JP2002065311A - Method for manufacturing shoe midsole made of lightweight and soft cork - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a material of good properties in moisture penetration, diffusion, ventilation, and cushion, by shaping in one piece a mixture of sponge rubber, etc., and cork, which are two heterogeneous materials. SOLUTION: The sponge rubber, which is wrapped or bonded with cloth, is sandwiched between cork mixture sheets preheated by hot blast, pressurized and depressed in a mold, and cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an insole for indoor and outdoor shoes suitable for a physically handicapped person and middle-aged and elderly people who have difficulty walking.

[0002]

BACKGROUND OF THE INVENTION There are generally three types of conventional insole techniques. That is, solid rubber, urethane resin, ethylene
A sponge of a vinyl acetate copolymer, a urethane sponge, and a nonwoven fabric made of polyester fiber. With the conventional insole manufacturing technique, the load on the joints of the feet and hips is extremely large for physically handicapped persons and middle-aged and elderly persons who have difficulty walking.
The reason is that it has not been possible to integrally mold the cork portion and the sponge rubber or the like. Solid rubber, urethane resin, and urethane sponge are products that are put into a mold and heated and pressed to form the desired shape. This is because the non-woven fabric made of polyester fiber is a product which is heated and softened, put into a mold, pressed, cooled and molded into a desired shape.

[0003]

The unhealthy person has a large amount of sweat on the sole of the foot, and the weight on the foot is large and not constant. Naturally, light weight, cushioning property, breathability, moisture absorption, dissipation, and elasticity are required. Conventional solid rubber, urethane resin, and urethane resin sponge do not have air permeability and generate stuffiness. Sponge rubber and ethylene / vinyl acetate copolymer sponge have poor air permeability and moisture permeability because they are single foams. Since the nonwoven fabric of the polyester fiber has poor rebound resilience, it causes distortion and becomes thin, which impairs comfort. The present invention makes it possible to integrally mold cork and sponge rubber to produce a lightweight soft cork insole (specific gravity: 0.4). The purpose is to reduce the load on the joints, reduce discomfort, and to walk safely.

[0004]

Means for Solving the Problems Conventionally, different materials such as cork and sponge rubber could not be integrally formed. However, in order to achieve the above object, the present invention relates to a cork ventilation body (Patent No. 20).
96299) and sponge rubber or ethylene / vinyl acetate copolymer sponge.

DETAILED DESCRIPTION OF THE INVENTION

[0005] 25-100 parts by weight of a polyamide fiber is kneaded with 100 parts by weight of a thermoplastic resin or a thermoplastic rubber while applying friction.

[0006] The kneaded material obtained in the above step is added to the cork grains 25 to 100.
The parts by weight cork particles are mixed so as not to be crushed and rolled into a sheet.

[0007] The sheet obtained in the previous step is cut into the size of a molded product, preheated with hot air, and expanded.

[0008] The sheet expanded in the previous step is preheated with hot air,
It is again in a softened state.

[0009] The softened cork kneaded material obtained in the previous step is placed on a mold, and a rubber sponge or the like wound with a cloth is placed thereon.
Further, a cork sheet, a cloth or a synthetic leather is overlaid, pressed and cooled to form an integrally molded product.

[0010] The thermoplastic synthetic resin and the thermoplastic rubber are used by blending. Polyamide fiber 2 per 100 parts by weight of thermoplastic synthetic resin to improve moldability in mold
5 to 100 parts by weight and 10 to 50 parts by weight of a thermoplastic rubber are mixed. As a result, the mixture of cork grains, which are different materials, also flows better in the mold.

[0011]

EXAMPLE 100 parts by weight of an ethylene / vinyl acetate copolymer (vinyl acetate content 30%), 20 parts by weight of a thermoplastic rubber, and 50 parts by weight of a polyamide fiber are kneaded for 20 minutes. The kneaded material is wound around a roll machine and cork grains are charged. 5mm
30-150 ° C preheated sheet sheeted to a thickness of 30
Inflated 4 times in minutes. Repeat this expansion sheet for 100
Place in an atmosphere temperature of ~ 120 ° C for 5 minutes to soften. The softened cork mixture (FIG. 2-4) is placed on a mold, and a rubber sponge (FIG. 2-3) having a thickness of 6 mm is further wound around a cloth. Place a 2mm thick cork sheet (Fig. 2-2). Put cloth or synthetic leather (Fig. 2-1) and press
By cooling, a cork insole formed as one piece was obtained.

