JPH05111404A - Production of injection molded shoes - Google Patents

Abstract

PURPOSE:To increase the value of a merchandise by forming the point of calif sewing of the injection molded shoes consisting of the uppers having a calif-sewn insole cloth so as to be invisible from an outside as well as to simplify stages and to reduce costs. CONSTITUTION:The insole or semi-insole laminated with a hot melt type synthetic resin on one surface is previously placed on the foot contact surface of the uppers calif-sewn with the insole cloth during an injection molding stage and the hot melt type synthetic resin is melted by the pressure from shoes molds and the heat from a lower mold, by which the insole or semi-insole is bonded to the insole cloth and the stitches of the calif-sewing are simultaneously covered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an injection-molded shoe capable of reliably adhering an insole or a semi-insole to the inner surface of an instep by caliphing by a simple process.

[0002]

2. Description of the Related Art Generally, an injection molded shoe is constructed by suspending an instep cover in which a calf cloth is sewn on an insole into a shoe mold, and combining it with a lower mold. It is manufactured by heating, cooling. This method is usually called a direct sawing method. In the injection-molded shoe obtained by this method, a line is formed in the seam between the lower instep peripheral edge and the insole peripheral edge on the inner surface, that is, the foot contact surface, and the injection-filled resin leaks from the seam and is unsightly in appearance. Especially unsuitable for high-end shoes.
Therefore, in order to cover this line and make it invisible, a method of inserting the insole inside the shoe, a method of attaching the semi-insole to the insole cloth, and a method of attaching the insole to the insole cloth have been carried out. ..

According to the above method, if the insole is made of soft synthetic leather or a polymer sponge, the toes of the toes flip over the insole when taking off the shoes after wearing, and this is repeated. In most cases, the method described in the above, that is, the method of attaching the semi-insole or the insole to the insole is applied, because it is bent and damaged at last. There are a method using a natural vulcanization type pressure-sensitive natural rubber latex and a method using a hot melt resin.
To attach the insole to the insole using natural vulcanization type pressure-sensitive natural rubber latex, apply the latex to the back of the insole with a roller and keep the shoe boots clean. It is attached by inserting it inside, holding it lightly with your hand, leaving it for a while, and then pressing it again with your hand when it is about to dry. The latex was applied to the above with a brush, the insole was placed on it, and it was attached by pressing it by hand in the same manner as described above. To attach the semi-soles or insoles to the insole using hot-melt resin, apply hot-melt resin to the back surface of them and make the resin surface the lower surface, and insert it inside the shoe. It was pressed and adhered by a heated shoe mold.

[0004]

However, the method of sticking the half insole to the insole cloth by using the natural vulcanization type pressure sensitive natural rubber latex is to use the latex coated on the back surface with the latex to cover the shoe boots. When inserting it inside the shoes to keep it clean,
It requires extremely careful attention, requires skill and time, and is difficult to put into practical use in practice. Also, the method of sticking the insole to the insole using the latex is to the toes inside the shoe. There was a drawback that the latex could not be applied sufficiently and the portion was immediately peeled off.

On the other hand, the method of sticking the insole or the insole to the insole using the hot melt resin is a method of pressing with a heat press machine. It was difficult to replace the pressing surface of the heat press machine so that the pressing surface of the heat press machine would match the three-dimensional shape of the insole cloth surface, which was different from each other, and it was not possible to reliably bond them. The invention is aimed at overcoming the drawbacks of all the above-mentioned methods.

[0006]

According to the present invention, a hot-melt synthetic resin is laminated on one surface of an insole or a semi-insole, and after temporarily adhering to the lower surface of the shoe mold so that the laminated layer faces downward, an insole cloth is formed. The main point is to combine the instep cover that is sewn with a caliper with a hanging lower mold, inject the synthetic resin compound for the outer bottom into the cavity formed at that time, heat it at a suitable temperature and then solidify by cooling. Is. Here, as the hot-melt synthetic resin, a low melting point, for example, an ethylene / vinyl acetate copolymer having a temperature of 70 to 80 ° C., polyurethane, polyester, polyamide or the like is used.

In order to temporarily attach the insole or the semi-insole to the lower surface of the shoe mold, a removable silicone adhesive is applied to the heel of the shoe mold, or pores communicating with the outside are provided to form the inside of the shoe mold. It is performed by sucking more air. If the last has a split heel, it is easy to remove the molded shoe from the last.

[0008]

The operation and effect of the present invention is that the hot-melt synthetic resin applied to the entire surface of one side of the insole or the half insole becomes a molten state by the heat and pressure at the time of molding the outsole, and at the same time, at the time of molding the outsole. Since the insole or semi-insole and the insole are adhered to each other, there is no need for a separate adhering step that has been conventionally performed, and at that time, the entire surface is securely adhered. However, there is no possibility that the insole and the insole cloth are separated from each other. Also, in the case of a half insole, after being bonded, the surface of the half insole and the surface of the other part, that is, the surface of the insole cloth, are at the same level, and only the half insole is protruding. Therefore, even if the wearing is repeated over a long period of time, the semi-insole does not easily peel off.

[0009]

Example 1 An ethylene / vinyl acetate copolymer (Hirodine (registered trademark) manufactured by Hirodyne Industry Co., Ltd., ethylene content 78%, vinyl acetate content 22%) was formed on the back surface of a polyurethane synthetic leather insole having a thickness of 2 mm. 80) was laminated with a T-die for 80 μm and was temporarily attached to the lower surface of the shoe mold (heated to about 80 ° C.) so that the laminated layer faces downward. For temporary attachment, a silicon adhesive (YR3340 manufactured by Toshiba Silicon Co., Ltd.) to which 10% of calcium carbonate was added was used. The reason for adding calcium carbonate is to ensure removability. The instep cover with the insole cloth sewn on is hung on this last, and combined with the lower mold, polyvinyl chloride (average polymerization degree 1
000), 80 parts by weight of plasticizer DOP, 3 parts by weight of stabilizer butyl / tin / laurate, and 5 parts by weight of titanium oxide were injection-filled at 180 ° C., cooled, and then demolded. The shoes thus manufactured by a very simple process were worn for 7 to 8 hours per day and continued for 6 months, but the half insoles did not peel off at all.

[0010]

Example 2 A polyester synthetic leather insole was used in place of the polyurethane synthetic leather insole in Example 1, and an average of 6 on the lower surface of the shoe was used as a temporary attachment means with the lower surface of the shoe. A shoe was manufactured in the same manner as in Example except that pores were provided at some places and suction was performed from the inside, and the same effect was obtained.

Claims (1)

[Claims] 1. An instep in which a hot-melt synthetic resin is laminated on one surface of an insole or a semi-insole and is temporarily attached to the lower surface of the shoe so that the laminated layer faces downward, and then the insole cloth is sewn in caliph. A method for manufacturing an injection-molded shoe, which comprises suspending a cover, combining the lower mold with the lower mold, injecting a synthetic resin compound for an outsole into the void formed at that time, heating at an appropriate temperature, and then cooling and solidifying.