, and CC7 is given in Table 23 above.

[0482] In this embodiment, for the manufacture of an outsole 4, the support 5b is in the form of a plate with six outsole impressions 9 fixed to the plate, namely three impressions for the right foot and three impressions for the left foot. This allows for the simultaneous manufacture of three outsoles 4 for the right foot and three outsoles 4 for the left foot.

[0483] The said platform is perfectly synchronized with the 24a cobot so that all the movements of the impressions are perfectly coordinated.

[0484] The six outsole molds are made of TPU using 3D printing, offering versatility and responsiveness for testing numerous design and sizing options. Once 3D printed, the molds are coated with silicone to facilitate the removal of the sprayed layers.

[0485] These molds are sized to allow the formation of outsoles 4 with dimensions adapted to the upper 2 previously manufactured. These molds have ribs, the hollows of which create grooves in the underside of the outsole 4, the relief of which ensures good grip of the outsole 4 on the ground.

[0486] In this example, we assumed that five liters of composite material (liquid composition + filler) for spraying would be required. To facilitate the initial setup of the installation and to achieve the necessary pressure and homogeneous spraying conditions, 10 liters of composite material were produced. Indeed, to ensure a constant supply pressure to the spraying units, it is important to have sufficient liquid solution and fibers to prevent the pumps and compressor from cavitating.

[0487] The weight composition (kg) for each layer is given in the table below.

[0488] [Table 24] intended to be in contact with the ground, is carried out by the following steps: draining and cleaning of the three tanks 21a, 21b, 21c, the two pumps 20a, 20b, the compressor 20c and the spraying unit 19, including the three spray nozzles 26a, 26b, 26c, although only nozzle 26a suitable for spraying a composite mixture will be used here; weighing of the two binders, i.e. 5 kg of Vytex® and 0.8 kg of Impranil® DL 1545 respectively; weighing of the water, divided into two equal volumes i.e. 1.5 kg each; weighing of the bio-based load (calcium carbonate powder) divided into two equal volumes, i.e. 0.25 kg each; weighing of the coalescing agent (ethylene glycol monoethyl ether acetate) divided into two equal volumes, i.e. 0.25 kg each; mixture of 5 kg of Vytex® with 1.5 kg of water, 0.35 kg of coalescing agent, and 0.25 kg of bio-based filler, i.e.: 5 + 1.5 + 0.35 + 0.25 = 7.1 kg of a first mixture designated as M9; mixture of 0.8 kg of Impranil® DL 1545 with 1.5 kg of water, 0.35 kg of coalescing agent and 0.25 kg of bio-based filler, i.e.: 0.8 + 1.5 + 0.35 + 0.25 = 2.9 kg of a second mixture designated as M10; filling the first tank 21a with 7.1 kg of mixture M9; and filling the second tank 21b with 2.9 kg of mixture M10.

[0490] The contents of the first and second tanks 21a, 21b are summarized in the table below:

[0491] [Table 25]

[00492] A trial adjustment of the spraying system is then performed. For this purpose, the two pumps 20a, 20b and the compressor 20c, respectively connected to the first, second, and third tanks 21a, 21b, 21c, are started, and the spraying unit 19 is initially supplied with compressed air at 4 bar to ensure that the first spray nozzle 26a is not obstructed. The support 5b with the three pairs of indentations 9 is also put in place, the indentations 9 being aligned and spaced 20 cm apart so that, with the adjustments of the spraying unit 19, there are no homogeneity impacts when the cobot 24a moves the spraying unit 19 from one indentation to another.

[0493] After this, the spray unit's work program is defined for the first pass. With the sole impressions positioned, the collaborative work function of cobot 24a is used. The spray unit 19 is positioned on the cobot 24a's arm. The operator's experience allows them to define a trajectory suitable for spraying the composite mixture.

[0494] To do this, the operator manually moves the spray unit 19 within the space in front of all the footprints, moving from one footprint to the next. Once this step is complete, the trajectory is recorded. A further step involves verifying this trajectory by running the cobot without a load until an OK signal is obtained. This OK is confirmed by adding compressed air to the first spray nozzle 26a to ensure its correct distance from the application surface. Flour, previously deposited using a fine-mesh sieve (120-mesh nylon filter), is then applied to the sole footprints to observe, as the spray unit passes over them with compressed air, whether the flour is properly cleaned, area by area. If this is not the case, the trajectory is optimized directly in the program.

