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 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 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.

The invention is about a valve system to grip a sleeve over a mandrel in a press, in particular on how the gripper is brought toward and away from the mandrel and sleeve assembly. The gripper is disengaged from the sleeve, following first a straight path and then a helicoidal path, thanks to an ad-hoc slot machined on an axle. This allows to disengage the gripper and set it out of the way for handling the sleeve, with a single motor and a single instruction.

A method for operating a device for printing hollow cylinder is provided. The device comprises a rotating segmented wheel with a plurality of printing cylinders arranged successively along the periphery of the device. A plurality of plate cylinders are provided in association with the segmented wheel. According to a printing process to be performed, a selected quantity of plate cylinders is thrown onto the segment wheel or is thrown off the segment wheel. In a first printing process, a first partial quantity of thrown-on plate cylinders transfers printing ink to a plurality of the printing blankets arranged on the segment wheel. At the end of the printing process, at least some of the plate cylinders, that were thrown on the segment wheel in the first printing process, are thrown off the rotating segment wheel. During constant uninterrupted rotation of the segment wheel, for the implementation of a second printing process, a second partial quantity of plate cylinders is thrown onto the segment wheel and respectively transfer printing ink to a plurality of the printing blankets arranged on the segment wheel. The respective printing forme of at least one plate cylinder involved in the first printing process, and uninvolved in the ongoing second printing process, is changed during the ongoing printing process.

A method for operating a device for printing hollow cylinder is provided. The device comprises a rotating segmented wheel with a plurality of printing cylinders arranged successively along the periphery of the device. A plurality of plate cylinders are provided in association with the segmented wheel. According to a printing process to be performed, a selected quantity of plate cylinders is thrown onto the segment wheel or is thrown off the segment wheel. In a first printing process, a first partial quantity of thrown-on plate cylinders transfers printing ink to a plurality of the printing blankets arranged on the segment wheel. At the end of the printing process, at least some of the plate cylinders, that were thrown on the segment wheel in the first printing process, are thrown off the rotating segment wheel. During constant uninterrupted rotation of the segment wheel, for the implementation of a second printing process, a second partial quantity of plate cylinders is thrown onto the segment wheel and respectively transfer printing ink to a plurality of the printing blankets arranged on the segment wheel. The respective printing forme of at least one plate cylinder involved in the first printing process, and uninvolved in the ongoing second printing process, is changed during the ongoing printing process.

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.