Marc Graindourze discusses the benefits of aqueous inks for inkjet printing.

Water-based pigment inks for inkjet printing have gained traction as high-performing, environmentally friendly, safe, and cost-efficient inks. Agfa’s Marc Graindourze, Business Manager Industrial Inks, explains their use for industrial applications.

What is the potential for aqueous inkjet printing?

Agfa is known for its UV-curable inkjet inks for industrial applications, which are characterized by their excellent jetting reliability and the fact that they deliver durable prints (resistant to light, water, solvents, physical damaging). UV inkjet will stay the preferred printing technology for several applications for many years, but water-based inkjet is the challenger and will grow when it meets the requirements in terms of image quality, durability and cost. Aqueous ink technology has improved strongly in recent years and allows for consistent performance thanks to a well-aligned ink-print system approach.

What are the key benefits of aqueous ink technology?

Firstly, aqueous inks are versatile: they can deliver high-quality prints for a range of applications. This includes porous substrates, such as papers, corrugated boards, and cardboard. We opt for pigmented inks because they are more durable than dyes, offering better light- and water-fastness. They deliver a high color coverage, and they can be used to print great designs without surface relief, thanks to the thin dried layer.
Furthermore, aqueous ink formulations can be more easily designed in view of limiting safety risks for operators as well as end users, and for printing on food packaging (although carefully designed UV inkjet inks can also be used). In addition, prints with aqueous inks can potentially be recycled (to be proven by case-by-case studies).
Finally, aqueous inks use a carrier comprising water and organic co-solvents, which are low-cost compounds. Depending on the other ink compounds (pigment, dispersion agent, binder) and the ink amount needed, the aqueous ink can deliver attractive economic benefits.

How are aqueous pigment inks designed?

Formulating aqueous pigment inks requires tailoring the ink properties to the jetting process with piezo print heads, as well as controlling the drying of the ink; both are key elements for mastering image quality.
The jetting process requires low viscosity (about 2 to 10 mPa.s at jetting temperature, i.e. between room temperature and 35°C). This greatly limits the selection of ink compounds.
The combination of all ink compounds in the correct ratio results in ink formulations that produce sharp, high-quality images, tailor-made for specific applications. We take the entire print system into account during the ink development, and spend a lot of care on the very detailed study of jetting performance and long-term jetting reliability. Furthermore, the full production process (including pre- and post-processes) is considered during the entire ink design.
The addition of a binder can deliver an important contribution to the durability of the print, but its impact on jetting reliability needs to be limited. Many different binder chemistries can be used in water-based inkjet inks. At Agfa, we base our selection on the combination of adhesion to the substrate, durability of the print, and jetting performance. In some cases, no binder is needed.

Which aspects of ink design hold the key to a truly great ink?

Pigment dispersion is the key element. Agfa has a very long history in dispersion technology of pigments. We have tuned our technology specifically to inkjet printing, where a very narrow particle size distribution of pigment particles is crucial for all ink performance aspects. The Agfa technology results in aqueous inks with a wide color gamut, excellent jetting reliability and a long shelf life.


What types of industries could benefit from aqueous inkjet printing?

One of the industries currently exploring inkjet printing solutions is the laminate flooring and furniture market. A second industry is the packaging industry, especially corrugated packaging. In both cases the nature of the substrate is most suited to be printed on with aqueous inks, but the ink formulation is a key element in the design of the complete inkjet printing system. The combination of water-based pigment inkjet ink sets with a primer needs to be considered, depending on the image quality target.
What are the main advantages for the laminate flooring and furniture market? Typically, décor laminates are printed using rotary gravure, with spot colors mixed prior to printing, to create a natural wood-effect design. The inks are printed onto décor paper and then laminated to a base layer, usually by impregnating a melamine resin under high temperature and pressure. Adopting digital printing enables customers to introduce new designs more quickly, increase productivity, and reduce printing and storage costs – especially for short runs. They can print more colorful designs, and decrease product and cylinder stocks.

How can the packaging industry benefit?

Traditionally, corrugated packaging is printed using analog flexographic or offset printing technology. However, smaller runs, just-in-time printing and e-commerce are driving demand for digital printing directly onto corrugated packaging. The result is an ever-increasing number of print systems for corrugated boards on the market. Agfa’s water-based corrugated ink technology takes the complete board production process into consideration: printing on liner or primed liner, covering printed images with overprint varnishes, and even folding the board to the right shape.

What difference do aqueous pigment inkjet inks make for everyday business users?

In today’s fast-paced business environments, the demand for high-speed document printing, for example for direct mail, and promotional and transactional purposes is ever-increasing. Agfa’s aqueous inks help meet these needs: variable data can be printed on demand, with changes in text, graphics, and images made from one printed piece to the next, without stopping or slowing the printing process.


Why choose Agfa’s aqueous inkjet inks?

• As experts in pigment dispersion, we focus on delivering outstanding color strength.
• Designed for batch-to-batch consistency, the inks produce consistent print results with little variation in performance, especially because of their excellent jetting reliability.
• The composition and pigment dispersion qualities yield inks with the greatest longevity, up to 24 months.
• We formulate and use the most appropriate binders to optimize print performance, with or without use of primers.
• The inks are ideal for use on porous substrates, and are also suited for coated papers and cardboards. In future, this will be extended to other types of substrates.

Thanks to Specialist Printing Worldwide for sharing this article which they originally published
https://www.specialistprinting.com/