Last, method of manufacturing a last, method of manufacturing an upper

Abstract

To provide a reusable last, a manufacturing method of a last, and a manufacturing method of a shoe upper. A last for molding a shoe upper, the last being composed of a plastic material that reversibly changes between a solid state having a fixed form at the time of molding the shoe upper and a plastic state having fluidity that changes in form.

Description

TECHNICAL FIELD

[0001] The present application relates to a last for molding a shoe upper, and further relates to a manufacturing method of the last and a manufacturing method of the shoe upper. BACKGROUND

[0002] In making a custom-made shoe that conforms to a user's foot, the last is user-specific, so after the shoe upper is molded using the last and the shoe is made, the last is no longer needed except for the case of being stored in advance for future use.

[0003] The specification of U.S. Patent Application Publication No. 2018 / 0014609 discloses manufacturing footwear in a portable housing. The specification of U.S. Patent Application Publication No. 2016 / 0206049 discloses a last preform that can be reshaped by a shape memory polymer. The specification of Chinese Patent Application No. 109732913 discloses a last formed by 3D printing. The specification of U.S. Patent No. 1550232 discloses a last containing paper pulp inside.

[0004] However, in each of the above documents, there is no specific and explicit disclosure regarding the reuse of an unnecessary last. SUMMARY

[0005] Therefore, an object of the present application is to provide a reusable last, a manufacturing method of a last, and a manufacturing method of a shoe upper.

[0006] The present application is a last for molding a shoe upper, the last being composed of a plastic material that reversibly changes between a solid state having a fixed form at the time of molding the shoe upper and a plastic state having fluidity that can change in form.

[0007] Further, the present application is a manufacturing method of a last for molding a shoe upper, the last being formed by 3D printing a paper pulp aggregate in which a plurality of paper pulp materials are collected in a medial-lateral direction based on a wearer's foot. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1A A last relating to one embodiment of the present application is shown in a state in which a user's foot is photographed in order to obtain foot shape data.

[0009] Figure 1B is a perspective view of the last.

[0010] Figure 1C shows a state in which the last is dissolved to become a dissolved body.

[0011] Figure 2 shows a state in which the last is formed halfway by a 3D printer.

[0012] Figure 3A is a longitudinal sectional view showing the central portion and the peripheral portion of the above-mentioned last.

[0013] Figure 3B is a main portion longitudinal sectional view showing a state in which the outer circumference of the main body portion of the above-mentioned last is covered by the protection portion.

[0014] Figure 4 is a side view showing a state in which the pre-forming upper is covered on the above-mentioned last, and steam heating is performed in the inside of the heating box.

[0015] Figure 5A is a perspective view showing a state in which the forming mold is formed by cutting in the case of forming the above-mentioned last with the forming mold.

[0016] Figure 5B is a perspective view showing the above-mentioned forming mold.

[0017] Figure 5C is a perspective view showing a state in which the above-mentioned last is formed with the above-mentioned forming mold.

[0018] Figure 6 is a perspective view showing a last of another embodiment of the present application.

[0019] Figure 7 is a perspective view showing a last of another embodiment of the present application.

[0020] Figure 8 is a perspective view showing a last of another embodiment of the present application.

[0021] Figure 9 is a perspective view showing a last of another embodiment of the present application. DETAILED DESCRIPTION

[0022] With regard to the present application, embodiments are illustrated together with the drawings. In the following description, the "medial-lateral direction" means that the direction toward the foot of the wearer of the shoe is the "medial direction", and the direction toward the outside of the shoe is the "lateral direction". Also, in the following description, when the pre-forming and post-forming uppers 2 are described, in order to distinguish, sometimes, the pre-forming upper 2A and the post-forming upper 2B are also indicated.

[0023] The shoe tree 1 of the present embodiment is not a shoe tree for shoes of mass-produced products, but a custom-made shoe tree 1 that conforms to the user's foot F. However, the present application does not completely deny the application to shoe trees for shoes of mass-produced products, and can also be applied. The shoe tree 1 can also be manufactured in a shop that sells shoes, and can be manufactured in a factory that is remote from the shop by transmitting and receiving data for 3D printing and foot shape data using a communication unit as described later. The shoe tree 1 of the present embodiment is composed of a plastic material at least in the outer peripheral portion (a portion that contacts the upper 2 when the upper 2 is molded). The "plastic material" referred to here is a material that reversibly changes between a solid state (see the shape of the shoe tree 1 shown in Figure 1B ) that has a fixed shape when the upper 2 is molded by covering the shoe tree 1 with the material of the upper 2 (the upper 2A before molding) and heating and the like, and a plastic state (see Figure 1C ) that has fluidity. The "fluidity" referred to above is a property that a liquid (or a substance similar to a liquid) has, and is a property in which the shape (outer shape) can be freely changed. In addition, the upper 2 is, for example, cloth, and in the present embodiment, cloth composed of a fiber sheet having thermal shrinkability is used.

