FR3084847A1 - MANUFACTURE OF A SHOE WITH IMPREGNATION OF A THERMOSETTING RESIN ON AN ENVELOPE THEN WELDING OF A SOLE - Google Patents

Abstract

A method of manufacturing a shoe comprising: - a step of placing an envelope, porous or fibrous, on a spatial conformation element to give a predefined spatial conformation to the envelope; - Then, a step of impregnating a first thermosetting resin in the envelope, allowing after the polymerization of the first resin and after the removal of the spatial conformation element, the maintenance of the envelope in said predefined spatial conformation ; - Then, a step of molding a sole against the envelope, the sole comprising a second thermosetting resin of the same nature as the first resin, the molding step comprising a crosslinking reaction of the second resin with the first resin beforehand impregnated in the envelope, the molding step being carried out while the first resin impregnating the envelope at the end of the impregnation step is not yet completely polymerized.

Description

Manufacture of a shoe with impregnation of a thermosetting resin on an envelope then welding of a sole

Technical field of the invention

The present invention relates to a method of manufacturing a shoe, in particular a sports shoe.

State of the art

The manufacture of a shoe conventionally comprises a stage of flat preparation of the part enveloping the foot, called a "rod", then a stage of spatial closure of this rod. This closure can be practiced by sewing directly from the rod previously formed flat, or by adding an additional piece.

The elements making up the stem are assembled while it is still flat. These can be sewing, injection, welding, gluing or printing steps.

Then, the upper is placed on an element of spatial conformation called “shape” in the field of shoes, which is an internal mold and which serves as a guide for the upper. The operator can then attach the sole to the upper. The attachment of the sole to the upper is generally carried out by sewing the edges of the sole to the upper or by gluing the sole to a plantar surface of the upper. Another technique consists in directly injecting a plastic material, generally foamed, on the previously shaped rod. When the sole is assembled by gluing, the upper generally requires a step of preparing the plantar surface to allow the glue to adhere. This preparation step can consist in scraping the plantar surface to make it porous and / or in stripping with the aid of a chemical product such as acetone.

This manufacturing technique unfortunately remains long, complex and therefore relatively expensive because it requires many steps, tools and specialized know-how. In addition, it is difficult to obtain a very good fit from the shaping of a flat base. In order to improve comfort and simplify manufacturing, publication FR3026924 discloses a method of manufacturing a sports shoe using a tubular mesh element shaped using resin according to a predefined spatial conformation. . However, the attachment of the sole to the mesh element remains complex to perform and the retention of the sole against the mesh element may be insufficient to prevent separation of the sole. In fact, the bonding may have defects, for example if the adhesive has not been applied to all of the surfaces to be bonded, or else the pressure applied for the bonding is not uniform or sufficient.

Subject of the invention

The object of the invention is to provide a manufacturing process overcoming the above drawbacks and improving the manufacturing processes known from the prior art. In particular, the invention makes it possible to carry out a process which is simple to implement and which makes it possible to obtain a shoe with a more efficient assembly of the sole with the upper.

The invention relates to a process for manufacturing a shoe, the manufacturing process comprising:

a step of placing an envelope, porous or fibrous, on a spatial conformation element to give a predefined spatial conformation to the envelope;

then, a step of impregnating a first thermosetting resin in the envelope, allowing after the polymerization of the first resin and after the removal of the element of spatial conformation, the maintenance of the envelope in said predefined spatial conformation;

then, a step of molding a sole against the envelope, the sole comprising a second thermosetting resin of the same nature as the first resin, the molding step comprising a crosslinking reaction of the second resin with the first resin previously impregnated in the envelope, the molding step being carried out while the first resin impregnating the envelope at the end of the impregnation step is not yet completely polymerized.

The envelope may include an interior surface and an exterior surface, the exterior surface comprising a first surface intended to receive a sole, and a second surface complementary to the first surface and intended to cover the top and the sides of a foot, the first resin being impregnated during the impregnation step on a first zone of the first surface and on a second zone of the second surface.

