A Simulation Approach to Crystallinity Gradients Developed in the Injection Molding Process of Slowly Crystallizing Polymers

A modified three-dimensional (3D) rectilinear flow model is considered to study and analyze crystallinity gradients of slowly crystallizing polymers, such as syndiotactic polystyrene (s-PS) and poly (p-phenylene sulfide) (PPS), developed during the injection molding process. A slit mold is used. Highly efficient computational procedures are achieved through a specially designed order-two parallel splitting formula. Detailed three dimensional crystallinity distribution, together with the temperature, pressure and velocity profiles, is predicted through the simulation and compared with experimental results with satisfaction. The computational method developed can be further generalized for more complicated flow model problems in irregular injection molds.