| 摘要 |
1,115,143. Drawing and annealing polyester filaments. E. I. DU PONT DE NEMOURS & CO. 31 Oct., 1966, No. 48710/66. Heading B5B. A single step process for hot drawing and annealing polyester filaments comprises forwarding a filament bundle under drawing tension through an enclosure positioned between feed and draw-rolls and within the enclosure splaying the filament bundle by inpinging thereon a jet of steam to raise the temperature of the individual filaments almost instantaneously to at least the second order transition point, and withdrawing the filaments from the enclosure. The filaments may be fed continuously to the enclosure from the filamentforming step without interruption. The filament bundle may leave the jet at a speed of 2500-3200 y.p.m. The steam jet may have a component of travel in the direction of filament travel. The filaments fed to the enclosure may have a non-aqueous based finish on their surfaces. The filaments may be drawn at a draw ratio of at least 4 at a steam temperature between 200‹ and 450‹ C. and leave the enclosure at a speed of at least 2500 y.p.m. The steam may impinge on the filaments with a velocity which may be at least 500 ft./sec. or may be at least sonic velocity. The filament temperature within the enclosure may be at least 118‹ C. whereby the filaments have a boil-off shrinkage not exceeding 10%. The filament inlet of the enclosure may be 6 inches or less from the feed roll. The length of the filament path in the enclosure may be no greater than about 1 inch. |
