| Summary: | 碩士 === 國立高雄應用科技大學 === 模具工程系 === 98 === Injection molding is a flexible fabrication in industrial plastic processes. Light Guide Plate (LGP) is an important parts in Back Light Module manufacturing by injection molding process. Manufacturing for Wedge-Shaped LGP commonly exist dimensional error due to warpage. The aim of study is reduced warpage by chaging cooling channel system design. A 15-inch wedge-shaped LGP with varied thickness from 2.3mm to 0.8mm is implemented evaluating small warpage with changing cooling channel system dimensions, such as distance between cooling channel and mold surface. Amorphous thermoplastic polymethyl-methacrylate (PMMA) is used in numerical analysis and experiments. The research process is investigated varied cooling channel positions in x-, and y-axis to optimize cooling time, mold temperature, and cooling water temperature by using practical equations system and MoldFlow. Step by step the distance between cooling channels in x-axis was maintained and changed distance in y-axis. Then the desired mold temperature and the cooling time are used recalculating new cooling channel distances in x-, and y-axis. The numerical model implementing in simulation analysis was 15-inch wedge-shaped LGP with varied thickness from 1.5mm to 0.8mm instead model LGP with thickness from 2.3mm to 0.8mm.
Results of this study show that ejection time was reduced due to shorter cycle time. Moreover, the cooling water maintaining temperature during cooling stage. Therefore, cooling stage was significantly affected on warpage and especially in Z-direction result. Finally, the study was obtained that changed distance in y-axis was significantly affected on warpage.
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