Optimization of injection molding process parameters and axial surface compensation for producing an aspheric plastic...

Form accuracy is an important parameter to measure whether a plastic lens can be used in imaging optics. Form accuracy exhibited by an aspheric plastic lens produced by injection molding is affected by process parameters and mold core. This paper proposes to optimize the process parameters through two stages. Stage one: An initial selection of process parameters was conducted in a wide range of the Taguchi method, and the process parameters were determined based on the signal-to-noise ratio, which significantly affected the axial deformation. Then the initial process parameters were obtained. Stage two: The regression model of process parameters was established according to the response surface methodology, with the optimal process parameters finally determined. For reducing the form accuracy error of aspheric plastic lens caused by material shrinkage and machining error of the mold core, an axial deformation compensation model was established. The aspheric plastic lens with form accuracy of 1.013 μm was experimentally verified, which met the requirements of imaging optics.