Reducing the Shrinkage in Plastic Injection Moulded Gear via Grey-Based-Taguchi Optimization Method

摘要

The application of plastic moulded gears in contrast of metal base gears are limited to functionally less important component due to its weak mechanical properties and divergent mechanism of failures. Shrinkage behaviour is one of the crucial problem in plastic moulded gear which negatively impacting the dimensional stability and accuracy of the involute profile, concentricity, roundness, tooth spacing uniformity and the size of the gear. Integrating the grey relational analysis and Taguchi method, the shrinkage behavior in tooth thickness, addendum and dedendum circles of moulded gear is investigated via optimization of processing parameters. From the results of analysis and optimization, the optimal combination of processing parameters for the moulded gear to achieve minimum shrinkage was predicted as A_2, B_2, C_3, and D_1. The melt temperature showed the strongest comparability sequence among the four important injection moulding process parameters investigated in this study followed by packing pressure, cooling time and packing time.