An injection molding method for optical lenses with high-quality consistency by regulating the closing behavior of non-return valve

Injection molding is one of the most important polymer processing methods, and the traditional injection molding process cannot meet the high repeatability requirements necessary for the production of optical lenses. The impact of melt flow behavior and non-return valve closing behavior on injection molding repeatability is studied in this paper. A strategy of adjusting the closure behavior of the non-return valve is proposed, which can improve the repeatability of injection molding without the need for specific modifications to the injection molding machine. In this paper, variables such as the reversal action, reversal speed, forward movement action, and forward speed of the screw were investigated. It was found that the reversal action and forward movement action had the most significant impact on the closure stability of the NRV. Through the implementation of this process, injection molding repeatability can reach 0.019%.