The temperature control of the plastic injection molding

Temperature control of the plastic injection molding
1. Barrel temperature(plastic injection molding): the temperature to be controlled in the 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. Each kind of plastic has different flow temperature. For the same kind of plastic, due to different sources or brands, its flow temperature and decomposition temperature are different, which is due to different average molecular weight and molecular weight distribution. The plasticization process of plastic in different types of injection machines is also different, so the temperature of material barrel is also different.

2. Nozzle temperature(plastic injection molding): the nozzle temperature is usually slightly lower than the maximum temperature of the barrel, which is to prevent the "salivation" of molten material in the straight through nozzle. The temperature of the nozzle should not be too low, otherwise the nozzle will be blocked due to the early setting of the melt, or the performance of the product will be affected due to the injection of the early setting material into the mold cavity.

3. Mold temperature: mold temperature has a great impact on the internal performance and apparent quality of products. The mold temperature depends on the crystallinity of the plastic, the size and structure of the product, performance requirements, and other process conditions (melt temperature, injection speed, injection pressure, molding cycle, etc.).