A process for the automatic control of the thickness of extruded film
lowers the deviations in the thickness of the film more quickly after the
start of the extrusion process. The process includes the measurement of
the thickness profile of the film just extruded by means of a
thickness-measuring probe. The thickness-measuring probe is moved along
the surface of the film substantially perpendicular to the conveying
direction of the extruded film. The thickness-measuring probe records a
thickness profile of the film for each measuring cycle at least over
parts of the expansion of the film perpendicular to its conveying
direction. While providing statistical values in relation to older
measured values, the latest measured values during a predetermined
time-frame at the start of the extrusion process are more heavily
weighted by a computer than those measured during the normal operation.