Impact of Ink/Paper Interactions on Printability of Aqueous Publication Gravure Inks - Part I. Dynamic Contact Angle and Paper Wetting

Dynamic behavior of a printing ink within the first 1,500 milliseconds of contact with the paper surface was examined. Waster based and solvent based inks, as well as their components, and a representative set of paper substrates were included in the study. Dynamic Surface Tension (DST), and chemical interactions between the ink and substrate, were found of unique importance with the water based system. Viscosity, surface tension and solvent penetration into the substrate, had about the same strong impact on the behavior of both solvent and water systems. The dynamic surface tension data alone were inadequate in explaining the ink/paper interactions which appeared to be a complex function of all the factors mentioned above. It was also confirmed that DST values would become relevant to a high speed printing process only if obtained under dynamic conditions respective to about 30 - 60 bubbles per second, whereas the DST data quoted most often in the literature relate to rates at 5 - 10 bubbles/sec.