FIBROUS FILTER MEDIUM FOR TREATING SEWAGE

PROBLEM TO BE SOLVED: To provide a fibrous filter medium for treating sewage which is used for separating solid materials from sewage, which has no outflow of fibrous flocks and has a high porosity. SOLUTION: Crimped polypropylene fiber filaments (1) is mixed with another polypropylene fiber filaments (2) coated with polyethylene of low melting point and the mixture is bundled to obtain a fiber bundle (A) in which the filaments (1) and (2) are arrayed in string-like forms. The filament (1) or (2) is wound (B) around the bundle (A). The bundled and wound filaments are fused with one another by blowing hot air, and the resultant material is then cut by the prescribed length to obtain the fibrous filter medium (3) from which fibrous flocks hardly outflow since the medium is prepared by cutting the fused bundle (A). The fibrous filter medium (3) has uniform and high porosity and hardly frays since the filament (1) or (2) is wound around the bundle (A). The density of the medium (3) is kept by the crimped filament (1). COPYRIGHT: (C)2004,JPO