[0495] To continue, the spray unit's work program is defined for a second pass at a 90° angle to the first, to ensure an isotropic effect. The spray unit is positioned on the cobot arm, oriented at 90° to its previous orientation. The operator's experience allows them to define a trajectory suitable for spraying the composite mixture. To do this, the operator manually moves the spray unit in the space in front of all the indentations, going from one indentation to the next. Once this step is complete, the trajectory is recorded. A further step involves verifying this trajectory by running the cobot without a load until a "OK" signal is obtained. This OK signal is confirmed by adding compressed air to the spray nozzles to ensure the correct distance between the spray nozzle and the application surface.Flour, previously deposited using a fine-mesh sieve (120-mesh nylon filter), is applied to the sole impressions in various positions to observe, when the compressed air spray unit passes over them, whether the flour is effectively cleaned. If this is not the case, the trajectory is optimized directly within the program.

[0496] Below is a table summarizing the parameters of the experiments carried out and the results obtained:

[0497] [Table 26]

[00498] In this example, the composite mixture is quite viscous and the parameters chosen for the two passes are as follows: Spraying power: 1200 Watts Nozzle diameter: 2 mm Spray rate: 500 ml / min Spraying distance: 15 cm Spraying time: 1 minute per pass. Number of passes: 2

[0499] At this point, we therefore have two prepared composite mixtures M9 and M10 contained respectively in the first tank 21a and in the second tank 21b, the support 5b (containing three left foot 9 impressions and three right foot 9 impressions) positioned, two trajectories validated in empty and validated spraying parameters.

[0500] The pumps 20a, 20b and the solenoid valves 22a, 22b associated with them are suitable for supplying the first nozzle 26a with the two mixtures M5 and M6, the first nozzle 26a being adapted for spraying the composite liquid compositions of the CC5 layer, that is to say that the diameter of the first nozzle 26a as well as the pressure are chosen as specified above.

[0501] With the prepared composite mixtures M9 and M10 mixed in the multiport valve 28, spray tests are then carried out via the first nozzle 26a onto an adjacent surface to prime the pumps 20a and 20b and ensure a constant flow rate. The solenoid valves 22a and 22b and the pumps 20a and 20b are controlled to guarantee a homogeneous mixture. It is also verified that the composite mixtures M9 and M10 are available for spraying.

[0502] The spraying program is now initiated with two spray passes using the M9 and M10 mixtures through the first nozzle 26a to cover the six indentations, in two opposite directions. For each spray of the CC5 layer, the spraying time is 1 minute per pass, with a spraying pressure of 70 bar.

[0503] This spray program is followed by drying the CC5 layer at 90°C with circulating hot air for 2 minutes.

[0504] This step is completed by a stabilization treatment of the first CC5 composite layer once it is dry, using an atmospheric plasma at 200 Watts for 1 minute. The gas used is CF4 fluorinated gas to make the external surface more hydrophobic.

[0505] We then have six impressions covered with a first layer of CC5 composite material from an outsole 4, and we proceed to apply the second layer of CC6 composite material. To do this, we prepare the material as indicated below.

[0506] The preparation of the mixtures for the second CC6 composite layer, which is the layer that will be sprayed second, is carried out by the following steps: draining and cleaning of the three tanks 21a, 21b, 21c, the two pumps 20a, 20b, the compressor 20c and the spraying unit 19, including the three spray nozzles 26a, 26b, 26c, although only nozzle 26b suitable for spraying a composite mixture and nozzle 26c suitable for spraying loose fibers will be used here; weighing of the two binders, i.e. 0.8 kg of Vytex® and 4 kg of Impranil® DL 1545 respectively; weighing of the water, divided into two equal volumes i.e. 1.7 kg each; weighing of the non-bio-based filler, i.e. 0.5 kg of synthetic polyurethane fibers; weighing of the bio-based filler (0.6 kg of calcium carbonate powder and 0.5 kg of Agaricus bisporus mycelium powder) divided into two equal volumes, i.e. 0.55 kg each; weighing of the non-bio-based filler (0.5 kg of synthetic polyurethane fibers); weighing of the coalescing agent (ethylene glycol monoethyl ether acetate) divided into two equal volumes, i.e. 0.1 kg each; mixture of 0.8 kg of Vytex® with 1.7 kg of water, 0.1 kg of coalescing agent and 0.55 kg of bio-based filler, i.e.: 0.8 + 1.7 + 0.1 + 0.55 = 3.15 kg of a first mixture designated as M9; mixture of 4 kg of Impranil® DL 1545 with 1.7 kg of water, 0.1 kg of coalescing agent, and 0.55 kg of bio-based filler, i.e.: 4 + 1.7 + 0.1 + 0.55 = 6.35 kg of a second mixture designated as M10; filling the first tank 21a with 3.15 kg of M9 mixture; filling the second tank 21b with 6.6 kg of M10 mixture; and filling the third tank 21c with 0.5 kg of synthetic polyurethane fibers.

