The invention relates to a piston (5) for a printhead (1) of a 3D printer, particularly a metal printer, comprising a piston rod (17) and a ram (18), the ram (18) having a discharge side (19) that has a convex or tapering surface (39). The invention also relates to a printhead (1) for a 3D printer, particularly a metal printer, comprising a housing (3), a device (28) for supplying a metal (14), a reservoir (7, 27) for a liquid phase (8) of the metal (14), a nozzle device (2) comprising a guide sleeve (11) and a nozzle plate (9), and a piston (5) according to one of the preceding claims, the ram (18), the guide sleeve (11) and the nozzle plate (9) forming a displacement chamber (21), and the ram (18) and the guide sleeve (11) forming at least one area (40) for conducting the liquid phase (8) between the reservoir (27) and the displacement chamber (21).

A printer is configured for printing with conductive ink for applying a conductive pattern to a surface including a wheeling structure for moving the printer over the surface and a transfer unit for applying a layer of electrically conductive ink to the surface. To provide accurate printing with the ability to obtain fine tolerances, the transfer unit has a printing drum rotatable about a printing drum axis and defining a printing drum periphery moving between a first zone and a second zone by rotation of the printing drum. The printing drum periphery, in the first zone, receives the conductive ink and in the second zone transfers the ink to the surface.

A method of forming a feature by dispensing a metallic nanoparticle composition from an ink-jet print head is disclosed. A jetting waveform is applied to piezoelectric actuator to dispense droplets of the metallic nanoparticle composition through nozzle opening. The droplets range in volume between 0.5 picoliter and 2.0 picoliter. The jetting waveform includes an intermediate contraction waveform portion, a final contraction waveform portion after the intermediate contraction waveform portion, and an expansion waveform portion after the final contraction waveform portion. During the intermediate contraction waveform portion, an applied voltage increases from an initial low voltage to an intermediate voltage and then is held at the intermediate voltage. During the final contraction waveform portion, the applied voltage increases from the intermediate voltage to maximum voltage and then is held at the maximum voltage. During the expansion waveform portion, the applied voltage decreases from the maximum voltage to a final low voltage.

A drop-on-demand printing method comprising performing the following steps in a printing head: discharging a first primary drop of a first liquid from a first nozzle outlet to move along a first path (pA) with a first speed; discharging a second primary drop of a second liquid from a second nozzle outlet to move along a second path (pB) with a second speed, lower than the first speed, wherein the second path (pB) is inclined with respect to the first path (pB) along an axis inclined at an angle (?) from 3 to 60 degrees and crosses the first path (pA) at a connection point; controlling the flight of the first primary drop and the second primary drop to combine the first primary drop with the second primary drop into a combined drop at the connection point so that a chemical reaction is initiated between the first liquid of the first primary drop and the second liquid of the second primary drop; applying electric charge to the combined drop; wherein the path of flight (pC) of the combined drop is altered no more than 20 degrees from the axis of the path of flight (pA) of the first primary drop; and controlling the path of flight (pC) of the combined drop with applied electric charge by deflecting electrodes.

A method for operating a printer can include draining a print material from a printer, placing a sacrificial metal into the printer, ejecting the sacrificial metal from a nozzle of the printer, and cooling to printer to a temperature that is below a melting point of the print material and the sacrificial metal. The print material can be or include aluminum and the sacrificial metal can be or include tin. The print material can be drained from the printer when the print material is in molten form, for example, from about 600? C. to about 2000? C. The sacrificial metal can be ejected from the nozzle at a temperature above the melting point of the sacrificial metal but below the melting point of the print material, for example, below about 300? C. The method can reduce or eliminate cracking of various printer structures such as the nozzle during a shutdown or cooling of the printer.

An inkjet printing device includes an ink containing a silver particle and water; and an ink discharging head including multiple nozzles to discharge the ink, individual liquid chambers communicating with the multiple nozzles, a common liquid chamber to supply the ink to the individual liquid chambers, a circulating flow path communicating with the individual liquid chambers, a common circulating liquid chamber communicating with the circulating flow path, and a pressure generator to apply a pressure to the ink in the individual liquid chambers, wherein the proportion of the silver particle to the ink is from 1 to 15 percent by mass.

An ink jet printer includes an ink jet head and an ink jet head control circuit supplying a control signal to control the ink jet head. The ink jet head includes a nozzle, an ink chamber, an actuator configured to change a pressure of the ink chamber to eject ink from the nozzle, a driver circuit that is connected to a signal line on which the control signal is supplied and configured to generate a drive waveform for driving the actuator according to the control signal, and a non-volatile memory connected to the signal line and configured to store information of the ink jet head. The ink jet head control circuit includes a drive control circuit connected to the signal line and configured to output the control signal to the signal line, and a non-volatile memory control circuit that accesses the non-volatile memory via the signal line.

Systems and methods for additive manufacturing, and, in particular, such methods and apparatus as employ pulsed lasers or other heating arrangements to create metal droplets from donor metal micro wires, which droplets, when solidified in the aggregate, form 3D structures. A supply of metal micro wire is arranged so as to be fed towards a nozzle area by a piezo translator. Near the nozzle, an end portion of the metal micro wire is heated (e.g., by a laser pulse or an electric heater element), thereby causing the end portion of the metal micro wire near the nozzle area to form a droplet of metal. A receiving substrate is positioned to receive the droplet of metal jetted from the nozzle area.

The electrohydrodynamic print head includes a nozzle layer with a plurality of nozzles. A feed layer is arranged above nozzle layer. It contains feed ducts for feeding ink to the nozzles as well as electrically conducting feed lines for feeding voltages to electrodes at nozzles. The feed layer includes one or more dielectric sublayers, which is/are structured to form the feed ducts and feed lines. Some of the sublayers contain vertical via sections and others contain horizontal interconnect sections. The feed layer is structured for customizing the print head easily.

Devices, systems, and methods are directed to applying magnetohydrodynamic forces to liquid metal to eject liquid metal along a controlled pattern, such as a controlled three-dimensional pattern as part of additive manufacturing of an object. The magnetohydrodynamic force can be pulsed to eject droplets of the liquid metal to provide control over accuracy of the object being fabricated. The pulsations can be applied in fluid chambers having high resonance frequencies such that droplet ejection can be effectively controlled over a wide range of frequencies, including high frequencies suitable for liquid metal ejection at rates suitable for commercially viable three-dimensional fabrication.