Doctoring apparatus and method employing prestressed doctor blade

摘要

A doctor blade assembly has a doctor blade supported in a blade holder. The blade has a projecting front edge adapted to be placed in contact with a moving surface to be doctored, and a rear edge adapted to be received in the blade holder. The blade is preloaded in a manner such that tensile stresses are induced in the front edge thereof. The level of such tensile stresses is below the yield strength of the blade material, yet high enough to prevent compressive stresses from developing at the blade front edge as a result of heat being generated by frictional contact between the blade and the moving surface being doctored.