scholarly journals The Impact of Paraffin-Thermal Modification of Beech Wood on Its Biological, Physical and Mechanical Properties

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1102 ◽  
Author(s):  
Ladislav Reinprecht ◽  
Miroslav Repák
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Beech Wood ◽  
Physical And Mechanical Properties ◽  
Brown Rot ◽  
European Beech ◽  
White Rot ◽  
White Rot Fungus ◽  
Poria Placenta ◽  
The Impact

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%.

scholarly journals Efficacy of Caffeine Treatment for Wood Protection—Influence of Wood and Fungi Species

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3758
Author(s):  
Miloš Pánek ◽  
Vlastimil Borůvka ◽  
Jana Nábělková ◽  
Kristýna Šimůnková ◽  
Aleš Zeidler ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Beech Wood ◽  
Ecological Integrity ◽  
Treated Wood ◽  
Physical And Mechanical Properties ◽  
Brown Rot ◽  
European Beech ◽  
Brown Rot Fungi ◽  
Wood Protection ◽  
Caffeine Treatment

In the future, we can expect increased requirements to the health and ecological integrity of biocides used for the protection of wood against bio-attacks, and it is therefore necessary to search for and thoroughly test new active substances. Caffeine has been shown to have biocidal efficacy against wood-destroying fungi, moulds and insects. The aim of the research was to determine whether the effectiveness of caffeine, as a fungicide of natural origin, is affected by a different type of treated wood. Norway spruce mature wood (Picea abies), Scots pine sapwood (Pinus sylvestris), and European beech wood (Fagus sylvatica) were tested in this work. The samples were treated using long-term dipping technology or coating (according to EN 152:2012) and then tested against selected wood-destroying brown rot fungi according to the standard EN 839:2015, wood-staining fungi according to EN 152:2012, and against mould growth according to EN 15457:2015. The penetration of caffeine solution into wood depth was also evaluated using liquid extraction chromatography, as well as the effect of the treatment used on selected physical and mechanical properties of wood. The test results showed that the type of wood used and the specific type of wood-degrading agent had a significant effect on the effectiveness of caffeine protection. The most resistant wood was the treated spruce, whereas the most susceptible to deterioration was the treated white pine and beech wood. The results of the work showed that caffeine treatment is effective against wood-destroying fungi at a concentration of 2%, and at 1% in some of the tested cases. It can be used as an ecologically acceptable short-term protection alternative against wood-staining fungi in lumber warehouses and is also partially effective against moulds. It also does not have negative effects on changes in the physical and mechanical properties of the tested wood species.

Changes in sorption and electrical properties of wood caused by fungal decay

Holzforschung ◽  
2019 ◽  
Vol 73 (5) ◽  
pp. 445-455 ◽  
Author(s):  
Christian Brischke ◽  
Simon Stricker ◽  
Linda Meyer-Veltrup ◽  
Lukas Emmerich
Keyword(s):  
Beech Wood ◽  
Sorption Isotherms ◽  
Brown Rot ◽  
European Beech ◽  
White Rot ◽  
White Rot Fungus ◽  
Decayed Wood ◽  
Vapor Sorption ◽  
Fungal Decay ◽  
Dynamic Vapor Sorption

Abstract As wet wood is prone to degradation by wood-destroying fungi, the monitoring of the moisture content (MC) of wood can be used to quantify the risk of fungal infestation. Fungal decay alters the sorption and electrical conductivity of wood, and thus the goal of the present study was to measure the electrical resistance (R) of wood after fungal decay as a function of MC. Scots pine sapwood (Pinus sylvestris L.) and European beech wood (Fagus sylvatica L.) were submitted to decay by Coniophora puteana (a brown rot fungus, BR) and Trametes versicolor (a white rot fungus, WR) and the mass loss (ML) due to the fungal metabolism was measured. The sorption isotherms were determined by dynamic vapor sorption (DVS), and comparative gravimetric- and R-based MC measurements were conducted. BR and WR reduced the sorption of wood and lowered its R in the hygroscopic range, where the decay led to an overestimation of wood MC, while wood MC was dramatically underestimated above fiber saturation (FS). Specimens showed an MC well above FS if measured directly after harvesting and an increased R compared to undecayed wood at a given MC. BR-decayed specimens were dried and rewetted, and such specimens showed an elevated R beyond FS. In the case of WR-decayed wood, the R was reduced at a given MC.

