In this study, we developed the technology for intra-oral scanner lenses. The lenses were 11mm in diameter, 8.26mm in effective diameter and 25mm in focal length. And it was comprised of three aspherical optical lenses (A, B and C). The mold design were two cavities. The application of mold flow analysis software Moldex3D assisted mold design to be a reference base for initial design in this study. And the injection molding focuses on the influence of different injection parameters on peak to valley of the lens.
In injection molding, by Taguchi method analysis showed that the optimum parameters of the lens A were A1, B2 and C3 (mold temperature of 95 °C, the resin temperature 250 °C and holding pressure 65MPa), among which the contribution of the holding pressure can reach 56.83%; optimal parameters of lens B were A3, B1 and C3 (mold temperature of 110 °C, the plastic temperature 240 °C and holding pressure 65MPa), among which the contribution of the holding pressure can reach 84.83%; optimum parameters of lens C were A3, B3 and C3 (mold temperature of 110 °C, the plastic temperature 260 °C and holding pressure 55MPa), among which the contribution of the mold temperature can reach 44.32%, then using the best parameter compensated for injection molding, the results of peak to valley of the lens are obtained 0.37um in lens A, 0.34um in lens B and 0.45um in lens C.