scholarly journals Influence of Densification on Bending Strength of Laminated Beech Wood

BioResources ◽  
2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Milan Gaff ◽  
Miroslav Gašparík
Keyword(s):  
Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1102 ◽  
Author(s):  
Ladislav Reinprecht ◽  
Miroslav Repák

The European beech (Fagus sylvatica L.) wood was thermally modified in the presence of paraffin at the temperatures of 190 or 210 °C for 1, 2, 3 or 4 h. A significant increase in its resistance to the brown-rot fungus Poria placenta (by 71.4%–98.4%) and the white-rot fungus Trametes versicolor (by 50.1%–99.5%) was observed as a result of all modification modes. However, an increase in the resistance of beech wood surfaces to the mold Aspergillus niger was achieved only under more severe modification regimes taking 4 h at 190 or 210 °C. Water resistance of paraffin-thermally modified beech wood improved—soaking reduced by 30.2%–35.8% and volume swelling by 26.8%–62.9% after 336 h of exposure in water. On the contrary, its mechanical properties worsened—impact bending strength decreased by 17.8%–48.3% and Brinell hardness by 2.4%–63.9%.


2020 ◽  
Vol 71 (1) ◽  
pp. 47-53
Author(s):  
Yaghoob Azimi ◽  
Mohsen Bahmani ◽  
Hamid Reza Riyahi Bakhtyari ◽  
Ali Jafari

The aim of this study was to determine the destructive capabilities of the two white rot fungi Pleurotus cornucopiae (Pc) and P. eryngii (Pe) compared with the standard fungus Trametes versicolor (Tv) on beech wood samples after 60 days of incubation. Understanding of the white rot decay is important as it is necessary for the development of effective solutions for wood protection. Measurements of mass loss, chemical, mechanical properties and light microscopical investigations were conducted prior to and after incubation. Mass loss of samples was found to be 9-22 % depending on fungi species. Impact bending strength is not as sensitive as presumed in classical literature. Light microscopy analysis revealed that decay patterns were similar for both fungi. Wood cell wall thinning, fungal colonization hyphae were also the same for both fungi. Results indicated considerable wood attack by both Pleurotus species, Pc being more destructive than Pe.


2021 ◽  
Vol 42 (3) ◽  
Author(s):  
Tomislav Sedlar ◽  
Bogoslav Šefc ◽  
Srđan Stojnić ◽  
Tomislav Sinković

This study quantified the physical and mechanical properties of sycamore maple (Acer pseudoplatanus L.) as a basis for assessing wood quality. The physical properties of oven-dry density, density at 12% MC, green density, basic density, longitudinal, radial, tangential and volumetric shrinkages were tested and the mechanical properties of bending strength, modulus of elasticity at bending, compression strength parallel to grain and compression strength in radial and tangential direction as well as of Brinell hardness on the cross, radial, and tangential section were determined. Five sycamore maple trees from Medvednica region were selected for the purposes of this research. The results were compared with known literature data on sycamore maple wood, beech wood from the same sight, and beech wood from Gorski Kotar region. For a better understanding of sycamore maple physiology, as well as for assessing the quality of wood products, the distribution of wood properties within the tree radius, from pith to bark, was investigated. There was a general bell shaped distribution, in the radial direction, in wood density, and mechanical properties of sycamore maple wood. Shrinkages decreased from pith to bark, except for tangential shrinkage with bell shaped pattern. All investigated wood densities of sycamore maple from Medvednica were similar to the findings of studies known in literature, as well as shrinkages, except for the lower longitudinal shrinkage. Investigated mechanical properties of sycamore maple wood were similar to the findings of studies known in literature, except for the lower bending strength and modulus of elasticity (MOE). Investigated sycamore maple indicated better dimensional stability than beech wood from two locations in the region, although it did not match the beech wood regarding mechanical properties, especially wood hardness.


2004 ◽  
pp. 141-153
Author(s):  
Zdravko Popovic ◽  
Nebojsa Todorovic

The basic mechanical properties of beech wood in coppice forest, locality Bor-Boljevac, Management unit "Crni Vrh-Kupinovo" were studied: Bending strength, modulus of elasticity in bending and shock resistance. Eight trees were taken from two series covered by the scientific-production experiment in this management unit. The statistically processed results were presented for each tree. There is a very strong correlation of the general linear form y=ax+b between the study properties, except between density and shock resistance. Static bending strength decreases mildly with tree height. The analysis shows that the average values of the study properties of beech wood at this locality are approximately the same as the values at other localities in the former SFRY. The only deviation is shock resistance.


Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Isoko Takahashi ◽  
Takanori Sugimoto ◽  
Yasuo Takasu ◽  
Mariko Yamasaki ◽  
Yasutoshi Sasaki ◽  
...  

Abstract Thermoplastic molding has been prepared from beech wood flour steamed at 180°C or at higher temperatures without any additives. It exhibited a smooth and lustrous surface and had a high density of approximately 1.45 g cm-3. The internal structure of molding revealed that the flour particles were completely surrounded by black resin-like substance which was thermoplasticized by heat and pressure during the molding process. The chemical composition of the steamed flour and physical properties of molding were examined as a function of steaming temperature. Maximum bending strength and Young's modulus of molding reached 63 MPa and 11 GPa, respectively, at 180°C of steaming, which were much higher than those of a hardboard. The water absorption of the molding was 8% or less and decreased with the steaming temperature.


2019 ◽  
Vol 70 (2) ◽  
pp. 169-174
Author(s):  
Evren Osman Cakiroglu ◽  
Aydin Demir ◽  
Ismail Aydin

The aim of this study was to investigate the use of birch wood, one of the most important wood species used in the plywood industry, especially in Europe, the Nordic countries, Poland, Belarus and Russia as an alternative to beech wood. For this purpose, comparison was made of their economic and technological properties. In five-ply plywood manufacturing, beech (Fagus orientalis Lipsky) and birch (Betula pendula) veneer sheets were used with melamine urea formaldehyde (MUF) and urea formaldehyde (UF) resins. Some mechanical properties such as shear strength, bending strength and modulus of elasticity of plywood panels were conducted according to EN 314-1 and EN 310, respectively. Mean mechanical strength obtained for birch plywood panels was quite above the limit values specified in the related standards. When taking into consideration the annual increment of beech and birch trees in 1 ha and the time they need to reach suitable diameters for the manufacturing of rotary cut veneers, it was calculated that birch trees provide 2.46 times more physical harvesting than beech trees.


2012 ◽  
pp. 73-80
Author(s):  
Igor Dzincic ◽  
Tanja Palija ◽  
Dragan Pavlovic

Limited information is available on end gluing hardwoods in contrast to softwoods, which have been extensively investigated. The objective of this study was to examine the influence of bending patern on bending strength of finger jointed beech wood. In structural uses finger jointing is finally the major method to end joint timber for the production of glue-laminated elements. There are no bending strength experimental results for finger-jointed hardwoods for investigations conducted in Serbia. Two finger jointed profiles were studied in accordance with DIN68140. The finger joints were made by side and by face of beam. Length jointed samples were loaded at the side and in the face. The obtained results led to the conclusion that the direction of load, gluing surface and the position of joint influence on the strength of continued longitudinal beams.


2018 ◽  
Vol 15 (7) ◽  
pp. 481-489 ◽  
Author(s):  
Ayoub ESMAILPOUR ◽  
Mohammad Sadegh TAHER TOLOU DEL ◽  
Hamid Reza TAGHIYARI ◽  
Adrian Cheng Yong CHOO ◽  
Hassan SIAHPOSHT

Ice-blasting (frozen CO2 at minus 78.5 ºC) is one of the modern methods of cleaning for industrial purposes without any contamination or hazard to the environment. Effects of ice-blasting were studied here on the basis of normal solid wood as well as nanosilver-impregnated Populus nigra and Fagus orientalis. The size range of silver nanoparticles was 20 - 90 nm. Specimens were free from any knots,  splits, rot, or other visual defects. Results showed that ice-blasting made impact strength decrease in beech by 8.4 %; however, an insignificant increase of 0.8 % was observed in poplar. Impregnating the specimens with a nanosilver suspension before ice-blasting made impact strength increase by 25.8 % in poplar; it also mitigated the impact loss in beech (5.2 % in comparison to control specimens). It can be concluded that the negative effect of ice-blast treatment is less in lower-density poplar wood; also, impregnation with nanosilver can even increase its impact strength. In higher-density beech wood, however, the impregnation can mitigate the significant negative effect of the ice-blast treatment on impact bending strength.


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