POROUS COMPOSITE

摘要

A 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 oilin g and cleaning high temperature fuser rolls in a photocopying machine, or as a filter.