The important process conditions for injection molding […]
The important process conditions for injection molding are the temperature, pressure and corresponding individual action times that affect the plasticizing activity and cooling. Injection molding is an engineering technique that touches on the transformation of plastic into useful and consistent products.
Temperature control (temperature required for injection molding process is barrel temperature, nozzle temperature and mold temperature, etc.) (wearing screw)
1. Nozzle temperature: The nozzle temperature is usually slightly lower than the maximum temperature of the barrel. This is to avoid the "flow phenomenon" of the melt in the straight-through nozzle. The nozzle temperature should not be too low, otherwise the early condensation of the melt will be formed and the nozzle will be blocked, otherwise the performance of the product will be affected by the injection of the early aggregate into the cavity. (halogen-free screw)
2. Barrel temperature: The temperature required for the injection molding process is the barrel temperature, nozzle temperature and mold temperature. The first two temperatures mainly affect the plasticization and activity of the plastic, while the mold temperature mainly affects the activity and cooling of the plastic. Each type of plastic has a different activity temperature. The same plastic has different activity temperature and synthesis temperature due to different sources or grades. This is due to the difference in uniform molecular weight and molecular weight distribution. Plastics are injected in different types. The plasticizing process in the machine is also different, so the temperature of the selected cylinder is also different. In response to this phenomenon, Dongguan Huahong Plastic Machinery Factory has developed a bimetal (alloy) screw barrel that is resistant to high temperature, corrosion and wear, which is well adapted to the various temperatures required for injection molding. .
3. Mold temperature: The upper and lower resolutions of the mold are determined by the presence or absence of crystallinity of the plastic, the size and configuration of the product, performance requirements, and other process conditions (melt temperature, injection speed, injection pressure, molding cycle, etc.). The mold temperature has a great influence on the intrinsic properties and apparent quality of the product.