What is hot runner injection mold?
A hot runner injection mold is a mold in which plastic resin in the manifold plates is kept at the melt temperature during injection molding process. Compare with traditional injection mold, hot runner mold does not have runner channel, so the hot runner system is also called runnerless molding system. Actually, the hot nozzle system is an extension of the nozzle and work as a distributor for melt to each cavity.
Advantages of hot runner injection mold
1) shorten the injection molding cycle time
Hot runner injection mold does not have to wait the runner to cool down, it shorten injection cycle time significantly, many hot runner mold can mold thin-wall parts at 5 seconds or less per cycle.
2) Saving the plastic materials
There is no cold runner in a hot runner injection mold, so there is no waste on runner. This is particularly significant advantage for expensive plastic resin molding. In fact, the major international hot runner manufacturers in the world have been rapidly developed while oil and plastic raw materials are expensive, because the hot runner technology is an effective way to save plastic material.
3) Increasing product quality
The plastic melt temperature in the hot runner manifold are controlled precisely, so the melt flow is uniform, consistent quality parts can be produced. The gate bar left on the part is small or sometime invisible, so a lot of high quality products on the market are produced by hot runner molds , such as MOTOROLA phones, HP printers, DELL laptop.