Simulation Of Flow Field In Adapter Between Twin-Screw Extruder And The Die

The adapter between twin-screw extruder and the die is an indispensable part of twin-screw extruder, and its structure has a great effect on the melt which is before entering the die. However, for such a seemingly simple structural components, for a long time, it has never been included in the research field of vision. At present, the design of adapter generally uses experiential method, and it is short of enough theory foundation, so that the great instability and unpredictability in products and the big waste of manpower and material resources are usually resulted.In this study, multiple structures of adapter were constructed based on the existing adapter, and the mathematical, physical and finite element models were built. By using the CFD software, POLYFLOW, the flow field in adapter was simulated and analyzed, and the profiles of pressure, velocity and viscosity of different adapters were obtained. According to the analysis of the flow field, the size of circular groove of the new-style adapter was researched, and the more optimized geometry parameters were obtained.The influence of the technological parameters such as the inlet flow, the outlet pressure and the screw speed were investigated through the analysis of the orthogonal experiment. The flow field in adapter was simulated and analyzed at the variation of technological parameters, and the profiles of pressure, velocity, viscosity and shear-rate were obtained. Based on the various technological parameters influences on flow profile, more optimized technological parameters were obtained.The structure of the adapter designed in this study is simple and manufactured easily. It ensures smoothness of flow passage, lower pressure loss and more uniform velocity distribution, improves the qualities of the melt. The result of the research in this paper is significant to optimizing design of adapter.