Macroscopically Perforated Porous Polytetrafluoroethylene Materials

摘要

A macroscopically perforated porous expanded polytetrafluoroethylene sheet material having a microstructure of nodes interconnected by fibrils wherein the perforations have a minimum diameter of about 0.1 mm and wherein the orientation of a fibril varies as a function of the proximity of a fibril to the edge of a perforation. The length of the fibrils may also vary as a function of the proximity of a fibril to the edge of a perforation. The sheet material may alternatively be provided in a tubular form.