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Gewählte Master / Diploma Thesis:

Franz Neumüller (2011): Untersuchung des Pressprogramms für Spanplatten aus alternativen Rohstoffen Grundlagen für zukünftige Optimierungsmaßnahmen.
Master / Diploma Thesis - Institut für Holzforschung (IHF), BOKU-Universität für Bodenkultur, pp 119. UB BOKU obvsg

Data Source: ZID Abstracts
Abstract:
This research examines the coherence between hot-pressing process and the mechanical and physical properties of particle boards made from different raw materials. Fracture properties as well as thickness swell and increase in board thickness after conditioning are analyzed in detail. By means of different examination methods an assessment is made. The examination uses 42 particle boards produced from three different raw materials in a laboratory scale. For the production of the particles a novel alternative chipping technology is applied and compared to conventional knife ring flaker. Spruce (Picea abies L. Karst) and poplar (Populus x euramericana cv. Pannonia) are used as raw material and particle moisture content is varied by 2 % and 5 %. Spruce, taken from industrial production process, is used as reference material and four year old poplar clones originates from an agricultural short rotation plantation. From the laboratory hot press a time-pressure curve is recorded. Force-displacement curves were gained for testing fracture energy of the specimen. In both cases a steep increase and an exponential decay of the pressure and force, respectively were observed. Data analysis uses integral method, calculation of slope intervals and one-phase exponential decay function for describing non-linear relations. Subsequent variance analysis is applied to test significance level on alpha=0.05. By using linear regression models it is attempted to predict fracture energy, increase in board thickness after conditioning and thickness swell with characteristic parameters of hot-pressing process. Raw materials of poplar show much higher thickness swell as well as increase in thickness caused by a higher densification at the surface layers. Further analyses of force-displacement curves e.g. peak force and slope at the different section of the curve provide more information about the raw material than simple calculation of the total fracture energy. Moisture content shows no significant influence during the examination. Results are not able to answer if effects are caused by alternative chipping method or affected by high particle geometry within the trail.

Beurteilende(r): Müller Ulrich
1.Mitwirkender: Weigl Martin

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