Effect of Fiber Length, Fineness, and Twist on the Bending Behavior of Polyester and Viscose Staple Rotor Spun Yams

Abstract

The effects of fiber length, fineness, and twist of polyester and viscose staple rotor spun yams have been examined for their bending behavior using a bending hysteresis tester. For the polyester staple rotor spun yarns, use of shorter and coarser fibers leads to a higher magnitude of bending hysteresis, yarn bending rigidity, and bending re covery ; the percent reduction in bending hysteresis and yarn bending rigidity is greater for coarser, shorter fibers with increasing twist. For the viscose staple rotor spun yarns, use of longer staple fibers leads to increased bending hysteresis and yarn bending rigidity; the percent reduction in bending hysteresis and yarn bending rigidity is greater for longer fibers with increasing twist. An increase in twist leads to a drop in the bending hysteresis and yam bending rigidity, regardless of the length or fineness. Wrapper fibers do contribute to the bending behavior of rotor spun yams.