VOLUME 58, ISSUE 4/2017

The Gülzow short rotation plantation with poplars and willows was established as a permanent field trial in 1993. Data from more than 21 years of management are available now. Biomass yields from seven harvests of the three-year rotation and three harvests of the six-year rotation were evaluated. This resulted in significant differences in yield depending on the species of tree, clone and rotation time. The evaluation method for the dry mass yields was converted to the quadratic regression in the course of the statistical evaluation, which has improved the meaningfulness and generalization possibilities. The yields of the poplars are clearly higher than those of the willows on the Gülzow site. In addition to the annual dry mass yield, additional features such as location, water supply and tolerance against thicksetting and diseases are important for selecting a clone.

This paper presents the results of oriented investigations to determine the raw density of bamboo on the basis of a method based on the principle of radiometric penetration. This method offers advantages over the gravimetric density determination, especially in the case of inhomogeneous materials and small sample dimensions, since it allows the determination of the raw density profiles over the cross-section. The determined raw density profiles of the internodes of the studied bamboo species clearly show the relationship between the increase of the vessel density and the increase of the raw density in the radial direction, thus confirming the results of other authors based on gravimetric methods.

In the first part of the study it was found that the use of polyurethane as a binder for wood-fibre insulation boards with a low density increases compressive stress and reduces flexibility as well as water absorption. The second part includes a potential assessment of the novel insulation material using the SWOT analysis. Product strategies derived from these results indicate a high developmental potential for these novel materials. This allows a wide range of applications, thus increasing the competitiveness of wood-fibre insulation boards compared to conventional insulation materials.

The project tested and characterized the glowing behaviour of wood fibre insulation boards by means of a testing apparatus developed at Fraunhofer Institute for Wood Research Wilhelm-Klauditz-Institut WKI. The in-house testing procedure allowed setting the glowing combustion acceleration as a characteristic value of flammable material. It was found that the characteristic value was influenced by a number of material parameters and boundary conditions. A small bulk density and a thin fibre size resulted in higher glowing combustion acceleration at the WKI testing facility, although, the impact of the bulk density was larger than that of the fibre size. In addition, for materials with low bulk density, an external airflow around the test specimen increased the glowing combustion acceleration significantly. In summary, all determined testing samples showed self-sustaining glowing combustion after overcoming the ignition energy and the process did not extinguished yielding residues of less than 5 % of initial mass in ambient conditions.

Non-film-forming treatments such as oxidatively curing oils, waxes, or combinations thereof, have a large share in both industrial as well as handcraft production of wooden floors. For those systems, no clear classification procedures are existent. Additionally, standardised testing methods and classification schemes are also missing. Some of the existing test methods such as scratch, abrasion or chemical resistance are not suitable for those systems. One aim of the research was therefore to provide a scientific basis for European normalisation of surface quality and to strengthen the position of European companies on the international market. This target was met by successful development of test methods for wet abrasion, on the chemical resistance and pollution resistance. All methods show a good correlation of the laboratory methods to the real-life behaviour, which was proven by three field tests on different locations. The reproducibility of the methods was confirmed in round robin tests.

Natural fibre products have always been used in the interior of a car. At the beginning when cars were produced there were no synthetic material on the market. The basic structure of the car corresponded to that of a carriage, but self-powered without horses. Only at the beginning of the 20th century did the design of the entire vehicle change. The interior also continued to evolve with new materials for seats, carriers and decors. The future of the interior components is determined by price, weight and worldwide availability.

Although organic aggregates like wood chips are rarely to be found as lightweight aggregate in concrete, in the last years several research papers treating wood-cement-mixtures have been released. However, basically material composites, for whom sawmill residue as organic aggregates for lightweight concrete has been used, must be distinguished from timber-concrete constructions. Actual approaches deal with exposed applications of wood lightweight concrete in the non load bearing areas of the interior construction and facade cladding.