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. 15, 1997
Filed:
Jun. 23, 1995
Udo Holzki, Worrstadt, DE;
Heinz-Joachim Muller, Bad Kreuznach, DE;
Tilo Renner, Langenionsheim, DE;
Seitz-Filter-Werke GmbH und Co., Kreuznach, DE;
Abstract
A multi-layer microfiltration membrane having an integrated prefiltration layer. Pursuant to a phase inversion process, several layers are successively poured out onto one another prior to phase separation of a lower layer, with the viscosity for the pour solution decreasing toward the upper layers. This produces a microporous, multi-layer, integral filtration membrane having a homogenous symmetrical pore structure for the final filtration layer and an open-pored structure for the prefiltration layer disposed therebelow. Even with small pore diameters, this membrane can be easily pleated for installation in filter cartridges without the formation of damage at the crease edges. High throughput rates are possible at a low tendency to clog.