JPS5810083B2 - How to make injection molded shoes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing injection molded shoes, and more specifically, injection molding allows the side parts of the sole to be colored in the vertical direction, and various designs and designs can be applied to the surface of the sole. When manufacturing shoes that have a colored pattern added to them to improve grip and the adhesive strength between the two layers, it is possible to partially attach a part of the primary sole to the surface of the secondary sole. The present invention relates to a method of manufacturing an injection molded shoe having an exposed dual layer sole.

2. Description of the Related Art Conventionally, a shoe manufacturing method in which a shoe sole and a shoe cover are integrated using an injection molding method is already known.

In addition, as a manufacturing method for injection molded shoes with color-coded upper and lower sides of the sole, a displaceable bottom mold is used to integrally mold the primary sole with the shoe covering material, and then the bottom mold is By moving or inverting the first sole, a nose cavity for forming a second sole is formed on the bottom surface of the first sole, and a filler is injected into the cavity for forming the second sole. After molding the primary sole by using a method of integrating the sole with the primary sole or by using a damini last mold, the dummy last mold is replaced with a last mold into which the shoe cover is hung. Then, a cavity for molding the secondary sole is formed on the upper surface of the primary sole, and a filler is injected into the cavity for molding the secondary sole to form the secondary sole. There were methods such as integrating it with the primary shoe sole and shoe cover.

However, in all of these conventional methods, the surface of the shoe sole is a single color, and the color sense is poor in terms of design.

Furthermore, in the conventional method, the sole surface is made of a single material, and it is difficult to change the hardness and strength of each part of the sole surface, resulting in poor grip and poor wearing comfort. There were drawbacks.

The present invention improves the shortcomings of these conventional methods, provides a richly colored design of the sole surface, and also allows the hardness and strength to be changed appropriately for each part of the sole surface, making it easier to slip. The purpose of this invention is to provide a new method for manufacturing injection molded shoes that improves ease of use and comfort.

That is, the present invention has a side mold 2 and a second mold that can be separated.
Convex portion 11 for forming the next shoe sole molding cavity 8
A filler is injected from a first injection port 6 into a first sole molding cavity 4, which is formed by combining a first bottom mold 3 with Next, a first step of molding the sole 5 integrally with the shoe cover 7, and removing the first bottom mold 3, leaving the concave part of the first sole formed by the convex part of the first bottom mold as a gap. A filler is injected from a second injection port 6' into a cavity 8 for forming a secondary sole formed by combining the second bottom mold, side mold 2, and primary sole 5. The second step is to mold the sole 9 integrally with the first sole 5.
A method of manufacturing an injection molded shoe in which a part of the primary sole is partially exposed on the surface of the secondary sole.

The first bottom mold 3 has an uneven surface that comes into contact with the filler, and the curved portion of the primary sole formed by the recess is deep enough to reach the surface of the second bottom mold. The convex portion may have a height that reaches the last mold 1 or may not reach the height.

The unevenness to be formed on the surface of the first bottom mold that comes into contact with the filler material may be directly carved into the mold, or a releasable resin plate 10 having unevenness may be installed. When using a mold that has been prepared, a mold release agent is applied to improve mold release properties, so there is residual mold release agent on the surface of the primary sole, and the mold is bonded between the primary and secondary soles. It is preferable to install a releasable resin plate since this will worsen the adhesion to the sole of the shoe.

The surface of the second bottom mold used in the second step is a relatively smooth surface with a shallow pattern similar to that seen on ordinary shoe soles, and a releasable resin plate 10 may be installed thereon. (FIG. 1 and FIG. 2 show the case where the releasable resin plate 10 is installed.

). Furthermore, the first bottom mold 3 used in the first step
The bottom surface of the concave part and the surface of the second bottom mold used in the second step have a suitable shape, so that the filler injected in the second step does not reach the concave part of the first sole. It is designed to prevent inflow.

This slit shape appears on the surface of the secondary sole 90.

Further, in order to improve the adhesive strength between the first and second soles 5 and the second sole 9, the surfaces where the two come into contact have a fine uneven pattern.

As fillers to be injected, all materials used to form injection soles, such as thermoplastic rubber, vinyl chloride resin, and polyurethane resin, can be used, but the grip, elasticity, and comfort of the sole may be used. In order to improve this, it is possible to change the materials of the primary and secondary soles, or even with the same material, the hardness and specific gravity can be changed depending on the purpose.

In order to improve the adhesion between the two layers, it is preferable that the primary and secondary soles be made of the same material, but for example, if urethane resin is used, the primary sole may be made of foamed urethane resin. By using resin and non-foaming urethane resin for the secondary sole, the hardness of each part of the sole surface can be easily changed, which is convenient for improving grip.

The resin forming the releasable resin plate 10 installed on the surface that contacts the filler of the bottom mold includes vinyl chloride resin,
Teflon resin, 27 resin, polypropylene resin, polyethylene resin, etc., which have poor adhesion to injection fillers such as thermoplastic rubber and polyurethane resin, can be used.

Creating a fine uneven pattern on the surface of the releasable resin plate is
This is necessary to firmly adhere the primary sole and secondary sole.

In addition, if it is undesirable for the boundary line between the primary sole and the secondary sole on the side part of the sole to be curved, such as a wavy line, only the outer periphery of the release resin plate may be smoothed. Just do it.

The releasable resin plate may be removably installed on the bottom mold, or may be installed permanently.

For removable installation, commonly used means such as screwing can be applied, and when installed removably, it is easy to change the color-coded border on the side of the sole or change the uneven pattern. It is convenient because it can be attached and detached.

Furthermore, it is sufficient to use a bottom mold or dummy last mold with a releasable resin plate installed only during the primary sole molding, but it is sufficient to use the bottom mold or dummy last mold when molding the secondary sole. It is advantageous to provide a releasable resin plate also in the bottom mold used in this case, since it can save the effort of applying a mold release agent.

The position of the primary sole exposed on the surface of the secondary sole may be uniform over the entire surface of the sole, or may be concentrated at the toe, heel, or the like.

Further, the shape, size, color, etc. of the exposed primary sole portion can be changed as appropriate in consideration of design.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams showing the manufacturing process of one example of the method of the present invention, FIG. 3 is a cross-sectional view of a shoe obtained by the method of the present invention, and FIG. 4 is a cross-sectional view of a shoe obtained by the method of the present invention. FIG. 1...Last mold, 2...Side mold, 3...
First bottom mold, 4... Primary sole molding cavity, 5... Primary sole, 6... First injection port, 6'...
. . . Second injection port, 7 .

Claims (1)

[Scope of Claims] 1. Formed by combining a side mold that can be divided, a first bottom mold having a convex portion forming a secondary sole molding cavity, and a last mold in which a shoe cover is hung. A first step of injecting a filler into a cavity for forming the first sole and molding the first sole integrally with the shoe cover, and removing the first bottom mold and molding the side mold and the first bottom mold. A filler is injected into a cavity for molding a second sole, which is formed by combining the second bottom mold and the first sole, leaving the concave part of the first sole formed by the convex part as a void. The first step consists of a second step of integrally molding the second sole with the first sole.
A method for manufacturing injection molded shoes in which a part of the second sole is exposed on the surface of the second sole. 2. The injection according to claim 1, characterized in that a releasable resin plate having a fine uneven pattern on the surface is installed on all or part of the surface of the first bottom mold that comes into contact with the filler. Method of manufacturing molded shoes. 3. The method for manufacturing injection molded shoes according to claim 2, wherein the releasable resin plate is any one of a Teflon plate, a polyethylene plate, a polypropylene plate, and a difluoride resin plate.