Ptfe membrane
AssigneePall Corporation
InventorsAndrew T. SITTERER, Amarnauth Singh, Joanna Fielding, Thomas C. Gsell, Michael G. Ishee
Life of this patent
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Abstract
Porous PTFE membranes comprising a first porous surface and a second porous surface, and a bulk between the first porous surface and the second porous surface, wherein the membrane has a pore rating of from about 2 nanometers to about 50 nanometers, and the first and second porous surfaces each comprise a ratio of non-fused nodule area to fused nodule area of about 1 or greater, and methods of making and using the membranes, are disclosed.
Claims13
A porous PTFE membrane comprising a first porous surface and a second porous surface, and a bulk between the first porous surface and the second porous surface, wherein the membrane has a pore rating in the range of from about 2 nanometers to about 50 nanometers, and the first and second porous surfaces each comprise a ratio of non-fused nodule area to fused nodule area of about 1 or greater.
A method of making a porous PTFE membrane, the method comprising:
- (a) subjecting a porous PTFE membrane to elevated pressure for a given exposure time;
- and;
- (b) subsequently subjecting the porous PTFE membrane to elevated temperature for an exposure time of at least about 10 seconds, wherein the elevated temperature is at least about 200° C. and less than 325° C., and wherein the membrane is not contacted by a heating element while being subjected to the elevated temperature.
Dependencies are inferred from the claim text.