Regulation of the dia. of extruded cable - automatically measures dia., draw=off speed and material flow rate and to allow for shrinkage from hot or cold state

摘要

A device for regulating the outer dia. (OD) of an extrusion, and a cable or similar in partic. has a gauge to measure its OD as it emerges from the extruder and this resultant signal is passed to a comparator where it is compared with the target value. Any difference produces a signal to a regulator which controls the speed of revolution of the screw and/or the speed of draw-off from the extruder. A second gauge measures the mass of the material flow and a third gauge generates a signal, proportional to the draw-off speed. A computer receives the above information from the three gauges, and taking into account the density of the polymer when hot and cold using the dia. for the hot state, provides a value of the dia. when cold, which value is compared by the comparator with the target value for the dia. when cold. ADVANTAGE - The system makes it possible to regulate the dia. of the cable when cold.