[0024] The plastic material in the present embodiment includes a solid component aggregate composed of a plurality of solid components, and a molding material that is mixed with the solid component aggregate and solidifies the solid component aggregate into the fixed shape described above. In the present embodiment, as the solid components, pulp materials (particulate, fibrous pulp sheets that are each smaller (finer) than the size of the entire shoe tree 1) are used. That is, the solid component aggregate is a pulp aggregate in the present embodiment. By being thus configured, the shoe tree 1 can be formed using a pulp material that is a general paper material, and therefore it is easy to obtain the material.

[0025] The molding material is dissolved from the solidified state to generate fluidity in the plastic material. The dissolution is performed, for example, by the addition of a different material (water in the present embodiment) to the molding material, heating, irradiation of light (ultraviolet rays or the like). The material used as the molding material is, for example, a water-soluble material such as a starch paste, a water-soluble resin, or the like that exhibits fluidity in the molding material by the addition of water. The molding material is, for example, a liquid in the initial state, and changes to a solid by being left in contact with the pulp aggregate for a certain period of time. Then, by dissolving the molding material, it can become a liquid in which the pulp aggregate as a solid is mixed. If a water-soluble molding material is used, the molding material can be dissolved with water to become a plastic state, and therefore it is advantageous in that a special agent or device for dissolution is not required.

[0026] The mixing ratio of pulp aggregate to molding material can be determined by taking into account the hardness required when using the outer periphery of the shoe last 1 (before and after molding the shoe upper 2), the surface roughness of the shoe last 1, the humidity in the atmosphere during use, and the time required for dissolution.

[0027] In the shoe last 1 constructed as described above, after the upper 2 is formed, it can change from a solid state to a malleable state, and then change back to a solid state. Moreover, this change is reversible. Therefore, it can be reused.

[0028] The shoe last 1 is formed by stacking pulp assemblies in the inward and outward directions. The stacking can be multi-layered or single-layered. Because the shoe last 1 can be formed through stacking, it can be formed without using a molding die. Therefore, for example, as... Figure 2 As shown, it can be formed using a 3D printer.

[0029] Additionally, the shoe last 1 can be solid, but it is preferred that the inside be hollow (see reference). Figure 2 (Partial cross-section of the last). When it is hollow, the main body 11 containing a malleable material is formed in such a way that it surrounds the hollow internal space 1a in the last 1. Even though it is hollow, the strength can be ensured by setting the thickness of the main body 11, so there is no functional problem. If the last 1 is hollow, no material can be placed in the center, so material can be saved. In addition, the time required to form the last 1 can be shortened. In addition, since the last 1 can be made lightweight, it is easy to handle. Thus, there are various advantages.

[0030] In addition, such as Figure 3A As shown, the shoe last 1 may also have a central portion 12 and a peripheral portion 13. The central portion 12 is a part that is pre-formed as the core material of the shoe last 1 and is always in a solid state. The central portion 12 can be solid or hollow. When it is hollow, the shoe last 1 can be made lightweight. The peripheral portion 13 is a part formed on the outer periphery of the central portion 12. The peripheral portion 13 is made of a malleable material. That is, this structure is a structure in which the central portion 12 is located in the internal space 1a of the above structure. By constructing the shoe last 1 in this way, the time required to form the shoe last 1 can be shortened, as with the structure described above. In addition, compared with a solid structure in which the shoe last 1 is formed uniformly as a whole, the amount of malleable material used can be reduced. In addition, when manufacturing shoes in a factory, by using the central portion 12 as the core material, the part that is stored in the factory for a long time is only the central portion 12, which is one size smaller than the shoe last 1. Therefore, compared to storing the entire shoe last 1, the number of shoes stored in each given space can be increased, thus saving storage space. In addition, even shoe lasts 1 of different sizes can have a uniform shape (size) of the central part 12, so there is no need to store them by size.

