JPH0773894B2 - Injection molding of multicolor soles - Google Patents

Description

TECHNICAL FIELD The present invention relates to an injection molding method for a multicolor shoe sole.

(Prior Art) In recent years, multi-colored soles have been used for awards. In this method of forming multi-colored soles, first the dummy last and bottom mold are used to form the grounding sole, and then the dummy last is removed. The bottom mold, which holds and holds the grounding bottom, sets the last that hangs the side mold and the armor cover, and the midsole is overlaid on the upper surface of the grounding bottom.

However, according to this method, when the dummy last is removed from the bottom mold after the ground bottom has been molded, the ground bottom comes into close contact with the bottom surface of the dummy last and rises from the molding surface of the bottom mold, and then onto the top surface of the ground bottom held by the bottom mold. When molding the midsole, the adhesion between the grounding bottom and the molding surface of the bottom mold is incomplete, and the midsole molding material enters the molding surface of the bottom mold and adheres as burrs to the side surface or the bottom surface of the grounding bottom. The visibility of the grounding sole and midsole was unclear and complicated, and the appearance of the sole was significantly deteriorated.

(Problems to be solved by the invention) When the dummy last is removed from the bottom mold after molding the grounding bottom, by improving the adhesion between the grounding bottom and the molding surface of the bottom mold, the boundary between the grounding bottom and the midsole is clear. It is intended to provide a shoe sole having a good appearance.

(Means for Solving the Problem) Hereinafter, the present invention will be described with reference to the drawings showing an embodiment thereof. In the present invention, a dummy bottom 1 and a bottom mold 2 are used to mold a grounding bottom and then a midsole is molded. In the method of molding a multicolor shoe sole, a flange 21 is formed as a bottom mold 2, a protrusion groove 22 opened on the upper surface 211 of the flange, and a grounded bottom molding cavity from the protrusion groove 22.
It is connected to the side surface of 01 (the side of the grounded bottom molding surface), is constricted at the opening of the grounded bottom molding cavity 01, and the protrusion groove 22
The gist of the invention is an injection molding method for a multi-colored shoe sole, which is characterized in that it is formed with an inflow hole 25 having a cross-sectional shape which is enlarged toward.

As shown in FIG. 1, the bottom mold 2 is formed with a concave ground bottom molding surface 20, on the bottom of which an uneven design 201.201 for forming a non-slip design is formed, and on the outer periphery thereof is a flange 2
1 is formed, and this flange portion 21 is designed to form a fitting portion with the side mold 3.3 during midsole molding. Further, the flange portion 21 is formed with a protrusion groove 22 which is opened in the upper surface 211 thereof. The protruding groove 22 may be formed in an arbitrary shape, but if it is formed in a cross-sectional shape enlarged toward the upper surface thereof, it is formed in the protruding groove 22 from the flange portion upper surface 211 side after the shoe sole is molded. It is convenient because the slag a formed can be easily removed. The protruding groove 22 may be provided around the flange portion 21 in a series, or may be formed as a plurality of partially independent grooves 22.22 ′ ... At regular intervals. Further, in the present invention, the inflow hole 25 which is provided so as to communicate with the side surface of the grounded bottom molding cavity 01 from the protrusion groove 22 may be provided in the flange portion in a tunnel shape as shown in FIG. It may be formed as a groove opened on the upper surface of the flange portion as shown in FIG.

The inflow holes 25 may be provided in an appropriate number toward the protruding groove 22. The inflow hole 25 is formed in a cross-sectional shape enlarged toward the protrusion groove 22. In injection molding of a multicolor shoe sole, the bottom mold 2 and the dummy last 1 are fitted to each other, and the bottom mold 2 and the dummy last 1 are fitted.
By injecting the grounded bottom molding material into the grounded bottom molding cavity 01 defined by and, a part of the grounded bottom molding material is filled in the protruding groove 22 through the inflow hole 25, and the inflow hole 25 and the protruding groove 22 are formed. Thus, the slag b and the slag a are formed integrally with the grounded bottom, and the grounded bottom g is held on the grounded bottom molding surface 20 of the bottom mold by the slug b and the slag a.
Therefore, when the dummy last 1 is removed from the bottom mold 2, the ground bottom g is not lifted or separated from the bottom mold ground bottom molding surface 20.

