Steps of mold injection molding

1. Heating, pre-plasticizing

Driven by the transmission system, the screw transports the material from the hopper forward and compacts it. Under the mixing action of shearing and friction between the heater outside the barrel, the screw and the barrel, the material gradually melts, and the material is gradually melted at the head of the barrel. A certain amount of molten plastic has accumulated in the upper part, and the screw slowly retreats under the pressure of the melt. The distance of retreat is adjusted according to the amount required for one injection of the metering device. When the predetermined injection amount is reached, the screw stops rotating and retreats.

2. Clamping and locking

The clamping mechanism pushes the die plate and the movable die part of the die installed on the movable die plate and the die movable die part of the movable die plate to close and lock the die to ensure that sufficient clamping force can be provided to lock the die during molding. 3. The injection device moves forward

When the mold is closed, the entire injection seat is pushed and moved forward, so that the nozzle of the injection machine and the main gate of the mold are completely fitted.

4. Injection and pressure keeping

After the clamping and the nozzle are completely fitted to the mold, the injection hydraulic cylinder enters the high-pressure oil, pushes the screw to move forward relative to the barrel, and injects the melt accumulated at the head of the barrel into the cavity of the mold with sufficient pressure. To make the plastic volume shrink, in order to ensure the compactness, dimensional accuracy and mechanical properties of the plastic parts, it is necessary to maintain a certain pressure on the melt in the mold cavity to replenish the material.

5. Pressure relief

When the melt at the gate of the mold freezes, the pressure can be released.

6. The injection device retreats

Generally speaking, after the pressure relief is completed, the screw can be rotated and retreated to complete the next feeding and pre-plasticizing process. (In the general case of existing injection molding, the action of the injection seat withdrawing from the main gate of the mold has been canceled, and this action is performed for materials with severe drooling, such as PA).

7. Mould opening and ejection of plastic parts

After the plastic parts in the mold cavity are cooled and shaped, the clamping mechanism opens the mold and pushes out the plastic parts in the mold.