Numerical Simulation And Experimental Study Of Drying Process Of R2R Gravure Printing Equipment

The drying system is one of the core units of the gravure press,and the substrate passes through the drying chamber in just 0.3 seconds,ensuring that the ink is completely dry and harmful residues are fully removed.The performance of the drying system is not only related to the quality of the printed matter,but also directly affects the energy consumption level of the printing equipment.Domestic printing equipment generally has the problems of high energy consumption and low efficiency,but there are few studies on the heat transfer phenomenon in the drying process,the water-based ink drying mechanism and the parameter perception system of ink drying equipment.If the printing industry wants to achieve energy conservation and emission reduction and realize the "green" development direction proposed by the "14th Five-Year Plan",it is necessary to strengthen the relevant research of ink drying systems.In view of the above situation,the following research is carried out:The heat transfer phenomenon in the drying system of gravure printing machine was analyzed.The principle and model of heat transfer of hot air jet impact are mainly studied.The drying mechanism of solvent-based ink and water-based ink was compared,the drying law of ink was revealed,and the energy demand model of drying water-based ink was established.A single-nozzle jet impact water-based ink drying principle experiment was proposed.The proportion of solvent in water-based ink was determined and the uncertainty was calculated,The effects of different hot air velocity,temperature,nozzle shape and nozzle-to-substrate distance on the drying curve of water-based ink were studied,and it was concluded that the wind speed and wind temperature of jet impact were proportional to the drying rate within a certain range.The hot air flow state in the drying chamber model of the gravure printing machine was simulated and the hydrodynamic analysis was carried out.Based on the fluid dynamics simulation software FLUENT,the internal fluid of the drying oven was numerically simulated,and the velocity field,pressure field and temperature field in the fluid domain were obtained,which provided simulation data reference for the optimization and energy efficiency evaluation of the drying oven.The fluid parameter perception platform of ink drying oven of gravure printing equipment was constructed,including the design of the drying oven test bench,the research and development of fluid parameter sensing device and the fluid parameter sensing system based on Lab VIEW.Through the pitot tube,temperature sensor and data acquisition system,the real-time perception of parameters such as the temperature inside the drying chamber of the gravure printing machine and the wind speed at the nozzle is realized,The optimal design of the experimental device is proposed,and the experimental data reference is provided for the energy efficiency evaluation of the drying system.The theoretical analysis of heat transfer of the hot air jet impact principle in the drying system of gravure printing machine,the establishment of ink drying energy demand model,and the research and development of drying oven fluid parameter perception system and device will provide an important basis for the formulation of energy efficiency evaluation standards for ink drying devices in China.