Abstract: A method of operating an inkjet printer operates solvent vapor generators that direct two flows of solvent vapor towards media on each side of each printhead in the process direction. The solvent vapor attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

Abstract: Alignment apparatuses include a frame and contact elements connected to the frame. The contact elements contact items that are to be transported in a processing direction relative to the frame. The contact elements are in permeant fixed positions relative to the frame, and do not move relative to the frame. Adjustable mounts are connected to the frame and move the frame in the processing direction and in a perpendicular cross-processing direction. A controller is electrically connected to the adjustable mounts, and the controller is adapted to control the adjustable mounts to simultaneously move the frame and all the contact elements in the cross-processing direction and the processing direction while rotating the frame. Methods laterally shift imaging on sheets that have had rotational correction performed by such alignment apparatuses.

Abstract: A printing system comprises a printhead to eject a print fluid to a deposition region. Print media are held against a movable support surface via vacuum suction, and the movable support surface transports the print media through the deposition region. A vacuum plenum comprises a vacuum platen over which the movable support surface moves. The vacuum platen has platen holes that communicate the vacuum suction from the vacuum plenum to the movable support surface. An airflow restriction mechanism forms a high impedance zone in the vacuum platen, the high impedance zone comprising a subset of the platen holes. The airflow impedance through the high impedance zone is relatively high compared to the airflow impedance through another subset of the platen holes, which are part of a low impedance zone. The high impedance zone may be located near the printhead to reduce airflow through uncovered platen holes near the printhead.

Abstract: A dross extraction system for a printer is disclosed. The dross extraction system includes an ejector defining an inner cavity associated therewith, the inner cavity retaining a liquid printing material. The dross extraction system also includes an inlet coupled to the inner cavity and a conduit external to the ejector having a distal opening, positionable to contact the liquid printing material to attract dross therein, thereby extracting dross from the liquid printing material when a negative pressure is introduced between an internal volume of the conduit and the dross.

Abstract: A printing system comprises a printhead to eject a print fluid to a deposition region. A movable support surface, such as a belt, is used to transport print media through the deposition region, with the print media being held against the movable support surface by vacuum suction through holes in the movable support surface. A media registration device loads print media onto the movable support surface and registers the print media to a location of the movable support surface. The movable support surface comprises no-suction-regions in which the vacuum suction through the movable support surface is prevented. The no-suction regions extend across the width of the movable support surface in a cross-process direction and are arranged at predetermined intervals along the process direction. The control system causes the media registration device to register each of the print media relative to a respective one of the no-suction-regions.

Abstract: An inkjet printer includes solvent vapor generators that direct two flows of solvent vapor on each side of each printhead in the process direction toward media passing the printheads in the printer. The solvent vapor attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

Abstract: An inkjet printer includes solvent vapor generators that direct two flows of solvent vapor on each side of each printhead in the process direction toward media passing the printheads in the printer. The solvent vapor attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

Abstract: A three-dimensional (3D) metal object manufacturing apparatus is equipped with an orifice cleaning system that removes metal drops that have adhered to a plate, an orifice in the plate, and a nozzle ejecting melted metal drops through the orifice during object forming operations. The orifice cleaning system includes an orifice cleaning tool that consists essentially of a soft carbon material, such as graphite. The orifice cleaning tool is configured with a handle that is gripped by an articulated arm to move the orifice cleaning tool against the plate, the orifice, and a portion of the nozzle at the orifice.

Abstract: A printing system comprises a print fluid deposition assembly, a media transport device, and an air flow control system. The print fluid deposition assembly comprises a carrier plate and a printhead arranged to eject a print fluid through an opening of the carrier plate to a deposition region. The media transport device comprises a movable support surface to transport a print medium along a process direction through the deposition region, the media transport device holding the print medium against the movable support surface by vacuum suction. The air flow control system is arranged to selectively flow air through the opening of the carrier plate between the carrier plate and the printhead based on a location of a print medium transported by the media transport device relative to the printhead.

Abstract: A coefficient of friction (COF) sensor on a carrier roll surface wetted with fountain solution transferred from an imaging member measures COF of the wetted carrier roll surface in real-time, even between or during printing operations. The transferred fountain solution may be concentrated and/or chilled to solidify before the measurement. The measured COF is used in a feedback loop to actively control the fountain solution layer thickness by adjusting the volumetric feed rate of fountain solution added onto the imaging member surface during an imaging or other printing operation to reach a desired uniform thickness for the printing. This fountain solution monitoring system may be fully automated.

