A Study of Micro Injection for Unibody Array LED Lampshade with Multi-Cavities

The unibody of LED lampshade is the expansion of a lampshade array from single-LED in order to decrease assembly time, the forming technique is complicated. This study employ solid model to build micro mold, and find out the optimal design parameters, such as gate position, running system, cooling system and holding pressure system. The improvement of gate system can reach flowing equilibrium when molten plastic flows into cavity, and no welding line is produced. In the cooling stage, the cooling speed at each cavity is also steady and balance in order to reduce residual stress and lens defects. This study utilizes multi-gate system and multi-stage holding pressure aided forming to decrease welding line and residual stress. This study improves traditional mold design to fit more multi-cavity LED mold design which includes cooling system redesigning, cavities layout, flowing balance in runner and reducing shear stress. The Taguchi method and orthogonal array are used in the study for each group of experiment; many factors are applied to obtain the minimum shear stress, minimum warp, reduction of flow mark and uniform stress distribution. The results can provide for industry reference.