Patent ID: 8337666
Filing Date: 2012-12-25
Classification: D21G

Abstract:
1. A doctoring system for a papermaking machine, said doctoring system comprising: a doctor blade coupled to a doctor blade holder, said doctor blade for cleaning a moving surface, and said doctor blade holder being coupled to a doctor-back; fluid assist means for providing a fluid under positive pressure that is higher than atmospheric pressure, said fluid being directed in a direction generally along a direction of movement of the moving surface to entrain air that is adjacent the moving surface and a following surface of the doctor blade such that a negative pressure that is lower than atmospheric pressure develops in a negative pressure zone adjacent the moving surface and the following surface of the doctor blade during movement of the moving surface, wherein said fluid assist means includes at least one aperture in the doctor blade holder, wherein said aperture is proximate the moving surface following the doctor blade and is in communication with a plenum that is internal to the doctor blade holder, and wherein the doctor blade holder includes a first surface that is proximate to and generally follows the moving surface following the doctor blade and is separated from the moving surface by a first distance, and the doctor blade holder includes a second surface that generally follows the moving surface and is separated from the moving surface by a second distance, wherein the second distance is larger than the first distance and wherein the at least one aperture is located between the first and second surfaces of the doctor blade holder.