Research on Optimized Design of Stamping Technology for Mobile Phone Keypad

Abstract

This research aims at discussing the steps and fractures on the surface of PMMA mobile phone keypad after the PMMA is stamped. Such steps and fractures are caused by the die structure, which leads to inward bending and displacement of the products during the punching process. Another reason is that the raw material is hard and brittle and the stress distribution of the punched position is dispersed, which results in irregular fractures. Taguchi Methods were employed to select die steel as the die material, and to choose the main factors: pipe diameter, pipe flow velocity and circulating water temperature as the control factors in the temperature control system. L16(44) orthogonal array was adopted for the experimental design, and the S/N ratios of Maximum-is-best was applied to measuring and analyzing the circulating water temperature of the circulating pipe. The verification shows that this system can greatly improve the die design and prevent the steps and fractures from happening, and the fractures were reduced by 90%, which indicated a significant improvement.