The fungal resistance of wood modified with glutaraldehyde

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Zefang Xiao ◽  
Yanjun Xie ◽  
Carsten Mai
Keyword(s):  
Scots Pine ◽  
Beech Wood ◽  
Weight Percent Gain ◽  
Brown Rot ◽  
European Beech ◽  
Soft Rot ◽  
Weight Percent ◽  
Fungal Resistance ◽  
White Rot ◽  
White Rot Fungus

Abstract Scots pine sapwood (Pinus sylvestris L.) and European beech wood (Fagus sylvatica L.) were treated with glutaraldehyde (GA) in aqueous solution in the presence of magnesium chloride as a catalyst to evaluate the durability improvement towards staining and rot fungi. The GA modified specimens were dipped in a spore suspension of the blue stain fungus Aureobasidium pullulans and incubated for 8 weeks. The growth on both pine and beech wood was restrained, when the weight percent gain (WPG) of the specimens was above 7%. Under this condition, GA-modified beech wood did not suffer any mass loss after incubation with the white rot fungus Trametes versicolor. The threshold to prevent decay of beech and pine specimens towards the brown rot fungus Coniophora puteana was at a WPG of only 3%. GA treatment to a WPG over 6% protected the Scots pine stakes from soft rot decay during 32 weeks’ exposure according to ENv 807 (2001).

An attempt to use „Tetra Pak” waste material in particleboard technology

2021 ◽  
Vol 114 ◽  
pp. 70-75
Author(s):  
Radosław Auriga ◽  
Piotr Borysiuk ◽  
Alicja Auriga
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
Waste Material ◽  
Thickness Swelling ◽  
The Core ◽  
Tetra Pak ◽  
The Impact

An attempt to use „Tetra Pak” waste material in particleboard technology. The study investigates the effect of addition Tetra Pak waste material in the core layer on physical and mechanical properties of chipboard. Three-layer chipboards with a thickness of 16 mm and a density of 650 kg / m3 were manufactured. The share of Tetra Pak waste material in the boards was varied: 0%, 5%, 10% and 25%. The density profile was measured to determine the impact of Tetra Pak share on the density distribution. In addition, the manufactured boards were tested for strength (MOR, MOE, IB), thickness swelling and water absorption after immersion in water for 2 and 24 hours. The tests revealed that Tetra Pak share does not affect significantly the value of static bending strength and modulus of elasticity of the chipboard, but it significantly decreases IB. Also, it has been found that Tetra Pak insignificantly decreases the value of swelling and water absorption of the chipboards.

The Influence of the Long-Term Storage of Hardwood on the Selected Physical and Mechanical Properties in View of Pulping

2016 ◽  
Vol 688 ◽  
pp. 10-16
Author(s):  
Blažej Seman ◽  
Anton Geffert ◽  
Jarmila Geffertova
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Continuous Production ◽  
Beech Wood ◽  
Physical And Mechanical Properties ◽  
Long Term Storage ◽  
The Impact ◽  
Term Storage ◽  
Strength In Bending

Wood is loosely stored to ensure continuous production inside paper mills where it is exposed to the effect of external factors. The impact of storage leads to some changes of mechanical and physical properties of wood, but these changes are not the same in all specimens. In this paper, it has been observed that the long term storage of wood influences the impact strength in bending and the permeability of wood for fluids. During the storage, there was a decrease of impact strength in bending of poplar heartwood by 28.3% and oak by 22.1% and mature beech wood by 37.3%. Also, there was decreased a permeability of wood, poplar sapwood 18.3 % and heartwood of 53.9%; oak sapwood by 20.0% and heartwood by 20.3%; beech sapwood 45.8% and mature wood by 48.2%. By decrease of the observed properties of the stored wood, a deterioration a quality of produced pulp can be expected (a higher Kappa number, amount reject and decrease the mechanical properties of pulp).

