| Summary: | 碩士 === 國立虎尾科技大學 === 機械與電腦輔助工程系碩士班 === 104 === The mobile phone industry gradually grows up owing to the development of 3C electronics industry. Housings of mobile phones have a great diversity of applications and the plastic material change to composite material, glass fiber, or acrylic (PMMA). End users often pursue the lightweight housings and beautiful appearance that is similar to the mirror finish without milling marks. Therefore, the use of cutting tools becomes a very important issue.
In this thesis, the first stage of the geometry design was to employ Taguchi orthogonal array and tungsten carbide cutting tool for processing test of PMMA due to this method can effectively reduce the time and cost, achieve the high efficiency, and improve the stability of the process. At the same time, the experimental control factors were all independent, so we applied the L9 orthogonal array to analyze the geometric angles of the cutting tools. Based on the experimental results, in order to obtain the optimal combination of the factors, the analysis of variance and the grey relational analysis were adopted to change from the multiple objectives to a single objective. Then, the full factorial design was utilized to verify the reliability of the optimal combination of parameter values, and analyze the influence of the geometric angles for processing of PMMA.
The second stage was the setting of the grinding parameters by using the L32 orthogonal array for each level of the control factors. According to the results of the analysis of variance and the grey relational analysis, one can converter the multiple objectives to a single objective to obtain the optimal combination of the factors. Thus, the surface roughness of the cutting tools and the geometric profiles were controlled inside the required tolerance range, and the grinding time was shortest.
From the first stage, we can find the optimal geometric angles of the cutting tools and the influence for milling PMMA. Furthermore, the optimal grinding parameters can improve the efficiency and reduce the manufacturing cost by the second stage.
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