Apparatus and method for cleaning a web substrate

Abstract

A system for cleaning a web surface including an axially oscillable contact cleaning roller (CCR) positionable to be in contact with the web surface on a free-span of the web. The CCR, which may be mounted in a frame, enjoys a wrap angle greater than 0.degree. and may also be positionable to be out of contact with the web for renewal of the CCR surface. The increased CCR wrap angle can improve the efficiency of particle removal relative to a nipped CCR installation. Either the frame or the roller itself is oscillable such that the CCR may be moved transversely of the web while in rolling contact with the web surface to distribute particles associated with the edges of the web over a broader area of the CCR. Preferably, the ratio of oscillation velocity to web velocity is less than about 0.01 and preferably the web tension is greater than about 0.5 pounds per inch of web width. Plastic and paper webs having a thickness as low as about 0.001 inch may be readily cleaned without wrinkling. Existing CCR web cleaning installations having backing rollers may be readily modified and simplified to provide free-span CCR cleaning in accordance with the present invention.

Dependencies are inferred from the claim text.