JPH0653081B2 - Injection molding shoe manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a toe or toe cap that is a reinforcement for the toe of a shoe upper, or a rising portion of an instep such as an out counter as a reinforcement for the heel. We manufacture injection-molded shoes with lightweight soles with an instep reinforced part on the outer surface and excellent cushioning properties, to firmly bond the partial soles together and to provide shoes with high durability. It relates to a method of manufacturing.

[Conventional technology]

Conventionally, in a method of manufacturing an injection-molded shoe that has a toe guard, a toe cap, an out counter, or the like, and integrally attaches these to the outer surface of the instep rising portion, a method of further imparting lightweightness and cushioning property to the shoe, The inventors have proposed in Japanese Patent Application No. 1-206229.

According to this method, the last mold with the instep attached, the side mold, and the dummy mold are combined and bonded and integrated with the outer surface of the rising portion of the instep to reinforce the instep. Molding voids for molding, and molding voids for molding the outsole by combining a bottom mold and a dummy mold are prepared separately, and injection molding materials are injected and injected into these molding voids. Separately molding the instep reinforced part that is integrally bonded with the instep and the outsole in the molding void of, and then remove the dummy mold that constitutes these molding voids, and then remove the molded instep reinforced part. While leaving the bottom mold on the side mold and the bottom mold respectively, a molding space for molding the middle bottom by combining these last mold, side mold and bottom mold is provided. And injecting a foamable injection molding material for molding an intermediate bottom into the molding void to cause foaming in the molding void to form a foamed intermediate bottom integrally bonded to the instep reinforced portion and the bottom. And a method for manufacturing an injection-molded shoe.

[Problems to be solved by the invention]

By the way, in the shoes obtained by these conventional manufacturing methods, a toe guard, a toe cap or an out counter is provided integrally on the outer surface of the instep rising portion such as an instep, and an intermediate bottom made of a foamable injection molding material is used as an adhesive boundary surface. It is possible to provide a shoe sole that is light-weight and has excellent cushioning properties by forming an integrated shoe sole with the outsole, and to provide a shoe sole that is lightweight and has excellent cushioning properties. At the adhesive tip (A) and the adhesive tip (B), the filling amount or the filling thickness of the intermediate foam bottom, which is interposed respectively, is 0, and in the vicinity thereof, the filling amount is small or the filling thickness is small. The durability was low and there was a problem in wearing as shoes.

Furthermore, while wearing the shoes obtained by the conventional manufacturing method, a linear shape in which the outer peripheral edge of the shoe sole, which has a high degree of wear, and the lowermost edge of the toe ghat, toe cap or out counter, etc., is in contact At the top end, wear defects are likely to occur, and as a result, a part of the foaming intermediate sole is exposed, which significantly deteriorates the appearance of the shoe, resulting in a great quality defect.

The present invention has been made to solve the problems and quality defects of the prior art as described above. From the lowermost end of the toe guard, toe cap, out counter, etc. The present invention aims to provide a method for manufacturing an injection-molded shoe that is unlikely to cause peeling and wear defects at the adhesive tip (A) of the above, and / or the adhesive tip (B) at which the outer periphery of the book sole is adhered to the foaming intermediate sole. It is an object of the present invention to provide a method for manufacturing an injection-molded shoe that is less likely to cause peeling wear loss during wearing.

[Means for solving problems]

That is, the present invention is a combination of a last mold with an instep, a side mold, and a dummy mold, and an instep reinforced portion for reinforcing the instep by adhering and integrating with the outer surface of the rising portion of the instep. , Forming a molding void so that its lower end portion is positioned as a part of the bottom contact portion, and separately providing a molding void for molding the bottom by combining a bottom mold and a dummy mold, The injection molding material is injected into the molding cavities, and the instep reinforced portion integrally bonded with the instep and the outsole are separately molded into the respective molding cavities, and then the dummy molds forming these molding cavities. After removing the above, the last mold, the side mold and the bottom mold are assembled while leaving the molded instep reinforced part in the side mold and leaving the outsole in the bottom mold. Forming a molding gap for molding the middle bottom together, part of the middle bottom forms a ground contact boundary surface with the instep reinforced portion, and at the same time forms a bonding boundary surface with the main bottom, and also the main bottom grounding portion. The foamable injection molding material for molding the middle bottom is injected and injected into the molding cavity formed so as to be exposed as a part of the design area, and is foamed in the molding cavity, and is bonded to the instep reinforced portion and the outsole. The present invention provides a method for manufacturing an injection-molded shoe, which is characterized by molding an integrated foaming midsole.

[Action]

According to the present invention, since the instep reinforced portion and the outsole can be molded with a commonly used molding material so as to have hardness by using such means, these strengths can be secured as expected. Also, after molding them, the middle bottom is molded by injection-injecting the expandable molding material in the middle molding space, which is limited by the molded outsole. And the presence of the effervescent midsole allows the overall sole to be lightweight, so that the manufactured shoe does not unnecessarily tire the wearer. Further, since the lower end of the instep reinforced portion is arranged as a part of the outsole ground contact portion, the end portion of the adhesive portion with the middle bottom is not located at the top end portion that is easily worn. It is possible to provide high-quality shoes without exposing the middle sole even if the wear progresses due to wear.