[0507] The contents of the three tanks 21a, 21b, 21c are summarized in the table below:

[0508] [Table 27]

[90509] A trial adjustment of the spraying system is then carried out with the second nozzle 26b, adapted for spraying mixtures M9 and M10, and with the third nozzle 26c, whose larger diameter is adapted for spraying loose fibers. For this purpose, the two pumps 20a, 20b and the compressor 20c, respectively connected to the first, second and third tanks 21a, 21b, 21c, are started, and the spraying unit 19 is initially supplied with compressed air at 4 bar to ensure that the second and third spray nozzles 26b, 26c are not obstructed.

[0510] The support 5b and its impressions 9 retain the position they had for the spraying of the first layer CC5.

[0511] For the first pass, the same spray unit work program is used as for the first CC5 coat.

[0512] Similarly, for the second 90° pass, the same spray unit work program is used as for the first CC5 coat.

[0513] The parameters chosen for the two passes are as follows: Spraying power: 1000 Watts Nozzle diameter: 2 mm Spray rate: 400 ml / min Spraying distance: 15 cm Spraying time: 2 minutes per pass Number of passes: 2

[0514] At that time, we therefore have two prepared composite mixtures M9 and M10, a support 5b positioned and comprising six impressions 9 covered with a first composite layer CC5 of an outer sole 4, two trajectories validated in a vacuum and validated spraying parameters.

[0515] With the prepared composite mixtures M9 and M10 mixed in the mixing solenoid valve 18, spray tests are then carried out via the second nozzle 26b on an adjacent surface to prime the pumps 20a and 20b and ensure a constant flow rate. The solenoid valves 22a and 22b and the pumps 20a and 20b are controlled to guarantee a homogeneous mixture. Spray tests are also carried out with the synthetic polyurethane fibers via the third spray nozzle 26c on an adjacent surface to prime the compressor 20c and ensure a constant flow rate. It is also verified that the composite mixtures M9 and M10 and the synthetic polyurethane fibers are available for spraying.

[0516] The CC6 layer spraying program is now launched. We begin with two spray passes using mixtures M9 and M10 through the second nozzle 26b to cover the entire deposition surface 501 of the impressions, in two opposite directions, to create the first layer of layer 006. We continue with a spray pass using synthetic polyurethane fibers through the third nozzle 26c to cover the first layer of layer 006, creating the second layer. Finally, we finish with two more spray passes using mixtures M9 and M10 through the second nozzle 26b to cover the second layer and form the third and final layer of layer 006.

[0517] For each spray, the spraying time is 1 minute per pass for the first layer, then 1 minute for the second layer and finally 1 minute per pass for the last layer, i.e. a total of 2 x 1 + 1 + 2 x 1 = 5 minutes, with a spraying pressure of 80 bars.

[0518] This spray program is followed by drying the CC6 layer at 90°C with circulating hot air for 2 minutes.

[0519] This step is completed with a stabilization treatment using an atmospheric plasma at 200 Watts for 1 minute. The gas used is oxygen to improve the hydrophilicity of the filler fibers and ensure better adhesion to the binder.

[0520] The first and second composite layers CC5 and CC6 of an outsole 4 are then laid down, and the third and final composite layer CC7 is applied. To do this, the material is prepared as indicated below.

[0521] The preparation of the mixtures for the third composite layer CC7, which is the layer that will be sprayed third, is carried out by the following steps: draining and cleaning of the three tanks 21a, 21b, 21c, the two pumps 20a, 20b, the compressor 20c and the spraying unit 19, in particular the three spray nozzles 26a, 26b, 26c, although only one will be used here, namely the first spray nozzle 26a suitable for spraying a composite mixture; weighing of the two binders, i.e. 4 kg of Impranil® DLP and 0.8 kg of Impranil® DL 1545 respectively; weighing of the water, divided into two equal volumes of 1.75 kg each; weighing of the bio-based load (0.8 kg of calcium carbonate powder and 0.7 kg of Agaricus bisporus mycelium powder) divided into two equal volumes of 0.75 kg each; weighing of the coalescing agent (ethylene glycol monoethyl ether acetate) divided into two equal volumes, i.e. 0.1 kg each; mixture of 4 kg of Impranil® DLP with 1.75 kg of water, 0.1 kg of coalescing agent and 0.75 kg of bio-based filler, i.e.: 4 + 1.75 + 0.1 + 0.75 = 6.6 kg of a first mixture designated as M11; mixture of 0.8 kg of Impranil® DL 1545 with 1.75 kg of water, 0.1 kg of coalescing agent and 0.75 kg of bio-based filler, i.e.: 0.8 + 1.75 +0.1 +0.75 = 3.4 kg of a second mixture designated as M12; filling the first tank 21a with 6.6 kg of mixture M11; and filling the second tank 21b with 3.4 kg of mixture M12.

