Modelling and analysis of the infl uence of ink transfer coefficients in the circular and axial directions on the distribution of the ink micro-fl ows at the ink-printing system output

Abstract

The paper is devoted to solving the problem of the integral in fl uence research of the coe ffi cients of circular and axial ink distribution on the uniformity of the ink thickness on the imprint surface. A mathematical and structural model of the ink-printing system of a sequential-parallel structure has been developed to demonstrate the suggested approach. An appropriate simulator has been built based on these models in the Matlab-Simulink software package that allows one to reproduce the processes of ink distribution and transfer, taking into account the operation of all elements of the ink-printing system. The simulation has revealed that an increase in the axial movement of the grinding cylinder leads to a signi fi cant redistribution of the ink fl ows at the output of the ink-printing system in the transverse direction of imprints. But there is no direct proportional relationship between the axial movement of the grinding cylinder and the zonal ink distribution. It has been found that increasing the value of the ink transfer coe ffi cient in the axial direction adversely a ff ects the uniform ink thickness on the imprint surface along the printing direction. It has been established that the change of the ink transfer coe ffi cients between the elements of the ink-printing system in the circular direction under the action of the grinding cylinder has a signi fi cant impact on the redistribution of the ink fl ows not only in the circular direction but also in the transverse direction, i.e. along the forming rollers and cylinders, and at the output of the ink-printing system. Thus, an increase in the ink transfer coe ffi cients in the circular direction signi fi cantly increases the uneven ink thickness along the width of the imprints. The results con fi rm the close relationship between the ink transfer coe ffi cients in the circular and axial directions and their e ff ect on the uniformity of the ink thickness on the imprint surface, which substantiates the need to ensure the stability of these coe ffi cients throughout the printing process.