JPS5848161B2 - How to mold boots - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for shaping boots, and its purpose is to prevent unevenness, that is, whiskers, from forming on the toes of the boots when the boots are shaped, thereby degrading the appearance. The aim is to prevent this from happening.

Conventionally, a primary shape material is injected and filled into the primary shape gap formed by the outer mold, the inner mold, and the primary sole mold through an injection hole provided at the rear of the treading part of the primary sole mold to form the main body of the boots. After the molding, the primary sole mold is replaced with a secondary sole mold, and the secondary shaped material is injected and filled into the secondary shaped gap formed by the sole of the boot main body and the secondary sole mold, thereby forming the boots main body. A method of welding the soles of boots to the soles was proposed in Japanese Patent Publication No. 10378/1973.

However, when the main boots are molded using this method, whiskers are formed on the toes of the main boots, which significantly deteriorates the appearance.

As a result of various studies on the cause of this problem, we found that when the main part of the boots is injection-molded using the conventional method, the primary molding void that also serves as a flow path for the primary molding material when molding the main part of the boots does not impose any restrictions on the bottom treading part. Therefore, the primary shaped material in a molten or liquid state is injected into the primary molding cavity through the injection hole provided at the rear of the treading part of the primary bottom mold.
First, the bottom shaped gap a is filled, and then the material filled in the bottom shaped gap a is formed into the body shaped gap b and the neck part by the injection pressure of the primary shaped material that is continuously injected from the injection hole. It flows into the molding cavity C, and finally into the toe molding cavity, forming the bottom molding cavity a, the trunk molding cavity B, and the lace molding cavity C.
It was found that the toe molding gap d was sequentially filled with the primary molding material.

The toe-shaped gap d, which is finally filled with the primary shaped material, is shaped with a complicated curved surface, so the tip a′ of the bottom-shaped gap and the left and right side edges of the bottom-shaped gap are The flow of the primary molding material from a2 and the toe molding gap C increases, causing air to be partially enclosed in the primary molding material filled in the toe molding cavity, temperature changes, and a drop in injection pressure. As a result, it was found that the cause of whiskers was a partial imbalance in the volume of the primary preform material filled in a certain void in the toe part.

In the conventional method of forming boots, this invention applies a simple modification to the bottom treading part of the primary forming gap, so that the final filling point of the primary molding material can be moved from the toe forming gap to the bottom forming gap. By moving the part forward, the above-mentioned drawbacks are eliminated.As will be explained below with reference to the drawings, it is formed by the outer mold 11, the inner mold 12, and the primary bottom mold 13, and the bottom treading part 211 A primary bottom-shaped treading portion 1 is inserted into the primary molding gap 2 in which the flow path is blocked or narrowed only in the
31 through an injection hole 132 provided at the rear of the boot body 31 to inject and fill a primary shape material to shape the boot main body 3, the primary sole mold 13 is replaced with a secondary sole mold 14 to form the sole part 31 of the boots main body. A boot shape characterized by injecting and filling a secondary molding material into a secondary forming gap 4 formed by a secondary sole mold 14 and welding a boots sole 5 to a sole 31 of the main body of the boot. The gist of the invention is the law.

In this invention, the primary molding cavity 2 also serves as a flow path for the primary molding material, and the flow path, that is, the primary molding cavity 2, is blocked or narrowed only at the bottom treading part 211, and the other parts are It is a matter of course that the flow path is formed continuously throughout, corresponding to the shape and wall thickness of the boot main body 3, as in the conventional case.

The flow path leading to the bottom stepping part 211 of the primary molding gap is preferably completely blocked if the melt index of the primary forming material is particularly good, but it is preferable that the flow path is simply narrowed. It's fine just by itself.

In order to block or narrow the flow path in the bottom treading part 211 of the primary molding cavity, a projecting wall 1311 is provided on the treading part 131 of the primary bottom mold as shown in FIG. If it is made to protrude from the treading part 211 of the gap, the bottom treading part 3 of the boot main body corresponds to the protruding wall 1311 when the boots are the main body.
Since the groove 3121 formed in the rubber boots 12 is partially filled with the secondary molding material when forming the sole of the boots, the adhesive strength between the main body of the boots 3 and the sole 5 of the boots is strengthened. Conversely, as shown in FIG. 4, a protruding wall 1211 may be provided on the treading part 121 of the inner mold, and this may be made to protrude into the treading part 211 of the primary shaped gap, or as shown in FIG. Primary bottom mold 1 as shown
3 and the medium size 12 by interposing a cushion body such as a sponge, which is integrated with or separately from the core bottom 7, or an insertion piece 8 such as a reinforcing material such as a resin board, hard paperboard, or a metal piece. If this is done, these insertion pieces 8 can be embedded in the bottom treading portion 312 of the boot main body during molding of the boot main body, thereby imparting cushioning properties or reinforcing properties to the bottom treading portion 312 of the rain boot main body.