〔Example〕

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, the manufacturing method of the shoe (S) of the embodiment of the present invention shown in FIG. 1 to FIG. 5 will be described. In this manufacturing method, the toe guard (1) as the instep reinforcement portion is provided with the instep (2). It is intended to be integrally formed on the outer surface of the toe part.

That is, as shown in FIG. 1, a side mold (5) for limiting the outer surface (4) of the toe guard (1) to the last mold (3) fitted with the instep cover (2) and a post-process. The lower part of the toe guard (1) that is bonded to the intermediate bottom (6) that is molded by is located as part of the grounding part, and is combined with the dummy mold (8) that limits the inner surface (7) To form a molding void (9) for molding the toe guard (1) so as to face the instep toe portion.

On the other hand, the dummy mold (8) is combined with a bottom mold (12) having a concave-convex design (11) on the grounding surface of the shoe sole (10) in its lower part to form a book-sole molding void (13). .

In the toe guard molding gap (9) and outsole molding gap (13) described above, either one first or simultaneously, the former is the runner.
By (R1), the latter injection-injects the molding material by the runner (R2) to form the toe guard (1) in the former and the outsole (14) in the latter. Since the runner (R2) is provided in the same bottom mold (12) in parallel with the runner (R3) used for injection injection of the intermediate bottom molding material described later,
In the figure, mainly the innermost part is shown by a dotted line.

Then lower the bottom mold (12) to remove the dummy mold (8).
By removing, the former toe guard (1) is left in the side mold (5) that constituted the former void (9), and it is molded in the bottom mold (12) that constituted the latter void (13). Retain the completed outsole (14).

Then, as shown in FIG. 2, the bottom mold (12) is raised to be combined with the last mold (3) with the instep cover (2) and the side mold (5) with the toe guard (1) left. , Forming a molding void (15) for molding the intermediate bottom (6). A foamable molding material is injected and injected into this by a runner (R3) to foam and fill the molding void (15). The foamed and molded middle bottom (6) adheres to the lower part of the instep cover (2) and the lower surface of the insole cloth (16) that were attached to the last mold (3), and also to the side mold (5). The toe guard (1) that was left adhered to the inner side surface (7) exposed facing the middle bottom molding void (15), and further, the bottom of the bottom (14) that was also left in the bottom mold (12). Glue to the inner surface (17).

Next, the side mold (5) and the bottom mold (12) are removed and the last mold (3) is removed to obtain the shoe (S) of this embodiment shown in FIG.

The middle sole (6) has a hardness (Shore A) of 50 to 60 degrees and is a white layer made of foamed polyvinyl chloride resin. The cushion part of the shoe sole (10) is formed by molding the foamed polyvinyl chloride resin. Has become.

The molding material for molding the soft middle bottom (6) is composed of, for example, polyvinyl chloride resin, a foaming agent, a filler, a plasticizer, a stabilizer, and a white pigment, and the mixing ratio is usually polyvinyl chloride. With respect to 100 parts by weight of the resin, 0.6 to 3 parts by weight of a foaming agent (azodicarbonamide, benzenesulfonyl hydrazide, etc.), 5 to 30 parts by weight of a filler (calcium carbonate, etc.), a plasticizer (dioctyl phthalate,
90 to 110 parts by weight of dibutyl phthalate, etc., 1.5 to 3 parts by weight of stabilizer (tin mercaptan, barium zinc, etc.), and 2 to 5 parts by weight of white pigment (titanium oxide, etc.).

Further, the hardness of the toe guard (1) and the outsole (14) both have a hardness (Shore A) of 60 to 70 degrees, are black and are made of polyvinyl chloride resin, and the mixing ratio of the molding material for molding them is For example, to 100 parts by weight of polyvinyl chloride resin, 5 to 30 parts by weight of filler (calcium carbonate, etc.), 65 to 100 parts by weight of plasticizer (dioctyl phthalate, dibutyl phthalate, etc.), stabilizer (tin-based mercaptan, barium zinc) Etc.) 1 to 3 parts by weight, and 1 to 2 parts by weight of black application material (such as carbon black).

The bottom mold (12) is designed with the uneven surface design (1
1) is engraved, but the concavo-convex design (11) partially protrudes as a circular protrusion (11A) such as a ring, and this bottom mold (12) is combined with the dummy mold (8). When the bottom molding gap (13) is formed by
Since the (11A) is made to abut the lower surface (18) of the dummy mold (8), this orbiting projection (11A) serves as a weir and the bottom molding material is not injected into the inside thereof, so that portion is
A hole will be formed in the outsole (14). Dummy mold
After removing (8), by molding the intermediate bottom (6) on the upper surface of this outsole (14) by the above-mentioned method, the foam molding material is injected also inside the orbiting upper protrusion (11A). The intermediate bottom (6) is partially exposed from this hole. In this embodiment, this hole is provided in the heel of the outsole (14), the base of the big toe, and the like. In those parts, the intermediate bottom (6) is exposed from the hole of the outsole (14) and protrudes to the extent that it touches the ground. Also, make it difficult to slip.