The first zone can form only part of the first surface, the molding step comprising an impregnation reaction of the second resin in a part of the first surface not impregnated with the first resin.

The second zone can form only part of the second surface.

The first zone and the second zone can be linked together.

The second area can include:

a first sector extending around the heel, and / or a second sector extending substantially around and / or above the toes, and / or a third sector extending on either side of the foot of the first surface up to at least one hole provided for the passage of a lace, said third sector comprising strips extending in the extension of a lace.

At the end of the impregnation step, the envelope may comprise a locally variable quantity of first resin. In particular, the envelope may comprise a first sub-part in which it is partially impregnated with the first resin, and / or a second sub-part in which it is saturated with the first resin, and / or a third sub-part in which it contains more of the first resin than it can impregnate.

The envelope may be a mesh or woven element and / or an element comprising microfibers and / or an element comprising split leather.

The envelope can be made in one piece or the envelope can include at least two pre-assembled sub-elements, in particular sewn or glued together.

The envelope may include a single opening through which the element of spatial conformation is introduced.

The first resin and the second resin may essentially consist of polyurethane or of epoxy polymer or of polyester or of silicone.

The molding step can include:

a first sub-step of casting the second resin in liquid form in a mold, followed by a second sub-step of closing the mold by affixing the spatial shaping element coated with the envelope, or the step of molding can include:

a first sub-step of closing the mold by affixing the envelope-shaped spatial conformation element, followed by a second sub-step of injecting the second resin in liquid form into the mold.

The manufacturing process may include moving the envelope by means of the spatial shaping element.

The manufacturing method may comprise a step of drilling at least one hole in a part of the envelope, the at least one hole being intended for the passage of a lace or intended to form a ventilation of the shoe, said part being previously impregnated with the first resin, in particular said part being previously saturated with the first resin.

The manufacturing process may include a step of manufacturing a spatial shaping element according to the particular dimensions and / or the particular proportions of a user's foot.

The molding step may include a sub-step for positioning an outer sole and / or inserts at the bottom of a mold and / or a sub-step for positioning inserts having an ornamental function, and / or a function for improving the stability, and / or a function for improving the cushioning of the shoe in the mold.

The manufacturing process may include a step of fixing accessory elements to the envelope, in particular a step of fixing a stability reinforcement, and / or a protective reinforcement, and / or a label, and / or a decorative piece.

Brief description of the drawings

These objects, characteristics and advantages of the present invention will be described in detail in the following description of a particular embodiment made without limitation in relation to the attached figures, among which:

Figure 1 is a side view of a shoe obtained by a manufacturing process according to an embodiment of the invention.

FIG. 2 is a view of a manufacturing flow diagram according to an embodiment of the invention.

Figure 3 is a schematic view of a first step in the manufacturing process.

Figure 4 is a schematic view of a second step in the manufacturing process.

Figure 5 is a schematic view of a third step in the manufacturing process.

Figure 6 is a schematic view of a first substep of a fourth step in the manufacturing process.

Figure 7 is a schematic view of a second substep of the fourth step of the manufacturing process.

Figure 8 is a schematic view of a third substep of the fourth step of the manufacturing process.

Figure 9 is a side view of the shoe at the end of the fourth step of the manufacturing process.

Figure 10 is a schematic view of a fifth step in the manufacturing process.

Figure 11 is a schematic view of a sixth step in the manufacturing process.

Figures 12 and 13 are schematic views of an alternative embodiment of the fifth step and the sixth step of the manufacturing process.

Figure 14 is a schematic view of a seventh step in the manufacturing process.

Description of an embodiment

In the following description, the terms "front", "rear", "top", "left" and "right" are defined according to the point of view of a user who has put on the shoe. The figures illustrate a shoe seen in profile and shows only one side of the shoe. The non-visible side of the shoe generally has the same characteristics as the visible side.

Figure 1 schematically illustrates a shoe 1 obtained by an embodiment of the manufacturing method according to the invention. The shoe 1 comprises an envelope 2 under which is fixed a sole 3. The shoe 1 also comprises a closure means, which in this case is made with a lace 4. Alternatively, any other closure means could be used. The shoe 1 can be intended for any type of use, in particular for the practice of sport, such as for example running.

