Porous composite

摘要

PCT No. PCT/GB96/01340 Sec. 371 Date Jul. 23, 1998 Sec. 102(e) Date Jul. 23, 1998 PCT Filed Jun. 6, 1996 PCT Pub. No. WO96/40510 PCT Pub. Date Dec. 19, 1996A porous composite laminate material comprises a layer (4) of expanded polytetrafluoroethylene (PTFE) membrane, and a layer (2) of non-expanded porous PTFE attached thereto. The non-expanded porous PTFE layer may be a sintered porous PTFE produced by sintering granular-type PTFE particles to form a porous integral network of interconnected particles; and may be produced in situ by spray application onto the membrane followed by baking. Modifiers including unsintered fine powder PTFE, thermoplastic fluorinated organic polymer, a low molecular weight PTFE and mixtures thereof may be included. The expanded PTFE membrane can be in sheet form or in the form of expanded PTFE fibres woven into a fabric. The laminate may be used for oiling and cleaning high temperature fuser rolls in a photocopying machine, or as a filter.