Research On The Acoustic And Temperature Field Distribution Of Polymer Ultrasonic Plasticizing Process

Micro-injection molding technology is a high-volume, low-cost ma nufacturing MEMS plastic parts, but there are difficulties in filling and other problems need be solved. Although Domestic and foreign scholars introduc ed ultrasound as an auxiliary in micro-injection molding, improved filling pr oblems initially, difficulty still cannot avoid the various problems which cau sed by the screw plasticizing. Our group summarize the basis of the previous studies, raising the "ultrasound plasticizing micro-injection molding", both expected to solve the problem of filling, and also avoid the screw plasticizing problems. The research conducted in this paper aimed at the polymer ultrasonic plasticizing process,which is the key process of the Ultrasonic plasticizing micro-injection molding.The main contents and conclusions showed as follows:(1)According to the requirements of polymer plasticizing ultrasound experiment, the polymer ultrasonic plasticizing components has been designed, including:Based on the electro-mechanical analogy method, derived the transfer matrix of a multi-stage compound sonotrode and designed the detailed demensions of the sonotrode.The rationality of the design has been validated by simulation and experiment; The insulation necessity of the plasticization barrel has been pointed out by thermal analysis using Ansys.As a result,the material of the insulation has been selected and the insulation board has been finnaly manufactured, resulting in reducing the ultrasound energy loss.(2)The sound spreading field and temperature field in the polymer ultrasonic plasticizing process has been simulated by Matlab and Ansys.The main contents include:derived ultrasonic propagation equation of ultrasound in the polymer.Numerical simulation has been conducted using Matlab, in order to study the amplitude of the ultrasound pressure distribution discipline and to reveal the effect of ultrasonic amplitude and frequency on the distribution of the ultrasound pressure amplitude;The co-simulation using Matlab and Ansys has been executed to study the temperature field distribution of polymer and to analysis the effect of ultrasonic parameters on the temperature field. (3)Conducted the experimental study of polymer ultrasonic plasticizing. Studied the impact of process parameters on the morphology of polymer plastics.It demonstrated that compared to the ultrasonic time, ultrasonic generator voltage and plasticizing pressure played a greater role on promoting the completeness of polymer plasticization;The ultrasonic sound pressure amplitude distribution of polymer at plasticizing chamber axis has been studied, indicating that the amplitude of the ultrasound pressure decreased with the increase of the distance to the sonotrode; The temperature field distribution of the polymer at plasticizing chamber axis has been studied, showing that the temperature of the polymer decreases with the increase of the distance to the end face of the sonotrode,verifing the advantage of the ultrasonic plasticization for micro amount of polymer.There are overall53figures and10tables in this paper.