Transfer Characterization of UV Flexo Inks

The aim of this study is to examine the transfer characteristics of free-radical UV flexographic inks on coated paperboard, with a special emphasis on the solid print ink lay. Printing tests were carried out in laboratory on two printing testers (IGT) : F1, specially dedicated to flexo inks and C1-5, usually dedicated to offset ink. UV Inks with different rheological properties were analyzed. Then corresponding tests were carried out on a flexographic press (narrow web). The results were analyzed by optical densitometry, gloss and surface energy measurements. The effect of the ink properties is studied. Finally, a first step towards modelling of ink transfer between plate and paper is proposed.