Computer Simulation For Flow Of Plastic Melts And Film Bolwing

In this thesis, the author simulated the process of blowing film systematically. Firstly the author solved blowing process model by MATLAB, provided illustrative and imagined pictures and rather accurate results. The main interface of the program was shown. It made the simulation interactively and concisely.The velocity field in blown film die was simulated by FEM method., and effects of center piece eccentricity on blowing process were analyzed. On the base of simplification and suppose, the mathematical model for single and two layer melts was set up. The isothermal and Newtonian model for single layer melt flow was analyzed, as well as the non-isothermal and non-Newtonian model. The paper showed the radius distribution, thickness distribution, temperature distribution, stress distribution, strain rate distribution and so on. The shape of blown field was shown, in comparison with former results, the good accord was got. The simulation for two layer melts was reported rarely. On the base of single layer flow simulating, the author built the mathematical model of two layer fluid., analyzed an example and got fine results. The analysis of thermal field was rather complicate .By a simplified model, the analysis of thermal field was completed.Using computer simulating, we can optimize the process conditions of blown film and determine the best working point. This paper provides theoretical references for designing blowing film die and accessory equipment.