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This study focused on the impact of the wood sawing pattern on 50 mm thick beech timber, followed by cross-cutting on the 3 m long, 50 x 50 mm beech blanks. The study analyzed two methods of cutting patterns of beech blanks (parallel to the surface of the timber and parallel to the grain fiber of the timber) regarding yield values and the size of longitudinal warping after air-drying. The yield values were higher (from 65.14 to 72.70 %) when producing long beech blanks using the method of sawing parallel to the timber's axis (B) compared to parallel to the edge of the blank (from 60.38 to 68.40 %). Results showed that a crucial factor for choosing the cutting method (A or B) is the taper of the logs. For blanks with a taper ≥ 1.3 cm.m-1, it is more advantageous in terms of longitudinal warping and yield to use the method of sawing parallel to the timber's axis. [ABSTRACT FROM AUTHOR]

The cost of raw materials has a major role in the wood industry. From this point of view, it is necessary to pay attention to the correct log-sawing pattern, which will optimize the sawing process and increase the quantity and quality of the material as well. For measurements, we used beech wood (Fagus sylvatica L.). Beech wood (Fagus sylvatica L.) is the most common wood species in the Slovak Republic; the total amount in forests is 34.8%. Beech wood has a high frequency of defects, such as red false heartwood, reaction wood (i.e., tension wood), dote, cracks, and so on. This research aimed to analyze the effect of the log-sawing patterns of through-and-through sawing, cant sawing, and quarter sawing on the resulting quantitative–qualitative yields of beech timber. The results showed that the highest quantitative yield was observed with the cant sawing pattern, at 84%, which was, on average, 17.3% higher compared to other types of cutting. It was found that quarter sawing resulted in a higher qualitative yield compared to through-and-through sawing or cant sawing (V5 = 62.69% and V6 = 47.86%). [ABSTRACT FROM AUTHOR]

The results of experimental research on the colour changes of beech wood at different depths of the tested layer are presented. Beech wood (Fagus sylvatica L.) dried in a conventional kiln was tested. Half of the wood samples were steamed prior to the drying process. Colour changes were measured at various depths after the face milling process was used to remove the material to expose to the deeper surface. The colour changes were measured based on the three-axis CIELAB system, recommended by CIE (Comission Internationale de l'Eclairage) and according to ISO 11664-2 and ISO 11664-4 standards. As a result of the analysis, four parameters were determined: the colour changes ( Δ E), the colour chroma (Cab), the hue angle (h) and the colour saturation (Sab). The performed experimental research revealed that the surface of steamed wood is more susceptible to colour change. A significant colour change in both steamed and dried wood occurs only up to a depth of about 2 mm. [ABSTRACT FROM AUTHOR]

The mechanical properties of wood have remarkable influence on its use in buildings. The improvement of the mechanical properties enables the reduction in the cross-sections of structural elements, particularly the increase in their load. The paper deals with the change in the mechanical properties of beech wood through the process of contact drying. Plate pressures of 1.0, 1.4, and 1.6 MPa at a temperature of 160 °C were used. It was found that contact drying increased the bending strength by more than 30% compared to convection drying. The value of Brinell's hardness measured on the surface of the samples increased by 80 to 98% after contact drying, and the measured values of impact toughness were higher, about 31.1% compared to the samples dried by the convection drying method. As a result of contact drying, the density in the absolutely dry state increased for radial samples by 102.3 kg·m−3 and for tangential samples by 83.1 kg·m−3. The pressure of the plates also had an effect on the change in density. [ABSTRACT FROM AUTHOR]

