Research Of Ink Transfer Characteristics In The Flexorgraphic Printing Process

In the printing process, ink must transmit, transport, then transfer to the surface of the Substrate. We maintain the ink during the transportation and transfer is always stability, uniform, modest. It is the guarantee to obtain the high quality of the print. Although the mechanism of the flexographic printing ink is very simple, the elasticity modulus is very small which is easy to deform and the dot gain is very high, so it is special important to choose the process condition for printing the high precision image. Therefore, we must solve other technical problems when we obtain the high accuracy flexographic print. The goal of the paper is building the predict model of plate deformation and flexographic print process through analyzing the deformation of flexographic plate during the printing process, then determining the key adjustment parameters of dot gain due to the plate deformation and enhancing the ink of the plate transfer properties.The key point of the paper has introduced the finite element analytic which solve the elasticity problems, and has analyzed the deformation of the flexographic plate as well as the dot gain problem due to the plate deformation, then has established the predict model of the flexographic printing process. At first, we determined the elasticity modulus and Poisson's ratio. We assume that the surface of flexographic plate is uniform and then analysis the deformation of plate by finite element method. We establish the analytic model of the plate deformation and calculate the stress, strain and offset of the plate nodes through Ansys finite element analysis software. Second, we study the viscoelasticity and relaxation properties of the photopolymer plates which effect the ink transformation. We establish the predict model of the flexographic printing process. We verify the predict model through the experiment. Finally we established the mathematical model of single dot, which detect the plate deformation and the image properties under the certain printing condition. We discuss the main parameters which affect the dot gain due to the plate deformation. Though a serial of flexographic printing experiment, we obtain the data of parameter and determine the different roll engagement and the screen which affect the dot gain, then make them quantization .It provides the reference solution of ink transfer problem during the flexographic printing process.