An ink recovery pipe comprises: an inflow port for receiving ink from an ink reservoir, and disposed at a position close to a first machine frame; and an outflow port for discharging ink into an ink container, and disposed at a position close to a second machine frame. A first restriction device is disposed at a position downstream of the inflow por. A first coupling part is configured to couple a high-pressure air generation part with the ink recovery pipe at a position downstream of the first restriction device. A first high-pressure air control device is configured to stop supply of high-pressure air to the ink recovery pipe, while ink is supplied to the ink reservoir, and supply the high-pressure air to the ink recovery pipe, after start of an ink recovery operation of recovering ink from the ink reservoir after completion of supply of ink.

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.

Based on evaporation of fountain solution from a rotating blanket cylinder to create an image that may be inked and printed, a digitally addressable heater array at or just below the blanket surface evaporates deposited fountain solution and forms a fountain solution latent image on the surface. The heater array has controllable heating elements (e.g., field effect transistors, thin film transistors) that provide a transient heat pattern on the surface to evaporate the fountain solution. Heat is generated by current flow in the heating elements, and power developed by the heating circuit is the product of source-drain voltage and current in the channel. Current may be supplied along data lines by an external voltage controlled by digital electronics to provide the desired heat at heating elements addressed by a specific gate line. The heater array may include a current return line that may be a 2-dimensional mesh.

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.

An ink fountain of an ink fountain device is provided with a fixed frame; a plate slidable on the upper surface of the plate; and an advancement and retraction mechanism advancing and retracting the plate with respect to the frame. The advancement and retraction mechanism comprises: a motor; a cam fixed to the output shaft of the motor which is integrally rotatable by rotation of the output shaft and has a cam surface shifted from an exact circle; and a rod in contact with the cam surface and advancing and retracting by the cam. The plate advances and retracts with respect to the frame by the advancement and retraction of the rod.

An ink recovery pipe comprises: an inflow port for receiving ink from an ink reservoir, and disposed at a position close to a first machine frame; and an outflow port for discharging ink into an ink container, and disposed at a position close to a second machine frame. A first restriction device is disposed at a position downstream of the inflow por. A first coupling part is configured to couple a high-pressure air generation part with the ink recovery pipe at a position downstream of the first restriction device. A first high-pressure air control device is configured to stop supply of high-pressure air to the ink recovery pipe, while ink is supplied to the ink reservoir, and supply the high-pressure air to the ink recovery pipe, after start of an ink recovery operation of recovering ink from the ink reservoir after completion of supply of ink.

A doctor blade, intended for a doctor blade chamber (6) for a flexography printing unit (1) equipped with a screened cylinder (4), presents in the form of a rectangular blade, with a functional longitudinal side (34) of which a longitudinal edge is capable of making contact with the screened cylinder (4), a longitudinal fastening side (33) and two lateral sides (36, 37).

The doctor blade comprises at least one opening located towards the functional longitudinal side (34) and towards the first of the two lateral sides (36, 37).

A printing system to hold printing material comprises a sealing interface to seal a container with respect to a printing chamber volume of the printing system, the container to hold the printing material. The printing system comprises a lifting system to move the container between a first position in which the container is to be lifted and a second position at which the container is lifted and contacts the seal so as to seal the container. The lifting system is to non-hyperstatically constrain the container.