[0522] The contents of the first and second tanks 21a, 21b are summarized in the table below:

[0523] [Table 28] spraying unit 26a adapted for spraying mixtures M11 and M12. For this purpose, the two pumps 20a, 20b respectively connected to the first and second tanks 21a, 21b are started and the spraying unit 19 is supplied first with compressed air at 4 bar to ensure that the first spray nozzle 26a is not obstructed.

[0525] The support 5b and its impressions 9 retain the position they had for the spraying of the two previous layers CC5 and CC6.

[0526] For the first pass, the same spray unit work program is used for the previous CC5 and CC6 layers.

[0527] Similarly, for the second 90° pass, the same spray unit work program is used as for layers CC5 and CC6.

[0528] The parameters chosen for the two passes are as follows: Spraying power: 1200 Watts Nozzle diameter: 2 mm Spray rate: 500 ml / min Spraying distance: 15 cm Spraying time: 2 minutes per pass Number of passes: 2

[0529] At that time, we therefore have two prepared composite mixtures M11 and M12, a support 5b positioned and comprising six impressions 9 covered with a first and a second composite layers CC5,CC6, an outer sole 4, two trajectories validated in a vacuum and validated spraying parameters.

[0530] The pumps 20a, 20b and the solenoid valves 22a, 22b associated with them are suitable for supplying the first nozzle 26a with the two mixtures M11 and M12, the first nozzle 26a being suitable for spraying the composite liquid compositions of the CC7 layer, that is to say that the diameter of the first nozzle 26a as well as the pressure are chosen as specified above.

[0531] With the prepared composite mixtures M11 and M12 mixed in the mixing solenoid valve 18, spray tests are then carried out via the second nozzle 26b on an adjacent surface to prime the pumps 20a and 20b and ensure a constant flow rate. The solenoid valves 22a and 22b and the pumps 20a and 20b are controlled to guarantee a homogeneous mixture. It is also verified that the composite mixtures M11 and M12 are available for spraying.

[0532] The CC7 layer spraying program is now launched. We begin with two spray passes using mixtures M11 and M12 through the first nozzle 26a to cover the entire deposition surface 501 of the impressions, in two opposite directions, to create the first layer of CC7. Finally, we complete two more spray passes with mixtures M11 and M12 through the first nozzle 26a to cover the first layer and form the second and final layer of CC7.

[0533] For each spraying of the CC7 layer, the spraying time is 1 minute per pass, with a spraying pressure of 50 bars.

[0534] This spray program is followed by drying the CC7 layer at 90°C with circulating hot air for 2 minutes.

[0535] This step is completed with a stabilization treatment of the type crosslinking by UV irradiation.

[0536] The three composite layers CC5, CC6, and CC7 of an outsole 4 are then available. After drying and stabilization treatment, the three pairs of outsoles 4 resulting from the superposition of the sprayed layers are removed from their respective molds and stored in open air. Quality controls (dimensional, weight) are then carried out.

[0537] Each outsole 4 will later be assembled with an upper 2 to form a complete shoe 1.

[0538] Shoe assembly:

[0539] Once the upper 2, midsole 3, and outsole 4 have been spray-molded, the outsole 4 is attached to the underside of the upper 2 by spraying a mixture of water-based polyurethane (PUD) resin from the Impranil® family, as described below. The midsole 3 is removable and is inserted into the bottom of the upper 2 in the designated space, specifically to ensure that the upper 2 retains its shape during subsequent steps.

[0540] To maximize adhesion, elasticity, and water resistance, and to ensure a strong and durable bond with a low tendency for delamination between the midsole 3 and the outsole 4, we have selected the components Impranil® DL 43031, Impranil® DL 1126, and Impranil® DLP and retained the following composition, taking into account the specific properties of each binder and their compatibility. The sprayed liquid assembly composition is given in the table below. The percentage of each component is given by weight relative to the total mass of the liquid assembly composition.

[0541] [Table 29] Preferably, this is the same support 5 as that which was used to manufacture the rod 2 by spraying.

[0543] The compounds in the table are then homogeneously mixed to ensure a uniform distribution of their properties during spraying.

[0544] The liquid assembly composition is then sprayed onto the underside of rod 2 using the same equipment as before.

