FILTER SHEET FOR AIR FILTER, MANUFACTURE OF FILTER SHEET, AIR-PEREABLE SUPPORTING MATERIAL TO BE USED FOR SAME FILTER SHEET, AND AIR FILTER

摘要

PROBLEM TO BE SOLVED: To suppress unevenness of face wind velocity of an air filter even in the case of manufacturing a filter pack by a separator-less method and prevent a porous structure of a polytetrafluoroethylene porous membrane, which is a collecting layer, from being affected with heat. ;SOLUTION: Projections 3 are previously formed on the surface of a ventilative supporting material 6 of such as non-woven fabric and the resultant air- permeable supporting material 6 and a polytetrafluoroethylene porous membrane 5 are layered to give a filter sheet for an air filter. The projections 3 are utilized as a spacer at the time of manufacturing a filter pack to stabilize the intervals of bent parts of the obtained filter.;COPYRIGHT: (C)1999,JPO