JPH0316843B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a method for manufacturing shoes having a foamed outer sole, and particularly relates to a method for manufacturing shoes having a foamed outer sole, and in particular, shoes having a carved pattern on the side surface and molded using a boat-shaped lower mold. The present invention relates to a method of manufacturing shoes having a foamed outsole.

(B) Prior Art As shown in FIG. 2, the outer sole 2 of the shoe 1 is made of a foam made of thermoplastic synthetic resin or thermoplastic synthetic rubber, and a carved pattern 4 is formed on the side surface 3 of the outer sole 2. For forming, as shown in FIG.
A carved pattern 7 is engraved on the surface 6 and a raised part 8
In consideration of the specific gravity of the intended foamed outsole, the outer sole cavity 14 is formed by combining a lower mold 10 having a peripheral edge 9 and a shoe last 13 covered with a shoe cover 11.
It was necessary to injection mold the thermoplastic synthetic resin or thermoplastic synthetic rubber 15 in an amount smaller than the volume of the outer sole cavity 14. In addition, 12 in the figure represents the inner sole material.

(C) Problem to be Solved by the Invention According to the above conventional method explained with reference to FIG.
must be used, and a thermoplastic synthetic resin or thermoplastic synthetic rubber 15 in a predetermined amount smaller than the volume is injected into the outer bottom cavity 14. Therefore, it had the following drawbacks. In other words, since the tip of the raised portion 8 is tapered, it is weak in strength, and iron must be used as the material, and iron has the engraved pattern 7 compared to the commonly used aluminum etc. It is difficult and time-consuming to do so, has low thermal conductivity and is difficult to cool, and it is not easy to precisely control and inject a predetermined amount of thermoplastic synthetic resin or thermoplastic synthetic rubber 15 into the outer bottom cavity 14. In fact, in order to obtain a foamed outsole with a low specific gravity, only a small amount of thermoplastic synthetic resin or thermoplastic synthetic rubber 15 can be injected, which makes it difficult to flow to every corner, making it virtually impossible to mold a foamed outsole with a small specific gravity. (For example, when polyvinyl chloride is used, it can only be molded up to a specific gravity of about 0.95.) Furthermore, there are drawbacks such as the formation of defective parts and an increase in the number of defective products.

(d) Means for solving the problem The present invention was invented in view of the above-mentioned circumstances, and the drawbacks are that the side mold and the upper surface are substantially flat and have an engraved pattern over the entire surface. A thermoplastic synthetic resin or thermoplastic synthetic rubber mixed with a foaming agent and other necessary compounding agents is injected and filled into the outer sole cavity formed by combining the lower mold and the shoe last covered with the shoe cover, Shoes were manufactured by immediately lowering the lower mold and then cooling and hardening it to form the outer sole and simultaneously fixing it to the lower surface of the shoe.

Polyvinyl chloride is used as the thermoplastic synthetic resin, and styrene-butadiene block copolymer is used as the thermoplastic rubber. These outer sole materials can be used by mixing foaming agents and other necessary ingredients; for example, in the case of the former,
A material having a temperature of about 180°C is injected into the outer sole cavity formed by the side mold, the lower mold, and the shoe last covered with the shoe cover. Immediately after filling, the lower mold is lowered, but if the lowering is too slow, the polyvinyl chloride will harden, and the shoe intended for the present invention, that is, the outer sole, is made of foam, and the engraved pattern is formed on the side surface. Formed shoes will no longer be obtained. In the case of polyvinyl chloride as described above, the lower mold must be lowered within 0.5 to 5 seconds after filling. During this time, since plasticity still remains, the polyvinyl chloride flows due to the foaming pressure.

In addition, the outer sole cavity formed by the side mold, the lower mold, and the shoe last covered with the shoe cover is always filled with polyvinyl chloride at a temperature of around 180℃, so the side mold and the lower mold are different from each other. It must be cooled with water, etc., and if the temperature is not below 40°C, it will take a long time to harden the foamed outer sole, which has a carved pattern on its sides, reducing efficiency.