[0012]

Since the present invention is configured as described above, it has the following functions and effects.

[0013] By kneading 25 to 100 parts by weight of a polyamide fiber with 100 parts by weight of a thermoplastic synthetic resin or a thermoplastic rubber, friction is applied and the stretched state of the polyamide fiber is promoted. When mixed with cork granules and heated by hot air, the thermoplastic synthetic resin or thermoplastic rubber becomes a fluidized state and relaxes the tensioned state of the polyamide fiber, and conversely becomes a crimped state to form voids and become bulky at the same time. .

As a result, this shoe insole is breathable,
Good air permeability prevents foot stuffiness.

Further, the elasticity is maintained by the elliptical swelling of the tread portion due to the sandwich structure and the curve from the non-step portion to the heel portion, so that the wearing comfort is not impaired.

By forming the radial grooves, lightness, cushioning property, air permeability, moisture absorption, and heat dissipation are good, and the foot and the insole are integrated so that an unhealthy person can easily walk.

[Brief description of the drawings]

[Figure 1] Top view

[Figure 2] Vertical sectional view

[Figure 3] Cross-sectional view

[Figure 4] Bottom groove explanatory diagram

[Explanation of symbols]

 AA Length from toe to heel BB Width of heel CC Width of arch space DD Center of gravity line H Highest part of arch 1 Midsole surface cloth 2 Cork part under midsole surface 3 Cloth wrapping sponge around midsole 4 Medium Bottom bottom cork part 5 Sponge layer at center of bottom

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C08J 5/18 C08L 21/00 C08L 9/00 23/00 21/00 23/08 23/00 53/02 23/08 77/00 53/02 97/02 77/00 101/00 97/02 A43B 10/00 101C 101/00 F term (reference) 4F050 AA01 AA06 BA02 BA03 BA40 BA55 HA20 HA53 HA58 HA71 HA73 HA82 HA85 KA10 LA01 LA02 NA54 NA57 4F071 AA02 AA10 AA12 AA12X AA14 AA15X AA22X AA28X AA54 AA73 AA75 AD01 AE17 AG27 AH19 BC01 4F072 AA02 AA08 AB06 AD01 AD02 AD04 AD05 AD08 AD52 AK05 AL04 4J002 AC06W AH003 BB01X01 BB01X01 BB01X01

Claims (7)

[Claims] 1. A method for producing a lightweight soft cork shoe midsole comprising the following steps (1) to (5). (1) A lightweight soft cork shoe midsole characterized by mixing cork particles in a kneaded mixture of polyamide fiber and thermoplastic synthetic resin or thermoplastic rubber. (2) The kneaded material obtained in the above step is rolled into a sheet so as not to crush the cork particles. (3) Preheat and expand the sheet obtained in the above step. (4) The cork mixture (FIG. 2-4) obtained by cutting the softened cork sheet obtained in the above step into a molded product is placed in a mold. A rubber sponge or an ethylene-vinyl acetate copolymer sponge (FIG. 2-3) is wrapped over the cork mixture with a cloth (FIG. 2-5). Furthermore, it is successively overlaid with fabric or synthetic leather (FIG. 2-1), pressed and cooled. That is, cork grain mixture (Figs. 2-2 and 4), rubber sponge, or ethylene
A lightweight soft cork shoe midsole characterized by being integrally formed of a vinyl acetate copolymer sponge (FIG. 2-3) and a fabric or synthetic leather (FIG. 2-1). 2. The method according to claim 1, wherein the thermoplastic synthetic resin is an ethylene / vinyl acetate copolymer having a vinyl acetate content of 19 to 45%. 3. The method according to claim 1, wherein the thermoplastic rubber is styrene / butadiene block copolymer rubber, polyolefin copolymer rubber, high-trans-1,4-polyisobrene. 4. The method according to claim 1, wherein the thickness of the sheet obtained in the step (4) is 3 to 6 times larger than before heating. 5. As shown in FIG. 1 (CC and DD portions), rubber sponge or ethylene / vinyl acetate copolymer sponge is inserted as an elliptical bulge of a step portion to improve cushioning properties. 6. FIG. 1 BB improves the foot contact by making an R curve (inside 40-55R outside 55-65R). 7. The wear comfort is further improved by forming radial grooves having a width of 3 to 5 mm and a depth of 2 to 5 mm at the bottom.