CN1055657C - Manufacturing method of integrally molded sole of different materials - Google Patents

Abstract

A method for manufacturing integrally formed soles of different materials uses vinyl acetate copolymer and polyurethane as raw materials, and includes three steps of insole forming, insole processing and outsole injection forming, wherein the insole forming is to form the vinyl acetate copolymer insole in a preset mould, the insole processing step is to treat the formed vinyl acetate copolymer insole and coat adhesive, the outsole injection forming is to place the processed vinyl acetate copolymer insole in another mould, and directly inject hot melt polyurethane liquid to form the outsole, so that the outsole and the insole are integrally combined to form the soles, thereby saving labor cost, simplifying manufacturing process and improving production efficiency.

Description

Manufacturing method of integrally molded sole of different materials

The invention relates to a manufacturing method for shoe soles, in particular to a manufacturing method for integrally forming shoe soles with midsoles and outsoles made of different materials.

The sole of general sports shoes must have wear resistance, good elasticity, waterproof, and comfortable, lightweight softness. Therefore, the structural design of the sole is divided into two parts: the outsole and the midsole, and they are made of different materials.

Generally, the outsole and midsole are made of different materials. First, the outsole and midsole are injection molded, and then the finished outsole and midsole are processed separately. The midsole and the outsole of the shoe are easy to combine, and the cleaning agent is used to clean the surface. Finally, the adhesive is applied on the joint surface of the midsole and the outsole, and the joint is manually connected to complete the sole of the midsole and the outsole of different materials.

However, the above-mentioned process has the following disadvantages:

1. Manual lamination is more likely to cause irregular alignment, which affects product quality, resulting in poor adhesion between the midsole and the outsole, and easy peeling off.

2. It is difficult to apply the adhesive evenly. If it is excessive, the adhesive will overflow from the junction of the midsole and the outsole to both sides when it is pressed manually, and the adhesive will turn yellowish brown after contact with air, so it will It affects the appearance of the shoe body. If the amount of coating is insufficient (especially on the periphery), it will make the bonding surface easy to seep water, cause the adhesive to degrade, cause the midsole and the outsole to peel off, and reduce the service life of the shoe body.

3. The midsole and the outsole must be reprocessed separately. The processing is very complicated. Not only is the manufacturing process long and labor is wasted, but also the production cost is increased and the production efficiency is relatively reduced.

In addition, there is a kind of using a layer of cloth as the bonding layer between the outsole and the midsole, first making a rubber outsole, and laying a layer of cloth on the top surface of the outsole, which can be used when the outsole is formed. It is infiltrated by the rubber liquid, and combined with the outsole, the outsole is placed in the mold and filled with PU (polyurethane) or EVA (vinyl acetate copolymer) foaming liquid. After the mold is closed and foamed, the foaming liquid can also penetrate into the mold. In the cloth surface, the rubber outsole and the EVA midsole are integrated, and the strength of the combination is determined by the material of the cloth surface. The cloth surface with good permeability has a better combination between the outsole and the midsole. However, the cost of the cloth with good permeability is relatively high. If the quality of the cloth is poor, the permeability will be poor, resulting in poor bonding between the midsole and the outsole, and easy to peel off, and this is followed by the use of the interface layer. False bonding Next, the degree of penetration of rubber liquid, foaming liquid and cloth surface is not easy to control, so the quality is not good.

In addition, in Taiwan Patent Publication No. 255824, in the manufacturing method of integrated molding of shoe outsole and midsole, PU foam materials with different foaming rates are injected into the mold successively, and integrated into a sole structure with different tissue densities. Although the midsole and the outsole of this molded sole have a good combination, the outsole and the midsole are made of the same material, and they are all PU materials. Molding density, however, because it is formed by foaming, fillers, foaming agents, bridging agents, processing aids, etc. must be placed in the PU foaming liquid. The deployment of ingredients will affect the quality of the product, and waste will also It will cause environmental pollution. Due to the characteristics of the material itself, the midsole should be soft and comfortable, while the outsole should be wear-resistant and waterproof. Therefore, using PU as the midsole is not only heavy in quality, but also softer than the EVA midsole. It is less comfortable, and the EVA midsole is strongly bonded to the upper body, while other materials such as PU or rubber are not well bonded to the upper body, so it is easy to peel off. Therefore, EVA is often used as the midsole in general shoemaking, and PU is the upper body. Outsole molded sole.

The object of the present invention is to provide a manufacturing method for integrally molding shoe soles made of different materials, which is a manufacturing method for integrally molding shoe soles of EVA midsole and injection molding PU outsole in an injection molding bonding manner, reducing manufacturing processes to improve production efficiency.