[0031] In the case where the last 1 has the center portion 12, the center portion 12 can be formed of a material having higher heat transfer properties than the peripheral portion 13. For example, the center portion 12 can be made of metal (aluminum alloy, etc.). By so configuring, when the upper 2 is molded by heating (refer to Figure 4 ), the center portion 12 of the last 1 is also heated, whereby the upper 2 can also be heated from the center portion 12 side (i.e., the upper 2A before molding is heated from both the inside and the outside). Therefore, compared to the case where heating is performed only from the outside, the heating time can be shortened, and the upper 2 can be molded efficiently (in a short time).

[0032] Further, as shown in Figure 3B , the last 1 can have the above-described main portion 11 and a protective portion 14 that covers the outer periphery (the outer surface) of the main portion 11, which is in a layered or film-like shape. Here, as described above, the main portion 11 corresponds to the portion that surrounds the internal space la in the case where the last 1 is hollow, to the entirety of the last 1 (excluding the protective portion 14) in the case where the last 1 is solid, and to the peripheral portion 13 in the case where the last 1 has the center portion 12 and the peripheral portion 13 (refer to Figure 3A ). By so configuring, the main portion 11 can be protected from damage by the protective portion 14. In addition, the last 1 can be given heat resistance and ultraviolet resistance by the protective portion 14. Furthermore, the protective portion 14 can be peeled off from the main portion 11. In order to enable peeling, for example, the protective portion 14 is adhered to the main portion 11 using an adhesive that can be peeled after adhesion, or the protective portion 14 is formed of a material having weak adhesion with respect to the main portion 11. By so configuring, by peeling the protective portion 14 from the last 1, the main portion 11 is protected in the state of the last 1, while making it easy to reuse the main portion 11.

[0033] The protective portion 14 can be, for example, a metal film (aluminum film, etc.), an ultraviolet curing resin (epoxy resin, etc.) that is applied and cured, a silicone resin, or a rubber. In addition, it can be a layer formed of fine particles (sand, etc.) that are blown to the outer periphery of the main portion 11. In addition, a coating film formed by impregnating the main portion 11 in a liquid resin can be the protective portion 14. In addition, a coating film formed by spraying a liquid resin to the main portion 11, or applying a liquid resin using a brush, a roller, or the like can be the protective portion 14.

[0034] Next, the manufacturing method of the last 1 will be described. The last 1 is formed by layering a moldable material (a mixture of a pulp aggregate and a molding material) in the inside-outside direction using 3D printing. This formation is, for example, as shown in the cross-sectional view in Figure 2 , formed in a hollow shape. In addition, in the case where the last 1 has the center portion 12 and the peripheral portion 13, the portion that is layered to the peripheral portion 13 on the outer periphery of the center portion 12 (refer to Figure 3ABy using 3D printing, shoe lasts can be easily formed without the use of molds. 3D printing uses... Figure 2 The process is carried out using a 3D printer with nozzle N as shown. The aforementioned mixture in a plastic state is ejected from nozzle N and, as shown, is formed by sequentially stacking it from bottom to top. Figure 2 The image shows the shoe last 1b during the molding process.

[0035] When the shoe last 1 is formed by 3D printing, the forming speed of the shoe last 1b during molding can be adjusted. It is possible to form the entire shoe last 1 at a uniform speed, or, for example, to shorten molding time, to precisely mold the instep of the shoe last 1 (which significantly affects the user's wearing comfort) at a slower speed in the shoe upper 2B, while roughly molding the other parts at a faster speed. Furthermore, it is also possible to precisely mold the outer layer of the shoe upper 2 at a slower speed and roughly mold the inner layer at a faster speed. Additionally, it is possible to increase the density of the outer layer and decrease the density of the inner layer during molding.

[0036] As a preliminary stage in forming the shoe last 1, the following steps are performed: a data acquisition step to obtain the user's foot shape data; and a data generation step to generate 3D printing data based on the obtained user's foot shape data. Then, a shoe last forming step is performed to stack the aforementioned pulp assembly based on the generated 3D printing data. Through these steps, a customized shoe last 1 that conforms to the user's foot F can be formed.

[0037] The aforementioned 3D printing data is generated based on foot shape data for each of the multiple users. By generating 3D printing data in this way, it is possible to perform detailed customization of the shoe upper 2 for each user.

