Patent ID: 6682576
Filing Date: 2004-01-27
Classification: B01D,Y10S

Abstract:
An air filter medium, comprising:a porous polytetrafluoroethylene film; and a non-woven fabric laminated on at least one side of said porous film, said non-woven fabric on at least one side of said porous film having an apparent density satisfying the equation: apparent density (g/cm3)<1.5Ã—(basis weight (g/m2)/1000)+0.11, said non-woven fabric on at least one side of said porous film having a compressibility satisfying the equations:compressibility (%)<0.2Ã—(basis weight (g/m2))+66, and compressibility (%)=(d1000 (&mgr;m)/d20 (&mgr;m))Ã—100, where d1000 (&mgr;m) is a thickness (&mgr;m) of said non-woven fabric under a load of 98 (kPa) and d20 (&mgr;m) is a thickness (&mgr;m) of said non-woven fabric under a load of 1.96 (kPa),said porous polytetrafluoroethylene film having a Performance Factor value of at least 22 subsequent to lamination with said non-woven fabric.