scholarly journals Analysis of glue line and correlations between anatomical characteristics of Eucalyptus grandis × Eucalyptus urophylla glued-laminated timber

2019 ◽  
Author(s):  
Rafael G. E. Oliveira ◽  
Fabricio G. Gonçalves ◽  
Pedro G. A. Segundinho ◽  
José Tarcísio S. Oliveira ◽  
Juarez B. Paes ◽  
...  
Keyword(s):  
Apparent Density ◽  
Pearson Correlation ◽  
Eucalyptus Grandis ◽  
Vessel Diameter ◽  
Glue Line ◽  
Eucalyptus Urophylla ◽  
Line Thickness ◽  
Adhesive Penetration ◽  
Eucalyptus Wood ◽  
Glued Laminated Timber

AbstractThe main goal of this study was to analyze glue line on eucalyptus wood. In order to do that, thickness of main and secondary glue lines were measured as well their interaction with apparent density of elements glued with resorcinol-formaldehyde (RF) and castor polyurethane (CP) adhesives. Anatomical wood characterization of Eucalyptus grandis × Eucalyptus urophylla was performed by correlating glue line thickness. According to normative instruction, specimens were produced for delamination tests. The experiment was conducted in a completely random 2 × 2 design factorial scheme (two classes of apparent density and two adhesives). Pearson correlation (t < 0.01) was performed among variables. It was found that there was adhesive penetration into wood pots and rays. Glue line thickness was higher in woods with density higher than 0.58 g cm−3 glued with RF adhesive. There was low correlation among density, vessel diameter, main and secondary glue lines (t < 0.01).

scholarly journals ANATOMICAL, ULTRASTRUCTURAL, PHYSICAL AND MECHANICAL WOOD PROPERTIES OF TWO-YEAR-OLD Eucalyptus grandis × Eucalyptus urophylla CLONES

2018 ◽  
Vol 42 (2) ◽  
Author(s):  
Antonio José Vinha Zanuncio ◽  
Amélia Guimarães Carvalho ◽  
Angélica de Cassia Oliveira Carneiro ◽  
Mario Tomazello Filho ◽  
Paulina Valenzuela ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Radial Direction ◽  
Eucalyptus Grandis ◽  
Basic Density ◽  
Wood Properties ◽  
Eucalyptus Urophylla ◽  
Wood Basic Density ◽  
Eucalyptus Wood ◽  
Adult Trees

ABSTRACT Eucalyptus wood from adult trees is used for several purposes; however, the wood of younger trees has limited use. This study aims to characterize and propose uses of two-year-old eucalyptus wood. Six two-year-old Eucalyptus grandis × Eucalyptus urophylla clones have been selected and their anatomical, ultrastructural, physical and mechanical wood characteristics evaluated. The wood of Clone A shows more robust fibers with better microfibril arrangement, resulting in better mechanical properties, and therefore, a better performance for structural use. Clone F showed a low variation of wood basic density in the radial direction, facilitating its machinability, and with the Clone B, showed a lower anisotropy, and therefore, the wood is recommended for locations with high variations of humidity. The heterogeneity of the wood characteristics of the evaluated clones confirms the need for further studies, to choose those most adequate to each use.

Study on the Improvement of the Permeability of Eucalyptus grandis× Eucalyptus urophylla by Microwave Radiation

2014 ◽  
Vol 556-562 ◽  
pp. 3335-3339
Author(s):  
Jiang Tao ◽  
Kai Yuan Pen ◽  
Gui Long Wu ◽  
Jian Ping Sun ◽  
Xiu Rong Li ◽  
...  
Keyword(s):  
Microwave Radiation ◽  
Eucalyptus Grandis ◽  
Treated Wood ◽  
Untreated Wood ◽  
Microwave Treatment ◽  
Modulus Of Rupture ◽  
Test Material ◽  
Eucalyptus Urophylla ◽  
Eucalyptus Wood ◽  
Weak Points

