Improved Method of Producing a Cotton Covered/Polyester Staple-Core Yarn on a Ring Spinning Frame

A new, better method of producing cotton covered/polyester staple-core yarn on a modified ring spinning frame is described. The method uses the concept of twisting a “sandwich” formed by two drafted strands of cotton (rovings) on the outside and a drafted strand of polyester on the inside, thus using a total of three rovings. The earlier method used only one cotton roving and one polyester roving [10]. The new method is simple and easily adaptable to the existing spinning frames; piecing of broken ends is also easy. A 67/33 cotton/high tenacity polyester staple-core yarn produced by the new spinning system is evaluated. The core of the yarn is almost totally covered with a firm sheath of cotton, giving the an appearance of a 100% cotton spun yarn. Compared with conventional yarns of 100% cotton and 67/33 cotton/polyester intimate blends, the core yarn is significantly stronger than the equivalent 100% cotton yarn and the intimate blend yarn of regular tenacity polyester. These yarns may be useful where a co-axial segregation of different fibrous materials is important or critical. The new staple-core spinning technology can be applied to produce yarns from a variety of core and sheath materials, such as Kevlar, PBI, Nomex, cotton, and wool, among others.