In this way, the bottom mold 2 in which the grounding bottom g is molded and held is assembled with the side mold 3 and the last 4 covered with the covering u, and the midsole molding cavity is formed on the upper surface of the grounding bottom.
02 is formed, a midsole molding material is injected and introduced into this midsole molding cavity 02 to mold the midsole m, and the covered u and the grounding bottom g are laminated and integrated via the midsole m.

After the multicolor shoe sole is formed on the lace u in this way, the bottom mold 2 is lowered and the side mold 3.3 is opened by a conventional method, and the multicolor shoe integrated with the lace u overlaid on the last 4 is formed. Remove the shoe with the sole. In this way, a shoe with a multicolor sole according to the invention is obtained.

(Effects of the Invention) Since the present invention is configured as described above, when the ground bottom g is injection-molded using the dummy last 1 and the bottom mold 2, the ground bottom is provided in the inflow hole 25 and the protruding groove 22. Since the grounding bottom g is held by the bottom mold 2 by the slugs b and a formed integrally with g, when the dummy last 1 is removed from the bottom mold 2 and the dummy last 1 and the last 4 are replaced, The midsole can be injection-molded in a state where the g is not lifted or separated from the grounded bottom molding surface 20 of the bottom mold and the grounded bottom g is held in close contact with the grounded bottom molding surface 20 of the bottom mold. Therefore, during molding of the midsole, the midsole molding does not stick out to the side surface or the bottom surface of the ground contact bottom and adheres as burrs, and a multicolor shoe sole having a good appearance can be obtained. Also, after molding the shoe sole, lower the bottom mold 2 and set the side mold 3.3.
Since the inflow hole 25 is narrowed at the opening of the bottom mold cavity when the multi-colored shoe sole formed by opening the mold is released from the mold, the boundary line between the slug b and the grounded bottom g is narrowed and formed. The slug b and the ground contact bottom g can be easily torn off simultaneously from the narrowed portion, and the inflow hole 25 has a cross-sectional shape enlarged toward the protrusion groove 22 from the opening of the mold cavity. Corresponding to this, since the cross section is enlarged toward the slag a in which the protrusion groove 22 is formed, when the slag a is pulled out from the flange portion upper surface 211 and removed, the slag a and the slag b are simultaneously flanged. It can be easily pulled out and removed from the upper surface 211 of the part.

[Brief description of drawings]

The drawings show the embodiment of the present invention, FIG. 1 is a sectional view of an essential part showing a molding state of a grounding bottom, FIG. 2 is a plan view of a bottom mold, and FIG. FIG. 4 is a cross-sectional view of an essential part showing a molded state of a midsole, and FIG. 4 is an enlarged cross-sectional view of an essential part of a bottom mold in another embodiment. (Explanation of symbols) 01 …… Grounding bottom molding cavity 02 …… Midsole molding cavity 1 …… Dummy last, 2 …… Bottom mold 20 …… Grounding bottom molding surface, 201 …… Uneven design 21 …… Flange part, 211 …… Upper surface 22 (22 ′) …… Overflow groove 25 …… Inflow hole 3 …… Side mold 4 …… Last a …… Slug, b …… Slug g …… Grounding bottom, m …… Mid sole u …… Cover

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Claims (1)

[Claims] 1. A method for molding a multicolored shoe sole, which comprises molding a ground sole using a dummy last 1 and a bottom mold 2 and then molding a midsole. Of the cross-sectional shape enlarged toward the projection groove 22 and the projection groove 22 opened to the side surface of the ground-bottom molding cavity 01, communicating with the side surface of the ground-bottom molding cavity 01. An injection molding method for a multi-colored shoe sole, characterized in that it is formed with an inflow hole 25.