| 摘要 |
Porous, fibrous structures comprising polytetrafluoroethylene fibers in a fluorocarbon binder are prepared by laying down a stabilized dispersion of the fibers, stabilizing agent, and liquid carrier on a support, removing at least a portion of a liquid carrier, preferably drying the laydown, applying an emulsion of a fluorocarbon binder to the laydown and curing the fluorocarbon binder. The resulting structures have void volumes of from about 40 to about 99 percent, strengths of from about 200 to about 6,000 grams per inch of width, and air pressure drops of from about 0.0025 to about 0.1 inch of water at a flow rate of 28 standard cubic feet per minute per square foot of the fibrous structure.
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