POROUS MATERIAL, AIR FILTER MEDIUM, AIR FILTER UNIT AND SUPPORT MATERIAL FOR AIR FILTER MEDIUM

摘要

An air filter filter medium having a polytetrafluoroethylene porous membrane and an air-permeable support material laminated on at least one surface of t he porous membrane, wherein the porous membrane and the support material are bonded together via a fibrous hot-melt adhesive concatenated by independent fibers and/or knots, thereby keeping a high trapping efficiency of an air filter filter medium and a pressure loss as low as that encountered with a fusion bonded one.