Abstract: A method of operating a printer supplies an ink solvent or mixture of ink solvents to porous members positioned adjacent printheads. The ink solvent or solvent mixture evaporates from the porous members to provide a solvent vapor environment in the vicinity of the nozzle plates of the printheads. The solvent vapor environment attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

Abstract: A three-dimensional (3D) metal object manufacturing apparatus is equipped with a magnetic field generator to form a magnetic field selectively about a nozzle from which melted metal drops are ejected. The drops ejected in the presence of the magnetic field have their velocities reduced from the initial velocity at which they are ejected. The reduced velocity increases the time in flight of the drops before they impact their landing areas. The increased travel time enables the melted metal drops to oxidize sufficiently that they bond less tightly than the drops ejected without passing through the magnetic field. Thus, the apparatus can form metal support structures that adhere less tightly to the part portions of the object so they can be more easily removed after printing of the object.

Abstract: A printing system comprises a printhead to eject a print fluid to a deposition region. Print media are held by vacuum suction against a movable support surface, which moves over a vacuum platen to transport the print media through the deposition region. The vacuum platen has platen holes through which the vacuum suction is communicated. Multiple vacuum plenums are provided to supply the vacuum suction to different groups of the platen holes. A first vacuum plenum is fluidically coupled to a first group of the platen holes located at least partially in the deposition region, and to a second group of platen holes located upstream of the first group. A second vacuum plenum is fluidically coupled to a third group of the platen holes comprising at least some platen holes located between the first and second groups of platen holes.

Abstract: A three-dimensional object printer includes a controller that operates at least one ejector to place a layer of photopolymer material on a substrate. The controller is configured to cure the ejected photopolymer layer partially and position fiber on the cured layer before continuing to eject photopolymer material onto the fibers. The fibers can be loose or organized into a mesh. The pieces of mesh position on a cured layer can be pre-cut or a cutting device can be operated to cut pieces of mesh having a shape that corresponds to the shape of the layer of photopolymer material. The fibers reinforce the layers of photopolymer material and add strength and durability to the overall part being formed with the photopolymer material.

Abstract: A method of operating a printer supplies an ink solvent or mixture of ink solvents to porous members positioned adjacent printheads. The ink solvent or solvent mixture evaporates from the porous members to provide a solvent vapor environment in the vicinity of the nozzle plates of the printheads. The solvent vapor environment attenuates the evaporation of ink solvent from ink drops on the nozzle plates or from the ink in the nozzles of the printheads. Thus, the ink on the nozzle plates and in the nozzles does not dry out and the operational status of the inkjets is preserved.

Abstract: A three-dimensional (3D) metal object manufacturing apparatus is configured to eject melted metal drops from an ejector head at different velocities to form different portions of metal object layers with different measurable values of a same physical property. The different velocities are achieved by operating the ejector head with two different electrical voltages. The greater voltage that achieves the higher velocity is about 25% greater than the voltage used to achieve the lesser velocity. By operating the ejector head with the two different voltages different portions of the object can be formed with different physical property characteristics.

Abstract: A method of automatically diagnosing media handling defects on sheets, the method including receiving a first image of a first sheet, determining that the first image includes a detected media handling defect, determining that the detected media handling defect matches one or more known media handling defects in a database, and displaying a rectifying action.

Abstract: A printing system comprises a print fluid deposition assembly, a media transport device, and an air flow control system. The print fluid deposition assembly comprises a printhead to eject a print fluid through an opening of a carrier plate to a deposition region. The media transport device holds a print medium against the movable support surface by vacuum suction and transports the print medium through the deposition region. The air flow control system comprises an air supply unit to selectively flow air through the opening based on a location of a print medium relative to the printhead. The air supply unit comprises an air guide structure comprising an air outlet portion extending into the opening of the carrier plate between the printhead and the carrier plate, the air outlet portion terminating in an end wall that is angled obliquely relative to the movable support surface towards a reverse-process direction.

Abstract: A three-dimensional object printer includes at least one ejector that is operated to form an uppermost layer of photopolymer material on a substrate. The ejected uppermost photopolymer layer is partially cured and a portion of mesh sheet is positioned on the partially cured layer before the at least one eject continues to eject photopolymer material onto the uppermost layer. The portion of the mesh sheet reinforces the layers of photopolymer material and adds strength and durability to the overall part being formed with the photopolymer material.

Abstract: An additive manufacturing system has an extruder and a printhead module with a conveyor for moving between the extruder and the printhead module. The extruder is operated to form a support layer having microneedle protrusions. The conveyor moves the support layer having the microneedle protrusions to a position opposite the printhead module for sharpening of the microneedle protrusions and the application of a medicament to the sharpened microneedle protrusions.