Claims
- 1. A process for preparing a yarn comprising poly(ethylene terephthalate) filaments having a boiling water shrinkage after drawing of at least 40%, a long period spacing of greater than 225 .ANG. and a crystallization from about 15% to 20%, comprising:
- cold drawing a feeder yarn having a birefringence of at least 0.0175 at a draw ratio in the range of from about 1.98 to about 2.10.
- 2. The process of claim 1 wherein said feeder yarn has a birefringence of at least 0.0200.
- 3. The process recited in claim 2 wherein said yarn comprises at least ninety percent ethylene terephthalate units.
- 4. The process recited in claim 3 wherein said feeder yarn is drawn at a draw ratio in the range of from about 1.98 to 2.05.
- 5. The process recited in claim 4 wherein said feeder yarn is produced by the following steps:
- (a) melt-spinning one or more fibers comprising poly(ethylene terephthalate) from a spinneret;
- (b) quenching said fibers;
- (c) applying a lubricating finish to said quenched fibers; and,
- (d) taking up said fibers at a speed in the range of from about 2,200 to about 3,000 meters per minute.
- 6. The process recited in claim 5 wherein filaments are taken up at a speed of about 2,750 meters per minute.
- 7. The process recited in claim 6 wherein said draw ratio is about 2.02.
- 8. The process recited in claim 1 wherein said cold drawing is between about 25.degree. C. and about 30.degree. C.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 07/323,735, filed 3/15/89, now abandoned, which in turn is a divisional of application Ser. No. 07/136,308 filed 12/22/87, now U.S. Pat. No. 4,826,949.
US Referenced Citations (5)
Foreign Referenced Citations (3)
Number |
Date |
Country |
1268908 |
Mar 1972 |
GBX |
1487843 |
Oct 1977 |
GBX |
1553020 |
Sep 1979 |
GBX |
Divisions (1)
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Number |
Date |
Country |
Parent |
136308 |
Dec 1987 |
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Continuation in Parts (1)
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Number |
Date |
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Parent |
323735 |
Mar 1989 |
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