[0545] The outsole 4 is then positioned on the underside of the upper, with the entire volume of the foot (upper 2 + midsole 3 + outsole 4 + support 5) positioned within the footprint of the outsole 4. This step ensures the perfect positioning of the outsole 4 and thus guarantees the reproducibility of the assembly process. This step, along with the weight of the support 5, also prepares the shoe for the final drying and shaping stage 1.

[0546] Finally, drying is carried out at 90°C with circulating hot air for 2 to 5 minutes depending on the thickness of the shoe 1.

[0547] Cohesion and adhesion tests are performed after assembly to evaluate the performance of the sprayed liquid assembly composition.

[0548] Finally, the laces are put on using the following steps: laser cutting of the lace passages in the upper 2, taking advantage of the presence of the support 5; installation of an eyelet in each lace loop; and inserting the laces into the eyelets.

[0549] Finally, a final finishing step can be carried out, comprising one or more of the following steps: decoration of shoe 1 by spray printing or hot stamping; functionalization of shoe 1 by gluing elements onto it; laser cutting on the instep of the space required for threading the foot, this cutting being done at the end to guarantee perfect support and perfect reproducibility of the previous manufacturing steps.

[0550] The resulting shoe (shoe 1) is then stored in the open air. Quality checks (dimensions, weight) can be carried out. It is then ready for sale.

[0551] Although described through a number of examples, variants and embodiments, the process according to the invention includes various variants, modifications and improvements which will be obvious to a person skilled in the art, it being understood that these variants, modifications and improvements form part of the scope of the invention.

[0552] Tests and trials

[0553] In order to validate the feasibility of the invention, the applicant carried out numerous tests.

[0554] Among these trials, the applicant manufactured numerous elements of a footwear article using the process of the invention, including an upper (see [Fig. 18]), an intermediate sole (see. [Fig. 19]), an outsole (see [Fig. 20]). He also manufactured a sports shoe using the process of the invention (see [Fig. 21]). These tests, aimed at validating the manufacture of a footwear item using the process of the invention, are satisfactory from both an aesthetic and technical point of view, the sports shoe being particularly lightweight, attractive, and robust. It has an appearance similar to commercially available sports shoes and features a consistent thickness, is tear- and abrasion-resistant, and has excellent water repellency, providing protection against rain.

[0555] Other tests were also carried out by the applicant, which notably revealed that the textile materials obtained by the process of the invention exhibit satisfactory mechanical properties comparable to those of more conventional textiles. These tests also revealed that the blending of several water-soluble polymers makes it possible to significantly modify the mechanical properties of the components obtained by the process of the invention.

[0556] Tests that are still ongoing also show that adding a small amount of filler (e.g. less than or equal to 5% by weight), depending on its nature, can also significantly alter the mechanical properties of the component obtained by the process.

[0557] Many other tests are still underway.

Claims

1. 95 DEMANDS

1. A method for producing an article of footwear, in particular a shoe (1), and in particular a sports shoe, comprising an upper (2) and an outsole (4), characterized in that it comprises the following successive steps: - supply (E01) of a support (5), of at least one liquid composition and of at least one charge to be sprayed onto said support (5), this supply step (E01) comprising the following sub-steps: o supply (E101) of at least one liquid composition comprising at least one solvent predominantly water-based and at least one binder comprising one or more water-soluble polymers and / or polymers capable of forming a dispersion in water, mixing of said at least one solvent and said at least one binder, and obtaining at least one liquid composition comprising at least one solvent predominantly water-based in which at least one polymer is dissolved and / or in the form of a dispersion; o supply (E102) of at least one charge consisting of loose fibres and / or a powder; o supply (E103) of a support (5) in volume having a three-dimensional deposition surface (501) having the general shape of a foot; - formation (E02) of the stem (2) by spraying a composite layer, this formation step (E05) comprising the following sub-steps: o spraying (E201) onto the deposition surface (501) of a liquid composition resulting from the supply step (E01); and o spraying (E202) onto the deposition surface (501) of a filler consisting of loose fibers and / or a powder resulting from the supply step (E01); o the substep of spraying (E201) a filler being simultaneous with or subsequent to the substep of spraying (E202) the liquid composition to form a composite layer; o drying (E203) of the composite layer resulting from the spraying steps (E201.E202), solidification of the binder of the composite layer by evaporation of the water and fixation of the filler by the binder; o repetition (E204) at least once of the spraying (E201, E202) and drying (E203) substeps, and formation, on the deposition surface (501) of the support (5), of a rod (2) consisting of alternating layers96 composites; - formation (E05) of the outsole (4), assembly (E06) of the outsole (4) on the underside of the assembly resulting from the previous steps and formation of a footwear article; - removal (E08) of the footwear item from the support (5).

