Process Optimization Of Injection Part Based On Moving Least Squares Response Surface Method

How to reduce the warpage is always bothering the engineers. Only relying on experience, skills and trials cannot solve the problem. This study focused on the research of processing parameters'impact on the warpage of plastic part based on CAE simulation. A response surface model based on moving least squares method was proposed to be applied on the optimization of the processing parameters in order to set up a prediction model between warpage and processing parameters. The particle swarm optimization method was used to search for the minimum warpage value and its corresponding processing parameters. The main work of the study includes:1. An accurate and reliable CAE simulation model was set up. A typical electric housing part was chosen as the study object. The warpage result from the CAE simulation was compared with the actual part's warpage measured from CMM. The result proved the reliability of the CAE simulation for this electric housing part.2. The impacts of different processing parameters on warpage were evaluated using Taguchi method. The result showed that melt temperature and packing pressure have the most significant effect on warpage, while injection time, mold temperature, packing time have little effect on warpage.3. A response surface model based on moving least squares method was proposed. The algorithm was achieved in Matlab and validated by an example. The significant factors as melt temperature and packing pressure were used as design factors and warpage value was set as the optimization aim. The non-linear relationship between processing parameters and warpage was thus set up.4. The optimization of processing parameters was achieved by utilizing the particle swarm optimization method integrated with the response surface model. The result showed that the warpage was reduced by 44.8% after optimization.5. In order to reduce the warpage, a further study on structure optimization was carried out. The thickness of the part and the dimensions of the ribs added on the parts were selected as design factors and warpage was selected as the optimization aim. The Taguchi method was exploited to study the impact of different structure of the part. After the process optimization and strucutal optimizaiton, the warpage of the plastic housing part was reduced by 80.4%.