Method for operating a fleece layer

A method for operating a fleece layer for producing a fleece from a card web, the method comprising:

• providing a fleece layer including:
• an upper carriage, which moves in a transverse direction and through which a card web produced by a fiber web-forming device is conducted;
• a laying carriage, which moves in the transverse direction, through which the card web coming from the upper carriage is conducted, and which is adapted to deposit the card web onto an output conveyor belt;
• and
• at least two card web conveyor belts in the fleece layer to guide the card web to the laying carriage;
• providing a speed changing device arranged upstream of the fleece layer or integrated into an infeed area of the fleece layer for temporarily changing a speed of the card web, as a result of which the card web is supplied to the fleece layer at a variable card web infeed speed;
• whereby the upper carriage and the laying carriage are shifted back and forth substantially in a same direction during each of a plurality of laying cycles by means of forward and return movements, whereby the laying carriage, during each of the plurality of laying cycles, moves back and forth between two predetermined invariable reversal points of the laying carriage;
• whereby an average of the absolute values of a laying-carriage speed during forward movement of the laying carriage in each of the plurality of laying cycles or at least in some of the plurality of laying cycles differs from an average of the absolute values of the laying-carriage speed during return movement of the laying carriage;
• and
• whereby an average of the absolute values of the laying-carriage speed during forward movement of the laying carriage in each of the plurality of laying cycles or at least in some of the plurality of laying cycles differs from twice an average of the absolute values of an upper-carriage speed during forward movement of the laying carriage.