How to control the temperature during the two-color mold injection process?

Two-color mold is a mold in which two plastic materials are injected on the same injection molding machine, and the molding is divided into two times, but the product is only ejected once. So, how to control the temperature during the injection molding process of the two-color mold?

1. Barrel temperature
The temperature that needs to be controlled during the two-color mold injection molding process includes 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. Due to different sources or brands, the same plastic has different flow and decomposition temperatures. This is because the average molecular weight and molecular weight distribution are different, and the plasticization process of plastics in different types of injection molding machines is also different, so the temperature of the selected barrel is also different.

2. Mold temperature
The temperature of the two-color mold has a great influence on the internal performance and appearance quality of the product. Mold temperature depends on the presence or absence of plastic crystallinity, product size and structure, performance requirements and other process conditions (melt temperature, injection speed, injection pressure, molding cycle, etc.).

3. Nozzle temperature
The temperature of the nozzle is usually slightly lower than the maximum temperature of the barrel. This is to prevent the “salivation” that may occur through the nozzle. The temperature of the nozzle should 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 by the injection of the early solidified material into the cavity.