Controlling the temperature of plastic injection molding mainly starts from three aspects. The temperature that needs to be controlled in the plastic injection molding process includes barrel temperature, nozzle temperature and mold temperature. The first two temperatures mainly affect the plasticization and flow of plastics, while the latter temperature mainly affects the flow and cooling of plastics.
1. Barrel temperature, each plastic has a different flow temperature during the plastic injection molding process. For the same plastic, due to different sources or grades, its flow temperature and decomposition temperature are different; this is due to the average molecular weight and Due to the different molecular weight distribution, the plasticization process of plastics in different types of injection machines is also different, so the selection of barrel temperature is also different.
Second, the nozzle temperature, the nozzle temperature is usually slightly lower than the high temperature of the barrel, this is to prevent the "salivation phenomenon" that may occur in the straight-through nozzle. The nozzle is blocked due to condensation, or the performance of plastic injection molding products is affected due to the injection of early setting material into the mold cavity.
Third, mold temperature, mold temperature has a great influence on the intrinsic performance and apparent quality of plastic injection molding products. The level of mold temperature depends on the presence or absence of plastic crystallinity, the size and structure of plastic injection molding products, performance requirements, and other process conditions (melt temperature, injection speed and injection pressure, molding cycle, etc.).