Hubert Mitteramskogler is not an average businessman. In the past two decades, his hardwood sawmill has become the market leader in the segment of thermal wood based on innovation and determined efforts. Almost as a by-product, European standards were developed on this topic.
[2008-10-28] The high-temperature kiln does not look particularly exciting: a metal box as big as a booth in a car repair shop that is hollow inside and has black walls. It smells of a mixture of smoked meat and caramel. The smallest of the four chambers has room for ten cubic metres of wood and the biggest one for 36.
"There the hardwood is submitted to controlled heat treatment until it has the characteristics that we need," explains Hubert Mitteramskogler. Hardwood is input and wood having the quality of tropical wood is output. It is called "thermal wood" in the market and "thermal modified wood" in standardisation.
"When we started there were no standards and we simply had to try everything ourselves," says inventive Mr Mitteramskogler with pride. In August this year, the pre-standard ÖNORM CEN/TS 15679 on thermal wood was issued.
Its origins date back several years. At the end of the 1990s, Mr. Mitteramskogler discovered a long-forgotten technique through literature research. In 1924, coniferous wood was thermally treated in Canada: this raised the quality of wood by making it harder, more durable and more resistant to pests. Then, trials started in Upper Austria.
The very first steps: Experimenting and tinkering. In a do-it-yourself approach, Hubert Mitteramskogler and his team started with a high-temperature kiln from a glassworks in the year 2000. After the trial phase, the first industrial kiln was built two years later.
However, Mr. Mitteramskogler did not have to do everything single-handedly. For research and tests, he co-operated with research institutes near and far: His partners were and are EMPA - Swiss, ihd – Institut für Holztechnologie Dresden and universities in Liverpool, Madrid, Hamburg and Freiburg.
The products made by MIRAKO (Mitteramskogler) are now more than varied: splash-proof wooden flooring for bathrooms, pool decks, flooring for balconies, noise barriers and even musical instruments such as oboes and organ pipes. However, ingenious Mr. Mitteramskogler has even more new ideas: for example, a fully developed façade system made up of wooden cladding and support structure.
Standards are of special importance to him: "Similar products that do not live up to the high quality that we supply have appeared in the market. I see standards as a protection."
Oak, beech and ash are typical hardwood types whose quality is raised by the thermal treatment at MIRAKO’s plant. For instance, its durability significantly increases as measured in line with ÖNORM EN 351-2. It can achieve a quality class of 1 to (at worst) 3.
Moreover, the stability of the material considerably increases after it is submitted to temperatures of more than 160 °C. "The heat eliminates OH groups, the wood becomes drier and loses volume. In parallel, its structure changes so that water can hardly be introduced," explains Mr. Mitteramskogler.
The product holds another trump card: it is resistant to pests. Conventional wood is treated with lacquers and preservatives to prevent infestation by longhorn beetles, auger beetles and fungi.
Thermal wood can pass the tests without chemicals. As it is as compact as tropical wood, there is no room for wood-degrading fungi and bacteria. In addition, there is still another environmental aspect relevant for climate protection: Transport routes are short.
Mr. Mitteramskogler sees further potential for standardisation in the future. There is one special issue that is constantly on his mind: "Colour is clearly related to wood quality." In order to prepare the ground for standardising this relationship, sensors are mounted in the high-temperature kilns. Continuous monitoring permits the accurate production of specific wood grades.
It is still open when a standard on this topic will be drawn up. Mr. Mitteramskogler has invested much time and money in research and standardisation. What comes now after the period of sowing? — The harvest! Thermal wood products made in Gaflenz are in high demand from Scandinavia to Asia. The quality delivered in the market is guaranteed by standards.