Finite Element Numerical Simulation Of Flow Field Of Planetary Single Screw Integrated Extruder And Structure Optimization

Planetary extruder as a new type of polymer processing equipment has many advantages, get more and more attention and its application fields were also expanded. However, conventional planetary extruder has inevitable flaws, such as polymer melt pressure ability is low, extrusion stability performance is poorer, pressure and flow rate fluctuation is more noticeable. The defects of planetary extruder cannot be applied directly to extruded products, also hindered the further expansion of its application fields.Function combination design of mechanical equipment is the commonly used method of mechanical innovation design, the conventional single screw extruder and planetary extruder with the combination of structural function, got the planetary single screw integrated extruder. Planetary single screw integrated extruder has high performance in plastics polymer melting, strong build pressure, and was able to improve extrusion stability, and also further expanded the scope of its application.The structure of planetary single screw integrated extruder were complex, the polymer melt flow characteristics of planetary single screw integrated extruder was more complex, it is hard to use analytic method and experimental method in nature to know the flow of the polymer and mixing properties. In addition, using analytic method and experimental method of single screw part of planetary single screw integrated extruder optimization design also time-consuming, but with the help of modern computational analysis method the above problems can be solved well.To solve above problems, the paper’s main works were as follow:1. Planetary single screw integrated extruder 3D model was built, finite element numerical simulation of the model flow field by the CFD software Polyflow was carried. The pressure distribution, pressure characteristic, velocity distribution, local shear rate and other flow characteristics of planetary single screw integrated extruder were analyzed in depth.2. Orthogonal numerical simulation experiment was designed,3D experiment model were built and finite element numerical simulation were carried. The voltage characteristics, pressure fluctuation, velocity distribution, shear rate and other flow field features of each model were analyzed. Through analysis and comparison, the optimal experimental group of flow field characteristics was got, the group of single screw structure parameters combined with planetary section as the benchmark for subsequent analysis.3. Based on the orthogonal numerical simulation experiment results, single factor numerical simulation experiments were designde,3D experiment model were built and finite element numerical simulation were carried. The main structure parameters of single screw segments (screw diameter, screw pitch, thread shape etc) in planetary single screw integrated extruder’s flow field were analyzed in depth.4. According to the results of orthogonal numerical simulation experiment and single factor numerical simulation experiment, optimization numerical simulation experiment was designed. Other structure parameters of single screw (flight width, barrel clearance etc) were analyzed, and a more reasonable structure parameters of single screw was found eventually, the optimization design of planetary single screw integrated extruder were implemented.