scholarly journals Influence of incubation time on the vibration and mechanic properties of mycowood

Holzforschung ◽  
2016 ◽  
Vol 70 (6) ◽  
pp. 557-565 ◽  
Author(s):  
Marjan Sedighi Gilani ◽  
Jürg Neuenschwander ◽  
Markus Heeb ◽  
Roman Furrer ◽  
Sergio J. Sanabria ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sound Velocity ◽  
Treatment Time ◽  
Characteristic Impedance ◽  
Weight Ratio ◽  
Physical And Mechanical Properties ◽  
Longitudinal Direction ◽  
White Rot ◽  
White Rot Fungus ◽  
Fungal Treatment

Abstract The goal of the current study was to investigate the physical and mechanical properties of mycowood as a high quality tone-wood, obtained from Norway spruce by treatment of the white rot fungus Physisporinus vitreus as a function of the treatment time. In focus was the stiffness to weight ratio, which is often considered a main criterion for tone-wood selection. The vibro-mechanical properties were tested by non-destructive methods. The change of color and density were also measured after 4–12 months of fungal incubation. Density decreased up to 5% after 12 months of fungal treatment. Sound velocity was measured in small size specimens by means of the free-free vibration approach, while in large specimens the air-coupled ultrasound method was applied. The two techniques gave similar results and indicated that the sound velocity decreased in mycowood. Internal damping was increased in mycowood to a higher extent than the reduction in the specific modulus of elasticity (E/ρ) and thus the sound velocity in the material. The sound velocity was decreasing with increasing incubation times and scattering of data with this regard was larger in the transversal than in the longitudinal direction. The sound radiation coefficient and the characteristic impedance were enhanced in mycowood and its color was more brownish and richer in tone.

scholarly journals Ability of some species of fungi of the Basidiomycetes class to degrade cellulose and lignocellulose substrates

2014 ◽  
Vol 19 (2) ◽  
pp. 323-330
Author(s):  
Zdzisław Tagoński
Keyword(s):  
Beech Wood ◽  
Brown Rot ◽  
White Rot ◽  
White Rot Fungus ◽  
Cellulolytic Enzymes ◽  
Pine Wood ◽  
Wood Meal ◽  
Fomes Fomentarius

Studies were carried-out on the ability of 18 strains of 15 white-rot and brown-rot basidiomycetons fungi to degrade wood components and to synthesize cellulolytic enzymes and laccase. 28,5% lignin and 26,1% carbohydrates of pine wood meal, 46,2% lignin and 67,8% carbohydrates of beech wood meal was degraded after 6 weeks incubation by the white-rot fungus <i>Phanerochate chrysosporium</i>. The highest activity of laccase was obtained in from fungi <i>Coriotus zonatus</i> and <i>Fomes fomentarius</i>.

Effects of Decay on the Mechanical Properties of Nailed Joints in Light Wood Frame Structure

2021 ◽  
Vol 71 (1) ◽  
pp. 46-57
Author(s):  
Ying Gao ◽  
Shiyi Mei ◽  
Xingxia Ma ◽  
Xinmiao Meng
Keyword(s):  
Weight Loss ◽  
Brown Rot ◽  
Maximum Load ◽  
White Rot ◽  
White Rot Fungus ◽  
Correction Coefficient ◽  
Loading Test ◽  
Brown Rot Fungus ◽  
The Impact ◽  
Linear Decline

Abstract For this study, spruce–pine–fir (Picea–Pinus–Abies [SPF]) specification material, oriented strand board (OSB), and domestic twisted nails that were driven vertically and perpendicular-to-grain were selected. Referring to GB/T 13942.1-2009, nailed joints specimens were exposed both to white rot fungus and brown rot fungus for 1 month to 6 months. The monotonous loading test was applied to the specimens based on ASTM D1761-88. The holding power of the nails and weight loss of both OSB and SPF were investigated. Theoretical maximum load of the nailed joints was calculated according to Eurocode5. Results illustrated that the load, stiffness, and energy consumption of the nailed joints showed significant linear decline with the decay time. A linear decline of the ductility coefficient was not obvious, and there was no obvious difference between white rot fungus and brown rot fungus. Effect of decay on the OSB was much greater than the impact on the SPF. The decay grade of the nailed joints was established according to the linear relationship between weight loss and maximum load. Based on Eurocode5, the study calculated the maximum load of the nailed joints and introduced the correction coefficient γ to better predict the maximum load.

