Perforated roll for guiding a flexible material web

A device for guiding a flexible material web within a machine, the device comprising

• a drum comprised of a circumferential jacket and having a hollow interior within the jacket, the jacket having opposite lateral ends and having an exterior;
• a respective cover at each lateral end of the drum, the covers being shaped for closing the respective lateral ends of the drum against flow of air, and a bearing journal for the drum at each cover;
• a plurality of passage openings through the jacket for permitting the flow of air between the interior and the exterior of the jacket;
• at least one impeller in the drum interior for directing air axially along the drum interior, the impeller having a suction side in the interior of the drum and a pressure side in the interior of the drum, and wherein the impeller is adapted for creating negative pressure in the drum on the suction side of the impeller, whereby air may be drawn into the interior of the drum through the passage openings at the region of the drum with negative pressure;
• the impeller is so positioned along the interior of the drum as to divide the interior of the drum into separated chambers at opposite axial sides of the impeller which are at the suction side and the pressure side.