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:
Jun. 25, 2002
Filed:
Dec. 10, 1999
Robert John Klare, Oxford, PA (US);
David Elliot Chubin, Overland Park, KS (US);
BHA Technologies, Inc., Kansas City, MO (US);
Abstract
A method of treating a membrane ( ) comprises the steps of providing a membrane ( ) with a structure of node ( ) and fibrils ( ). Surfaces of the nodes ( ) and fibrils ( ) define a plurality of pores ( ) extending through the membrane ( ). The membrane ( ) is made from an expanded polytetrafluoroethylene material. A water-based dispersion of oleophobic fluoropolymer solids in a water-soluble solvent is provided. The dispersion has surface tension and relative contact angle properties such that the diluted dispersion is incapable of wetting the polytetrafluoroethylene material of the membrane ( ). The dispersion is diluted with a liquid wetting agent so the diluted dispersion can wet the membrane ( ). Surfaces of the nodes ( ) and fibrils ( ) are coated with the solids in the diluted dispersion. The wetting agent material and other fugitive material are removed. Solids in the diluted dispersion are thermally coalesced on surfaces of the nodes ( ) and fibrils ( ) without completely blocking the pores ( ) in the membrane ( ).