A plastic injection Mold parts machine consists of four major parts- the feed hopper, screw, heated barrel, and the mold cavity.
Injection molding involves two basic steps:
Melt Generation by a rotating screw.
The propelling movement of the screw helps to fill the mold cavity with the molten resins which passes the injected resin under high pressure.
A hopper and runner system is used to place the raw plastic resins into a heating barrel carefully.
There’s a reciprocating screw inside the barrel which creates heat with a frictional force with heater bands. The plastic melts there.
As the machine is still moving (with the help of the screw), the plastic is then injected through a nozzle from where it gets inside a mold cavity through a gate system. It almost looks like a tunnel.
Finally, we get the desired shape of the plastic resins, which cools as it is inside the cavity.
While the plastic is inside the cavity, the machine applies a holding pressure. If you didn’t know, particles expand when they heat.
When the molded plastic inside the mold cavity cools down, its volume will decrease as well, so we need some pressure to compensate for that.
Ejector pins are used to take the material out from the machine after it solidifies.
As the screw moves, another batch of granular plastic is fed to the heating barrel. The process continues from there, and the ejector pins help remove the injection mold plastics after it cools and hardens.