Abstract: Multilayered filter material is provided with at least two layers having different filter properties (coarse filter layer and fine filter layer), for which the separation ratio of the coarse filter layer is selected depending on the number of layers of the filter material as well as the total separation ratio of the complete filter material. The separation ratio of the first layer is proportioned such that at least 20% of the total particles are filtered out by it. The first layer has a porosity of at least 95%. For the remaining filtration of the fine particles, at least one fine filter layer is present, which has a porosity of somewhat greater than 85%.
Type:
Grant
Filed:
October 6, 1995
Date of Patent:
June 16, 1998
Assignees:
Corovin GmbH, Kalthoff Luftfilter und Filtermedien GmbH