What is a hot runner?

Hot runner technology is an advanced technology applied to the pouring runner system of plastic injection mold. It is a hot trend in the development of plastic injection molding technology.

The so-called hot runner molding means that the plastic sent to the sprue from the nozzle of the injection machine always keeps the molten state, and it does not need to be solidified to be taken out as waste when the mold is opened each time. The molten material stuck in the gating system can be injected into the cavity when the injection is repeated.

An ideal injection molding system should form uniformly dense parts that are free from all runways, flaps, and watering holes. Relative to the cold runner, hot runner to do this, it is necessary to maintain the melting state of the material in the hot runner, will not be sent out with the formed parts. The hot runner process is sometimes called hot collector piping or runner-less molding. Basically, the hot collector tube can be considered as an extension of the barrel and the nozzle of the injection molding machine. The function of the hot runner system is to deliver the material to each gate in the mold.