Principle

In the present construction of the FlatJet decreasing the vibrating mass and increasing the vibration amplitude by creating an appropriate vibrational concentrator appear to be more suitable for the relatively small quantities of ink than an increase in input efficiency. In the FlatJet system the following solution has been found to the problem mentioned above:

The plate resonator is attached to the liquid conducting tube in the junction marked “e”. In the junction the vibration created in the resonator is transmitted to the liquid conducting tube where the laminar mode becomes bending mode and the vibration goes on towards the ends of the liquid conducting tube.

If the design of the system comprising the resonator and the liquid conducting tube is appropriate all of the resonator’s vibration energy can be transmitted to the liquid conducting tube. Since the vibrating mass correlated with the length in the movement direction of the wave is considerably smaller than in the resonator the vibration amplitude increases significantly.

The vibration amplitude can be increased further if the vibrating mass correlated with the length is reduced gradually. In the case of the FlatJet system this was achieved by cutting the end of the liquid conducting tube at an angle.

The 0.3mm² flat surface can be regarded as a nozzle (Fig. 7) with a vibration amplitude of 0.005-0.007mm. The maximum speed of the surface is approx. 8m/sec. and when the direction of the movement changes the acceleration can be up to 1.000.000 G.

Another characteristic of the system is that in static condition the ink remains in the hole and during vibration the necessary ink quantity moves onto the nozzle. Ink supply to the nozzle is provided by capillary effect and a small overpressure in the liquid conducting tube.