Ink formulation with the new Multi-Phase Ink Model

The multi phase ink setting mechanism gives new insight into lithographic sheet fed offset ink modifications. The ink setting in sheetfed offset is by absorption and oxidation and the inks have a relatively high tack. Because of the wide variations in sheet-fed offsetink formulations the ink to paper interactions are extreme.The problems related to ink setting is mainly set-off (slow setting), mottling (ink setting variations), ink tack build up and surfacestrength problems (fast setting) and other print quality defects that can be caused by paper variations, print variations, slow/fast inksetting, dusting, base paper and coating structure, etc.The trend for more porous coatings with better whiteness, printed colour gamut, and light scattering properties will require inkmodification to control the ink setting phenomena. It is assumed that by changing the resins, solvents etc. of the printing ink, it ispossible to adjust the ink setting in such way that the printing result is good for papers with different coating porosity volumes andporosity size distributions.