Core-spun elastic composite yarns having a filamentary core and ring-spun staple fiber sheath, and denim fabrics which include the same
View Patent ↗Composite yarns have a filamentary core provided with at least one elastic performance filament and at least one inelastic control filament. A fibrous sheath, preferably formed from spun staple fibers, surrounds the filamentary core, preferably substantially along the entire length thereof. The at least one elastic performance filament most preferably includes a spandex and/or a lastol filament. The at least one inelastic control filament is most preferably formed of a textured polymer or copolymer of a polyamide, a polyester, a polyolefin and mixtures thereof. Preferably, the fibrous sheath is formed of synthetic and/or natural staple fibers, most preferably staple cotton fibers. The elastic composite fibers find particular utility as a component part of a woven textile fabric, especially as a stretch denim fabric, which exhibits advantageous elastic recovery of at least about 95.0% (ASTM D3107).
1. A twill weave denim fabric comprising woven warp and filling yarns, wherein at least one of the warp and filling yarns comprises a core-spun elastic composite denim yarn capable of being repeatedly cycled between tensioned and relaxed states, the composite denim yarn comprising:
a filamentary core consisting of at least one continuous elastic performance filament and at least one continuous inelastic control filament, and
a fibrous sheath consisting of an incoherent mass of entangled, randomly oriented cotton fibers ring-spun around the filamentary core to thereby surround and visibly hide the entire length of the filamentary core when the composite denim yarn is in each of the tensioned and relaxed states thereof, wherein
each inelastic control filament of the core is a filament formed of a polymer or copolymer of a polyamide, a polyester, a polyolefin and mixtures thereof, and wherein
each inelastic control filament is loosely twisted around the elastic performance filament when the denim yarn is in the relaxed state thereof to allow extension of the elastic performance filament to the tensioned state of the denim yarn whereby an extension limit of the inelastic control filament is reached, and wherein
the fabric exhibits a stretch of at least about 15% or greater when the denim yarn is in the tensioned state thereof, and a percent elastic recovery of at least about 95.0% according to ASTM D3107 from the tensioned state of the denim yarn to the relaxed state thereof.
2. A denim fabric as in claim 1 , wherein the percent elastic recovery is at least about 96% according to ASTM D3107.
3. A denim fabric as in claim 1 , wherein the at least one elastic performance filament of the core-spun elastic composite yarn comprises a spandex and/or a lastol filament.
4. A denim fabric as in claim 1 or 3 , wherein the inelastic control filament of the core-spun elastic composite yarn is a textured filament.
5. A denim fabric as in claim 1 , wherein the core consists of a single elastic performance filament and multiple inelastic control filaments.
6. A denim fabric as in claim 5 , wherein the multiple inelastic control filaments are textured.
7. A denim fabric as in claim 1 , wherein the elastic performance filament of the core-spun elastic composite yarn has a draft ratio of at least about 2.0, and wherein the inelastic control filament of the core-spun elastic composite yarn has a draft ratio of about 1.0.
8. A denim fabric as in claim 7 , wherein the elastic performance filament has a draft ratio of at least about 3.0.
9. A denim fabric as in claim 1 , wherein at least one of the elastic performance filament and the inelastic control filament of the core-spun elastic composite yarn has a denier of between about 10 to about 140.
10. A denim fabric as in claim 9 wherein each of the at least one elastic performance filament and inelastic control filament has a denier of about 70.
11. A denim fabric as in claim 9 , wherein the fibrous sheath of the core-spun elastic composite yarn is ring spun from a cotton staple fiber roving having a cotton hank yarn count of between about 0.35 to about 1.00.
12. A denim fabric as in claim 1 , wherein the at least one elastic performance filament of the core-spun elastic composite yarn has a draft ratio which is at least two times the draft ratio of the at least one inelastic control filament of the core-spun elastic composite yarn.
13. A denim fabric as in claim 12 , wherein the draft ratio of the at least one elastic performance filament is at least three times the draft ratio of the at least one inelastic control filament.
14. A denim fabric as in claim 12 , wherein the at least one elastic performance filament of the core-spun elastic composite yarn comprises a spandex and/or a lastol filament.
15. A denim fabric as in claim 12 , wherein the inelastic control filament of the core-spun elastic composite yarn is a textured filament.
16. A garment which comprises a denim fabric as in claim 1 , 5 or 6 .