The bark as a product of the dividing of wood and cork cambium consists of a set of protective layers of cells, which protect the living tissue (cambium) from the external environment and separate the bark from the wood. The structure of bark as a component of a living tree is completely different from wood. This article describes the testing of the adhesion of wood/bark in the longitudinal and tangential anatomical direction during the dormant and growing season on three choice wood species (oak, beech, and spruce). The results show a remarkable influence of the wood species and anatomical direction, as well as period of vegetation (dormant or growing season). All wood species had higher values of shear strength in the longitudinal direction compared to the tangential direction. The highest average values in the longitudinal direction were measured in the dormant period for sessile oak (0.49 MPa) and beech (0.48 MPa). The lowest value of shear strength in the longitudinal direction was measured for spruce (0.36 MPa). During the growing season, the highest average shear strength values were also measured in the longitudinal direction at beech (0.46 MPa) and oak (0.39 MPa). The lowest value of shear strength in the longitudinal direction was measured similarly for spruce (0.26 MPa). [ABSTRACT FROM AUTHOR]

Beech wood has a high frequency of defects such as red heartwood, reaction wood (tension wood). For the experimental measurements four logs without visible defects like red heartwood, which can noticeably affects the measurements' results were qualified. The drying medium temperature in the first phase of the process before the moisture content of the specimens fell below the FSP was maintained at 45 °C. Then, the temperature was gradually increased to the maximum value 65 °C. The results showed that different initial wood moisture content does not affect to final value of tension and normal wood. The colorimetric parameter L* was much higher for tension wood. After steaming, there were greater differences in the colorimetric parameters, respectively, a* and b*. After drying the difference of all colorimetric parameters between tension and normal wood was significantly less. The color changes were only noticed in the surface layers of specimens. Differences were small, and thus, the impact of the tension wood on the color changes was not confirmed. However, since the lightness of tension wood plays a key role for its visual detection, it may be adequate to only measure the lightness parameter (L*). [ABSTRACT FROM AUTHOR]

This study examined the changes in the properties of beech wood (Fagus sylvatica L.) after intense drying. Beech wood with false red heartwood was selected as the test specimen. The test samples had dimensions of 50 mm thickness, 180 mm width, and 350 mm length. The specimens were divided into two groups, false red heartwood and sapwood. These specimens were selected with different angles of the growth rings (radial and tangential). The results showed that samples with red heartwood, in comparison to samples with sapwood content, had a remarkable effect in covering. Observation of specimens with false red heartwood and sapwood before and after drying process revealed significant differences in color changes and measured values during the covering-slicing test, but not between samples with different growth ring angles. [ABSTRACT FROM AUTHOR]

The structure of a bark as a component of a living tree is completely different from wood. Different structures significantly influence the physical and mechanical properties of the bark. In the processing of logs, it is in most cases necessary to separate the bark from the wood. Problems can arise mainly in the pulp and paper industry. The research focused on the impact of storage conditions on shear strength, showing that the value of shear strength decreased remarkably due to the storage. A decrease in strength can mainly be explained by the changes in the moisture content of bark, remarkably affected by the surrounding environment (climate). The research showed that three months of storage seemed to be the most appropriate and effective period for removing the bark in the case of beech logs and that a storage time of up to five months was the best in the case of oak logs. [ABSTRACT FROM AUTHOR]

Beech wood is mainly used for furniture, plywood, decorative veneer manufacturing or packaging. Timber or lumber is traditionally dried in kilns by processes often taking several weeks. This research deals with more rapid process called contact-drying process. Drying was performed using the heating plates with a temperature of 160 °C and pressures of 1.0 MPa, 1.4 MPa and 1.8 MPa. The results were compared to conventional warm-air drying. The warm-air drying mode was divided into two phases, with and without free water and bound water in the dried wood. The density of the samples increased remarkably during the contact-drying. The effect of the pressure of the heating plates was substantial. The difference in the average density between the pressure of 1.0 MPa and 1.8 MPa was more than 22 kg·m−3. The pressure of the heating plates affected the process and the resulting change in the sample thickness. The change in the sample thickness was more considerable in the case of the tangential samples. The thickness did not increase significantly after air conditioning. During contact-drying, the hygroscopicity and absorptivity of wood reduced on average by 21.24% and 25%, respectively, compared to warm-air drying. [ABSTRACT FROM AUTHOR]