Modeling additional twists of yarn spun by lateral compact spinning with pneumatic groove

Compact spinning with pneumatic grooves is a spinning process to gather fibers by blended actions of airflow and mechanical forces. Modified from the ring spinning system, the lateral compact spinning with pneumatic grooves can improve yarn appearance and properties due to generated additional twists. In this study, we investigated additional twists of the lateral compact spinning with pneumatic grooves via a finite element (FE) method. An elastic thin rod was used to model a fiber to simulate its dynamic deformation in the three-dimensional space, and the space bar unit was used to simplify the fiber model for the dynamic analysis. The stiffness equation of the elastic rod element and the dynamic equation of the rigid body mass element were derived from the differential equation of the elastic thin rod. In the analysis of the nonlinear geometric displacement of the space elastic thin rod unit, the large deformation problem was solved with the stepwise loading successive approximation. The simulation results explained the mechanism of generating additional twists, and the experiment results proved the existence of additional twists. The study demonstrated that the FE model is effective for predicting additional twists of fiber bundles in the agglomeration zone, and for simulating the fiber motion in the compact spinning with pneumatic grooves. © This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.