Principle classification of inkjet printers

1. Continuous Inkjet Printer
Under the pressure of the ink supply pump, the ink passes through the ink pipeline from the ink tank, adjusts the pressure, viscosity, and enters the spray gun. As the pressure continues, the ink is ejected from the nozzle. When the ink passes through the nozzle, it is affected by the piezoelectric crystal. Breaking into a series of continuous ink droplets with equal spacing and the same size, the jetted ink stream continues to move downward and is charged through the charging electrode, where the ink droplets are separated from the ink line. A certain voltage is applied to the charging electrode. When the ink droplet is separated from the conductive ink line, it will instantly carry a negative charge proportional to the voltage applied to the charging electrode. By changing the voltage frequency of the charging electrode to make it the same as the frequency of ink droplets breaking, each ink droplet can be charged with a predetermined negative charge. The deflection plate with positive and negative voltage passes through the middle, and the charged ink droplets will be deflected when passing through the deflection plate. The degree of deflection depends on the amount of charge. The non-charged ink droplets will not be deflected, and will fly downward and flow into the recovery tube. , and finally returned to the ink tank for recycling through the recycling pipeline. The charged and deflected ink droplets fall at a certain speed and angle onto objects passing in front of the vertical jet.
2. Drop On Demand
There are three types of inkjet printers with on-demand inkjet technology, piezoelectric inkjet technology, pressure valve inkjet technology, and thermal foam inkjet technology, each of which works differently.
1) Piezoelectric inkjet technology: Piezoelectric inkjet printer is also called high-resolution inkjet printer or high-resolution inkjet printer. On the integrated nozzle, 128 or more piezoelectric crystals are used to control the nozzle plate. Through the processing of the CPU, a series of electrical signals are output to each piezoelectric crystal through the drive board, and the piezoelectric crystal is deformed, so that the ink is ejected from the nozzle and falls on the surface of the moving object, forming a Dot matrix to form text, numbers or graphics. Then, the piezoelectric crystal returns to its original shape, and new ink enters the nozzle due to the surface tension of the ink. Because of the high density of ink dots per square centimeter, the application of piezoelectric technology can print high-quality text, complex logos and barcodes.
2) Solenoid valve type inkjet printer (large character inkjet printer): The nozzle is composed of 7 groups or 16 groups of high-precision intelligent micro-valve. When printing, the characters or graphics to be printed are processed by the computer motherboard, and the The output board outputs a series of electrical signals to the intelligent micro-shaped solenoid valve, the valve opens and closes quickly, and the ink is ejected into ink dots by the internal constant pressure, and the ink dots form characters or graphics on the surface of the moving printed object.
3. Thermal Inkjet Technolog
Abbreviated as TIJ, it uses a thin film resistor to heat less than 0.5% of the ink in the ink ejection area to form a bubble. This bubble expands at an extremely fast rate (less than 10 microseconds), forcing the ink droplet out of the nozzle. The bubble continues to grow for a few more microseconds before disappearing back onto the resistor. When the bubbles disappear, the ink in the nozzles retracts. Surface tension then creates suction.

Post time: Feb-17-2022