Processes for forming fluoropolymer articles

Abstract

The present invention relates to a process for producing a fluoropolymer article having a high surface roughness and high coarseness which comprises the following steps: a) forming a paste comprising a fluoropolymer into a paste-formed fluoropolymer product at a temperature lower than 50° C., b) densifying the paste-formed product, and c) stretching the densified paste-formed fluoropolymer product in at least one direction. The present invention further relates to a fluoropolymer article obtainable by a process according to the invention. The present invention furthermore relates to a fiber comprising, or consisting of, a fluoropolymer having a surface roughness expressed as a peak to valley distance (Rt) greater than 10 micrometer and/or an average surface roughness (Ra) greater than 1.5 micrometer. The present invention furthermore relates to a membrane comprising, or consisting of, a fluoropolymer having a coarseness index ρ/EBP of at least 0.3, an air permeability of 15 ft3/ft2/min or higher and a node aspect ratio of below 25.

Dependencies are inferred from the claim text.