Study On The Reinforcement Of Ultrasonic Field On Mixing Process

In this paper, study on the reinforcement of ultrasonic field on mixing process was conducted based on the combination of experiment and numerical simulation method. The author introduced ultrasonic field into preparation mixing process of composite material for the first time, HDPE/CaSO4composite material preparation experiment was conducted in self-designed ultrasonic mixing device; Through the characterization results of HDPE/CaSO4composite material properties, the study on the reinforcement of ultrasonic field on the mixing process was carried out; Through numerical simulation, the three-dimensional isothermal quasi steady state flow field simulation of ultrasonic amplitude transformer’s pin reinforcement on mixing process was carried out. Combining the experimental results and the numerical simulation results to achieve a deeper understanding of the influence of ultrasonic field on the mixing process and the following main conclusions were achieved:(1) According to the experiments, it is found that the ultrasonic field prevents the agglomeration of CaSO4particles, enhances the compatibility between CaSO4particles and HDPE matrix and increases the comprehensive mechanical properties and processabilities of HDPE/CaSO4composite materials effectively both in the continuous mixer and the internal mixer experiments.(2) When the ultrasonic field was introduced into the twin-rotor continuous mixer, the tensile strength, breaking strength and elongation at break of HDPE/CaSO4composite materials were increased by10.5%,21.7%and8.4%. Through the GPC, DSC, TGA tests, only slight degradation was caused when the ultrasonic power reaches270w, and no obvious change was observed to its crystal structure, which shows that under a certain range of ultrasonic power, the effect of ultrasonic on the change of polymer material structure could be neglected.(3) The addition of pin didn’t change the characteristics of fluid field of twin-rotor continuous mixing process obviously, the pressure, the velocity contrast along X axial direction and the velocity along Z axial direction only present a small increase. Therefore, it can be concluded that the reinforcement effect on continuous mixing process mainly due to the ultrasonic rather than the pin function of ultrasonic amplitude transformer.