Spin annealed poly(trimethylene terephthalate) yarn
View Patent ↗A spinning process for poly(trimethylene terephthalate) and an analytical method wherein the process provides an aging resistant poly(trimethylene terephthalate) yarn and the analytical method provides predictability to the process.
1. A process comprising:
(a) extruding melted 3GT through a spinneret;
(b) quenching the extruded 3GT to form a threadline of solid filaments wherein the filaments have a tension at 130° C. greater than about 0.02 g/d;
(c) passing the filaments to a heated godet operated at a speed and temperature to heat the threadline wherein the speed and temperature to which the threadline is heated are sufficient to provide a yarn with a DWS value of about 4% or less; and
(d) cooling the yarn to a temperature of about 35° C. or less.
2. The process of claim 1 , wherein a finish is applied to the solid filaments after quenching.
3. The process of claim 1 , wherein the cooling is accomplished using a cool godet.
4. The process of claim 3 , wherein the speed of the cool godet provides a draw ratio between the heated godet and the cool godet of about 1.04 or less.
5. The process of claim 3 , wherein the threadline from the cool godet is wound on a package.
6. The process of claim 5 , wherein the winding is such that the true yarn speed is less than the speed of the cool godet.
7. The process of claim 3 , wherein the threadline tension is increased before passing to the cool godet.
8. The process of claim 7 , wherein the threadline tension is increased by at least about 0.005 g/d.
9. The process of claim 8 , wherein the threadline tension is increased by at least about 0.010 g/d.
10. The process of claim 9 , wherein the threadline tension is increased by at least about 0.015 g/d.
11. The process of claim 3 , wherein the speed of the heated godet is at least about 3000 m/m.
12. The process of claim 11 , wherein the temperature of the heated godet is about 90° C. to about 165° C.
13. The process of claim 12 , wherein the temperature of the heated godet is about 115° C. to about 160° C.
14. The process of claim 13 , wherein the temperature of the heated godet is about 125° C. to about 155° C.
15. The process of claim 4 , wherein the draw ratio between the heated godet and the cool godet is less than about 1.02.
16. The process of claim 15 , wherein the draw ratio is about 1.0 or less.
17. The process of claim 5 , wherein the filaments are wound on a package at a tension greater than about 0.04 g/d.
18. The process of claim 17 , wherein the filaments are wound at a tension greater than about 0.05 g/d.
19. The process of claim 17 , wherein the filaments are wound at a tension less than about 0.12 g/d.
20. The process of claim 19 , wherein the filaments are wound at a tension less than about 0.10 g/d.
21. The process of claim 17 , wherein the filaments are wound at a tension less than about 0.08 g/d.
22. The process of claim 20 , wherein the filaments are wound at a tension less than about 0.08 g/d.