|
|
Vliv tepelné modifikace na vybrané vlastnosti dřeva plantážově pěstovaného topolu
Horníček, Stanislav
The thesis deals with analyses of thermal modification process and assessment of the possibilities of using plantation grown polar wood clone MAX-4 (Populus Nigra and Populus maximowitzii) with modified properties in wooden products. Part of present thesis is to provide general state of art about recently developed thermal modification processes, research dealing with plantation grown wood species cultivation and its material properties, i. e. fast growing poplar hybrids mainly. Furthermore, assessment of possible use of thermally modified material for wooden products based on experimental results of physical and mechanical properties. The aim of present thesis is to evaluate material properties of thermally modified fast growing poplar clone. Improvemetns within material properties of plantation grown poplar wood has a huge potential for future use of this low-cost, low durable and fast-grown wood and therefore increase its utilization within products made of wood.
|
|
|
Nerovnoměrná tepelná úprava dřeva - vlastnosti
Daněk, Václav
Present study analyses the impact of Cross – section uneven thermal modification of wood caused by hot press at 200 °C. The beech wood was examined at radial and tangential direction. The resulting samples were chemically analysed by spectrophotometry to determine the penetration depth of the thermal modification. Also, was examined dimensional stability during soaking at water for 15 days. In the first part is a review of literature on the description of the heat treatment and common using methods in practice. Further, the material properties of the beech wood and the possibilities of using this material were examined. Measured data were statistically analysed, the results were discussed and compared with the literature.
|
|
|
Vliv hydrotermické úpravy na vybrané vlastnosti lisovaného dřeva
Jacko, Ondřej
This bachelor thesis deals with the influence of hydrothermal treatment on selected properties of compressed wood of plantation poplar and larch. There were examined the properties of wood which was hydrothermally modified in a saturated steam environment at 90 ° C. Dimensional stability, density and bending strength were among the properties studied. Dimensional stability was investigated in 4th cycles of soaking in water and subsequent drying. The dimensional stability was guaranteed for compressed specimens that had been steamed for 10 days. By boiling wood in water in the 4th cycle it has been shown that larch is more dimensionally stable.
|
|
|
Vliv tepelné modifikace na vybrané vlastnosti dřeva plantážově pěstovaného topolu
Horníček, Stanislav
The thesis deals with analyses of thermal modification process and assessment of the possibilities of using plantation grown polar wood clone MAX-4 (Populus Nigra and Populus maximowitzii) with modified properties in wooden products. Part of present thesis is to provide general state of art about recently developed thermal modification processes, research dealing with plantation grown wood species cultivation and its material properties, i. e. fast growing poplar hybrids mainly. Furthermore, assessment of possible use of thermally modified material for wooden products based on experimental results of physical and mechanical properties. The aim of present thesis is to evaluate material properties of thermally modified fast growing poplar clone. Improvemetns within material properties of plantation grown poplar wood has a huge potential for future use of this low-cost, low durable and fast-grown wood and therefore increase its utilization within products made of wood.
|
|
|
Vliv tepelné modifikace na vybrané vlastnosti bukového dřeva tlakově impregnovaného přírodními oleji
Daněk, Václav
Present study aims to analyze thermal modification of beech wood (Fagus sylvatica L.) press-impregnated by natural oil and its influence on physical and mechanical properties of wood. Beech wood was press-impregnated by hemp oil (O 1000) and thermally modified at 200°C for 3 hours. Influence of certain treatment (i.e. oil impregnation, thermal modification, combination) was experimentally investigated using physical and mechanical tests. Color changes (CIELab system), dimensional stability and bending strength were experimentally measured and results compared with reference group. Results of given work was further discussed and compared with literature. Results shows increase of dimensional stability about 18% after thermal modification (TM) and 22% for oil impregnated and thermally modified wood (OL+TM). Mechanical performance (bending strength) decreased about 5,2% after thermal modification as a results of degradation of wood cell wall. On the other hand, strength increase about 9% for wood impregnated by oils. Combined processed provide results within similar range as reference. Results should be further discussed and parameters of process (temperature levels) as well as influence of various oils parameters (drying, semi-drying, nondrying) tested in future.
|
guest ::
