| The trasparent twin screw extruder with glass windows, developed by Institute of Plastic Machinery and Engineering of Beijing University of Chemical Technology (EPME of BUCT), is of important significance and profound influence. By the extruder, the real material change in the twin screw extruder can be boserved, the extrusion mechanism is more easily studied, the applicable physical and mathematical models can be established, and the reasonable processing technology and composition can be explored. At present, there are a lot of literatures on the intermixing and melt handling in a twin screw extruder, but there are few articles on the material melting. It is obviously that only taking account of melt handling without considering material melting is not suitable to study twin screw extrusion theory thoroughly. The meltintg is a very important factor to affect the quality of products. After doing a lot of experiments on the transparent twin screw extruder and looking up the video tapes recorded by Dr. Liu Tinghua, a physical model of cylinder group of filled partially melting theory in the twin screw extruder and a mathematical model corresponding to the physical model are established. An approximately analytical solution of the problem is found out. In accordance with the operation conditions of the experiments done by the auther and the experimental data, the theoretical calculation has been carried out. The numerical results of the physical model are obtained by the finite element method, and the melting process of the cylinder group is simulated. Finally, the correctness and the reasonableness of the physical model, the mathematical model and the theoretical calculation are tested and verified with the experimental data. The following are the main aspects of this paper:1. In accordance with the oberserved results in experiments, the melting mechanism and the moving state of material in the twin screw extruding process are analysed, and the physical model of two phase cylinder group about the filled partially melting is proposed. In the light of some pypotheses in building the physical model, the mathematical model of the filled partially melting problem in the two screw extruding... |
