Insert Injection Molding Defects Analysis And Molding Cycle Optimization Based On CAE

In order to meet the need of lighter and thinner consumer electronic products, the stiffness and strength of plastic parts in the electronic products become higher and higher. People develop the insert injection molding based on the traditional injection molding technology. However, there are plenty of defects appearing in practice, such as short molding, weld lines, cavitation and warping. At the same time, how to decrease the cost of testing mold and how to decrease the molding cycle by Moldflow software becomes a key technology with the high labor costs in China’s coastal provinces and cities.The object of study in this paper is a connector in mobile communication device. The main contents and results of the research on the above problems are as follows:(1) Analysis of defects in insert injection molding. The filling process of insert molding was simulated by Moldflow software. Then, the defects in the simulation results and in the products were compared. The sizes of short molding in the simulation results and in the products were also compared and calculated by error analysis which could verify the practicability of molding defects analysis in Moldflow. Two gating system optimization schemes were proposed on the achievements of other researchers. The optimal scheme was based on Moldflow. At last, the simulation results under the optimal scheme(four gate) were tested.(2) Optimization for the insert molding cycle. An orthogonal test with six factors and five levels was designed. In the orthogonal test, the factors were mold temperature, melt temperature, the percentage of filling volume at V/P switch, the percentage of holding pressure, holding time and cooling time. The targets were shrinkage and molding cycle. The optimal parameters and the significant factor of every target were concluded by visual analysis and variance analysis. The optimal parameters(mold temperature is 100℃, melt temperature is 340℃, the percentage of filling volume at V/P switch is 99%, the percentage of holding pressure and the maximum filling pressure is 90%, holding time is 3s and cooling time is 18s) were obtained through the comprehensive consideration of two target parameters under comprehensive evaluation. At last, the practicability of Moldflow in the insert injection molding was verified under the error analysis for test results.Totally, the research results reveal that the method of numerical simulation combined with process test has an important guiding significance for reducing the surface defects, improving the process parameters and molding cycle.