The present invention is characterized in that, using EVA and PU as raw materials, the EVA midsole is first formed, then the EVA midsole is processed, and finally placed in the PU mold, and the hot-melt PU liquid is directly injected to form the outsole, so that the PU is large. The sole is integrated with the EVA midsole to form the sole, which can save labor costs, reduce the production process and improve production efficiency.

Technical scheme of the present invention is:

A method for manufacturing integrated shoe soles of different materials, characterized in that it comprises the following steps:

A. Molding of vinyl acetate copolymer midsole: Firstly mold the vinyl acetate copolymer midsole;

B, midsole processing: apply a treatment agent to the bottom surface and the peripheral side of the molded vinyl acetate copolymer midsole, and apply an adhesive;

C. Polyurethane outsole injection molding: Put the processed vinyl acetate copolymer midsole into another mold, inject hot-melt polyurethane liquid directly, and form the polyurethane outsole, so that the polyurethane outsole and vinyl acetate copolymer midsole Integrated molding.

The manufacturing method of the integrated molding sole of different materials is characterized in that:

In step C, the vinyl acetate copolymer midsole is placed in the male mold of the mould, and the female mold is inserted into the sole accessories, and the sole of the accessories is integrally formed.

The manufacturing method of the integrated molding sole of different materials is characterized in that:

In this step C, the injection temperature of the polyurethane outsole injection molding is 180° C. to 250° C.

The manufacturing method of the integrated molding sole of different materials is characterized in that:

The cooling time during the step C polyurethane outsole molding is 70 seconds.

The manufacturing method of the integrated molding sole of different materials is characterized in that:

The treating agent is a synthetic resin with a solid content of 3-5%.

The manufacturing method of the integrated molding sole of different materials is characterized in that:

The adhesive is heat-activated polyurethane adhesive with a solid content of 15-20%.

The manufacturing method of the integrated molding sole of different materials is characterized in that:

The activation temperature of the adhesive is above 140°C.

The manufacturing method of the integrated molding sole of different materials is characterized in that:

A curing agent is blended into this adhesive.

The manufacturing method of the integrated molding sole of different materials is characterized in that:

The curing agent is polyisocyanate with a solid content of 25-30%.

The manufacture method of sole of the present invention has the following advantages:

1. Because the manufacturing method is one-piece molding, two different materials are directly combined, and the adhesive is bonded during the injection process, and the degree of bonding is quite good, and there will be no degumming and other phenomena.

2. The operation method is easy and simple. There is only one action to put the EVA midsole into the mold, and the midsole does not need to be roughened, and the outsole does not need to be injection molded separately, and reprocessing and manual lamination can be done. cut costs.

3. The EVA midsole replaces the injected PU midsole, which reduces the weight of the entire sole and makes it more comfortable to wear. The combination of the upper and the sole is strong, prolonging the service life of the shoe body.

4. Because the production process is short, the production efficiency is improved.

5. There is no need to use cloth as an adhesive layer, so the product quality is good and easy to control.

6. PU is directly injection-molded, without adding foaming agent or other additives, without blending, and can reduce environmental pollution.

Fig. 1 and Fig. 2 are respectively the test point schematic diagrams of the combination of the sole and the vamp used for testing the adhesion of the present invention.

The manufacturing method of EVA midsole and PU outsole integral molding sole of preferred embodiment of the present invention comprises the following steps:

1. Forming of EVA midsole: First, prepare an appropriate amount of EVA foam material and put it into a predetermined mold, and then foam and mold the EVA midsole.

2. Midsole processing: apply a synthetic resin (Synthetic resin) treatment agent with a solid content of 3 to 5% on the bottom surface and surrounding sides of the formed EVA midsole to destroy the surface of the EVA midsole and make the EVA midsole The bottom surface and the peripheral side of the EVA midsole form a rough surface, and finally the adhesive is coated on the bottom surface and the peripheral side of the EVA midsole. The adhesive is mixed with a hardener, which is polyisocyanate (Poly isocynate) with a solid content of 25-30%, so that the adhesive can be solidified and used again next time.

3. PU outsole injection molding: put the processed EVA midsole into the male mold of another mold, and after matching with the master mold, directly inject hot-melt PU liquid. When the PU outsole is formed, its injection temperature is 180 ℃～250℃, at this time, the adhesive is activated by preheating, so that the EVA midsole and the PU injection liquid are combined into one, and adding a hardener to the adhesive can avoid preheating and reactivation of the adhesive, and injection molding Finally, the cooling time is about 70 seconds, so that the PU outsole is directly molded on the bottom surface and the peripheral side of the EVA midsole, and the sole is integrally formed.

