Density and some mechanical properties of densified and heat post-treated Uludağ fir, linden and black poplar woods

Pelit, Hüseyin; Budakçı, Mehmet; Sönmez, Abdullah

doi:10.1007/s00107-017-1182-y

Cited by 38 publications

(22 citation statements)

References 26 publications

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“…Due to these thermal processes, the dimensional stability of densified wood is significantly increased (Dwianto et al, 1997;Navi and Girardet, 2000;Kamke and Sizemore, 2008;Welzbacher et al, 2008;Fang et al, 2012;Kutnar and Kamke, 2012;Pelit et al, 2016;Kariz et al, 2017). However, thermal processes generally have a negative effect on the hardness or mechanical strength properties of densified wood (Welzbacher et al, 2005;Gong et al, 2010;Kwon et al, 2014;Dubey et al, 2016;Pelit et al, 2018). Another important method for fixing the compressed thickness in densified wood is impregnation with phenolic resins.…”

Section: Uvodmentioning

confidence: 99%

Effect of Water Repellents on Hygroscopicity and Dimensional Stability of Densified Fir and Aspen Woods

Pelit

Emiroglu

2020

Drv. ind. (Online)

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This study investigated the effect of pre-impregnation with water-repellent agents on the hygroscopicity and dimensional stability of fir (Abies bornmulleriana Mattf.) and aspen (Populus tremula L.) woods. After pre-vacuum treatment, the samples were impregnated at atmospheric pressure with paraffin, linseed oil and styrene, and then densified at compression rates of 20 % and 40 % at 120, 150 and 180 °C. The results showed that water repellents significantly affected the hygroscopicity and dimensional stability of the densified wood samples. Compression recovery rate (CRR), thickness swelling (TS), equilibrium moisture content (EMC), and water absorption (WA) values of the densified samples decreased with impregnation pretreatments. The linseed oil treatment gave more positive CRR and TS results than paraffin. Lower EMC and WA values were found in the paraffin-treated samples. However, the most successful results for all tested properties were determined in the styrene pretreated samples in which hygroscopicity decreased and dimensional stability increased (especially for aspen) due to increases in the compression rate and temperature related to densification conditions. In the styrene pretreated samples, the high temperature (180 °C) and compression rate (40 %) significantly reduced CRR, TS, EMC and WA, total dimensional stability was nearly achieved and the water repellent effectiveness was close to 100 %.

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Section: Uvodmentioning

confidence: 99%

Effect of Water Repellents on Hygroscopicity and Dimensional Stability of Densified Fir and Aspen Woods

Pelit

Emiroglu

2020

Drv. ind. (Online)

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“…The wood density is related to mechanical properties 23,24 , dimensional stability 25 , water flow 26 , carbon fixation 27 , and climate change 28 . Hence, precise methods for its determination, such as X-ray densitometry, are becoming more important.…”

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confidence: 99%

RETRACTED ARTICLE: The effect of soil nutrients and moisture during ontogeny on apparent wood density of Eucalyptus grandis

