Patent ID: 8709210

Claim:
A method in a fiber web machine, comprising the steps of: producing on a fabric, a fiber web having two edges and a selected width between said edges, the edges defining therebetween a cross direction of the fiber web machine; changing the location of the fabric with respect to the fiber web by oscillating the fabric in the cross direction with a selected amplitude of cross machine direction movements so that the fabric is affected by wear over a width which is wider than the fiber web; wherein the fiber web as supported on the fabric as the fabric oscillates defines two portions of the fabric, a fiber web affected area on the fabric where the fiber web is supported on said fabric, and portions of the fabric outside of the fiber web affected area; wherein the fiber web affected area has a cross direction width, the fiber web affected area being bounded on either side by outside edges; controlling the amplitude of cross machine direction movement such that the width of the fiber web affected area is wider than the width of the fiber web, and so that as the fabric changes in width in the cross direction during operation, and the fiber web remains substantially of constant width, the fiber web does not cross between the fiber web affected area and the portions of the fabric outside of the fiber web affected area.