1. Establish back pressure, remove gas, prevent plastic melt casting, increase plasticizing capacity and measure material;
2. Forming pressure with the nozzle of the mold when shooting, keeping the nozzle and the nozzle of the mold in good contact, thereby forming a sealed flow path to prevent the plastic melt from overflowing under high temperature and high pressure;
3. When injecting, establish melt pressure, increase shear stress, convert the pressure head into speed head, increase shear rate and temperature rise, and strengthen mixing effect and homogenization;
4. Change the structure of the nozzle to match the mold and the plasticizing device to form a new flow channel form or injection molding system;
5. The nozzle has the functions of temperature regulation, heat preservation and material breakage;
6. Reduce the viscoelastic effect and eddy current loss of the polymer melt at the inlet so as to make it flow stably;
7. It is easy to fill the mold products during pressure keeping, and increase the backflow resistance during cooling to reduce or prevent the plastic melt in the mold from flowing back.