A hot runner system is an integration of heated components used primarily in plastic injection molds. It helps inject molten plastic into the hollow cavities of the mold. Where as, a cold runner system is simply a channel in between the two halves of the mold, designed to carry plastic from the injection molding machine to the cavities.
Every time the mold opens up to eject the newly formed plastic parts, the runner material is ejected too. This result in the wastage of the plastic deployed. On the contrary, a hot runner system includes a heated manifold. The primary purpose of the heated manifold is to allocate the plastic entering in the mold to the various nozzles and measure the injection points in the cavities. Read more