Research on Fiber Orientation and Dispersion of Plastics Composite with Injextion Molding for Preventing EMI

• Main Authors: Wei-Lieh Ni, 倪偉烈
• Other Authors: Chao-Chang A. Chang
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/63925116325668391256

碩士 === 淡江大學 === 機械工程學系 === 88 === The research is to investigate the EMI of injection molding by a transparent plastic material of Toray ABS-900 combined with the Bekaert stainless steel fibers (SSFs). Two types of SSFs are used and the dimension of long fiber is 6mm length and 8μm diameter and the short fiber is 4mm length and 11 μm diameter. Different weight percent (5wt%,10 wt% and 15 wt%) are used and the replaceable gates ( 120。,180。and 240。)are designed to change the gate angle for injection of the EMI disks . The back light and X-ray methods are used to investigate the fiber orientation on the EMI disk plane and the disks are cut for SEM to observe the fiber distribution. When aspect ratio of the fibers becomes larger, the fibers are segregating at end of EMI disks. Then the EMI tests are proceeded investigate the effects of fiber orientation and distribution. SEM results have shown that the SSFs in EMI disks of S-10-120~S-15-240 and L-5-120~L-15-240 have been bended by plastic flow so that the melted plastic can push the fiber into the mold cavity easily and good fiber distribution can be obtained. Experimental results of tensile tests have shown that the mechanical strength has no obvious relationships with the fibers weigh percent. Moreover, bonding strength of the base material and fiber is the main cause affecting tensile strength of EMI disks. From EMI test report, the best EMI effect of EMI disks with short fibers appears in gate angle of 120。 and that of EMI disks with long fibers appears in gate angle of 180。.