The envelope 2 is intended to cover a foot and replaces the upper of a conventional shoe. The casing 2 can have a tubular shape and can extend up to the ankle. The envelope is porous and / or fibrous, that is to say that it comprises a multitude of roughness on its outer surface and is capable of being impregnated with a liquid or viscous product. The envelope may be rough to the touch. Preferably, the envelope is a mesh or woven element, for example made from cotton, wool, split leather or polyester. The envelope may also include interlaced fibers or microfibers. More generally, the envelope can be made from any flexible natural or synthetic material which is porous and / or rough.

The envelope 2 includes a single opening 5 intended to allow the insertion of the foot. That is to say, in particular that the envelope is not perforated at the level of the toes and / or the sole of the foot. Envelope 2 can therefore look like a sock. The envelope nevertheless includes holes 6 of smaller dimension than the opening 5. The holes 6 are used to pass the lace 4. The envelope 2 may also include additional holes for the ventilation of the shoe.

The envelope comprises an interior surface (not visible in the figures), intended to be in contact with the foot, and an exterior surface, intended to be in contact with the outside air. The outer surface comprises a first surface 7 intended to receive the sole 3, and a second surface 8 complementary to the first surface and intended to cover the top and the sides of the foot. The first surface 7 is therefore a plantar surface of the envelope. The envelope 2 is made in one piece or the envelope comprises at least two pre-assembled sub-elements, in particular sewn or glued together. For example, the envelope may consist of a mesh or woven element assembled with an elastic element. Alternatively, as shown in FIG. 1, the envelope can be fitted with a comfort flange 9 at the front and at the rear of the opening 5.

The casing 2 is locally impregnated with a first thermosetting resin 10. The first resin 10 impregnating the second surface of the envelope remains visible. Preferably, the first resin essentially consists of polyurethane, epoxy polymer, polyester, or silicone. A first zone 11 of the first surface 7 and a second zone 12 of the second surface 8 are impregnated with the resin. The first zone 11 can form only part of the first surface 7 of the envelope 2. The second zone 12 can form only part of the second surface 8 of the envelope 2.

The second zone 12 comprises a first sector 13 extending around the heel. The second zone 12 also includes a second sector 14 extending substantially above and around the toes. Finally, the second zone 12 comprises a third sector 15 extending on the left side and on the right side of the foot of the first zone 11 of the first surface 7 to the holes 6 through which pass the lace 4. This third sector 15 is formed by bands 16 extending in the extension of laces. The assembly of the lace 4 to the shoe forms a plurality of strands 4 ’substantially rectilinear and intersecting. Each of these strands 4 ’is extended by at least one strip 16.

The first zone 11 and the second zone 12 are interconnected. More precisely, each of the sectors 13, 14 and 15 are connected to the first zone by a continuity of material.

The envelope 2, in particular the second zone 12 of the envelope, can comprise a locally variable quantity of first resin 10. In particular, the second zone 12 can comprise a first part in which the envelope is partially impregnated with the first resin 10 , that is to say that the pores and / or the volumes separating the fibers of the envelope are only partially filled with the first resin 10. The second zone 12 can also comprise a second sub-part in which the envelope is saturated with the first resin 10, that is to say that the pores and / or the volumes separating the fibers of the envelope are completely filled with the first resin. Finally, the second zone 12 can comprise a third sub-part in which the envelope comprises an excess of the first resin, that is to say more of the first resin 10 than it can impregnate therewith. In other words, the pores or the volumes separating the fibers from the envelope are completely filled with the first resin and an additional volume of the first resin covers the envelope at this point. The more resin the envelope receives, the more resistant it will be. An excess of resin locally strengthens the envelope. Advantageously, the envelope may include such an excess of resin around the holes 6 provided for the passage of the lace 4 since the periphery of the holes 6 is particularly stressed by the tension exerted by the lace.

