An injection-compression process can be sequential or simultaneous.
There are no constraints in injection-compression molding for a sequential or simultaneous process in which the compression unit is under speed control. However, for a simultaneous process in which the compression unit is under force control, the molding process may take longer. Even when the press force exceeds the press force used, the analysis will continue.
Sequential
The injection unit (filling, packing) and the compression unit (speed control, force control) do not work at the same time. Compression begins only after filling and packing are completed.
Sequential Injection-Compression
- The top line represents the injection unit, with A = filling stage and B = packing stage.
- The bottom line represents the compression unit, with C = press waiting time, D = press compression time, E = cooling stage, and F = mold open time.
Simultaneous
The injection unit (filling and packing) and the compression unit (speed control, force control) can be working at the same time. Compression begins during the packing stage.
Simultaneous Injection Compression
- The top line represents the injection unit, with A = filling stage and B = packing stage.
- The bottom line represents the compression unit, with C = press waiting time, D = press compression time, E = cooling stage, and F = mold open time.