In injection molding, the hot runner is used together with the mold and plays a very important role. For example, in the injection molding production of ultra-thin parts (such as cell phone battery covers), it is easy to produce high-precision, high-quality products using hot runner. For injection materials with poor fluidity (such as LCP), the use of hot runner can significantly improve the fluidity of raw materials and ensure the smooth injection production. For some large injection molding parts, such as car bumpers and door panels, TV rear housing, air conditioning housing, etc., the use of hot runner makes the very difficult injection molding relatively simple.

It is impossible to form the phenomenon of lack of hot runner in multi - chamber mould injection. It can be said that hot runner is the best technique to ensure runner balance. Due to the shear force of the plastic in the flow channel, no matter how reasonable the geometric balance of the mold, the weight of the molded product is difficult to keep consistent, especially for the multi-cavity mold, if the hot runner is not used, the molded product will be lighter than the inside.

For plastic processors, hot runner is very economical as long as there is a certain amount of injection molding production. This is because hot runner helps companies eliminate nozzles in injection molding production. In most cases, the socket cannot be reused. Sometimes, the weight of the nozzle is almost the same as the weight of the product. Using traditional nozzle injection means that as much material is wasted as is wasted in the product. By this calculation, the use of hot runner, can save 30% ~ 50% of raw materials. In addition, hot runner also helps reduce mold wear and prolong mold life. In general, the service life of the hot runner mould is 2 times longer than that of the thin nozzle mould.

Although the composition of the hot runner is relatively simple, each component plays an important role. In general, high quality hot runner requires higher design and materials.