During the last 20 years we have been conducting research regarding the print performance of different printing-and packaging papers for a wide range of printing technologies: Ink jet-, Offset-, Flexo-, Laser- and rotogravure printing. Please refer to the Finished Projects section on our homepage.
Our research in print performance comprises two fields of work:
Currently we have a project on inkjet printing and paper curl within the CD Laboratory for Fiber Swelling and Paper Performance.
Paper strength is governed by the strength of the individual pulp fibers and by the fiber-fiber bonding strength. In a string of several already finished research projects we have been investigating fiber-fiber bonding, fiber strength, paper chemistry and process conditions in order to improve paper strength.
Understanding and modelling the mechanical behaviour of paper mechanics is a key factor in improving its performance in during printing and coverting. In this field of research we have been working on models and analytical techniques to solve problems during printing (paper curl, dimensional stability) and converting (creasing, folding).
Both topics are also addressed in the CD Laboratory for Fiber Swelling and Paper Performance.
Pulp fibre characterisation has been in the focus of research activities at the institute for paper, pulp and fibre technology for about 20 years now. Several projects deal and dealt with different aspects of fibre characterisation (see also ´finished projects´). Part of the activities was on morphological characterisation of pulp fibres in flow cell devices (prototypes built for the given tasks) to evaluate standard morphological parameters but also fibre wall damage and fibre flexibility. Other activities are focused on fibre characterisation in the final sheet based on microtome cross sections to evaluate fibre collapse, fibre wall cross sectional morphology and network properties. A strong focus in recent years (project FLIPPR) lies on characterisation of the fines fraction of industrial pulp samples being it primary or secondary fines. Size distribution, fibrillar content, surface properties, chemical composition and swelling behavior are evaluated. But not only single fibre/particle properties are evaluated but also suspension rheology and flocculation behavior.
Fundamental aspects and application oriented research in the field of biobased materials are in the focus of this research area. Topics of interest comprise fundamental underlying aspects in the course of cellulose processing as well as the interaction of lignocellulosic substrates with other materials. In more applied studies we aim at exploiting this basic knowledge to create advanced materials potentially applicable in sensor design, electrochemical storage systems or smart devices. For both approaches, state of the art analytical techniques are employed comprising surface plasmon resonance spectroscopy, atomic force microscopy, as well as high end scattering techniques (SAXS, WAXS, XRR).
One research focus when it comes to the industrial process lies on the interrelation of retention, dewatering and formation. A lab scale device resembling a fourdrinier former allows simultaneous measurement of these three strongly interrelated parameters under industry oriented conditions with or without dosage of retention aids (single and double component systems) and variable shear forces affecting the additives in the approach flow. This setup allows pre-trials for process optimization in this field with reasonable effort to reduce the number and costs of industrial scale trials.
Another field of work is the is analysis and simulation of the production process. Here we have worked out analytical techniques and process simulation tools for reducing the energy consumption in different stages of the papermaking process.