Solvent- or water-based inks – What’s best for sustainability in gravure package printing?
von Ansgar Wessendorf,
“In the 21st century, sustainability has become a key issue and the gravure printing industry faces the challenge of finding ecologically sound solutions. The issue of environmentally friendly inks is complex and there is no simple answer to this pressing problem. In this context, it is important to examine various technical solutions,” explained Henrik Hildebrand of German company Windmöller & Hölscher (W&H) during the recent ERA event “International Gravure Days”.
For an in-depth analysis of the CO2 footprint of solvent-based and water-based printing inks, W&H test printed a BOPP film with a six-colour motif with the respective ink systems using the gravure printing process. The run length was 18,000 metres and the production speed 300 m/min. For this, they used laser-engraved gravure cylinders for water-based inks and electromechanically engraved cylinders for solvent-based inks.
The results show that water-based inks had a clear advantage in terms of ink consumption compared to solvent-based inks with a 144 kg CO2 equivalent. On the other hand, solvent-based printing inks had an advantage in terms of energy consumption, which led to a reduction of 75 kg CO2 equivalent. Surprisingly, it turned out that the advantage of solvent-based inks increased significantly with higher printing speed. At speeds of 500 m/min and more, the advantage was over 90 kg CO2 equivalent. Henrik Hildebrand commented: “Our tests showed that water-based colours generally have a lower CO2 footprint. Nevertheless, it is to note that these results demand extreme caution, as even small deviations in adjustment or application can have a significant impact on the environmental footprint”.
Concluding his presentation, he summed up: “The key to a more sustainable gravure printing industry lies in a balanced approach. The search for environmentally friendly printing inks requires openness to different technical solutions and a willingness to challenge the status quo. Only through joint efforts and innovation the gravure industry may take the right path and create a more sustainable future.”