(e) Examples Polyvinyl chloride (degree of polymerization 1000) 100 parts by weight Stabilizer (barium-gadonium type) 2 Foaming agent (azodicarbonamide) 0.5 〃 Filler (calcium carbonate) 10 〃 Plasticizer (dioctyl phthalate) 85 〃 First, a kneaded material having the above composition is prepared.

As shown in FIG. 1, a side mold 5, a lower mold 10 whose upper surface is substantially flat and has a carved pattern 7, a shoe last 13 on which a shoe cover 11 and an insole material 12 are attached are combined. An outer bottom cavity 14 is formed.

At this time, the side mold 5 and the lower mold 10 are cooled with water to below 40°C, and the lower mold 10 used has no raised part on the peripheral edge 9 and is flat like the other parts. .

The outer bottom cavity 14 is filled with the kneaded material 15, and the 2
After seconds, lower it in the direction of arrow 16. After lowering, the depth of the external basal cavity is 1.6 times the depth before lowering. As shown in FIG. 2, the shoes obtained by releasing from the mold after cooling had a design pattern 4 formed on the side surface 3 of the foam outer sole 2, and had a specific gravity of 0.6.

(F) Actions and Effects Polyvinyl chloride is applied to the hollow part of the outer sole formed by combining the side mold, the lower mold whose upper surface is generally flat and has a carved pattern, and the shoe last covered with a shoe cover. If the lower mold is immediately lowered when the mixture is still fluid, the volume of the outer bottom cavity will increase, and the volume of the filled kneaded material will also increase accordingly, resulting in foaming. At the same time, the peripheral edge of the lower surface of the filled kneaded material curls up and appears on the side surface, and the engraved pattern on the peripheral edge of the lower surface becomes the engraved pattern on the side surface, thereby obtaining the shoe aimed at by the present invention.

As a result, the lower mold used in the present invention is easy to manufacture because there is no need to provide a raised part on its periphery, and it is therefore possible to use materials that do not have as much strength, such as aluminum. , carved patterns can be easily engraved, and since heat conduction is good, cooling is also easy.

Furthermore, in the present invention, the kneaded material only needs to fill the cavities of the outer sole in all cases, regardless of the specific gravity of the foamed outer sole to be obtained, making process control easier. In addition, the specific gravity of the foamed outer sole can be freely controlled by the amount of foaming agent and the lowering distance of the lower mold, and products with low specific gravity can be easily molded, and at the same time, there are almost no defects.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the shoe manufacturing method of the present invention, Fig. 2 is a perspective view of shoes obtained by the present invention and the conventional method, and Fig. 3 is a sectional view showing the conventional shoe manufacturing method. be. 1... Shoes, 2... Outer sole, 3... Side surface, 4... Engraved pattern on outer sole side surface, 5... Side mold, 6... Surface, 7
... Carved pattern on the surface 6 of the lower mold 10, 8... Raised portion, 9... Periphery, 11... Folding cover, 12... Insole material, 13... Shoe last, 14... Outer sole blank Fossa, 15...
...Thermoplastic synthetic resin or thermoplastic synthetic rubber, 16
...The direction to lower the lower mold.

Claims (1)

[Claims] 1. A foaming agent and other necessary materials are applied to the outer sole cavity formed by combining the side mold, the lower mold whose upper surface is generally flat and has a carved pattern, and the shoe last covered with a shoe cover. Molding in which thermoplastic synthetic resin or thermoplastic synthetic rubber mixed with compounding agents is injected and filled, the lower mold is lowered appropriately, and then cooled and hardened to harden the engraved pattern on the periphery of the lower surface of the lower mold. A method for manufacturing shoes having a foamed outer sole, which is characterized by having a shape that appears on the side of the body and is molded using a boat-shaped lower mold.