The sole made by the present invention, because the PU outsole is directly injection-molded on the bottom surface and the peripheral side of the EVA midsole, through the cooperation of the adhesive, the two materials of PU and EVA can be firmly combined, when the PU outsole The top surface is combined with the bottom surface of the EVA midsole, and the periphery of the EVA midsole is completely covered by the PU outsole, so that the combination of the two is more firm. In this invention, the EVA midsole directly replaces the PU as the midsole in the past, so the overall weight is lighter, and it is more comfortable to wear, and the combination of the upper and the sole is also stronger. In addition, some soles are equipped with accessories, such as decorative pieces. 1. The inner seat (just the nail seat) can be placed in the EVA midsole, and the trim and the inner seat etc. are inserted in the master mold of the PU mold, and then the sole with accessories is injection molded.

The combination process of the EVA midsole and the injection molding PU outsole of the present invention is completed in a closed mold, and in the process of injection molding, there is a large injection pressure, so that the PU outsole and the EVA midsole are more closely combined, Although this kind of process is also used in the past lamination process, the pressure of injection molding is several times higher than the pressure of conventional lamination, and the injection pressure is comprehensive, unlike the past lamination where the sides cannot be pressed as well.

The present invention coats the treatment agent at the bottom of the EVA in order to destroy the surface molecular structure of the bottom of the EVA, and the adhesive used is a heat-activated adhesive, which must have a temperature of 170°C to 220°C during the bonding process. The high temperature activates the adhesive, so that bridging can be produced between the two different materials of PU and EVA. Therefore, the temperature of the injected PU must be between 180°C and 250°C to activate the adhesive to form a frame. The role of the bridge follows.

In addition, the adhesion test shown in Table 1 and Figures 1-2 is the combination of the sole and the upper of the present invention. After the cold resistance test of bending the toe of the shoe at -6°C for 100,000 times, GT-7010A -The test results of the PC computer system tensile strength tester (computer syslem tensile tester) are higher than the general test standards, so the bonding strength between the midsole and the outsole of the finished product of the present invention is generally better than manual lamination . Table 1 Pilot projects Adhesion Test product name Cold resistance test 100,000 times -6°C Test conditions general standard test results Test at a speed of 200m/m per minute 3.0kg/cm 4.48kg/cm

Claims (9)

1. the manufacture method of the one-body molded sole of unlike material is characterized in that comprising the following step:

End moulding in A, the acetate ethylene copolymer: earlier with the end in the mould molding acetate ethylene copolymer;

The processing of B, the middle end: with inorganic agent on the bottom surface at the end in this acetate ethylene copolymer of moulding and all sides, and the coating sticker;

C, ejection formation of the big end of polyurethane: the end, inserted in another mould in this acetate ethylene copolymer that will machine, and directly injects hot melt polyurethane liquid, the big end of molded polyurethanes, makes end one connecting shaping in the big end of polyurethane and the acetate ethylene copolymer.

2. the manufacture method of the one-body molded sole of unlike material as claimed in claim 1 is characterized in that:

In step C, the end is to place in the male model of mould in this acetate ethylene copolymer, and inserts the sole accessory in the master mold, and the sole of one-body molded tool accessory.

3. the manufacture method of the one-body molded sole of unlike material as claimed in claim 1 is characterized in that:

Ejaculation temperature during this step C polyurethane ejection formation of the big end is 180 ℃～250 ℃.

4. the manufacture method of the one-body molded sole of unlike material as claimed in claim 1 is characterized in that: be 70 seconds the cool time the during moulding of the big end of this step C polyurethane.

5. the manufacture method of the one-body molded sole of unlike material as claimed in claim 1 is characterized in that:

This inorganic agent is the synthetic resin of solid content 3～5%.

6. the manufacture method of the one-body molded sole of unlike material as claimed in claim 1 is characterized in that: this sticker is the hot activate polyurethane adhesive of solid content 15～20%.

7, the manufacture method of the one-body molded sole of unlike material as claimed in claim 1 is characterized in that:

The activation temperature of this sticker is more than 140 ℃.

8, the manufacture method of the one-body molded sole of unlike material as claimed in claim 1 is characterized in that:

Mix in this sticker and allocate curing agent into.

9, the manufacture method of the one-body molded sole of unlike material as claimed in claim 8 is characterized in that:

This curing agent is the PIC of solid content 25～30%.

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