In a method for operating a rotary printing press, preferably a flexographic printing press that processes webs, disturbances of a rotating printing cylinder are detected and reduced by changing the printing speed. Here, the disturbances are detected at an actuating drive of the printing cylinder. This leads to a cost-efficient way of printing without disturbances.

In a method for operating a rotary printing press, preferably a flexographic printing press that processes webs, disturbances of a rotating printing cylinder are detected and reduced by changing the printing speed. Here, the disturbances are detected at an actuating drive of the printing cylinder. This leads to a cost-efficient way of printing without disturbances.

A device and a method is disclosed to maintain plate and anilox mandrel position stability in print decks of a flexographic printing press. In one aspect, the mandrel bearings associated with at least one of the plate roll and the anilox roll are preloaded for the purpose of eliminating backlash and increasing the positional stiffness of the bearings, and thus the mandrel. In another aspect, the roll drive motor control system is enabled to provide a torque additive command the torque profile to maintain rotational consistency and otherwise overcome torque transients experienced by the motor during print bounce. Accordingly, the problem commonly referred to as print bounce and or print banding is alleviated.

Please add the Abstract of the Disclosure, as set forth on the separate accompanying sheet. This Abstract of the Disclosure is essentially the same, in content, as the Abstract which is a part of the published PCT application, WO 2020/187665 A1. No new matter is being presented by the addition of this Abstract of the Disclosure.

A device and a method is disclosed to maintain plate and anilox mandrel position stability in print decks of a flexographic printing press. In one aspect, the mandrel bearings associated with at least one of the plate roll and the anilox roll are preloaded for the purpose of eliminating backlash and increasing the positional stiffness of the bearings, and thus the mandrel. In another aspect, the roll drive motor control system is enabled to provide a torque additive command the torque profile to maintain rotational consistency and otherwise overcome torque transients experienced by the motor during print bounce. Accordingly, the problem commonly referred to as print bounce and or print banding is alleviated.

A device and a method is disclosed to maintain plate and anilox mandrel position stability in print decks of a flexographic printing press. In one aspect, the mandrel bearings associated with at least one of the plate roll and the anilox roll are preloaded for the purpose of eliminating backlash and increasing the positional stiffness of the bearings, and thus the mandrel. In another aspect, the roll drive motor control system is enabled to provide a torque additive command the torque profile to maintain rotational consistency and otherwise overcome torque transients experienced by the motor during print bounce. Accordingly, the problem commonly referred to as print bounce and or print banding is alleviated.

A method is disclosed, which method is or at least can be carried out in a flexographic printing press for the purpose of determining a position of mutual contact between a printing roller and at least one counter roller. An average position of mutual contact between the printing roller and the counter roller is calculated, based on every position of mutual contact between the printing roller and the counter roller that is determined for a specific angular position of the printing roller and is used to execute a printing process carried out by the flexographic printing press.

In a method for operating a rotary printing press, preferably a flexographic printing press that processes webs, disturbances of a rotating printing cylinder are detected and reduced by changing the printing speed. Here, the disturbances are detected at an actuating drive of the printing cylinder. This leads to a cost-efficient way of printing without disturbances.

In a method for operating a rotary printing press, preferably a flexographic printing press that processes webs, disturbances of a rotating printing cylinder are detected and reduced by changing the printing speed. Here, the disturbances are detected at an actuating drive of the printing cylinder. This leads to a cost-efficient way of printing without disturbances.

A screen-printing unit in a printing machine comprises a screen cylinder which carries a screen-printing stencil and in which a squeegee is moved, from the inside, into contact with, and away from the screen-printing stencil. The screen cylinder is moved into contact with an impression cylinder, such that a printing position is formed, and is moved away therefrom, such that a gap is formed. The screen cylinder is moved away from the impression cylinder, in a first phase, when the squeegee is in a non-contacting position. In a second phase, at least one sheet of printing material is passed through the printing position when the squeegee continues to be in a non-contacting position and the screen cylinder is at least temporarily in a contacting position. For subsequent sheets of printing material, in a third phase, the screen-printing unit is operated with the squeegee one of permanently and cyclically, such as at least once for each sheet of printing material, in a contacting position.