Castro

Chambi-Legoas

Filho

et al. 2020

Sci Rep

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Knowledge of the effect of soil nutrients, such as K and Na and their interaction with water availability, on the growth and wood properties of the eucalypts, is needed to increase the productivity of commercial plantation forests in Brazil that generate employment and taxes. The present study evaluates the apparent wood density (at 12% wood moisture) of Eucalyptus grandis trees at 12, 24, 36 and 48 months old under ambient and lower than ambient (66%) rainfall conditions and K and Na nutrient enrichment. The treatments were two water availability (100 and 66% of the rainfall) and the three nutrient treatments were: K (4.5 kmol/ha), Na (4.5 kmol/ha) and a control (natural conditions). The apparent wood density of samples at breast height (1.3 m) was determined by X-ray densitometry and digital images. Increased nutrients at all four ages and water availability at 36 and 48 months reduced apparent wood density in E. grandis trees, however, effects of nutrients are lower under water availability reduction. The radial profile of wood density was higher in four-year-old trees, but there was radial variation in apparent wood density at all ages. These findings predict that, under water stress, apparent wood density will not decline in commercial E. grandis plantations fertilized with potassium. The use of sodium, as a substitute of potassium, should consider their negative impacts on wood density of Eucalyptus grandis trees. In Brazil, eucalyptus species are usually cultivated in soils with low fertility, potassium and other minerals scarcity and water deficit 1. The expansion of forest plantations in the country depends on the understanding of the interaction between minerals, such as sodium and potassium, and water availability, and their effect on the seasonality of tree growth and wood quality. The total or partial replacement of potassium by sodium in forest plantations has practical and scientific interest 2,3. Potassium sources, with sodium in their composition, require less energy in the fertilizer production and, therefore, reducing its final prices. These minerals affect the tree water balance and increase water use efficiency under water stress and improve drought resistance 1,4. Because wood is a product of tree growth, factors that affects the growth rate can also affect wood anatomy and therefore wood density and other physical properties. Thus, the application of silvicultural traits in a changing environmental conditions have consider the potential impacts on wood quality. As well as volume productivity, the wood properties are important factors in forest management, since its affects the transformation process and quality of wood products. In pulp and paper industry wood density is an important attribute for yield and quality of pulp and paper products 5,6. However, the effects of mineral fertilizers in wood density of young eucalyptus trees is poorly studied and with controversial results, indicating an increase 7 , decrease or no effect on apparent wood density with moisture content between 12 and 1...

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“…Strength increases of specimens can be explained by increases in density. In previous studies, it was reported similarly that the strength properties of densified wood are higher than that of untreated wood and compression strength generally increases in proportion with the increase in density (Blomberg et al 2005;Morsing 2000;Pelit et al 2018).…”

Section: Factor Fir Aspenmentioning

confidence: 88%

“…Density increases in specimens differed depending on wood species, impregnation agent and densification conditions. In previous studies, it was stated that the amount of increase in wood density as a result of compression depended on the properties of wood species, compression ratio and springback effect (Pelit et al 2018;Rautkari 2012).…”

Section: Density Hardness and Compression Strengthmentioning

confidence: 99%

Density, hardness and strength properties of densified fir and aspen woods pretreated with water repellents

Pelit

Emiroglu²

2020

Holzforschung

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In this study, the effect of thermo-mechanical densification on the density, hardness, compression strength, bending strength (MOR), and modulus of elasticity (MOE) of fir and aspen wood pretreated with water repellents was analyzed. Wood specimens were impregnated with paraffin, linseed oil and styrene after pre-vacuum treatment. Then, the impregnated wood specimens were densified with compression ratios of 20 and 40%, and at 120, 150 and 180 °C. The results indicated that the density, hardness and strength properties of the all densified specimens (untreated and impregnated) increased depending on the compression ratio and temperature. For all tested properties, higher increases were obtained in the paraffin and styrene pretreated specimens compared to untreated samples. However, the increase rates in linseed oil pretreated specimens were generally lower than untreated specimens. Regarding water repellents the most successful results in all tested properties were determined in styrene pretreated specimens. The density, hardness and strength properties of all specimens increased with the increase in compression ratio. On the other hand, the increase in the compression temperature negatively affects the properties of untreated and linseed oil pretreated specimens, while having a generally positive effect on the properties of paraffin pretreated specimens. However, all tested properties of styrene pretreated specimens have increased significantly due to the increase in compression temperature. The increasing strength properties of wood as a result of densification have increased much more with paraffin and especially styrene pretreatment. These combinations can be considered as an important potential for applications that require more hardness and strength.

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Density and some mechanical properties of densified and heat post-treated Uludağ fir, linden and black poplar woods

Cited by 38 publications

References 26 publications

Effect of Water Repellents on Hygroscopicity and Dimensional Stability of Densified Fir and Aspen Woods

Effect of Water Repellents on Hygroscopicity and Dimensional Stability of Densified Fir and Aspen Woods

RETRACTED ARTICLE: The effect of soil nutrients and moisture during ontogeny on apparent wood density of Eucalyptus grandis

Density, hardness and strength properties of densified fir and aspen woods pretreated with water repellents

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