PROCESS FOR PRODUCING A HIGH STRENGTH POROUS POLYTETRAFLUOROETHYLENE PRODUCT HAVING A COARSE MICROSTRUCTURE

摘要

Porous polytetrafluoroethylene materials having high strength and coarse microstructure are produced by densifying the materials after removal of lubricant and then stretching. The term, "coarse," is used to indicate that the nodes are larger, the fibrils are longer, and the effective pore size is larger than conventional materials of the same matrix tensile strength. Densification can be achieved through the use of such devices as a densification die, a calender machine, or a press. This invention can be used to produce all kinds of shaped articles.