Ultra high molecular weight polyethylene (UHMW-PE) is a thermoplastic engineering plastic. It has the superior performance of most plastics, impact resistance, low temperature resistance, wear resistance, chemical corrosion resistance, self lubrication, absorption of impact energy. In recent years, UHMW-PE plastic products have been widely used in various fields in the world, and the demand is increasing.
Ultra high molecular weight polyethylene (UHMPE) is synthesized by ziegler type high efficiency catalyst at low pressure, and its molecular weight is more than 9-10 million according to needs. Considering the thermal degradation of molecules during processing, high density polyethylene with viscoaverage molecular weight greater than 9 million can be processed into various products to have better performance.
1, high wear resistance: in all current engineering plastics UHMW-PE wear resistance is the best, the most eye-catching. The higher the molecular weight, the more wear-resistant the material, and even more than many metal materials (such as carbon steel, stainless steel, bronze, etc.).
2, corrosion resistance: in alkali solution is not corroded, can be used in 80ºC concentrated hydroc-hloric acid, in 75% concentrated sulfuric acid, 20% Ni-tric acid stable performance, it is also very stable to seawater, liquid detergent.
3, very low friction coefficient: static friction coefficient of 0.07, good self-lubrication, is an ideal bearing, sleeve, slider, lining material. Choosing UHMW-PE as the friction part of the equipment can not only improve the wear life, but also get the effect of energy saving.
4, impact resistance: impact resistance in plastic first, whether external force strong impact, or internal pressure fluctuation, it is difficult to crack. Its impact strength is 10 times of nylon 66, 20 times of PVC, 8 times of PTFE; Especially in the low-temperature environment, its impact strength reaches the highest value, and its flexibility can provide a very safe and reliable guarantee for the conveying system.
5, aging resistance: stable performance, good aging resistance, ground, underground can be buried, 50 years of aging. According to ASTM method determination (load 4.6kg/cm2), the thermal deformation temperature of 85ºC, the use of temperature up to 90ºC, under special circumstances, allow the use of higher temperature. Uhmw-pe is a kind of excellent toughness material, its low temperature resistance is also very excellent, at -269ºC, still has a certain ductility, and there is no sign of brittleness. But the linear expansion coefficient is large, the thermal conductivity is very poor, so in the design of products, to give full attention.
6, electrical performance: large volume resistance, breakdown voltage up to 50KV/mm, dielectric constant is 2.3. In a wide range of temperature and frequency, suitable for electrical engineering structural materials.
7, health non-toxic: UHMW-PE tasteless, non-toxic, odorless, itself non-corrosive, with physiological inertia and physiological adaptability. The US Food and Drug Administration (FDA) and the US Department of Agriculture (USDA) allow it for use in situations where it comes in contact with food and drugs.
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