Processing Parameters Optimization Of Auto Lens Based On Simulated Annealing Genetic Algorithm

As the application regions are enlarging, the requirements of plastic products quality are increasing. To produce the high-quality plastic products, it needs to design reasonable structure of products and molds. Moreover, it is necessary to choose suitable parameters combination in order to avoid defects of products. Therefore, deep research on choosing the best processing parameters combination is significant for decreasing productive cycle, cost and promoting the competition of enterprises.The injection molding processing parameters of lens of auto fog lamps are studied in the dissertation aiming at optimizing the processing parameters combination, thus it can reduce warpage and shrink mark depth in the injection molding process and improve the quality and performance of products. The methodologies such as design of experiment and intelligent optimization algorithm are utilized in this dissertation to realize the optimization of processing parameters. The main work can be summarized as follows:Firstly, the reasons why warpage and shrink mark appear on lens of auto fog lamps are analyzed in theory, and then cooling、filling、packing and warpage are carried out for lens by Moldflow software, according to the result from Moldflow, warpage and shrink are analyzed in detail.Secondly, fractional factorial experiments are implemented incorporating an amount of experiment data, then analysis of variance is executed to compare the process parameters and their interactions on the influence degree of the warpage and shrink mark, thereby the main influencing factor of the warpage and shrink mark are screened out.Thirdly, based on the main influencing factor of the warpage and shrink mark screened by fractional factorial experiments, the least square method is used to match the experiment data derived from response surface design, then mathematical model is built between influencing factor and optimal objects.Lastly, the multi-objective optimization technology is utilized for comprehensive evaluation of warpage and shrink mark. First the sink mark depth is transformed into nonlinear constraint conditions, then the exterior penalty function method is applied to make constraint conditions convert to penalty term, thus multi-objective problem is transformed into single objective optimization problem, and finally simulated annealing genetic algorithm is chosen for global optimization of the model to get the best processing parameter combination.