A corrugated box finishing machine has a station where dust, debris and other particles are cleaned from the corrugated boards before they are conveyed to the printing station. Electrostatic charges on the particles are neutralized by a static bar and the particles are then removed from the boards by a rotating brush. The particles are drawn into a vacuum chamber underlying the path of conveyance of the boards, and the static bar is positioned in an enclosure in proximity to the boards but isolated from the vacuum in the vacuum chamber. The enclosure has surfaces which direct the particles away from the static bar which is oriented to further minimize contact with the removed particles. The cleaning brush includes a plurality of brush sections mounted on a rotatable shaft made from carbon fiber material.