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VOLUME 49, ISSUE 1/2008

Production of lignocellulosic briquettes by the use of natural bonding agents

Language: German
Pages: 5 - 9
Authors: Georg Vetter, Christian Schöpper, Alireza Kharazipour

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Renewable energies can be produced based on of briquettes under utilisation of by-products from agriculture and grain processing plants. These materials may help satisfy the increasing demand of renewable energies. Due to their structure, many of these by-products require a binder for briquetting. For these studies wheat bran, rye flour, straw and particles of grand fir have been briquetted in addition of lignin, protein and starch as natural binders. Determined parameters for the quality of the briquettes were the density, the internal bond strength, the transportability and the heating value. It was observed, that lignin and protein are suitable bonding agents for this process, whereas starch is not suited. The heating value was not influenced by the different Kinds of bonding agents.

Examinations to the influence of wood moisture on chosen wood properties of spruce, oak and beech

Language: German
Pages: 10 - 15
Authors: Norbert Horvath, Sandor Molnar, Peter Niemz

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Sound velocity in radial, tangential and longitudinal direction had been measured on samples of spruce, beech and oak after acclimation in different air moistures. Additionally shearing strength in LR, LT, RL and TL-plane had been determinate. Sound velocity depends strongly on wood species, it is highest in longitudinal direction, in radial direction higher than in tangential. Sound velocity decreases with increasing wood moisture. Shearing strength is clearly higher in longitudinal direction than vertical to it. Shearing strength decrease, when increased the EMC.

Cost savings in the wood industry by logistics optimization, process analysis and knowledge management Part 2: Process analysis and knowledge management

Language: German
Pages: 16 - 21
Authors: Andreas Kandelbauer, Manfred Gronalt, Herfried Lammer, Arnulf Penker, Günter Wuzella

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Consuming large amounts of raw materials and energy, the wood based industry depends on “High Tech” manufacturing processes with expensive production machinery for manufacturing low added value products. For being profitable on a long term perspective, overall cost minimization is vital. Aiming at comprehensive improvement, successful optimization strategies cover economic-logistic, industrialtechnological and strategic aspects. While in part 1, tools in logistics optimization were discussed, part 2 highlights the application of process analysis and knowledge management

based on recently finished industrial projects of the Wood Carinthian Competence centre (W3C) and closes with a short discussion of potential synergetic effects.

Wood age determinations on the basis of x-raydensitometrical wood density characteristics Part 3: Application of multivariate cross-dating to small historical timbers from the Cathedral and the Albrechtsburg Meißen

Language: German
Pages: 22 - 27
Authors: Jürgen König, Björn Günther, Claus-Thomas Bues

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Different results occur during the dating procedure of wood samples with less than 50 tree-rings by the application of the conventional (univariate) or the multivariate method. Generally by application of the multivariate method on the Basis of x-ray densitometrical tree-ring features correct Dating solutions can be found, like two examples from the dendrochronological practice demonstrate? 1. Example: During the restoration work in the Prince Chapel of the Cathedral Meißen dendrochronological investigations on two boards under the terracotta figures St. Mauritius and St. Viktor were accomplished. These boards were firmly connected with the figures. It was assumed that the installation of the boards took place at the same time with the terracotta figures into the Prince Chapel of the Cathedral. On the basis of the tree-ring structures it should be proven whether the both figures are the biggest monolithical terracotta figures from the Middle Ages. 2. Example: Dendrochronological investigations on ornaments in the roof structure of the west wing of the Albrechtsburg were necessary. In order to clarify whether these were inserted after the major fire from 1773 or originated from the establishment time of the Albrechtsburg (about 1489). Dating showed that the wooden ornaments came from the beginning of the 19th century. Therefore more mechanical and cheaper methods of reconstruction could be used.

Investigation on the influence of selected parameters on the production of cement bonded particleboards with the hot-press process Part 2: Influence of cement temperature and of cement additives

Language: German
Pages: 28 - 32
Authors: Holger Dube, Reinhard Scherfke

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The mechanical properties of cement-bonded particleboards, for which cement at ambient temperature (<30 'C) and heated cement of up to 80 'C, respectively, was employed for laboratory-production using the hot-press technology, could only marginally be elevated with the use of sodium water glass, which is normally used for the production of cementbonded particleboards using the cold-press technology.

Among the water soluble substances tested as accelerators, Substitute D achieved a prominent rank. It acted both as an inhibitor during and after mixing of the components and as an accelerator during hot-pressing (double function). Therefore it is possible to improve the mechanical Performance of cement-bonded particleboards on the one hand and on the other hand to compensate strength-losses during their production – especially at higher cement – or ambient temperatures, respectively. It can be assumed the use of Substitute D positively affects itself in place of lithium carbonate on the operating result with the production of cement chip boards. Further research is necessary to investigate to what extent Substitute D can be used with the cold-press technology.

The use of modified indigenous wood for windows and curtain wallings Part 2: Use of modified wood for innovative construction of windows and curtain wallings

Language: German
Pages: 33 - 38
Authors: Josef Schmid

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Inefficiencies of wooden windows and the improvement of properties of wood in its response to water and moisture by means of modification is being discussed in part 1. Part 2 focuses on the application of the respective findings. Should modified wood be used, any structures currently used for windows and curtain wallings must be adapted to the properties of modified wood. It has to be considered that the modification of wood changes its properties, such as fibre saturation, balance between relative humidity and equilibrium moisture content (EMC), as well as mechanical properties. This needs to be considered in the process of bonding of segments for profiles as used for windows and curtain wallings.

Settling behaviour of loose insulating material

Language: German
Pages: 39 - 45
Authors: Uwe Heisel, Johannes Tröger, Lucia Gross

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Renewable insulating materials have been gaining importance. Wood has a particular significance because of its regional availability and can be used without hesitation due to the ecological aspects. Since renewable insulating materials are processed either in the form of plates and mats or loosely, settling can be caused with loose insulating materials. In this article, the settling behaviour of loose insulation materials are examined, the testing methods to determine long-term loading of an insulating material are investigated and compared with standardized testing methods. Regularities were set to ensure set-safe installation densities. In addition, practicable possibilities are shown in order to prevent setting.

Improved test methodology regarding the electrostatic properties of laminate floor coverings

Language: German
Pages: 46 - 48
Authors: Helmut Bauch, Rico Emmler, Detlef Kleber

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The essential influence factors to the charge amount of floorings are the coating material, the surface resistance and the atmospheric humidity. Among the rigid floor elements, the DPL-Laminates (without antistatic modification) show the highest tendency to a high charging. Long-term screening tests on antistatic laminate floor coverings have shown that the antistatic additives partly show only a temporary effect and one has to face an increase of the chargeability of the floor in the course of its use. The rollapparatus Estameter whose friction wheel is covered various reference soling material is very well suitable for production accompanying control of the electrical properties of laminate floorings.

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