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:
Feb. 01, 1994
Filed:
Dec. 04, 1990
Applicant:
Inventors:
Kurt Seiler, Abtsteinach, DE;
Peter Heidel, Bobingen, DE;
Assignee:
Hoechst Aktiengesellschaft, , DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
428198 ; 55524 ; 55527 ; 55528 ; 156148 ; 156291 ; 156297 ; 1563082 ; 428134 ; 428136 ; 428212 ; 428215 ; 428219 ; 428284 ; 428286 ; 428296 ; 428297 ; 428298 ; 428300 ; 428181 ;
Abstract
There is disclosed a multilayered filter material comprising nonwovens made of fibers or filaments of identical or different polymers, said filter material being composed of a depth filter and a fine filter which both have a homogeneous density perpendicular to their surface and have been joined together in such a way that the area covered by the bonding dots does not exceed 75%. The depth filter is from 2 to 20 times thicker than the fine filter, and they have different densities. There is also disclosed a process for manufacturing the filter material.