The product of the present invention is a fabric woven from oriented polytetrafluoroethylene (PTFE) strands, in which the strands of the weave are interconnected by a multiplicity of fine PTFE fibrils. To produce this fabric, consisting entirely of PTFE, a woven PTFE fabric is heated substantially unrestrained...http://www.google.fr/patents/US4025679?utm_source=gb-gplus-shareBrevet US4025679 - Fibrillated polytetrafluoroethylene woven filter fabric
