Filter material of woven glass fibers

摘要

The filter has a woven filter material (1) of glass fibers, needled with temp. resistant polymer staple fibers. The staple fibers form <= 40 wt% of the filter material. The filter material (1) has a weight of /-350 g/m<2> and a thickness of at least 0.5 mm. The staple fibers (2) have a gauge of 0.8-8.0 dtex, and a length of at least 20 mm. The staple fibers (2) have a rougher outer surface than polytetrafluoroethylene (PTFE). The staple fibers (2) have a surface structure through a polymer coating with inorganic filling materials such as a synthetic silicic acid., after needling. After needling, the staple fibers (2) are heat shrunk at a temp. of /-150 deg C.