[0038] The foot type data of the above users is, for example, based on... Figure 1A The image data obtained by capturing the user's foot F shows the measurement dimensions of various parts of the user's foot F. Therefore, it is possible to use, for example, a digital camera or a smartphone P (see reference). Figure 1A Foot shape data can be easily generated. For example, in the case of a smartphone, foot shape data can be generated based on image data using pre-installed software. Alternatively, foot shape data can be created by combining captured image data with data stored on a server owned by the shoe manufacturer.

[0039] In addition, the image data described above can be captured, for example, at the user's home or at a store (a sales store) visited by the user. In this case, the image data can be transmitted to a server of a shoe manufacturer, and foot shape data can be generated in a factory of the shoe manufacturer, and then a shoe tree 1 and a shoe can be manufactured in the factory. In addition, the image data described above can be captured at a store, and a shoe tree 1 and a shoe can be directly manufactured at the store. Of course, a shoe tree 1 and a shoe can be manufactured at different places. In addition, the store is not limited to a fixed store, and can be a mobile store using a car or a trailer.

[0040] After the shoe tree 1 becomes unnecessary for the molding of the upper 2, a dissolving process is performed. In the dissolving process, the used shoe tree 1 is dissolved to be liquefied to become a dissolved body 1F (see FIG. 1). Figure 1C Figure 1C A state in which the dissolved body 1F is put in a container is shown. The shape of the container that holds the dissolved body 1F is not particularly limited. The dissolved body 1F is adjusted to have a degree of fluidity that can be ejected to the outside through a nozzle N of a 3D printer. In the case where the shoe tree 1 contains a water-soluble molding material, water is added to the used shoe tree 1 (after the molding of the upper 2) to be liquefied. The dissolved body 1F in this case is in a state in which the pulp material as a dispersed substance is dispersed in water as a dispersion medium. In addition, the molding material (starch paste or the like) is dissolved in the water that constitutes the dissolved body 1F. The molding material is added and dissolved in the dissolved body 1F as needed. In addition, an effect accelerator that accelerates solidification after ejection from the nozzle N can be added to the dissolved body 1F. In addition, since the pulp material does not precipitate in the container, a medicine can be added to the dissolved body 1F, or the dissolved body 1F can be stirred in the container. By thus performing the dissolving process, it is possible to return the solid component aggregate (pulp aggregate) to a plastic state, and it is possible to use it for 3D printing. Therefore, it is possible to recycle the used shoe tree 1 as a shoe tree 1 for another user.

[0041] In order to perform the dissolving process in a short time, hot water can also be added to the used shoe tree 1. In addition, a particle line (a division line) can also be formed in advance in the shoe tree 1 at the time of molding of the shoe tree. In addition, a mechanical device such as a cutting device (a chopper or the like) that disassembles the organization of the shoe tree 1 can be used before or after the water or hot water is added to promote the dissolution of the water or hot water.

[0042] Next, a manufacturing method of the upper 2 using the shoe tree 1 described above will be briefly described. For example, a material (a pre-molding upper 2A) of the upper 2 composed of a fiber sheet including a heat-shrinkable yarn is prepared. Then, the following processes are performed: a first molding process in which the pre-molding upper 2A is covered on the shoe tree 1 described above; and a second molding process in which the pre-molding upper 2A is molded by heating and shrinking the heat-shrinkable yarn. Figure 4 ​The pre-forming upper 2A is shown as being deformed along the shape of the last 1 into a post-forming upper 2B by heating. The heating method used in the second forming step is steam heating. As shown in Figure 4 As shown in outline, the pre-forming upper 2A is, for example, housed inside a heating tank 31, and heated by high-temperature steam 32 emitted from the inner surface of the heating tank 31. By this steam heating, the entire pre-forming upper 2A can be uniformly heated. Thus, the pre-forming upper 2A can be uniformly deformed in conformity with the last 1, becoming the post-forming upper 2B. Note that, in the second forming step, in addition to steam heating, hot air heating, hot water heating, or the like can be used. Alternatively, the heating of the pre-forming upper 2A can be performed only partially, rather than entirely.

[0043] After the second forming step, a sole mounting step is performed. In this sole mounting step, the post-forming upper 2B is mounted to a separately manufactured sole, for example, by adhesion. Alternatively, in addition to adhesion, the sole mounting step can be performed simultaneously with the second forming step by heat fusion or the like. In this case, if the central portion 12 of the last 1 is formed of a material having high heat transfer properties (for example, a metal such as aluminum, copper, stainless steel, or the like), heat fusion can be performed efficiently. In addition, the formation of a tongue, the processing of a toe cap, the mounting of eyelets for passing a shoelace, the mounting of a decorative member or a label, the printing of a logo, and the mounting of an insole can be performed appropriately in each of the above steps, or after all of the steps are completed.