Effects of white rot and brown rot decay on the drilling resistance measurements in wood

Holzforschung ◽  
2018 ◽  
Vol 72 (10) ◽  
pp. 905-913 ◽  
Author(s):  
Evgenii Sharapov ◽  
Christian Brischke ◽  
Holger Militz ◽  
Elena Smirnova
Keyword(s):  
Scots Pine ◽  
Free Water ◽  
Brown Rot ◽  
European Beech ◽  
White Rot ◽  
Drilling Tool ◽  
Significant Difference ◽  
Brown Rot Decay ◽  
Drilling Resistance ◽  
The Impact

AbstractAn IML-RESI PD 400 drilling tool and a standard spade drill bit (IML System GmbH, Wiesloch, Germany) were used to study the impact of white and brown rot decay on drilling resistance (DR) measurements in wood. In total, 720 drillings were made in specimens of Scots pine (Pinus sylvestrisL.) heartwood and sapwood, European beech (Fagus sylvaticaL.) and English oak (Quercus roburL.), which were decayed byConiophora puteanaandTrametes versicolor. Drillings were made with specimens conditioned in normal climate (20°C/65% RH) and with specimens vacuum-impregnated in water. DR and feeding force (FF) were negatively correlated with mass loss (ML) due to fungal decay. The intensity of reduction was higher for DR than for FF with increasing ML for all decay types and moisture contents (MCs). A significant difference (at 95% confidence level) in DR was found between decay types using water-saturated (WS) Scots pine specimens (3–35% ML). In most cases, DR revealed a higher predictive power of the models for ML prediction than FF. Free water in decayed specimens significantly reduced the DR and FF. Hence, the effect of ML on DR and FF of decayed and WS wood was less prominent.

scholarly journals What Happens to Wood after a Tree Is Attacked by a Bark Beetle?

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1163
Author(s):  
Štěpán Hýsek ◽  
Radim Löwe ◽  
Marek Turčáni
Keyword(s):  
Mechanical Properties ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Wood Decay ◽  
Physical And Mechanical Properties ◽  
Brown Rot ◽  
White Rot ◽  
Modulus Of Rupture ◽  
Tree Bark ◽  
Decay Fungi

Advancing climate change is affecting the health and vitality of forests in many parts of the world. Europe is currently facing spruce bark beetle outbreaks, which are most often caused by wind disturbances, hot summers, or lack of rainfall and are having a massive economic impact on the forestry sector. The aim of this research article was to summarize current scientific knowledge about the structure and physical and mechanical properties of wood from bark beetle-attacked trees. Spruce stands are attacked by a number of beetles, of which Ips typographus is the most common and widespread in Central Europe. When attacking a tree, bark beetles introduce ophiostomatoid fungi into the tree, which then have a greater effect on the properties of the wood than the beetles themselves. Fungal hyphae grow through the lumina of wood cells and spread between individual cells through pits. Both white rot and brown rot fungi are associated with enzymatic degradation of lignin or holocellulose, which is subsequently reflected in the change of the physical and mechanical properties of wood. Wood-decay fungi that colonize wood after infestation of a tree with bark beetles can cause significant changes in the structure and properties of the wood, and these changes are predominantly negative, in the form of reducing modulus of rupture, modulus of elasticity, discolouration, or, over time, weight loss. In certain specific examples, a reduction in energy consumption for the production of wood particles from beetle-attacked trees, or an increase in surface free energy due to wood infestation by staining fungi in order to achieve better adhesion of paints or glues, can be evaluated positively.

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