Dual-scale modeling and simulation of film casting of isotactic polypropylene

This paper presents a dual-scale model, which couples the macroscopic flow field of the film-casting process and the microscopic crystallization behavior of the material. In this dual-scale model, the finite difference method is used to calculate the macroscopic flow field variables such as temperature, extensional rate, and draw tension, while the Monte Carlo method is employed to predict the evolution of the crystallinity and the development of the crystal morphology. The effect of draw ratio during film-casting on the morphology of isotactic polypropylene crystallization is investigated both experimentally and numerically. Based on the fairly good agreement between the experimental results and simulation predictions, we conclude that the dual-scale modeling and simulation presented in this paper can well predict the film-casting process and give users more detailed insight into the flow field and morphological evolution.