[0044] Here, the structure involved in the embodiment of the present application and the effects thereof are summarized. The present embodiment is a last 1 for forming an upper 2, and the last 1 is composed of a plastic material that reversibly changes between a solid state having a fixed form at the time of forming the upper 2 and a plastic state having fluidity.

[0045] According to this structure, after the upper 2 is formed, the plastic material changes from the solid state to the plastic state, and then changes again to the solid state, so it can be reused.

[0046] Further, the plastic material can include a pulp aggregate composed of a plurality of pulp materials, and a forming material that solidifies the pulp aggregate into the fixed form, and the forming material is dissolved from the solidified state, thereby generating fluidity in the plastic material.

[0047] According to this structure, the pulp material, which is a general paper material, can be used, so the material is easily obtained.

[0048] Further, the forming material can be water-soluble.

[0049] According to this structure, since the molding material can be dissolved with water, a special agent or device for dissolution is not required.

[0050] Further, the last 1 described above can form the paper pulp aggregate by stacking the paper pulp aggregate in the medial-lateral direction with respect to the foot of a wearer.

[0051] According to this structure, since the last 1 can be formed by stacking without using a molding die, molding can be performed using, for example, a 3D printer.

[0052] In addition, the inside of the last 1 described above can be hollow.

[0053] According to this structure, since the material can not be disposed at the center, the material can be saved.

[0054] Further, the last 1 described above can have a center portion 12 that is formed in advance as a core material and is always in the solid state, and a peripheral portion 13 formed in the outer peripheral portion of the center portion 12 and composed of the moldable material.

[0055] According to this structure, the time required to form the last 1 can be shortened. In addition, compared to a structure in which the entire last 1 is formed uniformly, the amount of moldable material used can be reduced.

[0056] In addition, the center portion 12 described above can be formed of a material having higher heat transfer properties than the peripheral portion 13 described above.

[0057] According to this structure, when the upper 2 is molded by heating, the upper 2 can also be heated from the center portion 12 side, so the upper 2 can be efficiently molded.

[0058] In addition, the last 1 described above can have a main body portion 11 containing the moldable material and a protective portion 14 that covers the outer periphery of the main body portion 11.

[0059] According to this structure, the main body portion 11 can be protected by the protective portion 14.

[0060] In addition, the protective portion 14 described above can be a protective portion that can be peeled from the main body portion 11.

[0061] According to this structure, by peeling the protective portion 14 from the last 1, reuse of the main body portion 11 becomes easy.

[0062] In addition, the present embodiment is a manufacturing method of a last 1, which is a manufacturing method of a last 1 for molding an upper 2,

[0063] The last 1 described above is formed by stacking a paper pulp aggregate composed of a plurality of paper pulp materials in the medial-lateral direction with respect to the foot of a wearer by 3D printing.

[0064] According to the manufacturing method thus configured, the last 1 can be easily formed without using a molding mold.

[0065] In addition, the last 1 described above can be formed in a hollow shape by 3D printing.

[0066] According to the manufacturing method thus configured, the time required for forming the last 1 can be shortened. In addition, the amount of material can be saved.

[0067] Further, the last 1 described above can have a center portion 12 formed in advance as a core material, and a peripheral portion 13 formed on the outer peripheral portion of the center portion 12, and the portion formed by the 3D printing described above is the peripheral portion 13.

[0068] According to the manufacturing method thus configured, the time required for forming the last 1 can be shortened. In addition, compared with a structure formed uniformly as a whole, the amount of plastic material can be reduced.

[0069] Further, the manufacturing method can have a data acquisition process of acquiring foot shape data of a user, a data generation process of generating 3D printing data based on the foot shape data of the user, and a last forming process of laminating the pulp aggregate based on the 3D printing data.

[0070] According to the manufacturing method thus configured, the last 1 that conforms to the user's foot can be formed.

[0071] Further, the 3D printing data described above can be generated based on the foot shape data of the user generated individually for each of a plurality of users.

[0072] According to the manufacturing method thus configured, the customization of the upper 2 for each user can be performed.

[0073] In addition, the foot shape data of the user described above can be generated based on image data obtained by photographing the user's foot.

