| Summary: | 碩士 === 國立臺北科技大學 === 精密機構設計產業研發碩士專班 === 96 === Warpage is the main cause of dimensions of finished products, and also is a signification the performance of finished products. In general, the warpage of finished products is caused by volumetric shrinkage of melt polymer from high temperature to low temperature, and the volumetric shrinkage is decided by variation of specific volume. This research used simulation to analyze the shrinkage and warpage of thermoplastic and amorphous polymer PMMA with different melt and mold temperatures for thin plates 20 mm×20 mm×1 mm . The simulation parameters of this paper are listed as below: melt temperatures as 230℃, 245℃ and 250℃, and the mold temperatures as 70℃, 80℃ and 90℃. In this paper, the mold flow analysis software, "Moldflow" is used to analyze the shrinkage and warpage of finished products which are calculated by the volumetric variation of polymer undergoing liquid state, semi-solid state and solid state. In addition, this research utilizes the stress and strain analysis software "ANSYS" to analyze the shrinkage and warpage caused by the cooling shrinkage of polymer in the solid and liquid states respectively. Then, the results estimated from "Moldflow" and "ANSYS" were used to calculate the volumetric shrinkage and warpage of polymer in the packing stage. Finally, results show that the shrinkage in X-direction as 16.63%, the shrinkage in Y-direction as 16.22%, and the warpage in Z-direction as 20% at the conditions of melt temperature 250℃, mold temperature 90℃, and in semi-solid state in the injection molding process.
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