In addition, the envelope 2 may include accessory elements such as stability reinforcements, protective reinforcements, labels or decorative pieces. These accessory elements do not necessarily consist of the first resin 10.

The sole 3 comprises a second thermosetting resin 17 of the same kind as the first resin 10. In other words, the second resin and the first resin are chemically compatible, or else are capable of being welded to each other during a crosslinking polymerization reaction. That is, chemical molecules from the first resin are able to combine with chemical molecules from the second resin to form a network of tangled molecules. In particular, the second resin 17 can be identical to the first resin 10 or else be distinguished from the first resin by additives which do not modify its chemical properties, such as for example the presence of pigments to obtain a sole of different color or the agent content. foaming to obtain a different material density. Like the first resin 10, the second resin 17 is therefore also made of polyurethane, epoxy polymer, polyester, or silicone. Neither the first resin nor the second resin are thermoplastic resins. The sole can also comprise accessory components which are not necessarily made up of the second resin 17. For example the sole can comprise inserts (not shown) having an ornamental function, and / or a function of improving stability, and / or a function for improving the cushioning of the shoe. As can be seen in FIG. 1, the sole 3 comprises an outer sole 18, intended to be in contact with the ground, which is not necessarily made from the second resin. This outer sole 18 can have a relatively thin thickness compared to the part of the sole 3 made from the second resin. It can be made from a wear-resistant material such as for example rubber. The outsole 18 can also include patterns having an ornamental function, and / or a function for improving stability, and / or a function for improving the cushioning of the shoe. Advantageously, the outer sole 18 is made of a material chemically compatible with the second resin 18 in order to be able to weld to the second resin. An upper face of the outer sole 18, in contact with the second resin, may also include mechanical retaining means capable of drowning in the second resin 17 during the manufacture of the shoe.

FIG. 2 illustrates a flow chart comprising seven steps, E1 to E7, of manufacturing a shoe according to an embodiment of the manufacturing method according to the invention. According to the embodiment presented, the seven steps are carried out successively, that is to say one after the other, starting with the first step E1 and ending with the seventh step E7, however certain steps can be reversed. which will be specified later.

In a first step E1, called the placement step and illustrated in FIG. 3, the envelope 2 is placed on a spatial conformation element 20 to give a predefined spatial conformation to the envelope 2. The spatial conformation element 20 a therefore substantially the shape of a foot and it is introduced into the envelope through the opening 5. The envelope 2 covers the element of spatial conformation like a sock. The spatial shaping element 20 can be oriented so that the first surface 11, in other words the plantar surface, is turned upward in order to facilitate the later stages of the manufacturing process. Subsequently, the spatial conformation element can be used to move the envelope 2 close to different positions in an assembly workshop. Advantageously, the spatial shaping element comprises an interface capable of cooperating with a manipulation arm. Using the spatial shaping element as a conveyor allows the envelope to be moved without any contact with its outer surface.

In a second step E2, called the impregnation step illustrated in FIG. 4, the envelope of the first thermosetting resin 10 is impregnated. To this end, a first projection nozzle 21 projects the first resin in the form of fine liquid droplets on the outer surface of the envelope. As the envelope is porous or fibrous, the first resin penetrates at least partially into the thickness of the envelope which produces good adhesion of the first resin to the envelope. The first resin penetrates by capillary action into the envelope. Alternatively, the resin can be applied by another method, for example using a brush automatically fed with resin.

The envelope is impregnated with the first resin on the first zone of the first surface and on the second zone of the second surface. The first zone and the second zone are impregnated during the same spraying operation of the first resin. Thus, a continuity of the layer of first resin is obtained between the first zone and the second zone. At the end of this second step E2, the accessory elements such as the stability reinforcements, the protective reinforcements, the labels or the decoration pieces can be fixed against the envelope 2. As a variant, this operation can even be carried out before the second step E2 if their arrangement on the envelope does not cover the parts of the envelope intended to be impregnated with the first resin.

