A control method for an injection moulding system having an extruder, feeding material continuously to an accumulator, portioning material intermittently to an injection device, wherein the control method is configured to drive the extruder at a high speed or at a low speed respectively, the high speed and the low speed defining an extruder speed interval, the method comprising acquiring a value for an actual positional change for the accumulator (POS.sub.ACT), comparing the value for the actual positional change (POS.sub.ACT) with a predicted value for the positional change (POS.sub.PRED), and adjusting a speed of the extruder based on a result of the comparison.

A control method for an injection moulding system having an extruder, feeding material continuously to an accumulator, portioning material intermittently to an injection device, wherein the control method is configured to drive the extruder at a high speed or at a low speed respectively, the high speed and the low speed defining an extruder speed interval, the method comprising acquiring a value for an actual positional change for the accumulator (POS.sub.ACT), comparing the value for the actual positional change (POS.sub.ACT) with a predicted value for the positional change (POS.sub.PRED), and adjusting a speed of the extruder based on a result of the comparison.