Manufacturing Method of Three-Dimensional Cross-Linked Foam for Uppers of Shoes

Abstract

The present invention provides a manufacturing method of three-dimensional cross-linked foam for uppers of shoes, comprises preparing a plurality of foaming materials in a planar or three-dimensional shape with a cross-linked foaming suppressed; forming at least one interfacing pattern on at least one foaming material to prevent physical and chemical interactions between the foaming materials, the interfacing pattern formed of at least one interfacing material; cross-linked foaming of the foaming material having the interfacing pattern thereon to obtain a cross-linked foam in a planar shape, the cross-linked foam having at least one inner cavity structure therein; putting the planar cross-linked foam into close contact with the last and disposing the cross-linked foam and the last in a molding die having a cavity; and compression molding the cross-linked foam, inner and outer surfaces of the molded cross-linked foam having shapes corresponding to an outer surface of the last and a surface of the cavity of the molding die, respectively.

Description

TECHNICAL FIELD [0001]The present invention relates to a cross-linked foam, and more specifically a manufacturing method of three-dimensional cross-linked foam for uppers of shoes that has a shape corresponding to a last and has at least one inner cavity structure therein.BACKGROUND ART [0002]The shoes that we usually wears for protecting the feet from the external circumstance mainly comprise soles and uppers. The uppers of the shoes directly contact the feet and thus increase a feeling of unity. Besides, the uppers play a primary role in protecting the feet from an external impact applied to the feet.[0003]The uppers are usually formed using a last 10 that has a three-dimensional shape corresponding to completed uppers as shown in FIGS. 19 to 20. Because the last has a three-dimensional shape and the raw material for the uppers are planar, a measurement of each portion of the last must be taken and then converted to a measurement that can be applied to the planar raw material for ...

AI Technical Summary

Benefits of technology

[0041]According to the present invention, because the cross-linked foam for uppers of shoes is formed in a three-dimensional shape according to the shape of the last having a complex curved surface so that dimension and shape stabilities can be provided to the shoes.

[0042]Because the cross-linked foam of the present invention has at least one inner cavity structure therein formed simultaneously with the cross-linked foam and the inner cavity may have gas therein at a certain pressure, fitting feeling and supporting property is greatly improved.

[0043]The cross-linked foam of the present invention can provide air ventilation and waterproof properties to the shoes so that air in the shoes can effectively discharged out of the shoes while moisture can not permeates the shoes.

[0044]The cross-linked foam of the present invention can provide required physical property to each portion of the shoes without an additional cutting and sewing process by filling various materials in inner cavity structures formed in the cross-linked foam.

Problems solved by technology

Firstly, many components of the completed uppers basically has a thin planar shape and is formed of soft material, a stability of a shape and a dimension is low compared with the soles of the shoes that is formed by a molding die. In addition, once the planar raw materials are transformed into a three-dimensional shape, it is difficult to keep the completed uppers in a three-dimensional shape.

Accordingly, the injection-molded material is limitedly used for a certain portion of the uppers or for shoes designed for a special purpose.

However, it has been very difficult for the uppers to satisfy those required properties because the uppers of the related art has been usually made of the thin, planar and soft materials.

However, an applicable range of this method is very narrow considering that the upper is formed of thin planar material and has a smaller thickness than the soles of the shoe.

Moreover, if several shock-absorbing materials having a relatively big volume are inserted or attached to a certain portion of the uppers, the fitting feeling between the uppers and the feet becomes bad and a naturally curved appearance of the shoes also becomes bad even though a shock-absorbing property of the certain portion of the uppers is improved.

However, it is not easy to give such properties to the uppers of the related art formed of the soft material such as leather.

However, this method makes the total manufacturing process of the shoes complex and accordingly increases the manufacturing cost.

In case of the latter, though the total process to treat the surface of the uppers chemically is relatively simple compared with the former, an effect of the air ventilation and waterproof is relatively poor considering that the chemical treatment is done only on the surface of the uppers.

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