VOLUME 54, ISSUE 4/2013

For the decorative design of wooden materials, inkjet printing is gaining in importance. It allows the printing of single pieces or small series, without expensive equipment technical prerequisites artwork) must be created. To achieve a high quality direct printing, the wood material has to be prepared accordingly by means of grinding and priming. Also must be guaranteed that among the components of the composite wooden material – priming – ink – protective layer is a secure bond and the protective layer ensures the performance characteristics of each finished product. As part of a research project at the Institut für Holztechnologie Dresden (IHD) were examined relationships between material and device-specific influencing variables on the print quality, and tested ways of evaluation of inkjet printing.

In the present study, correlations between the dynamic and sound behaviour of bass guitar necks depending on the used wood species were investigated. The vibration behaviour was (objective characterization) examined using three manufacturing stages of the bass necks using the experimental modal analysis. To characterize the subjective sound of the respective total instrument listening tests were carried out. The results clearly show that the different dynamic behaviour of the respective wood species affects significantly the sound behaviour of the total instrument.

A new coating procedure using environmental friendly powder coating systems for wood based materials was developed in order to displace solvent lacquers. Based on the in-mould-coating (IMC) technique well established in the plastic industry, the powder coatings are applied onto a press tool. The final powder coated surface is achieved by a simultaneous melting and curing process in the press. The use of this technology allows the production of continuously produced, coloured wood based panels or wood-fibre based shell moulds (e. g. chair seat shells, back-rests, or WC seats). The suitability of this technique for wood fibre materials was demonstrated in pilot plant trials and by determination of the surface properties.

The investigations were performed on untreated and heat-treated laminated veneer lumber (LVL). The heat treatment (185 °C or 212 °C) of the veneers (poplar (Populus spp.), pine (Pinus sylvestris L.), beech (Fagus sylvatica L.), and oak (Quercus robur L.)), all of which are used for plywood manufacturing, was conducted prior to LVL manufacturing. For gluing; one 2K-PVA, one 1K-PU and one MF were used. The aim of this study was to analyse the influence of the thermal treatment and material combinations on the physical-mechanical properties of the laminated wood. It was found that for both types of wood (untreated and heat-treated), the heat treatment, as well as the adhesive had an impact on the studied properties. In relation to the reference samples (untreated material), the swelling behaviour was reduced by 21 % throughout heat treatment at 185 °C. At 212 °C heat treatment, the swelling behaviour was reduced to 40 %. The compressive strength reduced after heat treatment at 185 °C by 20 % and about 33 % at 212 °C, and the tensile shear strength by 8 % and 17 %, respectively. The reduction in bending strength was 8 % and 18 %, the decrease of the MOE in bending strength was 7 % and 12 %, and the resistance to axial screw withdrawal decreased by 12 % and 23 %, respectively.

Resistance drilling is used to inspect trees and timber since 1987. However, several application areas provide specific requirements referring precision, resolution, and technical application properties of the machine. Meanwhile, nearly ten different resistance drills are available. Because they differ strongly in many properties, it is very important to know and understand the major practical aspects of the applications as described in this paper to be able to select the appropriate drill version for a specific task. And the user has to understand that not every resistance drill is a real Resistograph®, because this internationally registered trademark is exclusively allowed to be used for labeling high-resolution precision drills providing a high linear correlation to wood density – the sole base for reliable profile interpretation.

The increasing importance of thermally modified wood products in recent years and the associated increase in the number of manufacturers and manufacturing processes requires regular internal and external quality control to protect the consumers and the industry against deficient products. A suitable mechanical test method is the High-Energy Multiple Impact (HEMI) Test and as optical test method showed the CIE Lab colour measurement good results concerning the quality determination of thermally modified timber (TMT). Both methods have in common a short testing time and a high prediction accuracy of the TMT quality.

Today the nano-technology belongs to the key technologies, on which the focus of promoting science and economy lies. Particularly innovative developments in virtually all areas of research are expected here. Ideas for the wood preservation part of the heritage preservation field were generated in collaboration with research centres already very early on (1996). Nano-scaled silica was to be used for wood preservation, wood modifiction, stabilisation and masking against leaking noxious substances. The sol-gel-technique could be used for this purpose. In the course of many years of work with various modified sols, research and experiences were collected on heritage buildings, which are discussed and presented. At the same time, these examples are to encourage a wider fundamental research in the context of relevant projects.

This report deals with a temporal quotation of those performances, which had been necessary to maintain a tradition of forest products research in Eberswalde grown up during a period of three decades. With regard to any investigations the above mentioned period of time could be filled generally, whilst in 1963 the academic teaching stopped.