OPTIMUM ADJUSTMENT OF BLOW FILM EXTRUSION OUTPUT BY USE OF PROCESS COMPUTER AND APPARATUS THEREFOR

摘要

In a film blowing plant comprising an extruder for the melt, a film blowhead, calibrating means for the blown tubular film, oscillatory take-off means for the film and a coiler for the flattened film, the output of the plant is set to an optimum figure by a process computer controlling the width and thickness of the film. The height of the line of solidification of the film above the blowhead is measured and, in response to a departure of this height from a given desired value, the output of the extruder is increased or reduced as the case may be.