Depth filter media

摘要

A porous filter medium is formed by a pleated cylinder of a depth filter medium. An absolute rated inner filtration layer is arranged between upstream and downstream drainage layers. The depth filter medium is formed from a continuous sleeve. Additionally or alternatively at least the downstream drainage layer may be formed integrally with at least a part of an inner filtration layer. The material of the medium may be a fibrous mass of non-woven synthetic polymeric micro-fibres which are free of fibre-to-fibre bonding and are secured to each other by mechanical entanglement or intertwining, with the diameter of the fibrous structure varying across the medium.