Cylindrical filter

摘要

A cylindrical filter is disclosed which comprises a wound up layer of a fibrous aggregate comprising melt-adhesive composite fibers bonded each other through the melt of a melt-adhesive component in the composite fibers and a layer of non-woven fabric of glass fibers, the layer of non-woven fabric is arranged on the outer surface of the wound up layer of the fibrous aggregate, and glass fibers have a smaller diameter than that of the melt-adhesive composite fibers. The cylindrical filter has an excellent filter rating and filter life.