Water-based inks for non-absorbent printing materials

For many years, water-based printing inks have been the main ink for use on absorbable media such as paper, paperboard, and the like. Most water-based inks contain components of solvents (such as alcohol), and some applications (such as printing on napkins, gifts, and some decorative paper) require that the ink contain absolutely no solvent components, and that this water-based The application range of ink is more and more widely accepted by manufacturers. This is a brief introduction to the current status of water-based inks for polyethylene (PE) films.

The main differences between water-based inks using water as a solvent and conventional solvent-based inks are as follows: 1. When printing on film, since the film does not have the ability to absorb moisture, it is necessary to have a drying unit on the printer. Completely evaporating water, the energy required to evaporate water is much greater than the energy required to evaporate some solvents, such as ethanol. 2. The surface tension of water is much greater than the surface tension of PE film, so it is difficult to wet well on film without external interference.

Therefore, in the development of water-based inks for polyethylene (PE) film, some improvements have been made to the mechanical technology and ink formulation:
1. Increase the amount of toner to reduce the amount of ink transferred without affecting rheology;
2. Select some raw materials with specific standards, such as some materials with the following characteristics:
-Quick drying (moisture evaporation);
- Water resistance, chemical resistance;
- good printability;
- Good fixation.

3, reduce the surface tension of water and improve the wettability of water-based ink on PE film. On-line corona pretreatment and extrusion of the film are two good ways to optimize the wettability of water-based inks on PE film.

Conclusion: Practice in recent years has shown that using a water-based ink to print on PE tote bags and PE bags without using a coagulant can achieve good printing quality and good ink fixation.