Study On Transfer Characteristics Of Flexographic Printing Ink

Flexographic printing is one of the manufacturing methods in the printing electronics industry.Accurate control of ink transfer quantity is the key and difficult point in the process of product consistency.Therefore,it is of great significance to study flexographic printing and determine the key technology of ink transfer and its influence law.In this paper,a two-dimensional flexographic printing model was established by using the computational fluid dynamics software COMSOL,and the VOF model was used to track the free interface to clarify the changes of ink transfer during flexographic printing.The model was verified by flexographic printing experiments,and the key technologies affecting the transfer of ink from flexographic printing and their influencing laws were studied.The specific research contents are as follows:(1)The micro unit model of ink transfer from anilox roller to plate roller was established,and the volume transfer equation of ink was defined based on momentum equation and continuity equation;(2)A two-dimensional flexographic simulation model was established,and the ink drawing phenomenon was found in the process of ink transfer.The ink is finally broken below the initial drawing point position;(3)Using the established model,the effects of printing speed,the shape of the mesh hole of the roller,the viscosity of the ink,and the initial contact state between the mesh hole and the plate on the ink transfer were numerically simulated.The results show that the ink transfer rate decreases with the increase of the speed from 5m/min to60m/min.Ink viscosity in the range of 800 mpa ?s to 1200 mpa ?s,ink transfer rate is negatively correlated;For the 600 LPI,800LPI,1000 LPI anilox roller used in the simulation,800 LPI anilox roller ink transfer rate is the highest;In the net hole and the initial position of the plate gap is small,the transfer rate of ink change little,in the range of more than 1?m,the transfer rate of ink significantly decreased;(4)Through the experimental analysis of factor speed,pressure,mesh hole shape on the impact of the transfer rate of ink,the results show that: the greater the speed,the lower the transfer rate of ink;The experimental machine pressure in the range of0.025 mm to 0.05 mm,ink transfer rate is high;Three specifications of the roller,800 LPI roller ink transfer rate is the highest.The experimental results are consistent with the simulation results,and the printing speed,the parameters of anilox roller,the pressure and the ink viscosity all have different effects on the ink transfer rate of flexographic printing.