Ink development and transfer in printing
VTT’s key competence lies in analysing and understanding factors affecting ink transfer in printing processes, and in modifying materials suitable for printing.
New areas of application are opening up for a whole range of printing methods in addition to traditional graphical printing. Novel inks or fluids and substrates and the use of different process flows can cause unexpected complications in printing performance.
VTT has a long experience in graphical printing and surface modification research. This creates a strong base for studying material runnability, and interactions with other printing materials in the process, regardless of the application. Procedures that extend beyond standard methods, coupled with our top-class equipment and interdisciplinary approach, allow us to respond to the most difficult of research challenges.
Highly valued competence in printing materials and processes
Our expertise covers the entire printing process: web runnability in roll-to-roll production, ink requirements of different printing methods, particle dispersing, nip phenomena, ink substrate interactions, substrate modification, and effect of drying on ink layer and substrate.
The research approach can be theoretical – studying ink transfer, spreading and absorption to substrate through finite element method (FEM) modelling – or more practical, in the form of printing material characterisations or test printings, for example.
FE-modelling of offset printing blanket feeding in nip, strain distribution. Positive feeding on left, negative feeding on right.
Versatile research equipment and methods
We carry out test printings in laboratory scale with gravure, flexo, sreen, offset and ink-jet methods, and pilot scale (roll-to-roll) with gravure, flexo, screen and inkjet methods. We also study the printing of 3D surfaces using a system based on the integration of six-axis robot and inkjet printhead. Where necessary, we can integrate the inkjet printheads to practically any existing roll-to-roll process.
Our wide selection of standard devices is complemented by internally developed innovative laboratory and online instruments, such as devices to measure web runnability, online imaging systems for continuous process, and high-speed imaging through nip. We can characterise and modify the chemical and physical properties of substrates using different treatments, such as plasma or corona, or by applying a thin coating layer.
Photovisualisation of electric assisted ink lifting in gravure printing.