The Salivation Process Of In Necking And Stability Studies

In this paper, the neck in and stability of the film casting process were researched through applying the theoretical and simulation analysis. Then the result of simulation was compared with the experimental result. The method to reduce the neck in and proper measures to predict the stability were presented.Firstly, a variety of models of polymer and film casting process were analysed. The geometric model of the film casting process was built to find out the boundary condition of the process. Simulation for the casting process was processed with finite element software of Ployflow to obtain the velocity profile and the thickness profile of film casting process.Secondly, The predicted formula for the thickness were achieved, through the analysis for impact of draw ratio and the gap between slit die and cooling roller on the thickness of the film. Several factors impacting on neck in such as draw ratio, air gap between slit die and cooling roller, width of slit die, temperature of the polymer extruded and viscosity of the polymer itself were discussed, and the improved parameters of the film casting process were obtained.Thirdly, in order to research the stability of the film casting process, the mathematical method of modified Giesekus model was adopoted. The stability of film casting process was improved and critical draw ratio was predicted with this method.In generally speaking, the film casting process was studied through simulation and experiment method in this paper. The thickness,neck in and stability were predicted and the efficiency of the industrial production were improved through the method.