Filtration medium

摘要

A filtration medium consisting of a single layer of a non-woven web of fibrous material comprises a blend of two or more types of fibre; the web having a ratio of tensile strengths in the machine and cross directions (MD:CD), ie the longitudinal and transverse directions, of less than 2:1 and preferably less than 1.5:1. The blend advantageously comprises a polyolefin (e.g. polypropylene) and an addition polymer (e.g. polyvinyl chloride and/or polyvinylidene chloride); and may further comprise a modacrylic polymer.