Barrel Temperature

The temperature that needs 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 plastic has a different flow temperature. For the same plastic, due to different sources or grades, its flow temperature and decomposition temperature are different.

This is due to the difference in average molecular weight and molecular weight distribution.

The plasticizing process in the machine is also different, so the selection of the barrel temperature is also different.

Nozzle Temperature

The nozzle temperature is usually slightly lower than the maximum temperature of the barrel, which is to prevent the “drooling phenomenon” that may occur in the straight-through nozzle.

The temperature of the nozzle should not be too low, otherwise, it will cause the premature solidification of the molten material and block the nozzle, or the performance of the product will be affected due to the injection of the early solidified material into the mold cavity.

Mold Temperature

The mold temperature has a great influence on the intrinsic properties and apparent quality of the product.

The temperature of the mold depends on the presence or absence of plastic crystallinity, the size and structure of the product, performance requirements, and other process conditions (melt temperature, injection speed, and injection pressure, molding cycle, etc).