VOLUME 58, ISSUE 5/2017

Industry 4.0 is the vision of tomorrow's manufacturing where in intelligent factories, machines, raw materials, and products are connected by Cyber-Physical Systems and communicate within an “Internet of things" and cooperatively drive production. Products find their way independently through the production process which enables a highly flexible, individualized and resource-friendly mass production. Based on the general state of the art of industry 4.0, which is strongly related to the automotive industries and their supply chains, some perspectives of such intelligent manufacturing systems for the wood industries are reviewed and discussed.

Due to the natural behaviour of wood, the change in moisture content yields to not negligible changes in its shape. Classic timber and glued laminated timber indicates 20 to 30 times greater shrinkage and swelling behaviour in the transverse coordinate direction, due to its unidirectional internal structure. A homogenization of these properties in plane of timber products can be achieved by a defined layer-wise assembling of the products during the production. The degree of homogenization exhibits a clear dependence on the internal structure. For solid wood and cross-laminated timber with very different layup characteristics (ratio of longitudinal to transverse layers) it is of relevance to investigate the shrinking and swelling behaviour depending on its internal structure. Within the scope of this work, these effects were carried out based on a theoretical approximation solution and based on selected tests on glulam and cross-laminated timber.

Thermally modified timber (TMT) is well established with a continuous, albeit moderate, growth of production volume. Essential aspects within the competition with other materials are the energy consumption (production costs, ecological assessment) and the negative effects of the process (e. g. reduced strength). Both plant suppliers and TMT producers are engaged to reduce production costs and process-caused disadvantages of the product, respectively. Within a cooperation of a TMT producer and the Institut für Holztechnologie Dresden (IHD) in scope of a RTD project, both process and product properties were to be optimised.

In Sweden and other Scandinavian countries, wood waste materials are normally used for biofuel production or waste incineration. From environmental perspective, it is favourable to recy-cle wood material and use the concept of multiple sequential use than just burning it for short-term energy production. One of the objectives of this pre-study was to investigate the feasibility of wood waste material use as a resource for the production of environmentally friendly particleboards with low formaldehyde emissions. In this study, clean and unpainted wood waste material was used to produce three-layered particleboards bonded by three different types of binders: tannin-formaldehyde resin (TF resin), combination of tannin-formaldehyde resin and PMDI resin (TF-PMDI hybrid resin) and just PMDI resin. The particleboards were produced with a target density of 620 kg/m³. For each panel variant the mechanical and physical properties were analysed and in addition, the extractable formaldehyde content and formaldehyde release of the boards were characterized as well. The results point out that it is possible to manufacture particleboards based on recycled wood waste material and bonded by a binder combination of TF and PMDI resin (25 % : 75 %). Furthermore, the mechanical and physical properties as well as extractable formaldehyde content of particleboards achieve the requirements of European standard EN 312 (2010) for particleboards type P2. Specifically, particleboards bonded with TF-PMDI hybrid resin show competitive bonding properties compared to pure PMDI bonded particleboards and do also show superior properties in thickness swelling (2 h and 24 h), water absorption (2 h and 24 h), internal bond strength and extractable formaldehyde content.

For the production of pressure-resistant wood fibre insulation boards in the dry process, only polymer diphenylmethane diisocyanate (pMDI) is currently used as a binder system. A new technological process was developed, revealing that in laboratory scale aminoplast resins and near-natural binders are also suitable to be applied in the production of wood fibre insulation boards in dry process. The hot-air/hot-steam process operates according to the principle in which the fibre fleece is initially treated with hot air and then with hot steam. This leads to a heating of the fibre fleece of well above 100 °C and compared to the current industrial process to a significant improvement of the mechanical and physical properties.

The surface finishing of wood (oak, eucalyptus, meranti, pine, spruce, beech) in an injection pressure blasting cabinet was investigated using different blasting materials (acryl, urea, polyamide, polycarbonate, maize cob grist). The blasting results were evaluated by 3D surface inspection and contact angle measurements. For window and chair manufacturing the technological parameters had to be defined. In the result there occurred a reduction of the material peaks but a deepening of material valleys. The interaction of both processes caused local minima in terms of roughness averages able to regard as optimal operating conditions. But these conditions depend on wood species and blasting material. However the blasting process itself is adaptable on individual products alone by adjustment of the technological parameters without changing the blasting material. The contact angle measurement showed a better wetting on the blasted against the sanded surfaces.

For a reliable and convenient diagnostic of relevant wood-decay fungi, two DNA macroarray kits, WDF-1 and WDF-2 (WDF = wood-decay fungi), were developed within a cooperation between Mykolabor Dresden and Chipron GmbH. In the first part of this publication, an optimised, automated DNA extraction protocol for fungal DNA from different types of wood and building material samples was introduced. This second part describes the generation of the fungus-specific probes of DNA macroarrays and their validation with practical samples from routine fungi diagnostics of Mykolabor Dresden.

This article gives an insight on the current research project DauerBuche of the Spitzencluster BioEconomy with the aim of wood modification with phenol formaldehyde (PF) polymer for the increase of resistance against fungal decay caused by basidiomycetes. It was a vacuum and pressure process which was tested for beech sawn wood and rotary cut beech veneer. Thereby, different resins, which were chosen from a pre-test and optimized with the producers, were used in different concentrations. Later on 8-layer Laminated Veneer Lumber (LVL) with parallel grain was produced from the modified veneers and was tested in a durability test (EN 12038, 2002). It was shown that the durability was dramatically increased by this process combined with a relatively low input of PF resin. Furthermore, it emerged that swelling in orthogonal direction to the board was reduced but compression of the LVL was counterproductive.