FILTER MEDIUM FOR AIR FILTER

摘要

PROBLEM TO BE SOLVED: To provide a filter medium for an air filter capable of being extended in its replacing cycle by uniformly putting the filter surface of the filter medium to practical use. SOLUTION: Discontinuous parts 4 are provided to the respective beads 2 and 3 on both surfaces of the filter medium 1 at the midslope parts of the respective folded ridges of pleats and the discontinuous parts 4 are set as boundaries to form the beads 2a and 3a on the trough side of the pleats so as to make them narrower than the beads 2b and 3b on the ridge side of the pleats. By this constitution, the intervals between the folded ridges of the pleats are inclined so as to become narrow in a depth direction to well filter inflow air in large quantities even from the inclined filter surface and the filter surface of the filter medium 1 is uniformly put to practical use to extend the replacing cycle of the filter medium 1.