Numerical Simulation of Screw Assembly Performance for Intermeshing Co-rotating Twin-Screw Extruders (II) Mixing Analysis

Mixing analysis was performed for different screw assemblies in a modular intermeshing co-rotating twin-screw extruder ZSK60 using a finite element package POLYFLOW. Based on the quasi-steady flow fields calculated at different rotational angles of twin screws, dynamic mixing processes in the screw assemblies were simulated through particle tracking analysis (PTA). By statistical treatment of flow trajectories for a large number of mass points, mixing performances of the screw assemblies were characterized in terms of the residence time distribution, distributive mixing index, and segregation scale, respectively. Furthermore, mixing analysis was also carried out under different processing conditions for the screw assemblies. Some of the numerical results were compared with previous experimental results.