| Printing industry is an important part of our national economy and a basic carrier of our cultural industry.With the constant development of printing industry,digital printing plays an increasingly important role.As an important way of digital printing,ink-jet printing technology can save a great amount of ink usage,having obvious environmental protection benefits and important practical significance for realizing green printing.Therefore,research on ink-jet printing technology has been an important part of domestic and external research.China also pointed out in the "12th Five-Year Plan" that the printing equipment manufacturing industry should intensify the research on ink-jet digital printing machines.Despite continuous efforts,considerable progress has been made in ink-jet printing related technologies.However,due to the late start of the research on ink-jet printing technology in China,better ink-jet printing equipment in the market still mainly relies on importation.Therefore,the key technologies for ink-jet printing in-depth study for the development of China’s printing equipment has important practical significance.In order to ensure the printing quality,it is very important for the ink-jet printing system to provide the ideal state of ink for the ink-jet head in time.Therefore,the performance of the ink-supplying system will directly influence whether the ink-jet cavity can realize the ideal ink-flow environment in real time.Thus,based on the law of ink natural parameters and printing quality,the paper studies the piezoelectric ink-jet mechanism,establishes the mathematical model of piezoelectric ink-jet drop forming,and analyzes the influencing factors of drop forming by simulation.Further analysis of the ideal ink-jet head demand for ink control system conducted in-depth study,developed a set of reasonable structure and more perfect function of the ink system.The research of ink supply system can detect the ink state parameters in real time to provide ideal ink flow for the nozzle cavity,and the research canprovide an important basis for realizing intelligent control of ink supply system.The main work of this paper is as follows:(1)Piezoelectric injection mechanism research.The influence of ink characteristics on printing quality was analyzed.The forming process of droplet and its influencing factors were studied by analyzing the working principle of piezo-electric sprayer and actuator as well as the wave conduction theory.(2)Numerical simulation of piezoelectric ink-jet process.Based on the finite volume method and the SIMPLC algorithm,the physical and mathematical models of the piezoelectric ink-jet process are established.Based on the finite volume method and the SIMPLC algorithm,the simulation of the ink-jet process is performed by using the FLUENT simulation software.The viscosity,surface tension and How ink inlets affect the drop forming process.(3)Piezoelectric ink-jet ink system design.By analyzing the characteristic parameters and ink-jet requirements of Gen5 printhead,the ink supply system pipeline plan was determined,the component selection and structure design of ink system were completed,and the ink supply control system was developed based on 89C52 single chip.(4)In order to further improve the control performance,in the light of the developed ink supply control system,a fuzzy PID controller is designed by selecting appropriate membership functions and fuzzy PID control rules.Via fuzzy reasoning in MATLAB / Simulink,the result proves that the system is more stable and it can further improve the dynamic and static response of the system compared with the conventional PID control.(5)The design of the ink supply system and control system were tested,the results show that it can achieve the desired goal,and further verify the feasibility of the system. |
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