In single hydraulic circuit, injection molding machine motion is under one hydraulic force guidance, all mechanical motion acts in sequence. Generally, the motion sequence of injection molding is as the following :
Mold Closing: Close the male mold to the female direction to be locked status.
Carriage forward: Move and fit the injection nozzle to the feeding port of mold.
Charging: Trough the rotation of screw, the granular material is fed into material pipe for heating to molten type.
Injection: Inject material into mold cavity.
Pressure holding: Keeping injection pressure to prevent material reverse flowing and shrinking of product.
Front suck: Screw retreat a certain distance for further feeding.
Charging: Trough the rotation of screw, granular material is fed into material pipe for heating to molten type.
Back Suck: After feeding, screw retreat a distance.
Cooling: Waiting for cooling and solidification of product.
Mold opening : Separating female And male molds.
Ejecting: Eject product from mold.
Again mold closing, injection, pressure holding, suck, and the cycle continues.
In the above process flow, pressure holding and front and back suck are not always exist, which depends on molding conditions. Hence the process flow of injection molding can be simplified as: mold closing, injection, feeding, cooling, mold opening, ejecting, mold closing and so on.