The ideal material for safety shoe soles: PU

First, what is polyurethane (PU)?

Polyurethane is an abbreviation for polyurethane. It is a polymer compound containing many repeating amino groups in the main chain of the polymer, and is formed by a chemical reaction of an isocyanate and a polyol compound.

Second, what soles with polyurethane?

Polyurethanes for shoe soles are microcellular elastomers between rubber and plastic. They are microporous elastic structures with open cells, cell diameters of 0.01 to 0.1 mm, free foaming densities of 0.25 to 0.35, (molding density of 0.3 to 1). , Usually 1~2mm self-crust, with excellent resilience and great energy absorption capacity. Polyurethane materials are widely used in shoes and safety shoes. Chining safety shoes soles are made of thermoplastic foamed polyurethane (PU), which is lightweight, highly wear-resistant, high-elastic, plus the use of imported additives/high-end technology. It is also resistant to hydrolysis, medium to low concentrations of acids, alkalis, and organics. Solvent, anti-aging and other excellent features!

Third, why is polyurethane the ideal material for manufacturing safety shoe soles?

1. Polyurethane soles are characterized by softness, warmth, oil resistance, flexing resistance, abrasion resistance, etc. They are more than 6 times abrasion resistant than rubber. They can be used to adjust its density and hardness in a wide range and can be made into two-color (double density). )'s double-sole, the bottom is a micro-foamed, high-abrasion work surface, and the inner bottom is a comfortable elastic foam.
2, very light, the proportion of only 0.3 to 0.8, much lighter than the commonly used sole material, more suitable for impact resistance, anti-perforation platform shoes, 45% of the world's safety shoes (labor safety shoes) polyurethane (PU) sole .
3, the mold requirement is lower, the production is convenient and the investment is saved (the pressure of the mold is smaller when foaming, only 0.14~0.2Mpa).
4. The molding method is simple. It can produce both soles and even shoes. (The adhesive strength of the PU base and various fabrics is particularly strong.) Variety of varieties and yields are flexible, suitable for modern industrial production.

Fourth, polyurethane sole production process?

The raw materials of group A and group B are completely melted in the raw material preheating oven, and C material (catalyst) and color paste are added into the material A as required, and they are added to the raw liquid tank of the sole molding machine, respectively, according to the formula requirements and the amount of pouring. The metering pump speeds of the two components (A1 and A2 and B), the two groups of stock solution are mixed in a mixing device at a high speed, and the chemical reaction occurs. The mixture is poured into the shoe mold (the size of the shoe mold cavity to adjust the computer The pouring time set by the programmer is stamped and sent to the drying tunnel of the annular production line for heating and curing (the production of two-color soles must be cured and then poured for the second time). After curing, the PU soles are demoulded and trimmed. , Finishing and inspection are finished products. After the mold is sprayed and released, the shoe mold is sent to the pouring. The entire production cycle can adjust the speed of the production line according to the ripening requirements of the raw liquid.

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