A method for checking the maintenance of register of printing images to be printed on two opposite sides of a printing material, in which the first side of the printing material is printed in a rotary printing press by a first printing unit cylinder, and in which the second side of the printing material, which lies opposite to first cite, is printed in the printing press by a second printing unit cylinder which interacts with the first printing unit cylinder. A printed image is printed by the first printing unit cylinder under the second printing unit cylinder. Afterwards, the printing material is printed in contact with the two interacting printing unit cylinders with the printing image, which is printed under the second printing unit cylinder, being printed onto the same side of the printing material together with an identical or a different printing image which is to be printed by the second printing unit cylinder during continuous printing of the rotary printing press. The printed images, which are printed together onto the same side of the printing material, are subsequently checked, with regard to their maintenance of register.

The present specification describes a reverse offset printing apparatus and a method.

The present specification describes a reverse offset printing apparatus and a method.

A flexographic printer is provided with: a printing plate for transferring ink at an ink transfer site to an object to be printed S; an anilox roll for supplying ink to the printing plate at an ink supply site; a plate cylinder on which the printing plate is wound and rotated; and an ink solvent supply unit for supplying a solvent for the ink on the surface of the printing plate in a post-ink transfer region that is downstream of the ink transfer site in the plate cylinder rotation direction and upstream of the ink supply site in the plate cylinder rotation direction.

A flexographic printer is provided with: a printing plate for transferring ink at an ink transfer site to an object to be printed S; an anilox roll for supplying ink to the printing plate at an ink supply site; a plate cylinder on which the printing plate is wound and rotated; and an ink solvent supply unit for supplying a solvent for the ink on the surface of the printing plate in a post-ink transfer region that is downstream of the ink transfer site in the plate cylinder rotation direction and upstream of the ink supply site in the plate cylinder rotation direction.

A cleaning apparatus includes an inker roller and an ink source holding ink for the inker roller. The inker roller contacts a reimageable surface of an imaging member downstream of an ink image transfer station that transfers an ink image from the surface to a print sheet, with the surface having residual ink remaining thereon after the transfer of the ink image. The inker roller applies ink from the ink source against the reimageable surface. However, instead of the ink transferring from the inker roller to the surface, the ink stays with the inker roller and removes the residual ink from the surface to clean the surface for a subsequent ink image. The inker roller is not contaminated from removing the residual ink as the inker roller is designed to be coated by ink that adds to its coating of ink via the removed residual ink.

A cleaning apparatus includes an inker roller and an ink source holding ink for the inker roller. The inker roller contacts a reimageable surface of an imaging member downstream of an ink image transfer station that transfers an ink image from the surface to a print sheet, with the surface having residual ink remaining thereon after the transfer of the ink image. The inker roller applies ink from the ink source against the reimageable surface. However, instead of the ink transferring from the inker roller to the surface, the ink stays with the inker roller and removes the residual ink from the surface to clean the surface for a subsequent ink image. The inker roller is not contaminated from removing the residual ink as the inker roller is designed to be coated by ink that adds to its coating of ink via the removed residual ink.

According to an embodiment of the present invention, a printing apparatus that satisfactorily sucks and recovers a printhead is provided. A printing apparatus that includes a transfer member, and the first and second printheads has the following arrangement. The apparatus includes the first and second suction units which suck a plurality of nozzles of the first and second printheads, a common negative-pressure generation unit which generates a negative-pressure for suction by these suction units, and a moving unit which moves these suction units from one end to the other end of each printhead. Then, the moving unit moves the first and second suction units so as to pass through concave gaps with respect to ink discharge surfaces of the first and second printheads corresponding to the first and second suction units at different timings.

An apparatus comprises a plate cleaner assembly. The plate cleaner assembly further comprises a frame, a roller coupled to the frame, a dry cleaning material coupled to the roller, and a spray assembly coupled to the plate cleaner assembly. The plate cleaner assembly further includes a controller coupled thereto. Moreover, the apparatus further comprises a printing plate cylinder and a printing plate coupled to the printing plate cylinder.

A viscosity control unit provides improved and efficient residual ink removal from an imaging member following the transfer of the majority of the ink from the imaging member to a substrate, and prior to the application of a subsequent ink application to the imaging member. The viscosity control unit hardens the residual ink on the imaging member to produce a hardened residual ink. By increasing the viscosity of the residual ink before it is removed by a cleaning station, the removal of the residual ink from the imaging member becomes easier and more efficient.