If the blockage or narrowing of the flow path is made approximately V-shaped or U-shaped toward the front part 212 of the bottom or shaped gap as shown in FIG. This is more effective because the filling of the toe forming gap 24 with the primary profile along the narrowing wall is promoted at an early stage of forming the main body of the boots.

In this invention, the primary molded material and the secondary molded material are made of injection moldable materials such as vinyl chloride, EVA, rubber, etc., but the primary molded material and the secondary molded material are They may be all the same, or may be blended so that the main boot body 3 and the sole 5 are different in physical properties such as hardness, abrasion resistance, and bending resistance, or in color, depending on the purpose of the boots to be molded. may have been done.

As described above, this invention provides the bottom stepping part 2 of the primary certain shaped cavity 2.
Since the flow path is configured to be blocked or narrowed only at the point 11, when the boots are being shaped, the injection hole 132 provided at the rear of the tread portion 131 of the primary sole type is injected into the primary void. The primary molding material in a molten or liquid state is first filled in the rear part 213 of the treading part in the bottom molding cavity, and then the material filled in the rear part 213 of the treading part is filled in the injection hole 132.
Due to the injection pressure of the primary shaped material that is continuously injected from When the flow path is finally blocked at the bottom treading part 211, the toe shaped gap 24 is used as the flow path, and when the flow path is narrowed at the bottom treading part 211, Toe section oval-shaped gap 24 and narrowed bottom cloth treading section 2
11 as a flow path, it flows into the front part 212 of the treading part of the bottom molding cavity, and sequentially flows into the body part shape cavity 23, the shank part shape cavity 23, the toe shape cavity 24, and the front part 212 of the bottom part molding part. Filled with primary molding material.

Therefore, in the present invention, sink marks on the toe portion of boots, which are caused by the final filling of the toe molding gap with the primary molding material as in the prior art, are completely avoided.

In this invention, air is partially encapsulated in the primary molding material in the front part 212 of the bottom molding cavity where the primary molding material is finally filled during the main molding of the boots, similar to the conventional toe molding cavity. , due to temperature changes and decreases in injection pressure,
Even if a beard is formed on the front sole 311 of the main boots, the sole 5 of the boots is welded to the bottom 31 of the main boots by injecting the secondary shape material, so the front front 311 of the bottom of the main boots
The shaped whiskers will not be exposed on the outside of the boots.

Therefore, the present invention can provide boots with excellent appearance.

In the drawings, numeral 6 indicates a backing cloth.

[Brief explanation of the drawing]

The drawings show embodiments, and FIG. 1 is a cross-sectional view of the main part of the first embodiment showing the boot-based condition, and FIG. 2 is a cross-sectional view taken along line Y-Y in FIG. 1. , FIG. 3 is a cross-sectional view of the main part showing the state of molding the sole of the boots of the first embodiment, FIG. 4 is a plan view of the primary sole mold of the first embodiment, and FIG.
FIG. 6 is a cross-sectional view of main parts showing the boots-based state in the embodiment, FIG. 6 is the boots-based state in the third embodiment, FIG. 7 is a cross-sectional view of the main part showing the conventional boots-based state, and FIG. Figure 7
It is a cross-sectional view in an X-ray. Explanation of symbols, 11... Outer type, 12...
Inner mold, 121...Treading part, 1211...
・Protruding wall, 13...Primary bottom mold, 131...
・Treading part, 1311... Protruding wall, 132...
...Injection hole, 14...Secondary bottom mold, 2...
・Primary molding void, 21...Bottom molding void, 21
1...Treading part, 212...Treading part front, 213...Treading part rear, 22...Body part or shaped gap, 23.・・・・・・Cut molding gap, 24...
...Toe-shaped gap, 3... Mainly boots, 3
1...Bottom, 311...Front, 312
......Treading section, 3121...Groove.

Claims (1)

[Claims] 1 The treading part 1 of the primary bottom mold is placed in the primary molding cavity 2 formed by the outer mold 11, the inner mold 12, and the primary bottom mold 13, and in which the flow path is blocked or narrowed only at the bottom treading part 211.
After the primary molding material is injected and filled through the injection hole 132 provided at the rear of the boots 31 to form the boots main body 3, the primary sole mold 13 is replaced with the secondary sole mold 14 to form the soles 31 and 2 of the boots main body. A method for shaping boots characterized by injecting and filling a secondary shaped material into the secondary molding gap 4 formed by the second sole mold 14 and welding or shaping the sole 5 to the sole 31 of the main body of the boots. .