Claims
- 1. A process of making polytrimethylene terephthalate staple fibers, comprising (a) providing polytrimethylene terephthalate, (b) melt spinning the melted polytrimethylene terephthalate at a temperature of 245-285° C. into filaments, (c) quenching the filaments, (d) drawing the quenched filaments, (e) crimping the drawn filaments using a mechanical crimper at a crimp level of 8-30 crimps per inch (3-12 crimps/cm), (f) relaxing the crimped filaments at a temperature of 50-120° C., and (g) cutting the relaxed filaments into staple fibers having a length of about 0.2-6 inches (about 0.5-about 15 cm).
- 2. The process of claim 1 wherein the temperature of the relaxation is below about 105° C.
- 3. The process of claim 1 wherein the temperature of the relaxation is about 55-about 105° C.
- 4. The process of claim 1 wherein the temperature of the relaxation is about 60-about 1 00C.
- 5. The process of claim 1 wherein the relaxation is carried out by heating the crimped filaments in an unconstrained condition.
- 6. The process of claim 1 wherein the drawn filaments are annealed at 85-115° C. before crimping.
- 7. The process of claim 6 wherein the annealing is carried out under tension using heated rollers.
- 8. The process of claim 1 wherein the staple fibers are 0.8-6 denier per filament.
- 9. The process of claim 1 wherein the staple fibers are 0.8-3 denier per filament.
- 10. The process of claim 9, wherein the drawn filaments are annealed at 85-115° C. before crimping and the staple fibers have a tenacity of at least 4.0 grams/denier (3.53 cN/dtex) or higher.
- 11. The process of claim 10 wherein the staple fibers have an elongation of 55% or less.
- 12. The process of claim 1 wherein the process is carried out without annealing and the staple fibers have a tenacity of at least 3.5 grams/denier (3.1 cN/dtex).
- 13. A polytrimethylene terephthalate staple fiber of 0.8-3 denier per filament having a length of about 0.2-6 inches (about 0.5-about 15 cm), a tenacity of 3.5 grams/denier (3.1 cN/dtex) or more and a crimp take-up of 10-60%, containing 8-30 crimps per inch (about 3-about 12 crimps/cm), prepared by the process of claim 13.
- 14. A 0.8-3 denier per filament polytrimethylene terephthalate staple fiber having a tenacity of 4.0 grams/denier (3.53 cN/dtex) or higher.
- 15. A polytrimethylene terephthalate staple fiber as claimed in claim 14 wherein the staple fiber has an elongation of 55% or less.
- 16. Textile yarn prepared with the fibers of claim 13.
- 17. Textile yarn prepared with fibers of claim 15.
- 18. Textile or nonwoven fabric prepared with the fibers of claim 13.
- 19. Textile or nonwoven fabric prepared with the fibers of claim 15.
- 20. Textile or nonwoven fabric as claimed in claim 18 further comprising fibers selected from the group consisting of cotton, polyethylene terephthalate, nylon, acrylate and polybutylene terephthalate fibers.
- 21. A process of preparing a polytrimethylene terephthalate staple fiber having a desirable crimp take-up comprising (a) determining the relationship between denier and crimp take-up and (b) manufacturing staple fibers having a denier selected based upon that determination.
RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Patent Application Serial No. 60/231,852, filed Sep. 12, 2000, which is incorporated herein by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60231852 |
Sep 2000 |
US |