[0074] According to the manufacturing method thus configured, the foot shape data can be easily generated using, for example, a digital camera or a smartphone.

[0075] Further, the last 1 described above can contain a water-soluble molding material that solidifies the pulp aggregate into a fixed shape, and further include a dissolving process of adding water to the last 1 described above after use to fluidize it.

[0076] According to the manufacturing method thus configured, the last 1 after use can be recycled as a last 1 for another user.

[0077] Further, the above-described embodiment is a manufacturing method of an upper 2, which includes a first molding step of covering a pre-molded upper 2A composed of a fiber sheet including a heat-shrinkable yarn over the last 1, and a second molding step of making the pre-molded upper 2A into a post-molded upper 2B by heating along the shape of the last 1.

[0078] According to the manufacturing method thus configured, the upper 2 can be manufactured by the reusable last 1.

[0079] The above-described embodiment is merely an example, and the last 1, the manufacturing method of the last 1, and the manufacturing method of the upper 2 of the present application are not limited to the above-described embodiment. Thus, the last 1, the manufacturing method of the last 1, and the manufacturing method of the upper 2 of the present application can be variously changed within a range not departing from the gist of the present application. In the above-described changes, for example, a case where a part of the plurality of elements configuring the above-described embodiment is replaced, a part is omitted, or elements belonging to different examples are appropriately combined is included. Further, a case where matters belonging to technical common sense regarding the last 1, the manufacturing method of the last 1, and the manufacturing method of the upper 2 are combined is also included.

[0080] For example, the plastic material can also be a resin. In a case where a thermoplastic resin is used as the resin, a plasticized state can be obtained by heating, and a solid state can be obtained by cooling.

[0081] Further, in the above-described embodiment, a pulp material is used as the solid component, but is not limited thereto. For example, a wood chip (sawdust or the like), a bamboo chip, a natural fiber sheet (yarn dust, a cut sheet of a plant fiber, or the like), a resin sheet (preferably, a resin sheet having heat resistance), a metal sheet, a paper sheet (a paper sheet larger than a pulp material and maintaining a state of paper), a cloth sheet, a plant sheet (a cut sheet of withered grass or the like), sand, earth, and mud can also be used.

[0082] Further, regarding the molding material, a material dissolved by a solvent other than heat and water can also be used.

[0083] Further, in the above-described embodiment, a method of layering the last 1 itself by 3D printing is described, but for example, a last 1 can also be manufactured by making a molding die 4 based on foot shape data, and flowing a plastic material into the molding die 4 to form the last 1. Further, the molding die 4 can also be formed by 3D printing. Figure 5B As illustrated in FIG. 6, the molding die 4 can combine a first molding die 4a in which a recess 41 is formed corresponding to one side (for example, the right side) in the width direction of the last 1, and a second molding die 4b in which a recess 41 is formed corresponding to the other side (for example, the left side) in the width direction of the last 1.

[0084] In this case, as illustrated in FIG. 6, the molding die 4 can combine a first molding die 4a in which a recess 41 is formed corresponding to one side (for example, the right side) in the width direction of the last 1, and a second molding die 4b in which a recess 41 is formed corresponding to the other side (for example, the left side) in the width direction of the last 1. Figure 5B In this case, as illustrated in FIG. 6, the molding die 4 can combine a first molding die 4a in which a recess 41 is formed corresponding to one side (for example, the right side) in the width direction of the last 1, and a second molding die 4b in which a recess 41 is formed corresponding to the other side (for example, the left side) in the width direction of the last 1.

[0085] First, such as Figure 5A As shown, to match the shape of the formed shoe last 1, recesses 41 are formed in the first forming mold 4a and the second forming mold 4b, for example, using a cutting tool C. Alternatively, small recesses can be pre-formed in the forming mold 4 before cutting. In this case, the size of the pre-formed recesses can be comparable to the standard shape of the shoe last 1. This minimizes the need for additional processing using cutting tools C, etc. The completed forming mold 4 is... Figure 5B The shape shown. By flowing plastic material into the recess 41 of the molding die 4, thus achieving the desired shape. Figure 5C The shoe last 1 is formed as shown.

[0086] Regarding the flow of plastic material into the molding die 4, it can be configured in a mode where the shoe last structures (a pair of left and right sides) formed by the flow of plastic material into the first molding die 4a and the second molding die 4b are then joined together, or it can be configured in a mode where the plastic material flows into the shoe last 1 after the first molding die 4a and the second molding die 4b are joined together.

