Core-spun elastic composite yarns having a filamentary core and ring-spun staple fiber sheath, and denim fabrics which include the same

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.