Bi-component spandex with separable reduced friction filaments
View Patent ↗Disclosed herein are spandex fibers having reduced friction combined to provide a multiple end spandex package. The spandex fibers have a sheath-core cross-section with a lubricating additive is included in the sheath. A fusing additive specifically excluded to avoid coalescence among the individual filaments in the yarn. When combined in a yarn package, the multiple filaments are separable.
1. An article comprising a package of bi-component polyurethane yarn;
wherein:
(a) said bi-component polyurethane yarn has a sheath and a core;
(b) said sheath includes a release agent blended into the sheath in an amount from about 1% to about 50% by weight of the sheath; and
(c) said yarn includes multiple, separable filaments and said yarn does not include a fusing additive in said sheath.
2. The article of claim 1 wherein said yarn includes 2 to 10 separable filaments.
3. The article of claim 1 , wherein said yarn is a solution-spun yarn.
4. The article of claim 1 , wherein said core comprises:
(1) a polyurethane,
(2) a blend of at least one polyurethane and at least one polyurethane-urea or,
(3) a polyurethane-urea.
5. The article of claim 1 , wherein the release agent is selected from the group consisting of at least one crystalline material which fractures, at least one low-friction polymer, and combinations thereof.
6. The article of claim 1 , wherein said release agent is selected from the group consisting of mica, graphite, carbon black, molybdenum disulfide, talc, boron nitride, fumed silica, a wax, and mixtures thereof.
7. The article of claim 1 , wherein said release agent comprises a fluorine-containing polymer.
8. The article of claim 1 , wherein said sheath comprises the release agent in an amount of about 10% to about 25% by weight of the sheath.
9. The article of claim 1 , wherein said sheath comprises about 1% to about 50% by weight of the yarn.
10. The article of claim 1 , wherein said sheath comprises about 10% to 20% by weight of the yarn.
11. A method comprising:
(a) providing a package of bi-component polyurethane yarn;
wherein:
(1) said bi-component polyurethane yarn has a sheath and a core;
(2) said sheath includes a release agent blended into the sheath in an amount from about 1% to about 50% by weight of the sheath; and
(3) said yarn includes multiple, separable filaments but does not include a fusing additive in said sheath;
(b) unwinding said polyurethane yarn; and
(c) separating said multiple, separable filaments.
12. The method of claim 11 , further comprising:
(d) separately, combining said multiple, separable filaments with staple roving fiber to provide core-spun yarn; and
(e) winding said core-spun yarn onto tubes to provide multiple core-spun yarn packages.
13. The method of claim 11 , further comprising:
(d) separately, passing said multiple, separable filaments through hollow-tube spindles carrying a non-elastic yarn;
(e) wrapping said multiple, separable filaments with said non-elastic yarn to provide a covered yarn; and
(f) winding said covered yarn onto tubes to provide multiple covered yarn packages.
14. The method of claim 11 , further comprising
(d) separately knitting said multiple, separable filaments to provide multiple fabrics.
15. The method of claim 11 , further comprising
(d) warping/beaming of said multiple, separable filaments to increase the number of thread lines on a warp beam.