Patent ID: 7643900

Claim:
A method of controlling a screw in a two-stage injection unit, the method executable at a computing apparatus associated with the two-stage injection unit, the method comprising: receiving an indication of an operational parameter associated with the screw of the two-stage injection unit; based on the indication of the operational parameter, determining a target speed (S TARGET ) for the screw, said target speed (S TARGET ) being sufficient to enable the screw to produce a required amount of material in a molten state; causing the screw to rotate at the target speed (S TARGET ), thereby causing the screw to operate in a substantially continuous manner, said operational parameter comprising at least: (i) an indication of recovery time (T RECOVERY ); (ii) an indication of idling time (T IDLE ); (iii) an indication of current rotational speed of the screw (S REFERENCE ); and wherein said determining comprises calculating said target speed (S TARGET ) based on a formulae expressed as: S TARGET = T RECOVERY T RECOVERY + T IDLE × S REFERENCE .