Numerical Simulation And Expemental Research For Mixing Process Of LLDPE/SBS

The Haake torque rheometer that is a mixer with superior mixing performance has a strong ability of distribution and dispersion. Better awareness and understanding of mixer in the mixing process with clear mechanism of mixing can help us control the process, get optimum conditions and eventually improve the performance of products. It is difficult to analyze the mixing efficiency accurately because of the limitation of the mixing theory. Although experimental research is the most accurate and direct method, whole process will cost many manpower and material resources. Further, the actual experiment can only get limited experimental data due to technical limitations. By comparison, numerical simulation methods can effectively overcome the above disadvantages, contribute to understand the mixing characteristics of the equipment, improve the mixing efficiency and product quality.The 3-D iso-thermal blend process of LLDPE/SBS polymer melts in HAAKE mixer were numerically simulated by using FEM software POLYFLOW. Mechanism of fluid mixing in the mixer was analyzed. On one hand, concentration distribution was used to represent the mixing distribution. The Distribution rule of SBS concentration during mixing process was analyzed, showing that mixing efficiency is centralized in the first 2 minutes. Higher shear stress and ratio of SBS, other than temperature, are in favor of enhancement in mixing ability and concentration uniformity by discussing the influence of position, rotating speed, ratio of disperse phase and temperature. The numerical results have good match with experimental results by experimental verification. On the other hand, a stronger role of shearing and tensile is in favor of mixing the dispersion through statistical function analysis of shear rate, shear stress and mixing index.