Spinning aromatic polyamide filaments - by using spinneret with linear aperture array and jetting laminar streams of coagulating liq.

摘要

Filaments are prepd. from polymer soln. by extruding the soln. through linearly arranged apertures in a spinneret to form a vertical warp traveling at a first velocity downward through an air gap. Opposed sheets of coagulating liq. traveling at a second velocity are jetted from opposite sides of the warp at an angle so as to meet at a common line across the width of the warp below the face of the spinneret. Each sheet of liq. is wider than the warp at the common line and the second velocity has a downward component which is less than the first velocity. Pref. the polymer is a para-aromatic polyamide, esp. poly(p-phenylene terephthalamide), in a soln. which is optically anisotropic. The coagulating liq. is water or water and H2SO4 and is transparent.