METHOD AND DIE FOR FORMING ULTRA-HIGH-MOLECULAR-WEIGHT POLYETHYLENE

摘要

PURPOSE:To improve the workability of a preformed and a formed product by a method wherein the preformed product of which the surface portion at least is made from ultra-high-molecular-weight polyethylene is heated at the plasticizing temperature under a specific pressure to make a formed product of the specified thickness. CONSTITUTION:The mixing powder made up of ultra-high-molecular-weight polyethylene or ultra-high-molecular-weight polyethylene containing filler is pressed and heated under the pressure 5kg/cm<2> or more and at the temperature 140 deg.C or higher to obtain a preformed product having a sintered surface portion and then cooled down to the ordinary temperature under pressure (the 1st process). The preformed product is heated and pressed under a pressure 5kg/cm<2> or more and at the plastisizing temperature to obtain a formed product having a specified thickness (the 2nd process). The mold 1 for the 1st process comprises a base plate 2, a bottom plate 3, a restriction box 4 and a top plate. The mold 21 for the 2nd process comprises a base plate 22 with a frame, a bottom plate 23, a restriction box 24 and a top plate 25.