Filter structure, filter panel comprising the filter structure and method for manufacturing the filter structure

摘要

A pleatable filter structure for use in a filter panel, containing ion exchange particles distributed within a fibrous framework is expanded to contain enough space to allow the ion exchange particles to swell or to be in a swelled state as compared to dry ion exchange particles, without additional expansion of the filter structure. A method of manufacturing the filter structure involves subjecting the filter structure to a moisture treatment in which it is exposed to a humid or water containing environment, whereby the ion exchange particles swell and cause a permanent expansion of the filter structure.