A method of operating a flexographic printing press having a printing cylinder carrying a sleeve with at least one flexographic printing forme or a flexographic printing cylinder, and an impression cylinder, includes adjusting contact pressure between the printing cylinder or the flexographic printing cylinder and the impression cylinder by motor. The adjustment is made in an automated way as a function of a dot density of the flexographic printing forme, i.e. of a location-dependent density of printing elevations on the flexographic printing forme or data computationally derived therefrom. A cost-efficient way of producing high-quality prints in an industrial flexographic printing process is thus provided. In addition, the method advantageously provides further automation of the printing process. A flexographic printing press, a flexographic printing press system, and a flexographic printing forme or sleeve for a flexographic printing forme are also provided.

Fountain solution latent images are provided on an inking blanket without using laser-induced evaporation systems. Approaches include a rotatable charge retentive surface configured to receive an unfused toned electrostatic pattern of toner particles adhered thereto via electrophotography. The toner includes small diameter polymeric or inorganic particles that may have no color pigment to appear transparent or translucent. Fountain solution is disposed on at least one of the toner, the charge retentive surface and a transfer substrate. The transfer substrate is adjacent the charge retentive surface and forms a nip therebetween, with the transfer substrate sandwiching the unfused toned electrostatic pattern of toner particles and fountain solution against the charge retentive surface at the nip. Fountain solution sandwiched between the surfaces splits as the surfaces separate downstream the nip, leaving a fountain solution latent image remaining on the transfer member surface based on the electrostatic charged pattern on the charge retentive surface.

Fountain solution latent images are provided on an inking blanket without using laser-induced evaporation systems. Approaches include a rotatable charge retentive surface configured to receive an unfused toned electrostatic pattern of toner particles adhered thereto via electrophotography. The toner includes small diameter polymeric or inorganic particles that may have no color pigment to appear transparent or translucent. Fountain solution is disposed on at least one of the toner, the charge retentive surface and a transfer substrate. The transfer substrate is adjacent the charge retentive surface and forms a nip therebetween, with the transfer substrate sandwiching the unfused toned electrostatic pattern of toner particles and fountain solution against the charge retentive surface at the nip. Fountain solution sandwiched between the surfaces splits as the surfaces separate downstream the nip, leaving a fountain solution latent image remaining on the transfer member surface based on the electrostatic charged pattern on the charge retentive surface.

A folding apparatus of an offset web-fed printing press includes a first transport means formed as belt conveyor system for a web-shaped printing material and configured such that belts thereof can be driven at a speed, which corresponds to the speed of the printing material, and a first cutting means arranged in the region of the first transport means configured such that it severs the printing material in a format-variable manner in those sections not covered by the belts of the first transport means, and a second transport means arranged downstream from the first transport means and formed as belt conveyor system, the belts of which are offset relative to the belts of the first transport means transversely to the transport direction of the printing material, configured such that the belts thereof can be driven at a speed larger than the speed of the belts of the first transport means.

A heating circuit having an array of switching heating elements (e.g., field effect transistors, thin film transistors) provides a transient heat pattern over a surface (e.g., substrate, imaging member surface, transfer roll surface) moving relative to the heating circuit, to produce a pixelated heat image and heat a target pattern on the surface. Heat is generated by current flow in the heating elements, and the power developed by the heating circuit is the product of source-drain voltage and current in the channel. Digital addressing may accomplished by matrix addressing the array. Current may be supplied along data address lines by an external voltage controlled by digital electronics understood by a skilled artisan to provide the desired heat at a respective heating element pixels addressed by a specific gate line. The circuit may include a current return line that may be low resistance, for example, by using a 2-dimensional mesh.

A heating circuit having an array of switching heating elements (e.g., field effect transistors, thin film transistors) provides a transient heat pattern over a surface (e.g., substrate, imaging member surface, transfer roll surface) moving relative to the heating circuit, to produce a pixelated heat image and heat a target pattern on the surface. Heat is generated by current flow in the heating elements, and the power developed by the heating circuit is the product of source-drain voltage and current in the channel. Digital addressing may accomplished by matrix addressing the array. Current may be supplied along data address lines by an external voltage controlled by digital electronics understood by a skilled artisan to provide the desired heat at a respective heating element pixels addressed by a specific gate line. The circuit may include a current return line that may be low resistance, for example, by using a 2-dimensional mesh.

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.

Ink-based digital printing systems useful for ink printing include a secondary roller having a rotatable reimageable surface layer configured to receive fountain solution. The fountain solution layer is patterned on the secondary roller and then partially transferred to an imaging blanket, where the fountain solution image is inked. The resulting ink image may be transferred to a print substrate. To achieve a very high-resolution (e.g., 1200-dpi, over 900-dpi) print with these secondary roller configurations, an equivalent very high-resolution fountain solution image needs to be transferred from the secondary roller onto the imaging blanket. To increase the resolution of the image on the secondary roller, examples include a textured surface layer added to the secondary roller for contact angle pinning the fountain solution on the roll. Approaches to introduce a micro-structure onto the surface layer of the secondary roller, and also superoleophobic surface coatings are described.

A formative surface having a conductive base covered with a dielectric and oleophobic/hydrophobic surface layer is created with defined pits to grow micro-puddles of a defined volume. The formative surface is brought into close proximity with a charge retentive surface carrying a charge image. Fountain solution vapor nucleates and grows preferentially on the base of the pits as micro-puddle droplets. The puddles are charged and extracted from the surface to provide a fog of charged droplets of narrow volume and charge distribution. The charged droplets are attracted and repelled respectively from the charged and discharged image regions of the charge retentive surface, thus developing the charged image into a fountain solution latent image. The developed latent image is then brought into contact with a transfer member blanket and split, thus creating on the blanket a fountain solution latent image ready for inking.

Ink-based digital printing systems useful for ink printing include a secondary roller having a rotatable reimageable surface layer configured to receive fountain solution. The fountain solution layer is patterned on the secondary roller and then partially transferred to an imaging blanket, where the fountain solution image is inked. The resulting ink image may be transferred to a print substrate. To achieve a very high-resolution (e.g., 1200-dpi, over 900-dpi) print with these secondary roller configurations, an equivalent very high-resolution fountain solution image needs to be transferred from the secondary roller onto the imaging blanket. To increase the resolution of the image on the secondary roller, examples include a textured surface layer added to the secondary roller for contact angle pinning the fountain solution on the roll. Approaches to introduce a micro-structure onto the surface layer of the secondary roller, and also superoleophobic surface coatings are described.