FILTER MEDIUM FOR AIR FILTER AND AIR FILTER UNIT

摘要

PROBLEM TO BE SOLVED: To provide a filter medium for an air filter from which dust is removed easily, the collection efficiency of which is hardly deteriorated even when the filter medium is washed with water and the pressure loss of which is made low and to provide an air filter unit using the filter medium for the air filter. SOLUTION: This filter medium 3 for the air filter comprises at least one layer of a porous membrane 1 of polytetrafluoroethylene and at least one layer of an air-permeable supporting material 2. At least one of two layers arranged as the outermost layers is the porous membrane of polytetrafluoroethylene. This filter medium 3 for the air filter has such a characteristic even when not used or even when washed with water and then dried that when the talc regulated in the fourth class of JIS test powder is brought into contact with one of the outermost layers, where the porous membrane of polytetrafluoroethylene is arranged, in the ratio of 25 g per m2area of the porous membrane of polytetrafluoroethylene and at 18.8 cm/second flow velocity, the regulated talc does not blow/leak out of the other of the outermost layers. COPYRIGHT: (C)2006,JPO&NCIPI