A Comparative Study of the Tensile Fatigue Behavior of Cotton—Polyester Blended Yarn by Cyclic Loading

Abstract

The purpose of this investigation is to report the fatigue behavior of cotton and cotton—polyester blended yarn. A mechanism of fatigue behavior of staple yarn is suggested. The expressed mechanism of staple yarn fatigue is based on three stages: yarn decrimping, fiber slippage arising from inter fiber friction, and fiber elongation. The yarn decrimp mechanism occurs just at the initial stage of fatigue. The region of the sharp variations of the yarn viscoelastic properties up to nearly 1000 cycles of loading is attributed to the ability of the fiber to reorganize inside the yarn structure. Finally, the region of the steady variations of the viscoelastic properties of yarn seems to be due to fiber elongation. In this research, cotton and cotton—polyester blended yarn has been produced by rotor spinning. The general yarn characterization analysis has been performed, and then the viscoelastic properties of yarn have been analyzed by the Dynamic Mechanical Analyzer DMA 2980. The fatigue results reveal that the polyester fiber component has an important role in improving the fatigue resistance of the yarn to tensile cyclic loading. It has also been demonstrated that greater variations of yarn viscoelasticity are obtained with higher strain percent, so that at 1% strain the 100% cotton yarn reveals immediate failure. These results are interesting in view of the weaving process.