Process for preparing subdenier fibers, pulp-like short fibers, fibrids, rovings and mats from isotropic polymer solutions
AssigneeE. I. Du Pont de Nemours and Company
InventorsSteven R. Allen, David M. Gale, Aziz A. Mian, Sam L. Samuels, Hsiang Shih
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Abstract
A process for preparing subdenier fibers and structures thereof from isotropic polymer solutions is disclosed. The process comprises extruding a stream of the polymer solution into a chamber, introducing a pressurized gas into the chamber, directing the gas in the flow direction of and in surrounding contact with the stream within the chamber, passing both the gas and the stream into a zone of lower pressure at a velocity sufficient to attenuate the stream and fragment it into fibers, and contacting the fragmented stream in the zone with a coagulating fluid.
Claims22
A process for preparing subdenier fiber from isotropic polymer solutions comprising 1) extruding a stream of an isotropic solution of a polymer through a spinneret orifice into a chamber, 2) introducing a pressurized gas into said chamber, 3) directing the gas in the flow direction of and in surrounding contact with said stream within the chamber, 4) passing both the gas and stream through an aperture into a zone of lower pressure at a velocity sufficient to attenuate the stream and fragment it into fibers, and 5) contacting the fragmented stream in said zone with a coagulating fluid.
A pulp-like poly(m-phenylene isophthalamide) fibrid having a diameter of about 0.1 to 50 micrometers, a length of about 0.2 to 2 millimeters, and a freeness value of about 100 to 2000 milliliters, said fibrid capable of forming 100% by weight poly(m-phenylene isophthalamide) porous sheets.
Dependencies are inferred from the claim text.