Whether banknotes, bags or newspapers, paper is called upon to meet extensive requirements in terms of aesthetics, durability and printing properties. Printing paper should fulfill the highest standards with regard to its stability and strength, gloss, smoothness, whiteness and coloring. Packaging material means the paper may also have to be dense, water-resistant and air permeable, and not deform in an undesired manner. In order to increase the quality of the paper in line with expectations, researchers at the new Christian Doppler Laboratory in Graz will spend the next seven years closely investigating the physical principles underlying paper in connection with the absorption of moisture and drying processes.
“We want to understand, describe and ideally be able to simulate water absorption and mechanical processes down to the individual paper fibers”, stated Ulrich Hirn, Laboratory Manager. The paper technology of the Institute for Paper, Pulp and Fiber Technology at the University of Graz provided an example. “Swelling processes within the paper fibers are particularly relevant in modern high-speed inkjet printing presses. Less swelling means faster drying. At the same time fiber swelling has a positive impact on paper stability.”
The team in Graz is cooperating with its corporate partners Mondi Europe and Oce to record precise swelling processes with respect to moistening and the drying processes of the paper, and develop simulation models for printing press development.