It is possible to adjust the projection power of the first projection nozzle 21 or to leave it longer or longer in the same position so as to locally obtain a variable quantity of first resin. Advantageously, more resin is sprayed into the parts of the envelope which are the most mechanically stressed during the use of the shoe, that is to say the three sectors 13, 14 and 15 defined above. Those skilled in the art will be able to identify, by their knowledge or by testing the shoe, the places of the envelope requiring reinforcement with a local resin supplement.

In a third step E3, illustrated in FIG. 5, there is a partial polymerization time of the first resin previously sprayed on the envelope. The duration of this third step is adapted so that the first resin is only partially polymerized at the start of the fourth step. The polymerization of the first resin can be carried out at room temperature. It is not necessary to place the envelope impregnated with the first resin in an oven to cure the first resin. Alternatively, this third step could be omitted and the fourth step executed in the wake of the second step.

In a fourth step E4, called the molding step and illustrated by FIGS. 6, 7 and 8, the molding of the sole 3 is carried out against the casing 2. This fourth step comprises a first sub-step E41 of preparation during which the molding of the sole is prepared. First, the outsole 18 is positioned at the bottom of a mold 23. Then, the inserts are positioned in the mold 23, above the outsole. A second injection nozzle 22 injects (or lets flow) the second resin in the liquid state into the mold 23. The second resin covers the outer sole 18 and, if necessary, enters the mechanical resistance means arranged on the upper face of the outer sole 18 and covers the inserts. The mold 23 has the shape of the sole 3. It has an upward opening, the shape of which is similar to the shape of the first surface of the envelope positioned on the spatial shaping element. A rest time can be observed during this fourth step to allow the second resin to polymerize, at most partially, before affixing the element of spatial conformation coated with the envelope on the opening of the mold. During this resting time, the second resin can, depending on its composition and in particular depending on its foaming agent content, expand in the mold. Note, the first injection nozzle 21 and the second injection nozzle 22 could be one and the same injection nozzle.

In a second substep E42 of the molding step E4, the sole 3 is molded against the casing 2. A manipulation arm 24 makes the spatial shaping element pivot by half a turn so the first surface of the envelope faces down. Then, the mold is closed by affixing the element of spatial conformation coated with the envelope on the opening of the mold. Sufficient pressure is applied to the spatial shaping element to close the mold and for the entire plantar surface of the envelope to be in contact with the second resin. This step is carried out while the first resin impregnating the envelope at the end of the impregnation step is not polymerized or is not yet completely polymerized. During this step, the second resin fuses or in other words is welded with the first resin impregnating the first area of the first surface 11. It is the simultaneous polymerization of the first resin and the second resin which makes it possible to obtain the weld of the two resins. The molding step therefore comprises a crosslinking reaction of the second resin with the first resin permeating the thickness of the envelope. When the first surface of the envelope is not completely impregnated with resin at the end of the second step, the molding step comprises a reaction of impregnation of the second resin in the parts of the first surface not impregnated with the first resin. In other words, the second resin impregnates the first surface in the parts of the first surface complementary to the first zone.

According to an alternative molding technique of the sole, the first sub-step E41 and the second sub-step E42 could be reversed. In other words, in the first sub-step, the mold is closed by affixing the element of spatial conformation coated with an envelope. Then in a second substep, the second resin is injected in liquid form into the mold by means of an injection nozzle opening directly inside the mold.

In a third sub-step E43 of the molding step E4, the mold is opened to extract the envelope 2 to which the molded sole 3 is secured. Advantageously, the shoe in the course of manufacture is always handled via the element of spatial conformation which avoids any contact with resin which would not yet be completely polymerized. The polymerization of the first resin or of the second resin can therefore be completed outside of the mold 23 as illustrated in FIG. 9.

In a fifth step E5, illustrated in FIG. 10, the spatial shaping element 20 is removed from the envelope 2 after the polymerization of the first resin and the second resin. The first resin allows the envelope to be maintained in the spatial conformation given by the spatial conformation element 20. The envelope therefore retains the shape of a foot: it does not collapse or only slightly collapses under its own weight.