2. A method for producing a footwear article further comprising an intermediate sole (3), characterized in that it comprises the following steps after the steps of supplying (E01) and forming (E02) the upper (2): - formation (E03) of the midsole (3) and positioning (E04) of the midsole (3) against the upper (2) to form a unit; - formation (E05) of the outsole (4), assembly (E06) of the outsole (4) on the underside of the assembly formed by the upper (2) and the midsole (3) and formation of a footwear article; - removal (E08) of the footwear item from the support (5).

3. A method according to claim 1 or 2, characterized in that during the formation step (E03) of the intermediate sole (3) and / or the formation step (E05) of the outsole (4), said sole (3,4) is obtained by one of the following techniques: - spraying of a composite liquid composition comprising a binder and a filler; - injection molding with a material containing a binder; or - cutting with a die in a thickness of material containing a binder.

4. A method according to claim 2 or 3, characterized in that the steps of forming (E03) the midsole (3) and positioning (E04) the midsole (3) against the upper (2) are carried out simultaneously and comprise the following substeps: - supply (E301 a) of a molding frame (6) in the form of an intermediate sole; - placement (E302a) of the molding frame (6) on the underside of the stem (2); - spraying (E303a) of a liquid composition and a filler inside the molding frame (6) and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying (E101) at least one liquid composition and supplying (E102) at least one filler; - drying (E304a) of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; - repetition (E305a) at least once of the previous spraying (E303a) and drying (E304a) substeps, and formation, on the underside of the stem (2) and in the frame97 of molding, of an intermediate sole (3) made up of alternating composite layers; and removal (E306a) of the molding frame.

5. A method according to claim 2 or 3, characterized in that the formation step (E03) of the intermediate sole (3) comprises the following substeps: - supply (E301 b) of a molding cavity (7) in the form of an intermediate sole; - spraying (E303b) of a liquid composition and a filler inside the molding cavity (7) and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying (E101) at least one liquid composition and supplying (E102) at least one filler; - drying (E304b) of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; - repeating (E305b) at least once the preceding spraying (E303b) and drying (E304b) substeps, and forming, in the mold cavity (7), a midsole (3) made of alternating composite layers; and - removing (E306b) the midsole (3) from the mold cavity (7).

6. A method according to any one of claims 2 to 5, characterized in that the steps of forming (E05) the outsole (4) and assembling (E06) the outsole (4) onto the assembly formed by the upper (2) and the midsole (3) are carried out simultaneously and comprise the following substeps: - supply (E501 a) of a molding frame (8) in the shape of an outsole; - placement (E502a) of the molding frame (8) on the underside of the stem (2) or on the underside of the intermediate sole (3) if the latter is on the underside of the stem (2); - spraying (E503a) of a liquid composition and a filler inside the molding frame (8) and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying (E101) at least one liquid composition and supplying (E102) at least one filler; - drying (E504a) of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; - repetition (E505a) at least once of the preceding spraying (E503a) and drying (E504a) substeps, and formation, on the underside of the upper (2) or on the underside of the midsole (3) and within the molding frame (8), of an outsole (4) consisting of alternating composite layers; and 98 removal (E506a) of the molding frame (8).

7. A method according to any one of claims 1 to 5, characterized in that the outsole (4) formation step (E05) comprises the following substeps: - supply (E501 b) of a molding cavity (9) in the shape of an outsole; - spraying (E503b) of a liquid composition and a filler inside the molding cavity (9) and obtaining a composite layer, said liquid composition and filler resulting from the substeps of supplying (E101) at least one liquid composition and supplying (E102) at least one filler; - drying (E504b) of the composite layer, solidification of the binder of the composite layer by evaporation of water and fixation of the filler by the binder; - repetition (E505b) at least once of the previous spraying (E503b) and drying (E504b) substeps, and formation, in the molding cavity (9), of an outsole (4) made up of an alternation of composite layers; and - removal (E506b) of the outsole (4) from the molding cavity (9).

8. A method according to claim 2, 3, 5 or 7, characterized in that during the positioning step (E04) of the intermediate sole (3) against the upper (2), the intermediate sole (3) is positioned inside the upper (2) and in that the assembly step (E06) of the outsole (4) on the underside of the assembly formed by the upper (2) and the intermediate sole (3) comprises the following substeps: - spraying (E601 a) of a liquid assembly composition onto the underside of the stem (2) and obtaining a layer of liquid assembly composition, said liquid assembly composition resulting from the substep of supplying (E101) at least one liquid composition; - positioning (E602a) and pressure (E603a) of the outsole (4) on the liquid assembly composition layer; and - drying (E604a) of the liquid assembly composition layer and solidification of the binder of the liquid assembly composition layer by evaporation of water.

