Droplets generator: Formation and control of main and satellite droplets

The continuous-ink-jet printing technology is of great importance in many fields of the industrial and scientific applications due to its low-cost, simplicity, and flexible to a wide variety of material, which entail important technological advantages over existing technology. The perturbation imposed on the surface of the jet-flow is one of the primary parameters to control droplets formation. Therefore, a simple method for producing steady disturbance is presented in this article for further development the technology of continuous-ink-jet printing. Using high-speed photography technology along with image processing, the formation of droplets are investigated at different nozzle diameter and disturbance frequency. The results showed that the droplets formation experienced different breakup modes at different nozzle diameters. The satellite droplet was produced by breakup of jet-tip at the nozzle diameter of 0.15 mm. When the nozzle diameter was increased to 0.33 mm, the satellite droplet was produced by breakup of the trailing of primary droplet. The vibration region of uniform droplets could be controlled by the change of the gas pressure. The wavelength of surface wave decreased with the rose of the disturbance frequency, and a model was established to illuminate the relationship between the disturbance frequency and the wavelength of surface wave. The diameter of droplets decreased with the rose of the disturbance frequency.