UHMWPE forming: heat treatment. With heat-treated ultra high molecular weight polyethylene (UHMW-PE) powder pressing the articles and not heat-treated UHMPWE products compared to polyethylene plastic sheet, the former have better physical properties and transparency, order ultrahigh molecular weight polyethylene plastic sheet, smoothness and low temperature mechanical properties of the product surface is greatly improved. UHMWPE forming: General. Extrusion. Extrusion equipment are ram extruder, a single screw extruder and a twin screw extruder. Use of a twin screw extruder co-rotating twin-screw extruder. The 1960s were powered by a ram extruder, the mid-1970s, Japan, the United States, West Germany has developed a single-screw extrusion process.