US 7,578,957 B2
	Process of making staple fibers
Jing Chung Chang, Boothwyn, Pa. (US); Richard Lee Dommel, Lugoff, S.C. (US); Ramunas L. Valteris, Seaford, Del. (US); Robert Mamoru Linek, Seaford, Del. (US); Alfred Harold Thompson, Seaford, Del. (US); and Nirmal Kumas Agarwal, Columbia, S.C. (US)
Assigned to E. I. du Pont de Nemours and Company, Wilmington, Del. (US)
Filed on Dec. 10, 2003, as Appl. No. 10/733,998.
Claims priority of provisional application 60/436989, filed on Dec. 30, 2002.
Prior Publication US 2004/0146711 A1, Jul. 29, 2004
Int. Cl. D01D 5/088 (2006.01); D01D 5/16 (2006.01); D01D 5/22 (2006.01); D01F 6/62 (2006.01)

U.S. Cl. 264—168  [264/210.5; 264/210.7; 264/210.8; 264/211.14; 264/211.17; 264/234]

38 Claims

1. A process for producing 6 to 25 dpf carpet staple fiber comprising the steps of: melt spinning poly(trimethylene terephthalate) into fibers on equipment having a quench zone shorter than 16 feet; accumulating the fibers under conditions to produce an aged undrawn yarn; prewetting the aged undrawn yarn, said aged undrawn yarn consisting essentially of poly(trimethylene terephthalate), at a temperature less than about 45° C.; drawing the yarn under wet conditions at a temperature of from about 45° C. to about 95° C. in a first stage to a length of about 30 to about 90 percent of its final length; further drawing the yarn in a second stage at a temperature from about 45° C. to about 98° C. under wet conditions; crimping the drawn yarn; thermo-fixing the crimped yarn in the presence of steam at a temperature from about 80° C. to about 100° C.; and drying the crimped yarn at 60° C. to 140° C.