Design And Critical Process Of Electrostatic Ink-Jet Head

Ink-jet printer is now popularly used in the ink-jet recording systems with low cost, simple production and easy operation, which can be used for printers, facsimiles, electronic manufacturing, bio-engineerng and bio-analysis, ceramic device and so on. The main mechanisms of ejecting ink drops are categorized in two groups: the piezoelectric ink-jet printing and the thermal bubble ink-jet printing. Both of the conventional ink-jet printers have their own drawbacks with structure and operation that can't be overcome. So in this dissertation, a novel electrostatic ink-jet head is brought forward to expand its applications, which can overcome such shortcomings.The main work in this paper are: based on the mechanism of electrostatic ink-jet head, an optimized electrostatic ink-jet head structure is achieved via theoretical analysis and finite element simulation of the ink-jet head. This paper includes five aspects listed as follows:·Bring forward a novel electrostatic ink-jet head based on related document and analysis of current situation of the ink-jet head. The electrostatic ink-jet head is composed of a three-layer structure: Si(upper Si substrate)—Si(oscillation plate)—Glass(lower substrate). The charging channel is located in the upper Si substrate; the diaphragm, ink cavity and nozzke are arranged in the oscillation plate, as well as the immovable electrode is positioned in the glass.·Obtain an appropriate diaphragm by theoretical calculation and simulation in ANSYS in coupled field. The diaphragm has a rectangular shape with 6000μm length, 380μm width, 5μm thickness, 1μm the distance between the diaphragm and the immovable electrode and 38V the applied voltage.·Optimize the charging channel by analysis and finite element simulation of the channel structure to reduce the reflux of the ink during the printing. The length, angle, neck width, depth of the charging channel are 300μm, 11°, 30μm and 30μm, respectively.·Analyse the Fluid-Solid-Interaction(FSI) during the ink printing, study the threshold of drop jetting out of the nozzle. When the Weber Number is between 1 and 12, the drop can break away from the liquid. Carry out the FSI simulation in ANSYS to get the fluid velocity in the nozzle, and obtain the result that the Weber Number is 8.5. It is between 1 and 12 which represents the feasibility of the head designed.·Design the process flow of the overall electrostatic ink-jet head, study the technological process of the oscillation plate, which will lay a foundation for fabricating the ink-jet head by the preliminary fabrication of 2.5μm thickness diaphragm.