Optimization Of The Rotors Of The Twin-Rotors Continuous Mixer And Studying Of Its Mixing Mechanism

Filled polymer modification is an important way to improve the performance of polymer. The performance of the filled polymer closely relates to the dispersion of fillers in polymer. As the polymer is certain, the dispersion will be determined by mixer. The excellent mixing performance makes the twin-rotors continuous mixer more and more popular. But the research on the twin-rotors continuous mixer is very few. Therefore, the 3-D isothermal flows of non-Newton fluid in mixing section of twin-rotors continuous mixer were simulated using a finite element package POLYFLOW. The mixing mechanisms of twin-rotors continuous mixer were studied. An optimal design of the structure of the rotors in the twin-rotors continuous mixer was carried out and the advantages and disadvantages of the rotors were compared. The main results are as following:1. The thrust face of the rotor forms a high-pressure area, and the other side of the rotor forms a low-pressure area. In the high-pressure area, the polymer is dispersed and mixed because of the pushing and the rolling of the rotors. Some polymer in the high-pressure area flow in to the low-pressure area through the gap between the top part of the screw flight and the mixer inner wall. It benefits to form disordered vortex flows of mixing and the distribution of materials. For the high of positive and opposite pressure, it is helpful to generate negative velocity in axial direction, which can form a reflux, thereby enhancing the effect of mixing.2. When the polymer melt flows through the gap between the top part of the screw flight and the mixer inner wall, it not only has the shear flow, but also the stretch flow.3. Compared with the traditional rotors, the mixing effect of the rotors whose meeting point of the screw flight is at its 1/3 length position is better.