Process for texturing polyester yarn
AssigneeE. I. Du Pont de Nemours and Company
InventorAdly Abdel-moniem Gorrafa
Life of this patent
Estimating the term…
Abstract
A process for draw-texturing polyester yarn which has been melt-spun at high speed. The process is performed on a conventional false-twist texturing machine modified for drawing and for the use of an air-jet texturing device instead of a second heater. The yarn is drawn at 1.3 to 2.0X draw ratio, false-twist textured, and then air-jet textured to provide a yarn having a low boil-off shrinkage, resiliency and spun-like aesthetics.
Claims5
In the process for producing textured polyester yarn wherein synthetic linear ethylene terephthalate polymer is meltspun into filaments at 3000 to 5000 yards per minute to form a yarn characterized by a break elongation of 70 to 180 percent, by a birefringence value of at least 0.025, and by polyester which is less than 30 percent crystalline and has a relative viscosity of at least 18, and the yarn is drawn and textured in a draw-twist zone of a false-twist texturing machine with a heater temperature of at least 180.degree.C;
- the improvement which comprises draw-texturing the yarn at 1.3 to 2.0 draw ratio and 20 to 70 turns per inch twist in said draw-twist zone, feeding the yarn from the drawtwist zone to an air jet at 8 to 35 percent overfeed without additional heating, jet-texturing the yarn with the air jet to form crunodal surface loops in the yarn, and packaging the resulting textured yarn at a package speed (P) greater than the takeup speed (T) from the air jet, the value of ##EQU3## being from -1 to -10 percent.
Dependencies are inferred from the claim text.