Numerical simulation on melt spinning of one-step process POY/FDY polyester combined yarn

POY (Pre-Oriented Yarn)/FDY (Fully Drawn Yarn) Polyester combined yarn made by one-step process, in which POY and FDY are spun and taken-up simultaneously on one machine, has been developed recently. However, as a newly developed process, exploration in the spinning and fiber formation of one-step process POY/FDY polyester combined yarn has not been reported. In this study, the mathematical model of melt spinning of one-step process POY/FDY polyester combined yarn was established first, the evolutions of the diameter, tension, velocity, temperature, birefringence and crystallinity of POY and FDY during the spinning process were then calculated numerically by MATLAB program and fourth-order Runge-kutta method. The results of simulation provide useful information for the production of one-step process POY/FDY polyester combined yarn.