Study Of Technological Parameter Optimization For Injection Compression Molding Of Aspherical Lens

With the exponentially increasing number of myope and the higher myopia degree, more and more people have higher requirements on the lens, sucn as beautiful appearance, safety, portability and so on. The traditional spherical lens is not only thick, but also gets a serious problem of aberration and distortion, which has badly affected the imaging effect. To the contrary, the aspheric lens has the advantage of aberration correction in optical system because of the different curvature on the surface, which increases the independent variable and enhances the aberrations correction ability so that the aspheric lens have a better imaging quality. Due to its excellent optical properties, aspheric optical element is becoming one of the most important optical components.Injection compression molding is the development and extension of injection molding. By injecting the melt into a slightly open mold and then compound die through external force for the second time before the injection molding finishes and the melt solidifies. Thereby the product performance is improved. This method can obviously improve the optical property of the products by reducing the degree of molecular orientation caused during injection process. In consequence, it is now widely used in the precision optic industry. It is a complicated craft process. The quality of the lens is affected by many factors, including the material selection, mold structure, process parameters and so on. As the process parameters affect the flow state of the melt, the parameters have the most direct effection on the lens. Therefore, in order to obtain lens with higher qualities, we must select the best combination of process parameters.In this paper, we first designed -4.00D double aspheric lens based on the optical design software ZEMAX and then achieved an ideal model after optimization. After then, we made use of the Moldflow software to do a numerical simulation to the designed lens after all optical performance indexes were excellent. By analyzing the flow and refrigeration result, we improved the effectiveness of the gating system and cooling system. During the molding process, the process parameters had great influence on the injection compression molding. In this paper, we made the maximum buckling deformation, maximum weld bond and double refraction (delaying) as three evaluation objectives. So as to optimize the three goals, we must find the most perfect optimal combination of process parameters. Two methods were compared and analyzed respectively. The first one was to find out an optimal process parameter combination by the way using orthogonal test and fuzzy mathematics together and then simulate and vertify the combination.And the second is to find out the factors which have significant influence by factor screening test, carry on a multiple objective response surface analysis, and finally simulate and veitify the calculation result.The research indicates that the combination method of orthogonal test and fuzzy mathematics can figure out effectively the multi-objective optimization problem, and the score of comprehensive evaluation after optimization is the highest. On the other hand, the combination method of factor screening test and response surface is more pointed for us to study multi-odjective problems. These two methods definitely have guiding significance in the study of improving the quality of lens.