PRINTER

PURPOSE:To prevent a happening of a trouble such as condensation of steam rising from a corrugated cardboard sheet inside a frame, staining of a corrugated cardboard sheet by formed waterdrops by dropping thereon in a printing process or lowering of the printing accuracy by waterdrops by falling on a plate on a plate cylinder. CONSTITUTION:A gate-shape frame 6 supports an impression cylinder 7, a plate cylinder 8, ink roll 9 and a doctor roll 10. A window 16 is formed on the top wall 15 of a cover 14 covering the ink roll 9 and the doctor roll 10 and a fan 17 is fitted to the window 16. Air in the cover 14 is force-discharged outside by the rotation of the fan 17 and rising air current is produced toward the cover 14 in a transfer channel for a corrugated cardboard sheet S which is transferred in the frame 6. If steam rises from the corrugated cardboard sheet S which is transferred between the impression cylinder 7 and the plate cylinder 8, the steam is discharged outward from the frame 6 by ascending air current and prevented from condensing inside the frame.