UHMWPE has excellent wear resistance, good low temperature impact resistance, self-lubricating, non-toxic, water-resistant, chemical-resistant, heat resistance is better than general PE, the disadvantage is low heat resistance (thermal deformation temperature), poor processing molding, external surface hardness, rigidity, creep resistance is not as general engineering plastics, expansion coefficient is too large.
UHMWPE has poor fluidity, extremely high viscosity in the melting state, and is a rubber-like high-viscosity elastomer. Early stage can only be molded by pressing and sintering methods, but also can be processed by extrusion, injection molding and blow molding methods. Production and processing because the molecular chain of ultra-high molecular weight polyethylene is winding, the viscosity is extremely large, almost no fluidity, so the processing is very difficult. It is difficult to form products processed with general processing equipment.
At present, the processing of ultra-high molecular weight polyethylene sheet is mostly based on sintering molding method, but also the use of plunger extrusion method But the output is very low. The production process of ultra-high molecular weight polyethylene sheet is generally adopted by molding method: The selection of raw materials for raw materials determines the quality of the plate products. The selection of molecular weight of more than 3 million of high-quality raw materials for scientific formulation, reasonable process to obtain high-quality products.
Ingredients first Test the performance indicators of raw materials (check the product inspection report). According to the determined formula proportion to add a variety of additives into the high-speed mixer, in a certain pressure, temperature mixed well to the ingredients, fully discharge the moisture in the raw materials. If the color of the plate is required, the corresponding pigment should also be added according to the requirements of the color.
Pressurized plasticizing will mix good raw materials into the mold plus a certain amount of pressure to discharge the air in the raw materials. Add high temperature to make the mold in the material plastic into a transparent paste body, to maintain a certain temperature and pressure to make it fully plasticized. After full plasticizing, the molding gradually reduces the temperature while adding high pressure. The lower the temperature, the greater the pressure, until the process requirements are met.
The demoulding plastic plate is removed from the mold and then stored for operation after artificial plastic surgery.