This research was performed in order to determine how the heating process affects sorption properties and dimensional and shape stability of oak, lime and birch wood. By subjecting specimens to 3 hours heating at 130, 160, 190 and 220 ºC temperatures, a decrease in volume, density and mass was observed in proportion to the applied temperature. It was established that when oak wood specimens underwent heating at 220 ºC temperature, the decline of mass was 1.2 times higher than in the case of birch specimens. Both heated and unheated specimens underwent moistening in air at 25 ºC ±1 ºC temperature for 3 weeks with relative humidity being 85 % ±1 % and were soaked in water at room temperature for 4 hours. It was found that after applying high temperature heating, specimens absorbed smaller amounts of moisture. It was demonstrated that during the soaking process, the volume of unheated specimens was 3 times higher than in the case of specimens heated at 220 ºC temperature. The change in the volume of unheated oak was 1.27 times smaller than in the case of lime specimens and 1.16 times larger than in the case of birch specimens, which underwent heating at 220 ºC temperature. In addition, specimens that were exposed to heat had more stable measurements and shapes. It was noticed that the heating process caused significant changes in moisture and dimensional stability of specimens, when higher temperatures ranging from 190 ºC to 220 ºC were used.

In the present research the investigation of finishing wood particle boards is presented. The testing process of wood particle boards involved an original stand. The following three types of finished boards underwent evaluation: finished with veneer on both sides, finished with veneer on the one side and with compensatory paper on the other side, and finished with melamine impregnated paper on both sides. It was established that the first vibrational modes of finished wood particle boards in two perpendicular directions share similarity with modes of the beam-shaped body in terms of their shape. It was obtained that the modulus of elasticity of wood particle boards with different finishing differs by approximately 30 % – 70 % in two perpendicular directions. It was established that when dealing with boards finished with veneer on both sides, with veneer on the one side and compensatory paper on the other side, and with melamine impregnated paper, the value of the modulus of elasticity in two perpendicular directions differs by 1.71, 1.54 and 1.34 times, respectively. It was found that in the case of boards finished with veneer on both sides and with veneer on the one side and compensatory paper on the other side, the coefficient of damping change in two perpendicular directions is less than the one of the board finished with melamine impregnated paper by 25 %.

DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2436

The problem of textile waste is obvious and relevant, and detailed research into the problem is still lacking. In particular, there is a lack of research on the recycling and reuse of textile waste in such areas as the construction industry. The aim of this research is to develop an interior finishing panel by combining denim textile waste with an eco-friendly binder, to investigate, analyze and evaluate the main physical–mechanical properties of this panel. The investigated panels were made from denim textile waste with different structures for interior decoration. The results have shown that different manufacturing methods provide different sound insulation, and better sound insulation properties were distinguished by a panel made from fabric threads. When assessing the surface hardness of the panels, it was found that a panel made from threads has a higher hardness than a panel made from fabric scraps. Thus, evaluating the results of the performed research, it can be seen that the use of textile waste in acoustic panels is possible, with textile waste as the main component. Scanning electron microscopy analysis confirmed that the strength properties of the panel are closely related to the technology and structure of the panel, and that panels made from scraps have poorer strength and acoustic properties than panels made from threads.

Timber and timber products are renewable materials that, due to their durability and strength properties, meet the requirements of the construction industry, are widely used in buildings. An analysis of the scientific literature has shown that there is a lack of detailed research that fully investigates the influence of the rate of increase of the moisture content of the timber on the mechanical and, especially, the strength properties of the LVL panels. Upon immersion into water of the bottom of the specimen, the water starts rising quite quickly at the edge of the specimen, and the first six hours are the most critical. The levels of water rise inside the LVL specimen were less significant than at the edges. It was found that water significantly affects the bending strength of the panels, which, when the strength of the wet panel compared to the strength of the dry panel, decreases to 45% after one soak cycle and almost to 52% after two soak cycles. The tensile strength of the wet specimens is ~40% less than that of the dry specimens. The strength of the panels that were dried back to their initial state was found to be sufficient again, different from the initial strength only within the error limits; the strength properties of the building structure will not be affected.

• This research paper examines the interdependence between wood sorption properties and its dimensions, species and drying temperature. The research was carried out on specimens of six species of wood (oak, ash, aspen, birch, spruce and pine)