In order to prevent raw material pollution and in the screw and accessories in the depression of old material or impurities, special resin with poor thermal stability, so before use, after stopping the machine are applied screw cleaning agent to clean each piece, so that it can not stick with impurities, when there is no screw cleaning agent, can use PE, PS and other resin to clean the screw. When temporarily shut down, in order to prevent raw materials from staying at high temperature for a long time, resulting in a drop, the dryer and barrel temperature should be reduced, such as PC, PMMA and other barrel temperature should be reduced to below 160℃ (hopper temperature for PC should be reduced to below 100℃).

The complexity of plastic material properties determines the complexity of injection molding process. And the performance of plastic materials because of different varieties, different brands, different manufacturers, and even different batches of different and different. Different performance parameters may lead to completely different molding results.

Warping and deforming of injection molded products means that the shape of injection molded products deviates from the shape of the mold cavity. It is one of the common defects of plastic products. With the development of plastic industry, people's requirements for the appearance and performance of plastic products are becoming higher and higher. As one of the important indexes to evaluate the quality of products, the degree of warpage deformation has been paid more and more attention by die designers. Mold designers hope to predict the possible causes of plastic parts warping in the design stage, so as to optimize the design, so as to improve the efficiency and quality of injection molding production, shorten the mold design cycle, reduce the cost.