Due to the high light transmittance of transparent plastics, strict requirements on the surface quality of plastic products must be required, without any markings, pores, and whitening. Defects such as haze, black spots, discoloration, poor gloss, etc. Therefore, during the entire injection molding process, great attention must be paid to the design of raw materials, equipment, molds, and even products.
Since most transparent plastics have high melting point and poor fluidity, in order to ensure the surface quality of the product, it is often necessary to make fine adjustments to the process parameters such as barrel temperature, injection pressure, injection speed, etc., so that the mold can be filled with the mold without producing internal stress causes product deformation and cracking. Therefore, strict operations must be performed in terms of raw material preparation, equipment and mold requirements, plastic injection molding process and product raw material processing.
1) Preparation and drying of raw materials: any impurity in the plastic may affect the transparency of the product. Therefore, in the process of storage, transportation, and feeding, you must pay attention to sealing to ensure that the raw materials are clean.
2) During the injection molding process, clean the barrel, screw and accessories. In order to prevent the contamination of raw materials and the presence of old materials or impurities in the recesses of the screw and accessories, especially the presence of resin with poor thermal stability, screw cleaning agents should be used to clean all parts before use and after shutdown to prevent sticking with impurities.