METHOD OF PRODUCING FINE AMORPHOUS POLYMER FIBRES, FINE AMORPHOUS POLYMER!FIBRES, AND SPINNERET FOR PRODUCING SUCH FIBRES

摘要

A method including the steps of extruding a melt including an amorphous polymer composition through a spinneret under a pressure of from 400 to 1500 psi to produce a spun fiber; collecting the spun fiber on a feeding roll without drawing the spun fiber; producing a solidified fiber from the spun fiber. The solidified fiber can have a dpf within a range of from greater than 0 to 2.5 dpf, and a shrinkage less than or equal to 2%. The method can also include collecting the solidified fiber onto a spool without subjecting the solidified fiber to a drawing step. A spinneret for producing fibers of at most 2.5 dpf from a composition comprising an amorphous polyetherimide polymer, the spinneret comprising a die having a plurality of round melt channels but no distribution plates. Fibers produced by the method and from the spinneret are also disclosed.