The experimental study included 180 samples of three kinds of wood: birch (Betula pendula Roth), European beech (Fagus sylvatica L.), and alder (Alnus glutinosa L.) originating from Slovakia). The elements designed to generate dust were prepared as blocks, with width w = 80 mm, length l = 600 mm, and thickness t = 40 mm, with an initial relative moisture content in the range of 54.7–58.2%. The moisture content of samples was measured by laboratory gravimetric method in accordance with standards EN 13183-1 [43 ] using a laboratory kiln MEMMERT UM110m, drying to constant non-changeable weight at temperature t = 103 ± 2 °C. From the difference in weights before drying (mw) and after drying (m0) we calculated the moisture content by Equation (1):
The moisture content of dried samples at moisture w = 12 ± 0.5% was performed by an electrical hygrometer FMD6, which gives a value of moisture in the depth of 2–3 mm below the surface of a sample.
For density measurements, the methodology was the same as the in previous case. The samples were first dried in a laboratory kiln MEMMERT UM110m, to constant non-changeable weight at temperature t = 103 ± 2 °C. After the samples dried out, they were placed in a glass exicator. After their cooling down to the temperature of the environment, density was measured on a digital density meter KIT 128 by RADWAG according to standards STN 49 0108 and internal methodology for measurement of density lower than φ ≤ 1000 kg·m−3 at Technical University in Zvolen. The methodology is based on Archimedes’ law, where the mass of the sample without moisture (m0) is weighted on air and in distilled water. The volume of the sample is measured from the mass balance of the samples from Equations (2) and (3):
The density of the sample is calculated from Equation (4):
The wood types tested were divided into four groups, each consisting of 45 samples. The control group remains unmodified (denoted as N). The second group was heat-treated with steaming mode I (T1), the third group was heat-treated with steaming mode II (T2), and the samples in the fourth group were heat-treated with the III steaming mode (T3).Table 1 summarizes the tested wood samples’ physical properties and thermal treatment variants.
The moisture content of dried samples at moisture w = 12 ± 0.5% was performed by an electrical hygrometer FMD6, which gives a value of moisture in the depth of 2–3 mm below the surface of a sample.
For density measurements, the methodology was the same as the in previous case. The samples were first dried in a laboratory kiln MEMMERT UM110m, to constant non-changeable weight at temperature t = 103 ± 2 °C. After the samples dried out, they were placed in a glass exicator. After their cooling down to the temperature of the environment, density was measured on a digital density meter KIT 128 by RADWAG according to standards STN 49 0108 and internal methodology for measurement of density lower than φ ≤ 1000 kg·m−3 at Technical University in Zvolen. The methodology is based on Archimedes’ law, where the mass of the sample without moisture (m0) is weighted on air and in distilled water. The volume of the sample is measured from the mass balance of the samples from Equations (2) and (3):
The density of the sample is calculated from Equation (4):
The wood types tested were divided into four groups, each consisting of 45 samples. The control group remains unmodified (denoted as N). The second group was heat-treated with steaming mode I (T1), the third group was heat-treated with steaming mode II (T2), and the samples in the fourth group were heat-treated with the III steaming mode (T3).
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