Patent ID: 6200423
Filing Date: 2001-03-13
Classification: D21F,Y10S

Abstract:
A method of controlling the cross-machine direction (CD) basis weight profile of a layered paper web comprising:(a) forming a layered paper web by using a layered headbox to deposit into a forming zone two or more aqueous suspensions of fibers, each of which corresponds to a different layering channel within the layered headbox;(b) providing each layering channel with an aqueous suspension of fibers through a tube bank comprising a multiplicity of tubes arranged in the cross-machine direction of the headbox;(c) measuring the cross-machine direction basis weight profile of each of the layers in the web or the dried sheet; and(d) in response to the measurement of the cross-machine direction basis weight profile, increasing or decreasing the dilution water to selected tube bank tubes to locally adjust the basis weight of each layer.