With Alussa, Agfa developed an inkjet system for decorating high-quality genuine leather as used by the fashion, upholstery and transport industries. We spoke to Dieter Jancart, Business Development Manager for Alussa at Agfa, about the specific challenges of the project and the benefits for users.

WHO SHOULD CONSIDER INVESTING IN AN ALUSSA LEATHER PRINTING SOLUTION?

Alussa sits on the intersection of the printing and the leather tanning industries. The main target market are tanneries, but Alussa can also be deployed by specialised print shops with an expertise in leather.

WHAT ARE SOME OF THE TYPICAL APPLICATIONS?

Alussa enables users to add vibrant and ultra-sharp graphics to high-quality genuine leathers – bovine leather as well as lamb or goat skin. It lets them create unique and durable digital prints on shoes, handbags, clothing, furniture and more and use any kind of graphical element, illustration or picture. Typically, end users are looking for leather with high durability. Alussa performs well in terms of flexibility and rub resistance, meeting the leather industries’ standards.

WHAT ARE THE ADVANTAGES OF PRINTING ON LEATHER WITH INKJET?

First of all, the typical advantages of inkjet printing: short start-up times and the possibility to produce both one-offs and large volume runs cost-efficiently, as well as customisation and personalisation.

What’s more, inkjet printing enables the tanning industry to vertically integrate the printing step in a relatively easy way. Installing a screen press would be a lot more challenging than adding an inkjet printer to their production process.

Another benefit, compared to for e.g. transfer printing, is that Alussa will make it possible to print on entire hides or sides, not just on rectangular transfers. This means that tanneries can reduce their leather waste up to 40% as they no longer need to throw away the non-decorated parts.

WHAT DEVELOPMENTS AND ADAPTATIONS WERE NEEDED TO CREATE A LEATHER PRINTING SOLUTION?

The first challenge was the chemical interaction of the ink with the different coating layers on the leather. The Alussa iUl 10 inks have been developed to suit the leather coatings and to reach high performance through optimized jetting behaviour.

Another challenge lay in the porosity and the fiber structure of the leather. The Alussa eTU 25 printer is based on Agfa’s award-winning Jeti Tauro LED large-format printer for sign & display applications. That means it offers great productivity for longer runs, up to 80m²/h. However, we needed to boost the vacuum system to keep the leather down on the table, which is why we added an extra felt belt that enhances the vacuum spread to the leather, resulting in a very good grip.

CAN ALUSSA PRINT DIRECTLY ON LEATHER?

The result after the wet and the drying stage of the tanning process is a so-called ‘crusted’ leather. It is still very absorbent and shows a lot of artefacts such as growth marks or insect bites. The tannery finishes this crust with different coating layers such as adhesive, filling, pigmented or PU layers. The chemical interaction between these layers and the ink layer lies at the core of the Alussa technology. That is why we always refer to it as a synergy between leather and ink.

IS THERE ANY TREATMENT NEEDED AFTER PRINTING?

The top or finishing coating depends on the final look and feel of the leather that the tanner wants to obtain. Typically, this coating is a water-based mix of polyurethanes with additives for a matt or gloss finish, depending on the application. The top coating for automotive leathers will be different than for shoes or bags, for example.

YOU TEAMED UP WITH TFL FOR THE TOP COATINGS. WHY?

At Agfa, we are well aware that the key to success is the perfect match between the different variables of the production process. During the development of the ink technology and the optimization of the printing equipment, we teamed up with speciality chemical producer TFL for its expertise in leather chemistry.

Every leather is different. Users can rely on the expertise of TFL to further fine-tune the coating chemistry to reach the correct formulation of adhesive layers, base coats, top coats and fixation in view of the end product.

Alussa Components

• Alussa iUL 10 UV full colour & white (CMYKlclm + W) inkjet ink set, specifically developed for genuine leather

• Alussa eTU25 UV inkjet printer uniquely adapted to leather with a productivity of 80 m²/h (colour only) or 40 m²/h (white + colour)

• Asanti workflow and colour management software, to streamline production and guarantee colour consistency

• Alussa coating formulation - TFL coatings to reach the highest performance up to 100K dry flexes

Installations

The first installation was at the French company La Maison Demeure, a creative studio specialized in leather digital printing based in Roubaix. La Maison Demeure is using Alussa to offer high-definition leather printing to the luxury fashion industry. 

Two other installations – one in the Netherlands and the other in Italy –  are scheduled for Q1 2021.

More information on www.agfa.com/alussa.