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:
Sep. 10, 1996
Filed:
Mar. 25, 1994
Dieter Beck, Bad Kreuznach, DE;
Peter P Breitbach, deceased, late of Bretzenheim, DE;
Thomas Breitbach, heir, Ingelheim, DE;
Rudiger Leibnitz, Bad Kreuznach, DE;
Gerd Ritter, Guldental, DE;
Seitz-Filter-Werke GmbH und Co., Bad Kreuznach, DE;
Abstract
A filter material forming a filter layer consisting substantially exclusively of celluloses and cellulose derivatives. In addition to cellulose acetate fibers, the filter layer contains, in the form of additives, microcrystalline cellulose and microfine cellulose, or else microcrystalline cellulose only. The amount of microcrystalline cellulose can be as high as 70% of the weight of the filter layer and that of microfine cellulose up to 50% of the weight of the filter layer. Cellulose acetate fibers can be excluded if in their place, microcrystalline cellulose having particle sizes less than 10 .mu.m. are used. The manufacturing method provides for cellulose acetate fibers to be first mixed in a wet state with microfine cellulose and microcrystalline cellulose, after which differently prepared celluloses are admixed. The mash formed by mixing is formed into a fleece by means of a known felting method, and the fleece is subsequently dried. With layers of the filter material, filtration efficiencies up to and including a sterilizing range are achieved, which renders them comparable to known kieselguhr layers.