Overview

UHMWPE usually refers to the linear structure polyethylene with an average molecular weight of more than 1.5 million (the molecular weight of ordinary polyethylene is only 2~ 300,000), due to the extremely high molecular weight, it has unparalleled wear resistance, impact resistance, corrosion resistance, low temperature resistance, self-lubrication, impact energy absorption, health and non-toxic comprehensive characteristics of other plastics. So it is called "amazing plastic" in Europe and the United States.

Second, performance and processing

Compared with other plastics, UHMWPE has the following advantages:

(1) Wear resistance: the crown of plastic, 2.8 times that of nylon, 3.8 times that of teflon, 7 to 10 times that of carbon steel and stainless steel.

(2) Impact strength: among the best in the whole engineering plastics, it is 5 times that of ABS, 2 times that of polycarbonate, and can be maintained at liquid nitrogen temperature, which is not a feature of any other plastics.

(3) Chemical resistance: in addition to strong oxidizing acid, in a certain temperature and concentration range can resist a variety of corrosive media (acid, alkali, salt) and organic media (except naphthalene solvent), at 20 ° C and 80 ° C 80 kinds of organic solvent immersion for 30 days, there is no abnormal appearance, other physical properties are almost no change.

(4) The impact energy absorption is the highest value, with good noise reduction effect.

(5) Rich white lubricity, low friction coefficient, in the field of tribology has been evaluated as "wood/ideal performance" friction materials.

(6) Non-adhesion, anti-adhesion ability and Teflon equivalent.

(7) Excellent low temperature resistance, the use temperature can be lower than -70℃, and even can be used at liquid nitrogen or liquid ammonia temperature.

(8) No water absorption, water absorption rate is only 1% of nylon.

(9) Completely hygienic and non-toxic, approved by the United States Food and Drug Administration (FDA) and the United States Department of Agriculture (USDA), can be used in contact with food and drugs.

In addition to heat resistance, UHMWPE can be comparable to the "plastic king" -polytetrafluoroethylene.

However, due to the extremely high melt viscosity (volume index ≈0), UHMWPE is difficult to be processed by traditional injection molding and extrusion molding methods. For a long time, the intermittent pressing sintering method has been mainly used at home and abroad to produce plates and some simple parts, with extremely low production efficiency and limited types of processed products. The UHMWPE special injection molding machine and its molding process and formulation technology developed by the Institute of Plastic Machinery and Plastic Engineering of Beijing University of Chemical Technology have successfully realized the efficient injection molding of UHMWPE, which makes the processing technology of UHMWPE leap to a new level.

Third, the application field is very wide:

Due to the above excellent comprehensive performance, UHMWPE has been widely used in textile, paper, packaging, transportation, machinery, chemical, mining, petroleum, agriculture, construction, electrical, food, medical, sports and refrigeration technology and many other fields.