The relationship between the waveform of the uv printer nozzle and the uv ink is as follows: the waveforms corresponding to different inks are also different, which is mainly affected by the difference in the sound speed of the ink, the viscosity of the ink, and the density of the ink. Most of the current printheads have flexible waveforms to adapt to different inks.
The function of the nozzle waveform file: the waveform file is the time process of making the nozzle piezoelectric ceramic work, generally there are rising edge (charging squeeze time), continuous squeeze time (squeeze duration), falling edge (squeeze release time), The different time given will obviously change the ink droplets squeezed by the nozzle.
1.Driving Waveform Design Principles
Drive waveform design involves the application of the three-element principle of the wave. Amplitude, frequency and phase will affect the final action effect of the piezoelectric sheet. The magnitude of the amplitude has an influence on the speed of the ink droplet, which is easy to recognize and feel, but the influence of the frequency (wavelength) on the speed of the ink droplet is not necessarily very profound. Usually, this is a curve change with a maximum peak (the most The best value) is optional, so the best value should be confirmed according to different ink characteristics in actual use.
2. The influence of ink sound speed on waveform
Usually faster than heavy ink. The speed of sound of water-based ink is greater than that of oil-based ink. For the same print head, when using different densities of ink, the optimum wavelength in its waveform should be adjusted. For example, the wavelength width of driving water-based ink should be smaller than that of oil-based ink.
3. The influence of ink viscosity on waveform
When the uv printer prints in multi-point mode, after the first driving waveform ends, it needs to pause for a while and then send the second waveform, and when the second waveform starts depends on the natural oscillation of the nozzle surface pressure after the first waveform ends. The change just decays to zero. (Different ink viscosity will affect this decay time, so it is also an important guarantee for stable ink viscosity to ensure stable printing), and it is better to connect when the phase is zero, otherwise the wavelength of the second wave will be changed. In order to ensure normal inkjet, it also increases the difficulty of adjusting the best inkjet waveform.
4.The influence of ink density value on waveform
When the ink density value is different, its sound speed is also different. Under the condition that the size of the piezoelectric sheet of the nozzle has been determined, usually only the pulse width length of the driving waveform can be changed to obtain the best pulse peak point.
At present, there are some nozzles with high drop in the UV printer market. The original nozzle with a distance of 8 mm is modified to a high waveform to print 2 cm. However, on the one hand, this will greatly reduce the printing speed. On the other hand, faults such as flying ink and color streaking will also occur more frequently, which requires higher technical level of uv printer manufacturers.
Post time: Jun-30-2022