| 摘要 |
PURPOSE:To form an offset press free from a printing plate by dispensing with a flat plate, by forming a magnetic latent image to a magnetic drum of which the outer surface have received hydrophylic treatment and supplying a magnetic fine powder having ink-compatibility imparting treatment applied to the surface thereof to a magnetized image line part and subsequently supplying ink to perform printing. CONSTITUTION:The data corresponding to the image line part of the part to be magnetized of a magnetic drum 1 is sent to a magnetic head 2 to be magnetized and, when the outer surface thereof passes a fine powder supply part 3, a magnetic fine powder containing a fixing resin and having ink-compatibility imparting treatment applied to the surface thereof is supplied to be applied only to the magnetic latent image part and, when the latent image part subsequently passes a fine powder fixing apparatus 4, the magnetic fine powder is strongly fixed to the magnetic drum 1. When the magnetic drum 1 passes a dampening water supply part at first in the next printing process, dampening water is supplied to the magnetic drum 1. Subsequently, ink is supplied from an ink supply part 6. When a printing process is finished, a solvent is injected from a cleaning part 7 and the magnetic powder is sucked to return the entire region on the magnetic drum 1 to a hydrophilic state and the magnetic latent image is erased by a demagnetizing head 8. |
