Patent ID: 9457322
Filing Date: 2016-10-04
CPC Classification: B01D

Claim Text:
1. A filter member, comprising: an upstream layer of polymeric nanofibers overlying an asymmetric microporous membrane, the asymmetric microporous membrane comprising ultra high molecular weight polyethylene and having a size rating of less than 0.1 microns, the filter member having: a) a liquid pressure drop in a test liquid that is less than a liquid pressure drop of the asymmetric microporous membrane in the test liquid or b) a liquid pressure drop in a test liquid that is within 15% of a liquid pressure drop of the asymmetric microporous membrane in the test liquid, wherein the test liquid is water or an organic liquid or comprises between 0.1% (weight/weight) and 0.3% (weight/weight) surfactant in water; and a particle retention under sieving conditions for test particles that is greater than a particle retention under sieving conditions of the asymmetric microporous membrane for the test particles.