Hot runner system is a combination, which includes nozzle, runner plate, temperature controller and spreader plate and so on. Hot runner is a common component in injection molding system to make sure plastic to keep molten state in runners and gates by heating. Because near or central of runner has heating rod and heating coil, so form the nozzle to the gate the entire runner is in a high temperature state to ensure plastic to keep molten. Besides, after stopping the operation generally do not need to open the runner and to clean freezing material. Hot runner is generally divided into open system and valve system hot runner. Open system hot runner has simple structure and has higher limitations on material. Furthermore, during the production it is easy occurs drawing and leakage and other problems, so it litter uses in precision molds. Valve system hot runner has a lot of advantages. It can save raw material, producing high quality products, so it usually use for precision mold production.
TZM alloy has good high temperature performance and corrosion resistance, so often used as raw material for hot runner system production. TZM hot runner system is a new structure which does not need to take out runner and gate. TZM hot runner system is divided into insulated hot runner system and hot half hot runner system. Insulated hot runner design is more complexity, but the effect is good, and maintenance costs are very low. Hot half hot runner structure is simple, easy to use and stable, and it has low failure rate, so many manufactures will use it for production.
TZM hot runner system has the following advantages:
1.TZM hot runner can maintain molten plastic for a long time. Beside, it is conducive to pressure transmission, to reduce runner’s pressure and temperature is more even and plastic has better liquidity, so products have low internal stress and low deformation possibility, which make products has better surface quality and has better mechanical property, so dwell time is prolonged and more effective, to reduce plastic products shrinking percentage.
2.Eliminate all or most waste in runner and increase effective utilization of materials.
3.To shorten the molding cycle improves the production efficiency.
4.TZM hot runner has high automation degree.
5.It can reduce injection pressure and help to protect the mold and prolong service life.