Claims
- 1. A stretchable synthetic polymer fiber having a substantially radially symmetric cross-section and comprising an axial core comprising a thermoplastic, elastomeric polymer, and a plurality of wings comprising at least one thermoplastic, non-elastomeric polymer attached to the core.
- 2. The fiber of claim 1, which comprises from 3 to 8 wings, has an after-boil-off stretch of at least about 20%, requires less than about 10% stretch to substantially straighten the fiber, has a substantially circular core cross-section, and wherein the weight ratio of non-elastomeric wing polymer to elastomeric core polymer is in the range of about 10/90 to about 70/30.
- 3. The fiber of claim 1, wherein the non-elastomeric polymer is selected from the group consisting of non-elastomeric polyamides, polyolefins and polyesters, and the elastomeric polymer is selected from the group consisting of thermoplastic polyurethanes, thermoplastic polyester elastomers, thermoplastic polyolefins, thermoplastic polyesteramide elastomers and thermoplastic polyetheresteramide elastomers.
- 4. The fiber of claim 1, wherein the non-elastomeric polymer is selected from the group consisting of a) poly(hexamethylene adipamide) and copolymers thereof with 2-methylpentamethylene diamine and b) polycaprolactam, and the elastomeric polymer is a polyetheramide.
- 5. The fiber of claim 1, wherein the non-elastomeric polymer is selected from the group consisting of poly(ethylene terephthalate) and copolymers thereof, poly(trimethylene terephthalate), and poly(tetramethylene terephthalate), and the elastomeric polymer is selected from the group consisting of the reaction products of poly(tetramethyleneether) glycol or poly(tetramethylene-co-2-methyltetramethyleneether) glycol with terephthalic acid or dimethyl terephthalate and a diol selected from the group consisting of 1,3-propane diol and 1,4-butane diol.
- 6. The fiber of claim 1, wherein the core includes on its outside surface a sheath of a non-elastomeric polymer between points where the wings contact the core.
- 7. The fiber of claim 1 further comprising an additive added to the non-elastomeric polymer of the wings to improve adhesion of the wings to the core, wherein this fiber has a delamination rating below about 2.5.
- 8. The fiber of claim 7, wherein the non-elastomeric polymer is selected from the group consisting of (a) poly(hexamethylene adipamide) and copolymers thereof with 2-methylpentamethylene diamine and (b) polycaprolactam, and the elastomeric polymer is a polyetheresteramide.
- 9. A stretchable synthetic polymer fiber having at least about 35% after boil-off shrinkage and which requires less than about 10% stretch to substantially straighten the fiber.
- 10. A stretchable synthetic polymer fiber comprising an axial core comprising an elastomeric polymer and a plurality of wings comprising a non-elastomeric polymer attached to the core, wherein the core includes on its outside surface a sheath of a non-elastomeric polymer between points where the wings contact the core.
- 11. A stretchable synthetic polymer fiber comprising an axial core comprising an elastomeric polymer and a plurality of wings comprising a non-elastomeric polymer attached to the core, wherein the core has a substantially circular or regular polyhedron cross section.
- 12. A stretchable synthetic polymer fiber comprising an axial core comprising an elastomeric polymer and a plurality of wings comprising a non-elastomeric polymer attached to the core, wherein at least one of the wings has a T, C, or S shape.
- 13. A garment comprising the fiber of claims 1, 9, 10, 11 or 12.
- 14. A melt spinning process for spinning continuous polymeric fibers comprising:
passing a melt comprising at least one thermoplastic non-elastomeric polymer and a melt comprising a thermoplastic elastomeric polymer through a spinneret to form a plurality of stretchable synthetic polymeric fibers having a substantially radially symmetric cross-section and comprising an axial core comprising the elastomeric polymer and a plurality of wings comprising the non-elastomeric polymer attached to the core; quenching the fibers after they exit the capillary of the spinneret to cool the fibers, and collecting the fibers.
- 15. The process of claim 14, comprising an additional step, after quenching, of heat-relaxing the fiber so that it exhibits at least about 20% after-boil-off stretch.
- 16. The process of claim 15, wherein the heat-relaxing is carried out with a heating medium of dry air, hot water or superatmospheric pressure steam at a temperature in the range of about 80° C. to about 120° C. when the heating medium is said dry air, about 75° C. to about 100° C. when the heating medium is said hot water, and about 101° C. to about 115° C. when the heating medium is said superatmospheric pressure steam.
- 17. The process of claim 14, comprising an additional step, after the quenching, of drawing the fiber so that it exhibits at least about 20% after-boil-off stretch.
- 18. The process of claim 14, comprising an additional step, after the quenching, of relaxing the fiber by in the range of about 1-35% based on the fiber length before relaxing.
RELATED APPLICATIONS
[0001] This application claims priority of U.S. Provisional Patent Applications 60/236,144 and 60/236,145, both filed Sep. 29, 2000.
Provisional Applications (2)
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Number |
Date |
Country |
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60236144 |
Sep 2000 |
US |
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60236145 |
Sep 2000 |
US |