The targeted development of water-based binder systems and additives has produced impressive, high-performing water-based ink systems that deliver razor-sharp print quality. These ink systems underline the quality character of a packaging and are characterised by excellent values in terms of bond strength. They can be used without any problems on the flexographic printing presses currently on the market. These are several of the reasons to try new approaches, as one example of packaging in the premium coffee segment shows.
By Dieter Finna – Pack.Consult
Even though water-based ink systems are very similar in principle to solvent-based systems (SB inks), the water-based binder systems enable the use of a very high pigment content in the inks. This leads to high opacity and brilliance of the inks, which is reflected in print quality that meets the highest of demands.
High print quality
To demonstrate the current state of water- based ink systems, Follmann has worked with partners to create a coffee packaging that combines the highest print quality with outstanding packaging properties. It impressively demonstrates the performance of water-based systems in terms of print quality, adhesion properties in the laminate and high resistance on the packaging machines.
The high colour intensity of the water-based inks can be seen in the deep black on the front and back of the packaging as well as in the rich red of the side panels. It ensures that the colours are vibrant and vivid, which increases the visual appeal making the design appear professional and highly attractive. Fine details and sharp contours in the negative font are shown to their best advantage.
Printing halftones
Water-based inks can be used for all standard flexographic screen rulings up to 80 lines/cm as well as frequency-modulated screen technologies. Compared to SB inks, water-based inks have a lower dot gain in the halftones, the dots print sharper and more pointed. If you look at the highlight area in detail, it starts very far down with the reproduction of the smallest screen dots, which merge into smooth gradients.
Printing presses
Water-based ink systems can be processed on all modern flexographic printing presses, meaning that no special investments are required. This is an important point when it comes to testing the inks.
Water-based inks have about three times the drying coefficient of SB inks, which is due to the different evaporation rates of water and the alcohols used in SB inks. Modern presses are designed to work with a correspondingly large amount of air at approx. 60°C, whereby less recirculating air is used for water-based ink to absorb the moisture. This ensures that each individual colour is sufficiently dry before the next colour is applied. As they do not contain any rapidly evaporating solvents, water-based inks are generally characterised by a high level of consistency in printing.
The coffee packaging shown here was printed at Ekaflex in Malgesso (VA), Italy
With regard to the use of water-based inks in printing, it should be emphasised that there are generally fewer formal requirements for operators, which is an advantage since there is hardly any emission load from volatile organic compounds (VOCs). The water-based inks in the Follmann Folco® Aquaflex Premium L series are formulated to be completely VOC-free.
This means that no systems are required to clean the exhaust air.
Bond values and seal resistance
The continuous development of binder systems has led to excellent adhesion values for water-based inks on a variety of substrates. In combination with the necessary corona pre-treatment and common adhesive systems, water-based inks achieve high bonding values during lamination.
The fastness of the binder systems and pigments of the inks are completely colour-stable, even at high sealing temperatures, for example with coffee laminates. This prevents fading of the ink layers during the sealing process on the packaging machines. With these properties, water-based inks offer customised packaging solutions for packaging developers and brand owners, which are used in a wide range of application segments for food packaging, pet food, cosmetics and other products.
Tradition meets innovation
Water-based inks have a long tradition, but for much of that time they were inferior to solvent-based systems. Today, this situation has changed fundamentally. It is also time to clear up misunderstandings and prejudices, especially the false assumption that water-based inks require primers for good adhesion. The development of modern aqueous ink systems has produced solutions that are both environmentally friendly and offer excellent print quality.
In addition, modern water-based ink systems are characterised by high efficiency and, as the coffee packaging strikingly demonstrates, can be used on existing flexographic printing presses. Costly new purchases are not necessary. The coffee packaging also shows that if water-based inks can be used on this existing machine, other print shops will be able to use them too, opening up new opportunities for the industry. In this way, high-quality print solutions can be achieved and systems with smaller print runs can be operated in an environmentally friendly manner.
To be successful, it is important to first train the pressroom team in the use of water-based inks and to communicate the special features of the ink system in order to promote the necessary acceptance. In this way, the transition to production with water-based inks, which have the added benefit of lower regulatory requirements, will be successful.
The protagonists of this winning project
Ekaflex was founded in 2005 by Karim Nardin and Emiliano Besozzi in Malgesso (VA), Italy. Their goal was to build a company with a strong innovative character and a ‘green soul’. A few years later, Cristian Nardin and Marco Carrara joined the management team. Continuous innovation, the constant search for more efficient materials and investments in modern converting technologies have already earned Ekaflex numerous international awards. This includes the Best in Flexo Award Milan 2023 with the ‘Caffé in grani Lorenzo’ packaging.
Follmann GmbH & Co. KG was founded in 1977 as a family-run company. This supplier of speciality chemicals such as water-based printing inks, adhesives, coatings and encapsulation technologies is based in Minden, North Rhine-Westphalia. With a global presence through subsidiaries in England, Poland, China and the USA, the Follmann Chemie Group employs more than 900 people and generated a turnover of over 250 million euros in 2023.
