Back Propagation neural network modeling for warpage prediction and optimization of plastic products during injection molding

• Published in: Materials in engineering 2011-04, Vol.32 (4), p.1844-1850
• Main Authors: Yin, Fei, Mao, Huajie, Hua, Lin, Guo, Wei, Shu, Maosheng
• Format: Article
• Language: English
• Subjects: A. Polymers; Automotive components; Back propagation; C. Molding; Computer simulation; F. Defects; Finite element method; Mathematical analysis; Mathematical models; Neural networks; Warpage
• ISSN: 0261-3069
• DOI: 10.1016/j.matdes.2010.12.022

► An accuracy and rapid warpage prediction model was established for plastic. ► Proposed a simple method to decrease warpage of the part. ► Energy consumption and production cycle were taken into consideration. ► Efficiency and practicality of the proposed optimization method was confirmed. Warpage of plastic products is an important evaluation index for Plastic Injection Molding (PIM). A Back Propagation (BP) neural-network model for warpage prediction and optimization of injected plastic parts has been developed based on key process variables including mold temperature, melt temperature, packing pressure, packing time and cooling time during PIM. The approach uses a BP neural network trained by the input and output data obtained from the Finite Element (FE) simulations which are performed on Moldflow software platform. In addition, a kind of automobile glove compartment cap was utilized in this study. Trained by the results of FE simulations conducted by orthogonal experimental design method, the prediction system got a mathematical equation mapping the relationship between the process parameter values and warpage value of the plastic. It has been proved that the prediction system has the ability to predict the warpage of the plastic within an error range of 2%. Process parameters have been optimized with the help of the prediction system. Meanwhile energy consumption and production cycle were also taken into consideration. The optimized warpage value is 1.58mm, which is shortened by 32.99% comparing to the initial warpage result 2.358mm. And the cooling time has been decreased from 20s to 10s, which will greatly shorten the production cycle. The final product can satisfy with the matching requirements and fit the automobile glove compartment well.