Injection process

- May 25, 2018-

temperature control

1. The barrel temperature: The injection molding process needs to control the temperature of the barrel temperature, nozzle temperature and mold temperature. The first two temperatures mainly affect the plasticization and flow of the plastic, while the latter temperature mainly affects the flow and cooling of the plastic. Each plastic has a different flow temperature, the same plastic, due to different sources or grades, the flow temperature and decomposition temperature are different, due to the difference in the average molecular weight and molecular weight distribution, plastic in different types of injection The plasticization process inside the machine is also different, so the choice of cylinder temperature is not the same.

2. Nozzle temperature: The nozzle temperature is usually slightly lower than the maximum barrel temperature. This is to prevent the "flow phenomenon" that may occur in the melt flow through the straight-through nozzle. The nozzle temperature should not be too low, otherwise it will cause premature coagulation of the melt and clog the nozzle, or affect the performance of the product due to the early injection into the mold cavity.

3. Mold temperature: The mold temperature has a great influence on the intrinsic performance and apparent quality of the product. The mold temperature is determined by the presence or absence of plastic crystallinity, product size and structure, performance requirements, and other process conditions (melt temperature, injection speed and injection pressure, molding cycle, etc.).