| 摘要 |
<p>A control system for a screw injection moulding machine is based on a microprocessor receiving a signal derived from melt temp. measurements by an infra-red thermometer at the output end of the extruder barrel. The microprocessor is also provided with signals from ram location and ram pressure levels for advancing or retracting the screw, to vary the injection rate as a function of the melt temp. in accordance with parameter limits set up in a reference data base. The rapid response of the infra-red thermometer system allows compensation between or within indivdividual injection cycles for the effect of any cycle interruptions, shear rate variations, hardware warm up etc., so that the required shot size can automatically be maintained, reducing rejection levels.</p> |
