Titanium zirconium molybdenum (TZM) hot runner nozzle according to the shape can be divided into open system and valve system TZM hot runner.
Open system TZM hot runner has simple structure, suitable for miniature hot half runner. Mainly because miniature hot half runner does not contact the product but contact with the tiny runner, so it usually uses the open system hot runner nozzle, used for high-precision molds. The advantages of open system hot runner are large plastic injection quantity, simple structure, and easy installation.
Valve system hot runner provides a processing program control, in favor of the injection molding process for accurate adjustment, commonly used in precision plastic parts or injection molding products having higher requirements. Valve system hot runner has many types including single pin point gate, multi point gate, and other special pin point gate. Valve system hot runner can control hot runner nozzle opening and closing time and sequence, for the products witch has many hot runner nozzle, it can adjust plastic injection balance of each nozzle and can control the position of waterline. In addition, valve system hot runner having lots of advantages, such as saving materials, beautiful and high quality products production, used in hot runner system is widely.
Valve system TZM hot runner working mechanism is as follows: installed hot nozzle and hot runner manifold on the injection mold, using the principle of heating, making the plastic remains in a molten state. Thermostat is using thermocouple control system to control the temperature of manifold and nozzle, melted plastic to maintain the plastic in molten state, playing temperature control role in hot runner system.
Valve system TZM hot runner according to injection principle can be divided into: cylinder type and spring type. Cylinder type design is simple, but the structure is more complex, so it has high requirement on molds and debugging and maintenance is complex. Spring type depends on the balance of springs and injection pressure to control valve switch, having simple debugging and maintenance, having low precision requirement on molds. It is widely used in home appliances, automotive accessories, and precision multi-cavity mold.