Investigation and simulation of geometric and optical quality for bi-convex lens produced by injection molding process

This study investigates the effect of injection parameters on the geometric and optical quality of a Bi-convex lens injected with PMMA polymer. An important part of this research is the effect of each parameter on the geometric and optical quality of the lens and the obtaining of optimal quantities for injection. According to the results of this study, the effective factors simultaneously on the geometric quality and the optical quality of these types of lenses are melt temperature, packing time, injection pressure and packing pressure, respectively. These factors indicate that the simultaneous control of the pressure, in the mold cavity both during the injection and at the packing stage, can represent a suitable injection with minimal optical errors. According to the collected data, the average volumetric shrinkage check is 5.847% singly, in this case the refractive index is equivalent to 7.12E-05. The refractive index analysis is 6.28E-05 singly. In this case, the minimum average volume contraction is 9.1%. Therefore, optimizing and minimizing one of the geometric or optical factors will not produce the proper values of the other factor. Using the multi response Taguchi method, is obtained the minimum average volumetric shrinkage is 5.503% and the minimum refractive index is 6.96E-05.