EXPANDED POLYTETRAFLUOROETHYLENE PRODUCTS AND PROCESS FOR THEIR PRODUCTION

摘要

Disclosed are expanded polytetrafluoroethylene products, such as porous polytetrafluoroethylene tubes, having high axial tear strength and a process for their production. Each expanded polytetrafluoroethylene product has a microstructure, which comprises fibrils and nodes interconnected with each other by the fibrils, and has an axial tear strength of not lower than 6,000 gf/mm as calculated in accordance with the following formula: L/[Tx(V/100)] where L (gf) is an axial tear load, t (mm) is a wall thickness, and V (%) is a volume ratio of resin The process for the production of the expanded polytetrafluoroethylene product includes a high-speed extrusion step.