Simulation and analysis of the twist propagation process of polyester staple yarn on the fiber scale

The twisting process of the sliver is an important part of the yarn spinning process, but this process has not been fully characterized on the fiber scale. Herein, based on the assumption that fibers are randomly distributed in the sliver, we analyzed the simulation twisting process of the sliver model on the fiber scale. The mathematical model of the twisting process of the sliver is set up and the non-free-end twisting process is simulated using the finite element software ABAQUS®. The simulation process clearly shows the configuration changes of the sliver caused with the increase of the twist. We also divided the twisting process into 11 stages and obtained a three-dimensional model of staple yarn. Then, the relationship curve between the ring-spun yarn fineness and the number of fibers in the cross-section of the ring-spun yarn was established by spinning the yarns of different counts of 20, 25, 30, 35, 40, 45, 50, 55, 60 and 65 Ne, and the fineness of the simulated yarn was calculated. The accuracy of the simulated yarn was verified by comparing the weight of the simulated yarn and the ring-spun yarn. The model established can be used to predict yarn properties for different purposes and can also be further utilized to study other phenomena in ring-spinning technology.