| Summary: | 碩士 === 國立高雄第一科技大學 === 機械與自動化工程所 === 95 === As the process ability will be affected by environment factors to lead to a high defective rate in injection molding, thus, the paper will employ the robust process parameter searching method to find a process parameter setting for the injection machine to increase the robustness. In the paper, single and multiple quality characters are discussed, and through Taguchi’s Method and the principal component analysis, the best parameter point setting can be found and then be checked whether the parameter point is robust enough within the allowable changes of the environment, if not, the robust point should be found by the robust process parameter searching method.
The research mainly uses the mold flow analysis software, Moldex3D to simulate different quality defects of plastic products to implement the robust point found out by the robust process parameter searching method to see if the robust point is strong enough to resist the environment changes, and the explored parameter includes temperature, mold temperature, injection pressure, packing pressure, packing time, injection speed, injection position and cooling time. The preciseness, good outward appearance, and optical characters of LGP are paid most attention so that the quality defects focus on stress, warpage and shrinkage.
The parameter point searched by the robust process parameter searching method and the ones found out by Taguchi’s Method and principal component analysis separately can be testified and compared through Monte Carlo Method, and we can discover that the initial value of the interference range of the former is more robust. The robust point of stress for single quality characters has been improved 44%, and the warpage is improved 33%; the multiple quality characters are improved 55%. From this, we can know that the cycle in the machine production process can be extended by searching for the robust process parameter to reduce the probability of defective rates.
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