9. A method according to claim 2, 3 or 5, characterized in that during the positioning step (E04) of the intermediate sole (3) against the upper (2), the intermediate sole (3) is assembled on the underside of the upper (2) by the following substeps: - spraying (E401) of a liquid assembly composition onto the underside of the stem (2) and obtaining a layer of liquid assembly composition, said liquid assembly composition resulting from the supply substep (E101) of at least one99 liquid composition; - positioning (E402) and pressure (E403) of the intermediate sole (3) on the liquid assembly composition layer; and - drying (E404) of the liquid assembly composition layer and solidification of the binder of the liquid assembly composition layer by evaporation of water.

10. A method according to claim 2, 3, 7 or 9, characterized in that during the positioning step (E04) of the intermediate sole (3) against the upper (2), the intermediate sole (3) is assembled on the underside of the upper (2) and in that the assembly step (E06) of the outsole (4) on the underside of the assembly formed by the upper (2) and the intermediate sole (3) comprises the following substeps: - spraying (E601 b) of a layer of liquid assembly composition on the underside of the intermediate sole (3) and obtaining a layer of liquid assembly composition, said liquid assembly composition resulting from the sub-step of supplying (E101) at least one liquid composition; - positioning (E602b) and pressure (E603b) of the outsole (4) on the liquid assembly composition layer; and - drying (E604b) of the liquid assembly composition layer and solidification of the binder of the liquid assembly composition layer by evaporation of water.

11. A method according to claim 8, 9 or 10, characterized in that a binder of the liquid assembly composition is chemically compatible with a binder of each of the two composite layers assembled by said liquid assembly composition.

12. A method according to any one of the preceding claims, characterized in that, after the step of removing the footwear article from the support (5) (E08), it comprises a finalization step (E09) of the footwear article, this finalization step (E09) comprising at least one of the following substeps: - rectification of the edges surrounding the opening of the stem (2); - cutting out lace passages in the upper (2) and fitting an eyelet in each lace passage; - decoration of the footwear item by printing, spraying or hot stamping; - Functionalization of the footwear by gluing elements onto it; and - cutting the instep of the footwear. 100

13. A method according to any one of the preceding claims, characterized in that, prior to the step of removing the footwear article from the support (5), it comprises a step of forming (E07) a finishing layer on an external face of the footwear article, this step of forming (E07) a finishing layer comprising the following successive substeps: - spraying (E701) of a liquid finishing composition onto an external surface of the footwear article and obtaining a layer of liquid finishing composition, said liquid finishing composition resulting from the sub-step of supplying (E101) at least one liquid composition; and - drying (E702) of the liquid finishing composition sprayed during the previous spraying substep (E701) and solidification of the binder of the liquid finishing composition layer by evaporation of the water.

14. A method according to any one of the preceding claims, characterized in that, during a drying substep (E203, E304, E404, E504, E604), the support (5) is subjected to vibrations.

15. A process according to any one of the preceding claims, characterized in that at least one drying substep (E203, E304, E404, E504, E604) is carried out at room temperature.

16. A process according to any one of the preceding claims, characterized in that at least one drying substep (E203, E304, E404, E504, E604) is carried out at a temperature between 50 and 90 °C.

17. A process according to any one of the preceding claims, characterized in that after a drying substep (E203, E304, E404, E504, E604, E702) of a layer of material, it comprises a stabilization step (E10) of the material of said layer by one of the following techniques: - a heat treatment; - plasma therapy; and / or - cross-linking by UV irradiation.

18. A method according to any one of the preceding claims, characterized in that at least a portion of a surface is textured in relief or intaglio, said surface being selected from: the deposition surface (501) of the support (5); one face of a molding impression (7) in the shape of an intermediate sole; and 101 one face of a molding impression (9) in the shape of an outsole.

19. A method according to any one of the preceding claims, characterized in that, during the substep of supplying (E101) at least one liquid composition, said liquid composition is such that: - the water-soluble polymer(s) and / or polymer(s) capable of forming a dispersion in water represents(s) 30 to 70% by weight of the liquid composition; - Water represents 30 to 70% by weight of the liquid composition.

20. A process according to any one of the preceding claims, characterized in that, during the substep of supplying (E102) at least one feedstock, at least 5% by weight of said feedstock is of bio-based origin.

21. A process according to any one of the preceding claims, characterized in that, during the substep of supplying (E102) at least one feedstock, 5 to 70%, preferably 10 to 60% and more preferably 20 to 50% by weight of said feedstock is of bio-based origin.

