UV flatbed printer inkjet printing principle
Before talking about the inkjet printing principle of UV flatbed printer, let's talk about the current inkjet printing technology. Inkjet printing technology can be divided into continuous inkjet and on-demand inkjet. The former can be divided into two-state and multi-state deviation according to the deflection mode; the latter can be divided into solid and liquid inkjet.
The working principle of continuous inkjet technology is to use a constant power device to give the ink a fixed pressure, make it continuously eject and separate into ink droplets under the action of the oscillator. The control system selectively adds charges to the ink droplets according to the printing information, and finally passes The deflection electric field deflects the charged charges and sprays them onto the surface of the substrate to form graphic information. The uncharged charges go straight into the recovery device. This is called bi-state deflection. , Called polymorphic deflection. Its controllability is poor and its use is less than on-demand.
On-demand inkjet technology controls whether or not ink droplets are generated by controlling electronic signals. When the printing information is transmitted to the output terminal, if ink droplets are needed, the ink droplets are ejected, so that the surface of the substrate is formed with graphic information, which is simpler than the ink droplet charging device and deflection hardware in a continuous inkjet system.
On-demand inkjet technology: Liquid inkjet technology is the mainstream of on-demand inkjet technology, which can be further divided into thermal inkjet technology and piezoelectric inkjet technology.
1. Thermal inkjet technology: Thermal bubble jet inkjet technology mainly relies on resistors to convert electrical energy into thermal energy during the heating process. The heat can vaporize the ink near the printer nozzle and eject the ink. The target image or text is printed on it.
2. Piezoelectric inkjet technology: The piezoelectric sheet generates mechanical vibration, and the entire process of controlling the inkjet is completed by the pressure of the piezoelectric element. The heating of the nozzle is not required, which saves energy and prolongs the life of the print head; precisely controls the size of the ink droplets And the ejection position, avoiding the problem of blurred images; reducing the requirements for ink selection, and inks that generate chemical reactions at high temperatures can also be used.
3. Comparison of thermal inkjet technology and piezoelectric inkjet technology:
Thermal Inkjet Technology Piezo Inkjet Technology
Ink is wasteful or needs to be recycled. Ink jet when needed, ink is not wasted
Long drop stroke Short drop stroke
Poor print quality high print quality
Suitable for printing on rough and irregular surfaces Suitable for printing on flat and smooth surfaces
Limited by the speed of heat conduction
Slow response, slower printing Fast response, faster printing
Unable to control ink droplet size
High temperature ink quality is not stable No high temperature, ink quality is stable
Ink tank with high temperature is not stable. Without high temperature, the quality of ink tank is stable.
With high temperature nozzles are not easy to block
Ink pigments are easier to find Ink pigments are easier to find
Electronic drive is simple Electronic drive is more complicated
Smaller volume larger volume
Need to replace the nozzle.