VERFAHREN ZUM ERFASSEN UND AUSGLEICHEN VON LEGEFEHLERN BEIM HERSTELLEN EINER BAHN EINES MEHRLAGIGEN VLIESES

摘要

In order to detect and correct folding errors during the manufacture of a web of multi-layer non-woven fabric by a folding machine in which a web of single-layer non-woven fabric is fed to a belt conveyor transversally to its direction of motion and laid alternately back and forth on the belt conveyor so as to form a multi-layer web, the thickness of the multi-layered non-woven fabric and/or its mass per unit area are continuously measured. The measurement signal is automatically monitored, preferably after a Fourier transformation, in order to detect disturbances in the form of periodic fluctuations in the signal amplitude. The speed of the belt conveyor and/or the feed rate of the web of single-layer non-woven fabric and/or the feed width of the web of single-layer non-woven fabric and/or the width of the web laid on the belt conveyor are adjusted so as to minimize the periodic fluctuations in the signal amplitude.