22. A process according to any one of the preceding claims, characterized in that, during the substep of supplying (E102) at least one feedstock, 5 to 70%, preferably 30 to 65% and more preferably 40 to 60% by weight of the bio-based feedstock consists of viscose fibers, cotton fibers, wool fibers, silk fibers, cashmere fibers, flax fibers, fur fibers, mammal hair, mycelium fibers, cellulose fibers, wood fibers, hemp fibers, mycelium powder, rice powder, wheat powder, wood powder, starch powder, alginate powder, carbon black powder, wheat flour, corn flour, millet flour, hemp flour, rapeseed flour, soybean hull powder, walnut hull powder, kernel powder olive oil, cellulose nanofiber powder, polyamide powder or fibers,of polypropylene powder or fibers, polyethersulfone powder or fibers, or polyurethane powder or fibers, taken alone or in mixtures.

23. A process according to any one of the preceding claims, characterized in that, during the substep of supplying (E102) at least one feed, 5 to 70%, preferably 30 to 65% and more preferably 40 to 60% by weight of the bio-based feed consists of micronized dried plant, which plant is selected from plants of the Plantain, Eclipta, Tulsi, Coleus, Bacopa, Centella families and mixtures thereof.

24. A method according to any one of the preceding claims, characterized in that, during the substep of supplying (E102) at least one load, 5 to 70%, preferably 30 to 65% and more preferably 40 to 60% by weight of the load, are made up of at least one 102 bio-based material comprising at least 5% by weight of calcium, preferably at least 10% by weight of calcium.

25. A method according to any one of the preceding claims, characterized in that, before a drying substep (E203, E304, E504) of a composite layer, the filler represents 30 to 60% by weight of said composite layer.

26. A method according to any one of the preceding claims, characterized in that, before a drying substep (E203, E304, E504) of a composite layer, the filler-to-binder weight ratio in said composite layer is in the range between 2:1 and 1:

2.

27. ​​A method according to any one of the preceding claims, characterized in that, before a drying substep (E203, E304, E504) of a composite layer, a bio-based filler represents 5 to 50%, preferably 10 to 40% and more preferably 15 to 30% by weight of said composite layer.

28. A process according to any one of the preceding claims, characterized in that during the supply substep (E101) of at least one liquid composition, the binder comprises at least 10%, preferably at least 30% and more preferably at least 60% by weight of bio-based and / or biodegradable polymer.

29. A method according to any one of the preceding claims, characterized in that during the supply substep (E101) of at least one liquid composition, the binder comprises at least 5%, preferably at least 30% and more preferably at least 70% by weight of elastomer.

30. A process according to any one of the preceding claims, characterized in that during the supply substep (E101) of at least one liquid composition, the binder comprises at least 5%, preferably at least 30% and more preferably at least 70% by weight of natural latex of vegetable origin, latex of vegetable origin treated to reduce its protein content, bio-based polylactic acid, bio-based thermoplastic polyurethane, bio-based polyurethane dispersion, rosin dispersion of vegetable origin, terpene dispersion of vegetable origin, bio-based acrylic polymer or polymer matrix hydrogel, taken alone or in mixture.

31. Footwear article comprising an upper (2) and an outsole (4), characterized in that the upper (2) comprises alternating layers of binder-based material comprising one or more water-soluble polymers and / or polymers capable of forming a dispersion in water, and at least one filler comprising a powder and / or fibers, said footwear article being a product103 resulting from the process according to any one of the preceding claims.

32. An assembly comprising at least one liquid composition, a charge and a spraying system (18) for carrying out the process according to any one of claims 1 to 29, characterized in that: - The spraying system (18) comprises the following equipment: o at least one spraying unit (19) equipped with one or more spray nozzles (26); o at least fluid displacement device (20); o at least one reservoir (21); o supply pipes (23) connecting at least one reservoir (21) to at least one fluid displacement device (20) and to at least one spray nozzle (26); o at least one support (5); - a liquid composition is contained in a reservoir (21) and comprises: o a binder comprising one or more water-soluble polymers and / or polymers capable of forming a dispersion in water, and o a solvent that is predominantly water-based, - a charge is in powder form and is contained in a reservoir (6), - a charge is in the form of loose fibres, taken alone or in mixture, and is contained in a reservoir (6); - at least one support (5) in volume has a three-dimensional deposition surface (501) having the general shape of a foot on which a rod (2) can be manufactured by spraying at least one fluid contained in a reservoir (21) and supplied by a fluid displacement device (20) to a spraying unit (19).

Images