Patent ID: 6076022
Filing Date: 2000-06-13
Classification: D21G

Abstract:
A method of controlling the formation of a sheet of wet stock comprising fibers wherein the wet stock is formed on a water permeable wire moving at a wire speed of a de-watering machine that has a headbox having at least one slice, wherein each slice has an aperture through which wet stock is introduced onto the wire at a stock jet speed, said method comprising the steps of:a) placing at least two water weight sensors underneath and adjacent to the wire and which are positioned at different locations in the direction of movement of the wire and upstream from a dry line which develops during operation of the machine;b) operating the machine and measuring the water weights of the sheet of wet stock with the water weight sensors;c) generating signals that are indicative of the water weight measurements and developing a water weight profile based on the signals; andd) adjusting at least one of said stock jet speed or wire speed so that the water weight profile match a preselected water weight profile by measuring the stock jet speed and the wire speed ratio and maintaining this ratio between about 0.95 to 1.05 provided that the ratio is not maintained at exactly 1.