Injection mold is main process of MIM technology, which can be divided into the following important steps:
① stock feeding
Before injection molding, set screw speed and pressure in the barrel, tightly close mold and contract ejectorbeam. In the during of injection, injection nozzle close to the runner, screw forward. At this moment, locking ring on the front of the screw is closed, in order to ensure feeding extruded from feed cylinder under pressure, filling mold cavity. When head of feed cylinder has enough feeding to inject into mold cavity, screw stops running.
②collosol and injection
Feeding in feed cylinder will melt when heating, then put it into mold.
Pressure maintaining is the process that screw presses feedstock when the screw reaches nozzle. It is the final step that feedstock is controlled by machine within molds. When pressure goes up inside mold chamber, feedstock liquidity decreases. Whilst when feedstock cools down, it means that stamping process finishes.
The very last procedure of injection molding is to get shaped bases out from molds, it is called de-molding.