This process can be broken down into six steps. It all starts with plastic pellets or powders.
Plastics are also available in sheet, plate, rod, and tubing form.
These plastic pellets or powder or granules are fed by a vibrating hopper into the heated cylinder where it forms a melt. The melt is then pushed into a split die mold through a nozzle by using a hydraulic plunger or a rotating and reciprocating screw as shown in the photo above. As soon as the pressure in the mold increases, the plunger or screw stop but continue to apply higher pressure for the melt to fully fill the mold cavity giving the part good dimensional stability and tolerance. The clamping force is applied hydraulically or electrically opposite to the nozzle. At this stage, the mold is held and allowed to cool.