The influence of oscillating climate conditions during the conventional drying of beech timber on drying time and drying quality has been analyzed. Three conventional drying cycles were carried out as well as nine cycles, in which the oscillations of equilibrium moisture content (EMC), temperature, and their combination were applied. The combinations of two amplitudes (10% or 20%) and two frequencies (3 or 6 h) were used in different test runs. Higher drying quality regarding casehardening was achieved both in runs with oscillations of EMC (gap values 2.2-2.4 mm) and in runs with temperature oscillations (gap values 2.3-2.4 mm) compared with conventional runs (gap values 2.5-2.9 mm). The oscillations of both temperature and EMC did not improve any of the observed parameters.

Some properties of plywood panels made from untreated and thermally modified (90 min. at 200 ºC) poplar veneers and their combinations have been analyzed. The change in equilibrium moisture content and the change in dimensions of the samples conditioned above water in closed containers were examined. The analysis using F-test (ANOVA) at the significance level of 95% confirmed that, regarding moisture content, all combinations of plywood panels differed significantly from the control panels. However, the analysis of thickness swelling showed that there was no significant difference among the plywood panels of similar construction. The highest values of anti-swelling efficiency were shown by plywood panels made from thermally modified veneers

Possibilities for use of thermally modified poplar veneer were evaluated for the production of plywood boards in industrial conditions. Formats of poplar veneer were treated at temperatures of 190 °C, 200 °C, 210 °C, and 215 °C for 1 h. By combining the treated and non-treated formats of veneer, thirteen different types of board were made. Analyses showed that the examined physical and mechanical properties were influenced by both the type of construction and the applied thermal treatment. Boards composed only of thermally modified veneer achieved the best results regarding moisture absorption and dimensional stability, and boards composed of the combined veneers had better mechanical properties. Treatments at 200 °C and 210 °C proved to be optimal, while the treatment at 215 °C was too harsh and should not be used for the thermal modification of poplar veneer.

Извод: Предмет овог рада је испитивање физичких и механичких својстава тополових LVL плоча споља додатно ојачаних буковим фурниром, као и испитивање чврстоће угаоних елемената везе за прозор израђених од овог материјала. Плоче су пресоване сувим врућим поступком у индустријским условима, а као везивно средство коришћен је FF фенол-формалдехидни лепак. Узорци за испитивање чврстоће угаоних спојева спајани су двоструким призматичним чепом и прорезом помоћу PVA-ц лепка класе D4. Статистичка анализа показала је да постоји значајна разлика у влажности и густини плоча по дебљинама док код тврдоће плоча значајност разлике не постоји. Резултати смицајне чврстоће у слоју лепка показали су да су и FF и PVA-ц D4 лепак испунили услове прописане стандардом. Подаци добијени испитивањем елемента везе за прозор показали су да спој двоструки чеп и прорез спојен помоћу PVA-ц лепка тип D4, у потпуности може применити у производњи и експлоатацији прозора појачане носивости.

The density, shrinkage and swelling of Paulownia elongata and P. fortuneii wood were researched. The study material was provided by Boda Vukovojac, B. Sc., who established the Paulownia plantation and sample plots on the territory of the Municipality Bela Crkva. The study results show the differences between the analyzed properties of these two species. The study results were also compared with the results of the similar species of wood. The data shows that the study wood can be used in wood products that are not subject to great loads during exploitation. Further study should investigate the liability of these wood species to form tension wood and deformations in the conditions of variable hygroscopic moisture