A method of operating flexographic printing presses having an impression cylinder, printing cylinder carrying a sleeve with a flexographic printing forme or cylinder, uses a sensor adjusting print register of the printing forme or cylinder relative to a further printing forme or cylinder and/or adjusts color density and/or implements color inspection. An image of the sleeve surface with printing forme is recorded by a camera and processed before printing, locating a register mark and/or a color measurement field in terms of x-y positions. A sensor automatically moves for recording the register mark to the y-position of the register mark before adjusting to record the register mark and/or a sensor moves for recording the color measurement field to the y-position of the color measurement field before adjusting to record the color measurement field. Cost-efficient, high-quality industrial printing and further automation is provided.

A printing machine includes a printing roll and an anilox roll or an anilox sleeve for inking a printing forme of the printing roll. The anilox roll or the anilox sleeve is assigned a machine-readable ID. A sensor or a camera detects the ID. A computer retrieves data which is stored in a digital memory in relation to the ID detected from the memory. The computer performs adjustments on the printing machine on the basis of the ID which is read or the retrieved data. A method for adjusting a printing machine is also provided.

In a gravure plate for wiring printing on which a recessed portion defining a wiring pattern is formed on a plate surface, a projecting portion for reducing a volume of the recessed portion is formed on a bottom surface of the recessed portion. A contour of the projecting portion in cross section parallel to the plate surface has a semicircular arc shape, which protrudes toward one side in one direction that is parallel to the plate surface, on the one side. The recessed portion has a side wall that is composed of a plane orthogonal to the plate surface and faces the projecting portion at a distance of 15 μm or less without coming into contact with the projecting portion. The contour of the projecting portion has a semicircular arc shape, which protrudes toward the side wall, also on a side closer to the side wall.

A drum member includes: a substantially cylindrical drum body having a hollow part extending in an axial direction; a sheet member wound on the drum body; an adjusting mechanism configured to adjust tension in the sheet member, the adjusting mechanism including a moving member that holds an end of the sheet member in a circumferential direction and moves in a depth direction of the hollow part, and a fixing member that fixes the moving member to the drum body; and one or more positioning members that position the moving member such that the moving member does not move in the circumferential direction of the drum body when the moving member is fixed with the fixing member.

A method and device change printing plates on a cylinder. The method includes opening a first clamping device and releasing a leading edge of a first printing plate and opening a second clamping device and releasing a trailing edge of the first printing plate. The first and second clamping devices are both opened before a first rotation process of a cylinder. The cylinder is rotated during the first rotation process in a first direction to dismount the first printing plate from a circumferential surface of the cylinder. The cylinder is rotated in a second rotation process in an opposite second direction to mount a second printing plate replacing the first printing plate to the circumferential surface of the cylinder. Because the first clamping device and the second clamping device are both opened before the first rotation of the cylinder, the set-up period required for a printing plate change is reduced.

Disclosed is a drum printing apparatus including: a vacuum drum rotatably supported and coupled to a base and including a drum body shaped like a drum a printing head unit configured to form a set image including a text and a picture in the vacuum drum; a clamping unit configured to perform unclamping for mounting paper from a paper feeder to the drum body and clamping for holding and pressing paper to the drum body; and a cam unit coupled to the base and configured to operate being interlocked with the clamping unit, the clamping unit including a clamping knife coupled to a knife rotating-shaft and configured to be rotatable between a clamping position for pressing paper and an unclamping position for separating from paper, and a pair of clamping brackets coupled to opposite ends of the knife rotating-shaft and configured to be interlocked with the cam unit.

Disclosed is a drum printing apparatus including: a vacuum drum rotatably supported and coupled to a base and including a drum body shaped like a drum a printing head unit configured to form a set image including a text and a picture in the vacuum drum; a clamping unit configured to perform unclamping for mounting paper from a paper feeder to the drum body and clamping for holding and pressing paper to the drum body; and a cam unit coupled to the base and configured to operate being interlocked with the clamping unit, the clamping unit including a clamping knife coupled to a knife rotating-shaft and configured to be rotatable between a clamping position for pressing paper and an unclamping position for separating from paper, and a pair of clamping brackets coupled to opposite ends of the knife rotating-shaft and configured to be interlocked with the cam unit.

An apparatus for mounting a flexible plate onto a print sleeve or cylinder, where the apparatus has at least two manipulator units located below the print sleeve or cylinder and support members provided on each manipulator unit and each support member has a curved profile for arching the flexible plate prior to its mounting onto the print sleeve or cylinder, is disclosed.

An Adhesive Printing Form Attachment Layer comprises a permanently sticky layer, characterized in that the Adhesive Printing Form Attachment Layer is in the shape of a tube, preferably a seamless tube, and the permanently sticky layer forms at least the outer surface of the tube. The Adhesive Printing Form Attachment Layer can be used to adhesively fix a printing plate, preferably a flexographic printing plate, to a printing cylinder during the printing operation. The Adhesive Printing Form Attachment layer provides for easy replacement and easy installation on a printing sleeve or printing cylinder. Also provided are an assembly, comprising an adhesive printing form attachment layer according to the invention mounted on a printing sleeve, and a method of operating a printing machine, the method comprising forming the assembly by pulling the adhesive printing form attachment layer over the printing sleeve.

A cylinder is arranged to receive one or more hollow cylinders on an outer surface of the cylinder. The cylinder has at least one movable stop with at least one movable element. In an idle position the at least one movable element does not protrude beyond the outer surface of the cylinder and allows hollow cylinders to be slid over the cylinder, and in an active position it protrudes beyond the outer surface of the cylinder and acts as a mechanical stop for hollow cylinders. The at least one movable element can be moved from the idle position to the active position, and vice versa, by means of a rotary movement. A method for positioning a hollow cylinder on a cylinder of this kind.