Research on Injection Molding Design and Mold Flow Analysis with Preventing Electromagnetic Interference Plastics Composite

• Main Authors: Hung, Huang-Lung, 洪煌隆
• Other Authors: Chen Chao-Chang
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/33653191282805449065

碩士 === 淡江大學 === 機械工程學系 === 85 === This research investigates the injection molding process of conductive plastic composite materials made of Acrylonitrile- Butadiene-Styrene Copolymer (ABS)compounded with aluminum flakes for the shielding effectiveness against electromagnetic interference (EMI). Design parameters of injection molds, mold flow analysis, operation parameters of injection molding, and the comparison with microscope structure and properties are the main concerns in this research. Since the aluminum flakes are used as metallic fillers to combine with polymer to produce conductive plastics composite resin, the EMI shielding effectiveness is significantly affected by the different aspect ratio, dispersion, content and the weight percent of fillers. Also, some phenomena of aluminum flakes such as orientation, fracture, and distortion, may easily occur in injection molding process. These phenomena need to be avoided to enhance the mechanical properties of final products. Therefore, mold design, resin flow and injection molding parameters need to be modified to improve the mechanical properties while maintaining the EMI shielding effectiveness.Consequently, a visible mold is designed and used in experiments to observe the mold design with a 180 degree ring runner and trapezoid gates. A computer simulation software, MOLDFLOW is adopted to simulate the resin flow and compare the simulation results with the observation from the visible mold. The technology of mold flow analysis is established in this research to decrease the cycle time of mold design, manufacture and test runs. Further, the observation technology of the visible mold has been constructed to visualize the process problems and to improve the mold design. Experiment results verify that the 180 degree ring runner and trapezoid gates of mold design can significantly decrease the fountain effect of resin flow and then can be used in improving the dispersion of aluminum flakes in plastic matrix.