FILTER MATERIAL

摘要

PURPOSE:To extend the life of a filter material and to enhance filtering capac ity, by providing recessed and protruded parts to the back surface of a filter material and forming a napping layer on the surface of the filter material in the upstream side of the flow of a fluid to be filtered. CONSTITUTION:Recessed and protruded parts are provided to the back surface side of a base material 1 not only to reduce the contact surface thereof with a punching metal but also to enlarge the filtering area thereof and napping parts 2 are provided to the surface of the base material in the upstream side of the flow of a fluid to be filtered to promote the formation of a dust cake layer. Voids 3 are provided so as to gradually reduce the diameter of each void 3 from the fluid inlet side of the base material toward the outlet side thereof with respect to the thickness direction of said base material 1 and the increase in a dust holding amount can also be achieved.