JPS6035122B2 - Molding method for rubber soles for shoes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method of forming a rubber sole for shoes by press-molding the unvulcanized rubber in a press-molding mold at a temperature that does not vulcanize it, taking it out, and then vulcanizing it in hot air. The present invention relates to a method for molding rubber shoe soles that can prevent deformation of the sole portion, which is particularly important when removing the unvulcanized rubber shoe sole from the mold after press molding.

As a related matter, as one of the methods for molding rubber soles for shoes, Japanese Patent Publication No. 46-21930 discloses molding an unvulcanized rubber sole in a press mold and vulcanizing it in hot air to form a vulcanized sole. The method described in Tokukan Sho 53-19663 and the like is known.

The latter also describes the molding of a rubber sole in which different types of rubber are disposed in a portion of the rubber sole. With these methods, during the process of manufacturing the rubber sole, the rubber sole is released from the mold in an unvulcanized state, so when designing a bottom with deep unevenness (especially when the intervals between the unevenness are narrow), the rubber sole and the metal The design surface of the mold is difficult to separate, and since the rubber sole is unfinished, some parts of it are stretched a little, causing the bottom design to collapse from the specified shape and the dimensions of the rubber bottom to be out of order. In the case of a regular pattern such as a circle, the deformation is particularly noticeable, and in particular, the deformation is even more noticeable in areas where different types of rubber are disposed. The present invention aims to solve the above-mentioned problems by providing a method for molding a rubber sole for shoes having the structure described in the claims.

Examples will be explained below. The press molding die shown in FIG. 2 is composed of a lower die 1 and an upper die 2,
The lower mold 1 is formed with recesses 3 for molding rubber soles for shoes, and the inner surface of each is filled with silicone resin, fluororesin, etc. for the purpose of facilitating the mold removal after molding of unvulcanized rubber soles for footwear. is coated. A closed partition wall 4 is provided on the design surface of the recess 3 of the lower mold 1 at a desired position such as a tread portion. In this embodiment, the contour of the partition wall 4 is a shape that is particularly sensitive to deformation, for example, a circle, and furthermore, a bottom design having a deep groove in the same D-circular shape is engraved in the protrusion 4. Of course, the design of the partition wall 4 and its bottom need not be limited to a circular shape. In order to mold a rubber sole for shoes using the above-mentioned mold, first, a rubber material of a color different from that of the first rubber material 5 that will become the outsole or The vulcanized rubber fabric of the second rubber material 6, which will serve as the grounding bottom piece, is loaded into the compartment wall 4 in a shape that is just fit, and then the vulcanized rubber fabric of the first rubber material 5 is loaded. 2nd above
The rubber material 6 is covered to fill the recess 3, and on top of that, an anti-stretch piece 7 made of cloth, non-woven fabric, or a material that is difficult to stretch is placed at the bottom of the partition wall 4, and is slightly larger than the contour size of the partition wall 4. After placing the upper mold 2 on the lower mold 1 and roughening the mold, pressure molding is performed using a press molding machine.In this case, the heating temperature is set at a temperature at which each unvulcanized rubber dough is not vulcanized, e.g. , 40~
Approximately 2 at a temperature of 70 qo and a pressure of about 150 kg/
The mold is heated under pressure for ~3 minutes, and then the mold is taken out from the press molding machine and the upper mold 2 is removed. As shown in FIG. Take out the bottom from lower mold 1. There was no deformation in the shape of the perfectly circular grounding bottom piece. If necessary, the anti-stretch piece may be glued to the adhesive surface of the outsole. This molded unvulcanized rubber sole can be directly vulcanized with hot air to make a vulcanized sole, or it can be bonded to a cape suspended from the last and then vulcanized with hot air to form the sole of a shoe product. do. As described above, when press-molding an unvulcanized rubber sole for shoes having a grounding sole piece of a different color or material from the main sole at a desired position on the grounding surface, the present invention is designed to simply have a size slightly larger than the outline of the partition wall 4. The shaped stretch prevention piece 7 is attached to the partition wall 4
By being in close contact with the outsole directly above the rubber sole, the elongation prevention piece 7 restricts its elongation when the unvulcanized but fully formed footwear rubber sole is taken out from the recess 3 of the lower mold 1. This prevents deformation and allows unvulcanized shoe rubber soles with regular pattern shapes to be taken out.

In particular, the boundary line between the outsole and the ground sole piece of a different color or material is clearly distinguished by a partition wall protruding from the design surface of the lower mold recess. The elongation prevention piece 7 can reliably prevent conspicuous deformation of the grounding bottom piece. In addition, the elongation prevention piece 7 prevents deformation even when handling the unvulcanized shoe rubber sole until it is vulcanized by hot air, or when it is being handled until it is transported, unraveled, or bonded to the insole. Since it is possible to maintain the regular pattern shape without deforming the pattern shape of the conspicuous grounding bottom piece, it is possible to increase work efficiency, lower the defective rate, and significantly reduce costs. Since the elongation prevention piece 7 can be brought into close contact with the main sole just above the grounding sole piece by an extremely simple operation, it has little effect on work efficiency or cost. In addition, the anti-stretch piece 7 has a shape that is only slightly larger than the grounding sole piece, and the outer circumferential surface of the outsole where the anti-stretch piece 7 is not tightly attached is secured as an unfinished rubber fabric. The workability of adhering this rubber shoe sole to the cape covered with a shoe last is good, it adapts well to the shape of the cape liquid, and the dissolution bond is strong not only with adhesive but also with just wiping with a solvent. Therefore, there is no dislike such as bottoming out.

[Brief explanation of drawings]

FIG. 1 is a back view of a rubber sole for shoes molded according to the present invention;
FIG. 2 is a sectional view showing an example of a molded state of a rubber sole for shoes according to the present invention. 1...lower mold, 2...upper mold, 3...recess, 4...compartment wall, 5...outsole, 6...
...Grounding bottom piece, 7...Elongation prevention piece. Figure 1 Figure 2

Claims (1)

[Claims] 1. In a method of molding a rubber sole for shoes, using a shoe sole press-molding mold, in which a grounding sole piece made of a second rubber material different from the outsole is arranged on a part of the outsole made of a first rubber material. A partition wall is provided integrally with the lower mold, surrounding the part corresponding to the area where the grounding bottom piece is to be placed on the bottom design surface of the lower mold having a concave portion for rubber sole molding, and a second mold is first installed in this partition wall. A vulcanized rubber material is loaded, and then a first unvulcanized rubber material is loaded into the rubber sole molding recess, and the contour formed by the partition wall in a portion corresponding to the portion on which the grounding sole piece is disposed from above. Place an elongation prevention piece with a larger shape than that, assemble the upper mold, etc., press at a temperature that does not vulcanize the unvulcanized rubber, take out the molded rubber sole from the mold, and heat it in hot air. A method for forming rubber soles for shoes, characterized by sulfurization.