Cellulose matrix filter material

US5554287A · kind A · utility

Assignee

• Seitz-Filter-Werke GmbH und Co. · DE

Inventors

• Dieter Beck · Bad Kreuznach, DE
• Peter P. Breitbach · Bretzenheim, DE
• Thomas Breitbach · Stuttgart, DE
• Rudiger Leibnitz · Bad Kreuznach, DE
• Gerd Ritter · Heidelberg, DE

Key dates

• Filing date: Mar 25, 1994
• Grant date: Sep 10, 1996
• Expiry date: Mar 25, 2014

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S264/48
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

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.