Numerical Simulation of Fiber Spinning Process with Structure Evolution of Polymer Chains

Numerical simulation of the high-speed fiber spinning process was carried out based on a two-phase microstructure model. Calculation predicts not only the variation of parameters along the spinline, but also the radially distribution of flow field variables, such as temperature, crystallinity and molecular structure. Considering the combined effects on the process such as flow-induced crystallization, viscoelasticity, filament cooling, air drag, inertia, surface tension and gravity, the simulated material flow behaviors are consistent with those observed for semi-crystalline polymer under various spinning conditions. The structural change of polymer coils in the necking region described by the evolution of conformation tensor is also investigated. Moreover, a three-dimensional (3D) simulation approach was also established to predict the complex fiber shape given the spinneret geometry under the actual processing conditions. The influences of surface tension and the take-up velocity on the final fiber shape are predicted numerically.