Production Process Of Polyurethane Material For Sole

The sole made of microporous polyurethane elastomer has the characteristics of high strength, good elasticity, comfort, abrasion resistance, folding resistance, oil resistance, corrosion resistance, light weight and skid resistance. It has buffering effect on the impact of the ground, and can be made into sole shoes of various colors and different kinds.

The main varieties include leather shoes, cross-country ski shoes, sandals, slippers, sports shoes, travel shoes, and antistatic and oil resistant safety shoes.

The poly propylene glycol system developed in the early years is now polyester system, and its preparation methods are different because of its different properties.

In the whole water foaming system, the foaming agent is water, and the water content in the A component must be determined, and its content is generally about 0.4%.

The B component is a terminal isocyanate prepolymer prepared by reaction of some polyester polyols with isocyanate.

The relative molecular mass of polyester is 1500~2000.

The ratio of pure MDI to liquefied MDI is 19B1 in isocyanate.

During the reaction, 1/10000 inhibitors must be added to prevent the occurrence of side reactions. 2h~3h can be kept at a certain temperature, and NCO% is controlled at about 19%.

C is a catalyst (added to the A component is a two component solution).

The three component system is suitable for two color, low hardness sports shoes and low-density sandals.

When used, mix the A component with the C component first, then mix with the B component.

Its characteristics are low viscosity and reactivity, small hardness, small size change and good molding stability.

The preparation of polyether raw liquid is mostly one-step method.

The A component is obtained by mixing polyether polyols, chain extender, foaming agent, catalyst and foamer in the mixer. The B component is modified isocyanate or liquefied MDI.

Polyester diols can give the sole high strength, wear resistance and strong adhesion with the shoe upper. The polyether shoe soles overcome the disadvantage of poor water resistance and low temperature elasticity of the polyester sole, and have good formability. While giving excellent low temperature flexibility and elasticity, the physical and mechanical properties of the sole can be maintained basically unchanged.

However, under low density conditions, the size stability of polyester sole is poor, while the polyether sole has good dimensional stability and low mechanical performance under the same density. Therefore, in the water foam system, the mechanical strength and wear resistance of the product can be improved by mixing two alcohols in a certain proportion.

This work has been reported in foreign countries, for example, poly (ether 2 ester) polyols of MipolurPE2PolidolA[2] are mixed polyols which contain both ether and ester at the same time. The properties of shoe sole materials are between polyester and polyether.

Domestic scholars have also done some work. Liu Sheng and other domestic polyether as the main raw material mixed polyester polyester polyols to improve the synthesis of poly (ester 2 ether) foam foamed material, its physical and mechanical properties are better than GB10508289 index, the cost is lower than pure polyester PU shoe sole material 10%~15%[3].

All polyurethane Boot Shoe soles, upper or upper are made of PU, of which all polyurethane shoes are made of micro PU elastic system. The boot is soft, soles are wearable, oil resistant and chemical resistant. The shoes are lightweight and have warmth and comfort.

PU soles are usually molded by low pressure casting or high pressure casting, and a few of them are molded by injection. The process flow is shown in Figure 1.

The molding equipment is sole casting machine.

The atmospheric pouring equipment used for polyester PU molding is mainly composed of pouring machine, loop or rotary dryer.

In the PU soles, the A and B components are all liquid and the reaction is acute. Therefore, the accurate measurement of the equipment and the mixture homogeneity of the components are the two important factors that directly affect the performance of the product.

For two-color soles, moulds with two color casting machines usually use the mould with an intermediate plate, and are subjected to two casting and heating curing.