VOLUME 56, ISSUE 5/2015

Hydrophobizing is one way to protect wood from moisture and the growth of fungi and to improve its dimensional stability. Beside the various chemical and thermal treatments and the use of synthetic modification chemicals as paraffin waxes natural oils and waxes has coming up for some years again. While these build up strong networks on the surfaces, they leak out by and by from the interior of wood and this leads to staining and the growth of mould. An impregnation method for beech wood based on modified isomerized natural oil, added with different copper compounds and the evidence of a complete hardening in the inner layers of beech wood specimen by a microwave treatment and air storage is presented. As expected elutriation experiments according to DIN EN 84 (1997) showed a significant improved resistance against basidiomycetes and mouldiness rot fungi. In dependence of the degree of cross-linking of the oil the mass lost maximum was below 5 % even without copper, what would permit a use of the treated wood in hazard classes 3 and 4.

A drying concept for sawn wood by a continuous drying of the boards in a sequence of different drying technologies is introduced. The advantage of this concept is the application of different drying methods within a specific stage of the whole drying process. Thus a significant acceleration of the whole drying process can be expected compared to the conventional batch drying. Furthermore every single board can be moisture monitored and can be put backwards at a specific stage of the process in the case of lagging behind the drying schedule. A process model is introduced and the potential of improvements concerning a reduction of the drying time can be shown in a discrete simulation model.

The up-cycling of alleged residues from industrial production processes provides a sustainable way to raw material procurement. In this work high density fibreboards (HDF) were manufactured with different leather amounts by using spruce fibres, as well as vegetable and mineral tanned leather shavings (Wet White, Wet Blue). Subsequently, their mechanical and physical properties were analysed and compared with each other, as well as with those of wood fibreboards. To gain an insight into the mechanical properties of the panels and their internal bond (IB), flexural modulus (E) and bending strength were tested. The results for the urea formaldehyde-bonded HDF boards show enhancement of the transverse IB with increasing Wet Blue leather content, whereas the other mechanical properties decline meanwhile. The results of this study underline the usefulness of integrating leather shavings to HDF and give an overview of their influence in wood fibre materials.

This article aims to 1) present a method for using the expertise of participants of an academic or industry congress to draw conclusions on specific questions, e. g. the future development of an industrial sector and 2) analyse and summarize the results of a survey of the German wood-based panel industry experts conducted at the 9th Colloquium for Wood based Materials (December 2011). The results are discussed in the light of previous research on the future of the German forestry and timber sector as a whole. Most experts see energy-efficient products, product systems and sustainability in the building sector as most important. Manufacturing technology and formaldehyde based adhesive systems will not change dramatically. Direct surface printing, smaller batch sizes and vertical integration will gain importance as well as raw material efficiency. More use of hardwoods will reduce costs.

For colour comparisons of transparent coatings on wood in the laboratory a measurement method was developed. It is based on the production of mirror-like surfaces from thicker wooden boards and a positioned measurement with a double sided template. A validation of the method was performed with identical coatings on both board sides in various transparent shades and resulted in identical colour values. On other specimens different coating materials of the same colour shade in brush quality and as diluted concentrate were applied. On these specimens the low visually recognisable colour differences were quantified.

The suitability of the PET foil was demonstrated in terms of their mechanical properties for the folding operation. By using this foil, the process could be further developed to the extent that by milling both sides of thin wood-based panels a "reverse folding" (Oregami) is made possible, which allows new body shapes in addition to the known folding concepts. The foil demonstrated its suitability as a hinge in folding durability tests. The machined V-grooves must be protected against the penetration of moisture. For this purpose, either tapes or impregnation liquids can be used. Single-component reactive polyurethane densifying material has proven particularly suitable. This agent leads to slight dark staining of the V-groove, but does not damage the film and its bonding. Besides a web tool for the design of foldable shelves, a first samples series of a small corpus system was developed, tested and presented.

A cooperation between the University of Applied Sciences Salzburg, located in Kuchl, and the University of Salzburg is working on a fingerprint of digital log end images of cross sections of round wood. Thereby round wood should be able to be identified within the wood supply chain by means of two digital images, whereas the first image is taken in the forest after felling and the second is taken in sawmill. Very similar to a human fingerprint, the pith location and annual rings in the cross section of round wood should provide biometric features that can be used for traceability purposes. Recent results showed, that, first, tracking round wood by means of such biometric features is inherently possible, and, second, how such features can be extracted from digital images.