Torsional properties of staple fibre plied yarns

Abstract

A mathematical analysis of the mechanical governing equations applying to the torsional behaviour of multi-ply yarns under tension has been carried out. This analysis clearly shows that there are two components, a geometric component that determines the slope or gradient of the torque due to tension and a component that determines the yarn torque at zero applied tension (intrinsic torque) that depends on the fibre number, fibre moduli and diameter as well as the strand structural geometry. The effect of the ratio of the ply twist to the spinning twist of the single strands on the torque properties has been numerically analysed for two, three and four-ply yarns prepared from single 31 tex yarns. The model has been compared with experimental torque data for a range of two-ply yarns plied at different percentages of the singles spinning twist and also with different yarn histories and test environments. The experimental data reflect the trends identified by the model.

Long Chopped Glass Fiber Reinforced Low-Density Unsaturated Polyester Resin under Different Initiation

“…Direct yarn, which was single-stranded roving, was a kind of continuous fiber obtained from large bushing with thousands of nozzles. On the other hand, two or more single yarn twisted together through a winder to fabricate plied yarn [ 20 , 21 , 22 ]. Different sizing agents lead to different softness of glass fibers.…”

Effect of fiber twisting on the Z-directional properties of composites

“…Xu et al 15 built three strand-contacting shapes model, and analyzed the influence of strand contact shape on spinning performance when spinning on the contact surface of static rod self-adjusting disc. Phillips et al 16 mathematically analyzed the slope or gradient of the tension-induced torque by the mechanical control equation for the twisting characteristics of a double-stranded yarn under tension, analysis effect of sandwich twist on the torsional properties of twostranded, three-stranded and four-stranded yarns formulated from 31 textile single yarns and 40 textile single yarns and 80 textile single yarns with singlestranded spinning twist.…”