Further, in this embodiment, as clearly shown in FIG. 3, the lower end of the toe guard (1) left in the side mold (5) is positioned as a part (7A) of the grounding portion, and At the time of molding the bottom (6), the molding material for molding the intermediate bottom (6) was filled so as to form an adhesive boundary surface with the toe guard inner surface (7), and the design was divided by the bottom mold (12). It is the designed end surface (6A) and is exposed on the ground contact surface of the sole. Also, the middle bottom molding material is
Upon completion of the filling, the toe guard (1) and the outsole (14) are bonded and integrated.

In this way, attach the lower end of the toe guard (1) to a part of the grounding part (7A).
Since the molding material for molding the intermediate bottom (6) is allowed to enter between the toe guard (1) and the outsole (14), the toe guard (1) and the outsole (14) already formed are It was possible to bond and integrate the intermediate bottom (6) at the same time, and both (1) and (14) were made of the same color and the same molding material, and the exposed design end face (6A) of the middle bottom was interposed between them. Since both of the components (1) and (14) are molded separately, it is as if the toe guard (1) and the outsole (14) are the same molded body after molding. It has a recognizable appearance.

〔The invention's effect〕

According to the present invention, since the instep reinforced portion such as the toe guard and the toe cap can be molded together with the outsole to have high hardness, these strengths can be secured as intended. Also, after molding the instep reinforced part and the outsole that reinforce integrally with the instep, inject the foaming molding material into the middle bottom molding space limited by them to bond and integrate them. Because I chose
Unlike the case where the foaming middle bottom is molded before the main bottom, there is no unevenness of deformation due to residual heat on the surface, so the main bottom and middle bottom have the desired shape with the desired thickness. Therefore, it is possible to impart durability to the shoe sole, reduce the weight of the entire shoe sole, and improve the cushioning property. Therefore, the shoes do not make the wearer tired more than necessary. Also, since the lower end of the instep reinforced part is located as a part of the bottom contact part, the end of the part bonded to the middle bottom is easily worn away, and the end of the part bonded to the middle bottom is easily worn. Since the portion is not located at the top end where it is easily worn, even if the wear is increased due to wearing, the middle sole is not exposed, and a high-quality shoe can be provided.

[Brief description of drawings]

1 to 5 show a method of manufacturing a shoe by injection molding a toe guard, an outsole and an intermediate sole by combining the last mold, the side mold, the bottom mold and the dummy mold of the embodiment of the present invention. Fig. 1 is a longitudinal sectional view in the shoe length direction showing the toe guard and the outsole, and Fig. 2 is a longitudinal sectional view showing the intermediate sole after the dummy mold has been removed. FIG. 3 is an enlarged view of a part in FIG. 2, and FIG. 4 is a plan view showing a last mold and a side mold with an instep at the time of molding of FIG. 1,
FIG. 5 is a front view of a shoe manufactured according to an embodiment, FIG.
FIG. 1 is a subordinate sectional view of an essential part showing a conventional example. In the figure, 1 ... Toe guard 2 ... Instep 3 ... Last mold 5 ... Side mold 6 ... Middle bottom 8 ... Dummy mold 9 ... Toe guard molding void 12 ... Bottom mold 13 ... Main bottom Molding void 14 …… Outsole 15 …… Middle voiding void

Claims (1)

[Claims] 1. An instep reinforced portion for reinforcing the instep by combining a last mold with an instep, a side mold, and a dummy mold, and adhering and integrating the same to the outer surface of the rising portion of the instep. A molding gap is formed so that its lower end portion is located as a part of the bottom contact portion, and a molding gap for molding the bottom by combining a bottom mold and a dummy mold is prepared separately from these. Injection molding material is injected into the molding cavities to separately mold the instep reinforced portion and the outsole that are integrally bonded to the instep into each of the molding cavities, and then form the dummy molds that form these molding cavities. After removal, combine the last mold, side mold, and bottom mold while leaving the molded instep reinforced part in the side mold and leaving the outsole in the bottom mold. Forming a molding space for molding the middle bottom, a part of the middle bottom forms a bonding boundary surface with the instep reinforced portion, and at the same time forms a bonding boundary surface with the bottom, and also a part of the bottom contacting portion. A foaming injection molding material for molding an intermediate bottom is injected and injected into a molding void formed so as to be exposed as a part design region, and foamed in the molding void, and is integrally bonded to the instep reinforced portion and the outsole. A method for manufacturing an injection-molded shoe, which comprises molding a foamed middle sole.