JPS61203902A - Injection molding of shoes - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) This invention relates to an injection molding method for boots.

(Prior art) Conventionally, a sock-shaped plain knitted or tricot knitted knitted lining fabric is closely attached to the last, this is set in a mold, and a boot-based molding material is injected into the mold cavity. 2. Description of the Related Art The injection molding method for boots, which involves molding the main body of the boots on a lining fabric, is generally well known. In this method, the lining fabric adhered to the last due to the elasticity of the stockinette fabric.

Therefore, fold-like wrinkles occur in the front part of the shoe last, which is formed by a complicated curved surface, and this inhibits the fluidity of the boot-based material in the mold cavity during the process of molding the shoe-based material. However, the lining fabric is exposed on the surface of the finished boots, and the finished products are partially chipped due to insufficient injection of the boot-based molding material into the mold cavity, resulting in inconsistent quality.

In order to eliminate the drawbacks such as
No. 19681 proposed a backing fabric in which rubber thread was woven into the front part of the lace, but this had the disadvantage of high cost.

(Problems to be Solved by the Invention) The present invention aims to eliminate these drawbacks and provide boots with uniform quality and low cost.

(Means for Solving Problems, Embodiments) Described below with reference to the drawings, the present invention is characterized in that the size of the area around the shoe opening is circular knitting, and the size of the area around the shoe opening is circular knitting, and from the toe part C to the unstepped part d. A knitted lining fabric 1 made of diagonally cut and sewn 11 is stretched and attached to the last 4, the last 4 with the lining fabric 1 attached is set in a mold 5, and the boots are placed in the mold cavity 6. By injecting the molding material, the boots main body 2 is made into lining cloth 1.
The gist of the invention is an injection molding method for boots, which is characterized by adhesive molding.

In this invention, the double-sided circular knit structure constituting the lining fabric 1 is a layered knit of rubber knit, and is called duple, rib, or generally smooth, and as shown in FIG. This is a knitted fabric in which 4 minutes of the surface wale 102 (7) of another lip is inserted into the part 101, and the knitted fabric has characteristics of being dense, rich in elasticity, and having a smooth surface due to its knitting structure.

The reason why we limited it to 40 to 70% is because if the dimensions of a and b are smaller than that, if the lining fabric 1 is stretched and attached to the last 4, the lining fabric 1 will stretch too much, and the boots will be damaged when forming the boots 2. There is a drawback that the main molding material seeps out from the interstitial gaps in the lining fabric 1 to the back side 12 of the lining fabric, deteriorating the appearance and comfort of the finished product. 1 is attached to the last 4, the adhesion of the lining fabric 1 to the last 4 decreases, and as the boot main body molding material flows in the mold cavity 6 during molding of the boot main body 2, the lining fabric 1 is attached to the last 4.
is partially expanded and contracted excessively on the last 4, causing fold-like wrinkles to occur in the lining fabric 1, and as in the past, the lining fabric 1 may be exposed on the surface of the completed boots, or due to insufficient injection of the boot-based molding material. There is a drawback that the finished product may be partially chipped.

In this invention, examples of the boots' main molding material include vinyl chloride resins, copolymers of ethylene and vinyl acetate, liquid polyurethanes, thermoplastic rubbers, etc., which are commonly used in the manufacture of injection-molded boots.

(Effects of the Invention) In the present invention, as described above, the lining fabric 1 is constructed by knitting both sides into a cylindrical shape and cutting and sewing diagonally from the toe part C to the untreaded part d. It is simple and inexpensive, and only requires one lining fabric.
is configured in a double-sided circular knit structure, so when it is attached to the last 4, its good elasticity provides good adhesion to the last 4, and its tightness allows the lining fabric 1 to be stretched. Even if the boots are attached to the last 4, the boot main molding material will not seep out from the tissue gaps of the lining fabric 1 to the back side 12 of the lining fabric during molding of the boot main body 2, and furthermore, due to the smooth surface of the lining fabric 1, the boots During the main body molding, the fluidity of the boot main molding material in the mold cavity 6 is not inhibited by the lining cloth 1, so that the lining cloth 1 is not exposed on the surface of the finished boots, and the mold cavity 6
To provide boots of uniform quality without partially chipping the finished product due to insufficient injection of the boots-based molding material into the boots.

[Brief explanation of the drawing]

The drawings show examples, and Fig. 1 is a cross-sectional view of the main part showing the molded state of the boots, Fig. 2 is a 9-dimensional view of the lining fabric, and Fig. 3 is a sectional view of the lining fabric. This is an organizational chart. Explanation of the symbols 1. Lining cloth 101... Back stitch wale 102... Back stitch fail 11. , sewing 12. Wife im2 mainly wears boots 4. Last 5. Molding die 6, mold cavity a, lining cloth opening b, heel edge of lining cloth 0
Toe part d of lining fabric Untouched part of lining fabric

Claims (1)

[Claims] The dimension around the shoe opening a is 40% of the dimension around the shoe opening of the last 4.
~70%, the dimension around the heel b is 40% to 70% of the dimension around the heel of the last 4, and is circular knitted on both sides in a cylindrical shape, and cut and sewn diagonally from the toe part c to the unstepped part d 11. Stretch the knitted lining fabric 1 and attach it to the last 4.
This injection molding method for boots is characterized in that the last 4 fitted with the boots is set in a mold 5, the boots main body molding material is injected into a mold cavity 6, and the boots main body 2 is adhesively molded on the lining fabric 1.