Aramid staple and pulp prepared by spinning
AssigneeE. I. Du Pont de Nemours and Company
InventorHung H. Yang
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Abstract
Directly spinning highly oriented staple fibers of para-aramids using a dry-jet wet-spinning process in which the filaments in the gap between the spinneret and the coagulating fluid are attenuated with a liquid jetted symmetrically about the filaments at a rate sufficient to break the filaments intermittently to form staple length fibers that taper along their length from an enlarged head.
Claims3
In a process for preparing high strength, high modulus aromatic polyamide fibrous material comprising extruding an optically anisotropic acid solution of an aromatic polyamide through at least one spinning capillary at a first velocity to form a filament, then passing the extruded filament through a layer of non-coagulating fluid into a coagulating bath, and discharging the coagulated filament through an exit tube together with overflowing coagulating liquid and a liquid jetted symmetrically about the filament in and near the entrance to the exit tube in a generally downward direction to provide a vertically downward component of jet velocity, the improvement comprising establishing a ratio of said vertically downward component to said first velocity sufficient to break the uncoagulated extruded filament intermittently into staple fibers as it leaves the capillary.
Dependencies are inferred from the claim text.