In a sixth step E6, called the drilling step and illustrated in FIG. 11, two series of holes 6 are drilled, for example by means of a punching machine 25 or by means of pliers. The two sets of holes are substantially parallel to a longitudinal axis of the shoe and arranged on top of the envelope. These holes under drilled in subparts of the envelope saturated or else having an excess of the first resin. These two series of holes are intended for the passage of the lace 6 for tightening the shoe. Other holes (not shown) may be provided on the second surface of the envelope for ventilation of the shoe.

Alternatively, as illustrated in Figures 12 and 13, the fifth step and the sixth step could be reversed. That is to say, the drilling of the holes would be carried out while the spatial shaping element is still in place inside the envelope. Such a variant would have the advantage of offering support to the casing for drilling the holes. The envelope would then not risk being deformed under the drilling force applied by the punching machine 25.

In a seventh step E7, illustrated in FIG. 14, a lace is assembled in a manner known per se through the holes 6 made during the sixth step E6.

The shoe obtained is simple to manufacture since the process comprises a limited number of steps. The manufacturing process does not use a sewing process, it does not use glue or any other chemical except the first resin and the second resin. The manufacturing process has the advantage of using a small amount of material and generating little waste, which is very beneficial for the environment. When the first resin and the second resin are made of polyurethane, the shoe obtained is particularly ecological because this material is easily biodegradable.

Advantageously, the manufacturing process can be implemented for the manufacture of a shoe called "custom". In such an implementation of the invention, a shape according to the particular dimensions and / or the particular proportions of the user's foot is produced and replaces the element of standard spatial conformation. Such a shape can, for example, be manufactured by means of a step of molding a foot of the user. Alternatively, the shape can be selected from a variety of shapes available based on foot size information complementary to the shoe size information, such as for example the width of the foot and / or the shape of the toes. We thus have a shoe whose shape is ideally suited to the morphology of the foot. Obtaining such a shoe may require only the adaptation of the element of spatial conformation.

The sole 3 adheres very well to the envelope 2 because on the one hand the second resin which constitutes it permeates part of the first surface of the envelope (the part of the first surface complementary to the first zone). On the other hand, the sole is welded to the first resin which grips on the second surface. The first resin acts like claws engaged on the top of the foot, which keeps the sole firmly held against the first surface of the envelope.

When the shoe is worn by its user, the foot is very well maintained by the cooperation of the lace 4, bands 16 of first resin and the sole 3. In fact, the bands 16 are arranged in the extension of the strands of the laces and are welded to the sole. The foot is thus tightened, in other words “tied”, by the lace cooperating with the bands welded to the sole. In addition, the first resin arranged in the first sector 13 provides reinforced support for the heel while the resin arranged in the second sector 14 protects the toes, in particular from impacts which may occur at the tip of the foot. The first resin impregnating the envelope increases the solidity and the abrasion resistance of the envelope and gives a better grip of the foot and / or a better stability of the shoe. The shoe remains light and airy because the second surface is not completely impregnated with the first resin.

Claims (17)

