Random Inkjet Technology

Drops from random inkjet printers are ejected from the nozzles only when they need to be printed (also known as on-demand), thus eliminating the need for a filter and recovery system for the ink pump and ink. Since the ejection speed of the ink is lower than the continuous type due to the inertia of the jet, in order to increase the ejection speed, the head is generally composed of a plurality of nozzles, and its structure and arrangement are similar to those of the dot matrix printer. According to the different excitation methods used in ink jetting, the random inkjet printer can be divided into piezoelectric type and bubble type.

The nozzle of the piezoelectric inkjet printer is filled with ink, and a piezoelectric crystal is arranged on the upper and lower sides of the nozzle, a pulse voltage is applied to the piezoelectric crystal to deform the pressure, and the ink jet is ejected by the extrusion nozzle, thereby controlling Injection of ink.

The bubble type inkjet printer is provided with a heating element on the wall of the nozzle, and a short pulse acts on the heating element, the heating element rapidly rises, the ink on the heating element vaporizes, and microbubbles are formed, and the microbubbles are thermally expanded to form a large steam. The membrane, thus creating a greater pressure, pushes the droplets out of the nozzle. After the ink droplets are ejected, a negative pressure is generated in the nozzle, and the ink is sucked into the nozzle from the ink cartridge, and the nozzle is returned to a stable state.