Natural materials technologies

Conceptual wood technology

The timber industry is generally characterized by a high awareness of tradition. Woodworking enterprises mainly manufacture mass products. The long depreciation periods of the manufacturing facilities determine the technologies for many decades. These technologies are therefore not critically questioned in terms of their economic viability and their effectiveness. The various production methods are integrated in their given form in research and teaching, whereby paradigms are created. Thus innovations in this area are mainly reduced to incremental improvements of these processes. However, we see the role of a technology institute in analyzing and critically questioning existing technologies. Therefore, we see it as a central task of conceptual wood technology to examine existing technologies and value chains in terms of their deficiencies and limitations, and, if necessary, to propose new solutions. For this purpose an analytical process with three stages is proposed. In stage 1 (=analysis stage) limitations and deficiencies of process steps, properties of semi-finished products and products are levied. In stage 2 (=estimation of potential) a comparison between the theoretically possible improvement potential and the state of the art is put on an abstract level. In stage 3 (=conception stage) completely new alternative production methods are considered aside from existing processes and technologies. Thereby, individual process steps or entire production chains are critically questioned and if necessary replaced by new ones. Currently there may not be any technical solutions for individual new process steps. The necessary need for research and development is therefore set by the conception stage.

Contact: Univ.Prof. Alfred Teischinger Further information: www.map.boku.ac.at/en/holztechnologie/

Historical wood utilization

Wood was and is still one of the most important raw materials - since 400.000 years, which is the oldest evidence of the utilization of wood as weapon and fire wood. One focus is “historical wood utilization”. At six different museums in Austria, 49 different domestic wood species were determined. Beside the main wood species like spruce, beech, oak and ash, many shrub- and small tree species were in use. These nowadays no longer used species have often very special characteristics, like a wood density of about 1000 kg/m³. The second focus “dendrochronology” deals with tree rings. The goal is on the one hand to date wooden objects with yearly precision. And on the other hand, climate-growth-relationships are analyzed. These analyses allow reconstructions of past climate.  Contact: Dr. Michael Grabner Further information: www.map.boku.ac.at/en/holztechnologie/

Wood modification and drying

Drying is an essential step in the whole wood production chain and precondition for further processing. Complex heat and mass transfer phenomena of any hydro-thermal treatment influence important quality properties such as wood colour and mechanical properties. This is especially true for thermal modification, where the composition of the cell wall material and its physical properties are modified by the exposure of higher temperature and conditions of reduced oxygen availability. The wood is altered in such way that at least some of the wood properties are permanently affected through the cross section of the timber. This can also be realized by means of chemical modification methods where a derivatisation of OH-groups takes place. General main targets of wood modification are: increased durability, decreased swelling and shrinking, hydrophobizing, wood colour, improved mechanical properties, resistance against weathering. Together with our scientific and industrial partners we investigate basic principles of wood drying and modification, and we develop and optimize new and established drying and modification processes. Contact: Dr. Christian Hansmann Further information: www.map.boku.ac.at/en/holztechnologie/

Engineered Wood Products (EWPs)

Engineered Wood Products gain importance beside classical wood based products. This group contains mainly materials used for constructive purposes and furthermore, materials exhibiting special property combinations such as high stiffness combined with low density as used in vehicle construction or for furniture applications.By coordinating the use and interplay of (wood) disintegration technologies, adhesion, material composition and engineering, EWPs are able to meet specific desired product properties. As a current challenge we see the efficient transfer of the physical properties from the raw material – which was already optimized by nature – to the generated product. Using state of the art material science approaches improved predictability and more reliable products in operation are intended. Contact: Ass.Prof. Johannes Konnerth Further information: www.map.boku.ac.at/en/holztechnologie/

Adhesion and adhesives

Adhesive bonding is regarded as the main connection technique for wood based products. By adhesion and cohesion the binder provides the wood composite mechanical strength. Just by introducing adhesive bonding, modern wood technology was able to use much more of the raw material wood than just simple sawn timber and beams. Thus, adhesive bonding is regarded as key-technology for the production of modern wood based composites and engineered wood products. The main topics of our research are on wettability, adhesion, interaction of adhesive and wood (chemical/physical, interface aspects, structure and morphology), mechanical performance and physical influencing factors such as time, temperature and humidity; adhesive distribution in wood products, emission, costs and technological aspects (handling, reactivity).  Contact: Dr. Erik Van Herwijnen Further information: www.map.boku.ac.at/en/holztechnologie/

Bio-based fibre materials

Cellulose fibres such as flax and hemp are of interest for the reinforcement of polymers, because of their low weight compared to glass fibre, which in turn allows the manufacture of light-weight composites with at least partly bio-based character. The discovery of microfibrillated cellulose has generated renewed interest and innovations in cellulose fibre-reinforced composites. For the first time, microfibrillated cellulose presents itself as a viable bio-based high-performance alternative to conventional fully fossil-based technical composites. The production of natural fibres and microfibrillated cellulose as well as their polymer composites are being studied together with structure-property relationships of the innovative materials. The research area bio-based fibre materials cooperates intensely with chemistry and natural materials technology. Partners from industry can be found in the wood and pulp/paper industries as well as in the agricultural sector.

Contact: Univ.Prof. Wolfgang Gindl-Altmutter

Further information: www.map.boku.ac.at/en/holztechnologie/