DRAWN AND SPLIT POLYETHYLENE MATERIAL AND ITS PRODUCTION

摘要

PURPOSE:To obtain the subject material exhibiting high tensile strength in twisted state, having high strength, flexibility and surface area and capable of easily forming a laminate with other material by drawing a polyethylene having a specific intrinsic viscosity and splitting the drawn product. CONSTITUTION:An ultra-high molecular weight polyethylene powder having an intrinsic viscosity of 5-50dL/g in decalin at 135 deg.C is thrown into a hopper 14 and dropped on the lower belt 6 of a pair of upper and lower endless belts 5, 6 tensioned with rolls l-4. The polyethylene is preheated with a heater 12, transferred to a zone for pressing with the upper and the lower endless belts 5, 6 and pressed in the form of a tape in a compression zone provided with a roller group 8 and a pressing plate 7. The tape is drawn at a total draw ratio of >=20 with nip rolls 18, 18' and the obtained drawn tape 17 is subjected to splitting treatment with a splitter 20 to obtain the objective drawn and split polyethylene material exhibiting a tensile strength of >=0.7GPa when twisted at a rate of 50-500 turns/m.