4. Liquid inks for flexographic and gravure printing

For both these processes, a low-viscosity ink (approx. 10 to 100 mPa · s) with very rapid drying is required. Spontaneous or forced (by heating) evaporation of solvents or water is therefore the fastest and most economical drying method in this context. However, the use of solvents is not without risks: they are generally highly flammable and sometimes toxic, and are today subject to very strict legislation both during ink manufacture and during evaporation during printing. This is why environmental and health pressures have led to an increase in the use of water-based inks.

Water-based inks offer an attractive way of improving working conditions while reducing the costs associated with solvent treatment (extraction, recycling). They have been used for years in flexography and, to a lesser extent, in rotogravure. Initially, water-based inks were used to print absorbent...