[0087] Regarding the molding die 4, it can also be made of the same plastic material as the shoe last 1, so that the used molding die 4 can be dissolved and reused for molding dies 4 used to form shoe lasts 1 of other shapes.

[0088] Alternatively, shoe last 1 can be set to... Figures 6-9 The shape shown is composed of multiple blocks made of malleable material, smaller than the shoe last 1, as shown in beads 5 and 6. Figure 6 The shoe last 1 shown is composed of a plurality of spherical beads 5. Each bead 5 is, for example, made of polyvinyl alcohol. By spraying water onto the plurality of beads 5, which are arranged into the shape of the shoe last 1 by means of embedding in a mold, adjacent and abutting beads 5 can be glued together. Through this glue, the shoe last 1 can be formed. The used shoe last 1 can be dissolved by adding water or heating.

[0089] in addition, Figure 7 and Figure 8 The shoe last 1 shown is composed of multiple cylindrical beads 6. By heating the multiple beads 6, which are arranged into the shape of the shoe last 1 through embedding in a mold or the like, adjacent beads 6 can be glued together. Through this glued bonding, the shoe last 1 is formed. The used shoe last 1 can be melted by heating. The cylindrical beads 6 can be... Figure 7 As shown, they are arranged axially in a vertical direction, or as... Figure 8 As shown, they are arranged with the axis oriented horizontally. Furthermore, they can also be arranged as follows: Figure 9As shown, at the rear of the last 1, a monolithic portion 7 is formed by layering a moldable material by 3D printing as in the above embodiment, and at the front, a portion is formed in which a plurality of beads 6 are gathered. In addition, although not shown, it is also possible to provide only the rear as a portion in which a plurality of beads 6 are gathered.

[0090] In addition, the last 1 can be formed as a shape identical to the shape of the user's foot F as a whole, but depending on design or functional reasons, for a particular portion, it is also possible to provide a shape that differs from the shape of the user's foot F by an amount corresponding to a desired size.

[0091] In addition, the manufacturing method of the upper 2 is not limited to the method of utilizing the heat shrinkage of the fiber sheet including the heat shrinkable yarn as in the above embodiment, and various methods such as weaving cloth around the last 1 or layering materials using a 3D printer can be adopted, for example.

Claims

1. A method for manufacturing a shoe last, wherein the shoe last is used to shape the shoe upper, wherein, The shoe last is formed by layering malleable materials in the inward and outward directions based on the wearer's foot. The shoe last, at least in its outer periphery, is made of a plastic material that can reversibly change between a solid state with a fixed shape and a fluid, malleable state that can change shape during the molding of the shoe upper. A peripheral portion is formed at the center of the core material pre-formed as the shoe last and always in a solid state. The peripheral portion is formed on the outer periphery of the center portion and is made of the malleable material. The interior of the portion made of the plastic material is hollow, and the portion made of the plastic material is a single layer. The plastic material comprises a pulp aggregate composed of multiple pulp materials, and a molding material for solidifying the pulp aggregate into the fixed shape. The shoe last is formed by making multiple blocks and assembling them. The multiple blocks are made of the plastic material and are smaller than the shoe last. By sprinkling water or heating the multiple blocks arranged in the shape of the shoe last, the adjacent and abutting blocks can be glued together. The used shoe last can be dissolved by adding water or heating.

2. The method for manufacturing a shoe last according to claim 1, wherein, The molding material is water-soluble.

3. The method for manufacturing a shoe last according to claim 1 or 2, wherein, The central part is the portion that is one size smaller than the shoe last. Even if the shoe lasts are different sizes, the size of the center part is the same.

4. The method for manufacturing a shoe last according to claim 3, wherein, The central portion is formed of a material with higher thermal conductivity than the peripheral portion.

5. The method for manufacturing a shoe last according to claim 1 or 2, wherein, The shoe last has a main body portion containing the malleable material and a protective portion covering the outer periphery of the main body portion.

6. The method for manufacturing a shoe last according to claim 5, wherein, The protective part can be detached from the main body.

7. A method for manufacturing a shoe upper, comprising the following steps: In the first molding process, a pre-molded upper, consisting of a fiber sheet containing heat-shrinkable yarn, is applied to the shoe last according to any one of claims 1 to 6; and The second molding process involves heating the shoe upper before molding to form the shoe upper after molding, following the shape of the shoe last.

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