| Summary: | 碩士 === 國立高雄應用科技大學 === 模具工程系 === 100 === The warpage of Front Bezel of LCD TV is not only caused by thin-wall injection and complex structures, but also the uneven thickness. Due Short-shot is caused by high flow ratio, the concern is that the residual stress also could lead warpage if the high pressure is applied. Meantime ,to increase the mold temperature higher to solve the cosmetic problem is needed such as High-gloss level and Welding line.
This research focuses on the Front Bezel of LCD TV, which is with average thickness 2 mm, length 799 mm, width 497 mm, depth ?? mm. To select engineering resin of PC+ABS as the material for the consideration of high flow ratio and sufficient impact feature. This product surface is fine finishing which requires high mold temperature and high injection speed at molding. The above injection conditions often cause high shrinkage and residual stress which defect the warpage. This study utilizes CAE Moldflow to simulate the injection status of Front Bezel and then utilizes Taguchi method to find out the optimized design parameters for further comparison with practical molded samples. This product study adopts different gate size to minimize warpage and optimize injection parameters and then utilize these molding parameters to verify samples in mold trials or for new molder development reference in the future. The theory ( Moldflow) after the trial verification to get precious experienced information is ,so-call, Know-How and Know-Why and its purpose is to set up a model of product development to expedite the developing schedule and to decrease the cost wastage of material and manpower for further similar products.
This study concludes in following four points: (1) Analysis result of warpage is greatly reduced by gate improvement according to references rather than experienced methods. (2) Planning and analysis by Taguchi method calculated the most important injection parameter which affect warpage of different gates. (3) The most contributed factor of warpage is melt temperature. (4) Trail experiment verifies that the optimum factor calculated by Taguchi method results in minimum warpage. This study provides the improvement of gate size design and molding. Afterward ones can follow this model to set up a procedure of mold design standard for developing more big size of LCD TV Front Bezel and to expedite and increase the competition of the design and manufacturing capability in the mold field.
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