The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 10, 2001
Filed:
Jun. 30, 1999
Applicant:
Inventors:
Assignee:
Nitto Denko Corporation, Osaka, JP;
Primary Examiner:
Int. Cl.
CPC ...
B01D 6/300 ; B01D 7/136 ;
U.S. Cl.
CPC ...
B01D 6/300 ; B01D 7/136 ;
Abstract
A filter medium for air filters wherein the collection performance of polytetrafluoroethylene (PTFE) membranes is not damaged even after processing, for example, pleating and bonding to air-permeable supporting members. The filter medium containing a laminate (,) containing at least three layers of porous PTFE membranes wherein the pressure drop of a porous PTFE membrane (,) located as an outermost layer has a pressure drop of 1/2 times or less the pressure drop of porous PTFE membrane (,) located as at least one intermediate layer. Air-permeable supporting members (,) are bonded to both outermost layers of the laminate (,) to obtain a filter medium for air filters (,).