Injection molding temperature control

1. Barrel temperature: The temperature to be controlled during 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 one mainly affects the flow and cooling of plastics. Each kind of plastic has different flow temperature. Due to different source or brand, the flow temperature and decomposition temperature of the same plastic are different. This is due to different average molecular weight and molecular weight distribution. The plasticizing process of plastic in different types of injection machines is also different, so the temperature of material barrel is also different.
2. Nozzle temperature: The nozzle temperature is usually slightly lower than the maximum temperature of the barrel, which is to prevent the "salivation" that may occur when the molten material is in the straight-through nozzle. The nozzle temperature shall not be too low, otherwise the nozzle will be blocked due to the early solidification of the molten material, or the performance of the product will be affected due to the injection of the early solidification 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.).