The part of a filter that undertakes the actual filtering action. Filter elements are generally designed so they can be replaced easily and are disposed of after use (exception: metal filters).
The tissue filter elements used most frequently are generally designed with multiple layers as (Figure F 15) shows. The actual element comprises, e.g. a glass fibre tissue, which is protected on both sides by a polyester mat that at the same time undertakes pre-filtering. Here the complete element is protected on both sides by a wire mesh that also provides support. .
Figure F 15: Layered structure of a multi-layered filter element (wire supporting mesh, polyester tissue, glass fibre tissue, wire supporting mesh)