claims 1. Method for manufacturing a shoe (1), characterized in that it comprises: - A placement step (E1) of an envelope (2), porous or fibrous, on a spatial conformation element (20) to give a predefined spatial conformation to the envelope (2); - Then, an impregnation step (E2) of a first thermosetting resin (10) in the envelope (2), allowing after the polymerization of the first resin (10) and after the removal of the spatial shaping element (20), maintaining the envelope (2) in said predefined spatial conformation; - Then, a step of molding (E4) a sole (3) against the envelope (2), the sole (3) comprising a second thermosetting resin (17) of the same kind as the first resin (10), l molding step (E4) comprising a crosslinking reaction of the second resin (17) with the first resin (10) previously impregnated in the envelope (2), the molding step (E4) being carried out while the first resin (10) impregnating the envelope (2) at the end of the impregnation step (E2) is not yet completely polymerized. 2. Manufacturing method according to one of the preceding claims, characterized in that the envelope (2) comprises an inner surface and an outer surface, the outer surface comprising a first surface (7) intended to receive a sole, and a second surface (8) complementary to the first surface (7) and intended to cover the top and the sides of a foot, the first resin (10) being impregnated during the impregnation step (E2) on a first zone (11) of the first surface (7) and on a second area (12) of the second surface (8). 3. Manufacturing method according to the preceding claim, characterized in that the first zone (11) forms only part of the first surface (7), the molding step (E4) comprising a reaction for impregnating the second resin (17) in a part of the first surface (7) not impregnated with the first resin (10). 4. The manufacturing method according to one of claims 2 or 3, characterized in that the second zone (12) forms only part of the second surface (8). 5. Manufacturing method according to one of claims 2 to 4, characterized in that the first zone (11) and the second zone (12) are interconnected. 6. Manufacturing method according to one of claims 2 to 5, characterized in that the second zone (12) comprises: - a first sector (13) extending around the heel, and / or - a second sector (14) extending substantially around and / or above the toes, and / or - A third sector (15) extending on either side of the foot of the first surface (7) up to at least one hole (6) provided for the passage of a lace (4), said third sector (15) comprising bands (16) extending in the extension of a lace (4). 7. Manufacturing method according to one of the preceding claims, characterized in that, at the end of the impregnation step (E2), the envelope comprises a locally variable quantity of first resin (10), in particular in that the envelope (2) comprises a first sub-part in which it is partially impregnated with the first resin (10), and / or a second sub-part in which it is saturated with the first resin (10), and / or a third sub-part in which it comprises more of the first resin (10) than it can impregnate. 8. Manufacturing method according to one of the preceding claims, characterized in that the envelope (2) is a mesh or woven element and / or an element comprising microfibers and / or an element comprising split leather. 9. Manufacturing method according to one of the preceding claims, characterized in that the envelope (2) is manufactured in one piece or in that the envelope (2) comprises at least two pre-assembled sub-elements, in particular sewn or glued together. 10. The manufacturing method according to one of the preceding claims, characterized in that the envelope (2) comprises a single opening (5) through which is introduced the spatial shaping element (20). 11. The manufacturing method according to one of the preceding claims, characterized in that the first resin (10) and the second resin (17) consist essentially of polyurethane or epoxy polymer or polyester or silicone. 12. Manufacturing process according to one of the preceding claims, characterized in that the molding step (E4) comprises: a first sub-step (E41) of casting the second resin (17) in liquid form in a mold (23), - followed by a second sub-step (E42) of closing the mold (23) by affixing the spatial shaping element (20) coated with the envelope (2), or in that the molding step ( E4) includes: - a first sub-step for closing the mold (23) by affixing the spatial shaping element (20) coated with an envelope (2), - followed by a second sub-step of injecting the second resin (17) in liquid form into the mold (23). 13. The manufacturing method according to one of the preceding claims, characterized in that it comprises a displacement of the envelope (2) by means of the spatial shaping element (20). 14. Manufacturing method according to one of the preceding claims, characterized in that it comprises a drilling step (E6) of at least one hole (6) in a part of the envelope (2), the at least one hole (6) being intended for the passage of a lace (4) or intended to form a ventilation of the shoe (1), said part being previously impregnated with the first resin (10), in particular said part being previously saturated with the first resin (10). 15. Manufacturing process according to one of the preceding claims, characterized in that it comprises a step of manufacturing a spatial shaping element (20) according to the particular dimensions and / or the particular proportions of a foot of an user. 16. Manufacturing method according to one of the preceding claims, characterized in that the molding step (E4) comprises a sub-step for positioning an outer sole (18) at the bottom of a mold (23) and / or a substep for positioning inserts having an ornamental function, and / or a function for improving stability, and / or a function for improving the cushioning of the shoe in the mold (23). 17. Manufacturing method according to one of the preceding claims, characterized in that it comprises a step of fixing accessory elements on the casing (2), in particular a step of fixing a stability reinforcement, and / or a protective reinforcement, and / or a label, and / or a decorative piece.