Low permeability of fast-growing eucalyptus wood restricts its high value in use. In order to explore effective ways of improving the permeability of eucalyptus wood, the method of applying microwave radiation to Eucalyptus urophylla (Eucalyptus grandis×Eucalyptus urophylla) is used to promote its rapid evaporation of water, by which vapor pressure highly increases inside, then vapor bubbles break through the weak points of the wood tissue, as a result, the permeability of the wood is improved. Under the same conditions, wood was tested to achieve the results of water absorption rate (WAR) and water loss rate (WLR) in water sorption measurement and saturated suction drying experiment respectively, after which the permeability, the modulus of rupture (MOR) as well as the modulus of elasticity (MOE) of the test wood are recorded. The results show that the WAR and WLR of the microwave treated wood is higher than that of the untreated wood. Thus it is concluded that microwave radiation can improve the permeability of urophylla wood. But the time of microwave pretreatment has a significant effect on the WAR and WLR, which may be associated with lower microwave power and the variability of the tested material. MOR and MOE of the test material did not change significantly after the microwave treatment.

scholarly journals Analysis of glue line and correlations between density and anatomical characteristics of Eucalyptus grandis × Eucalyptus urophylla glulam

2020 ◽  
pp. 0-0
Author(s):  
Rafael G. E. de Oliveira ◽  
Fabricio G. Gonçalves ◽  
Pedro G. de A. Segundinho ◽  
José T. da S. Oliveira ◽  
Juarez B. Paes ◽  
...  
Keyword(s):  
Eucalyptus Grandis ◽  
Glue Line ◽  
Eucalyptus Urophylla ◽  
Anatomical Characteristics

scholarly journals RELATIONSHIP BETWEEN THE ANATOMY AND DRYING IN Eucalyptus grandis X Eucalyptus urophylla WOOD

2016 ◽  
Vol 40 (4) ◽  
pp. 723-729 ◽  
Author(s):  
Antônio José Vinha Zanuncio ◽  
Amélia Guimarães Carvalho ◽  
Renato Augusto Pereira Damásio ◽  
Bráulio da Silva de Oliveira ◽  
Angélica de Cassia Oliveira Carneiro ◽  
...  
Keyword(s):  
Cell Wall ◽  
Wood Anatomy ◽  
Pearson Correlation ◽  
Eucalyptus Grandis ◽  
Cell Wall Fraction ◽  
Eucalyptus Urophylla ◽  
Wood Drying ◽  
Climate Chamber ◽  
Vessel Size ◽  
The Relationship

ABSTRACT Drying is an important step to using wood and anatomical characteristics influence this process. Thus, the objective of this work was to evaluate the relationship between anatomy and wood drying. Samples with 2 x 2 x 4 cm were obtained from eight Eucalyptus urophylla x Eucalyptus grandis clones at 1.3 m height to evaluate the anatomy and drying in climate chamber during 15 days. Cell wall fraction was established as the parameter that best correlated with drying, the Pearson correlation coefficient between this parameter and moisture was -0.8986, -0.6580, 0.9216, 0.8743, 0.7131 and 0.8727 for saturated wood, and after 1, 2.5, 5, 10 and 15 days of drying, respectively. The frequency and vessel size, as well as the height and width of the rays showed low relation with wood drying. Wood anatomy, mainly the cell wall fraction, influences moisture losses and should be considered in wood drying programs.

scholarly journals Effect Of Planting Spacing In Production And Permeability Of Heartwood And Sapwood Of Eucalyptus Wood

2019 ◽  
Vol 26 (spe1) ◽  
Author(s):  
Alice Soares Brito ◽  
Graziela Baptista Vidaurre ◽  
José Tarcísio da Silva Oliveira ◽  
João Gabriel Missia da Silva ◽  
Brunela Pollastrelli Rodrigues ◽  
...  
Keyword(s):  
Eucalyptus Grandis ◽  
Eucalyptus Urophylla ◽  
Stem Height ◽  
Eucalyptus Wood ◽  
Heartwood Percentage ◽  
Yellow Compound

ABSTRACT The objective of this work was to evaluate the influence of different useful areas provided by the planting spacings (3 × 1, 3 × 2, 3 × 3, 3 × 4 m) on the production and permeability of heartwood and sapwood of Eucalyptus grandis and Eucalyptus grandis × Eucalyptus urophylla clones at 4 years old. Regardless of the clone, there was no effect of planting spacing on the heartwood/sapwood relation and wood permeability. All clones showed a heartwood decrease with increased height, regardless of planting spacing, and E. grandis (B) was the only one that had its heartwood percentage positively and significantly correlated with the dendrometric variables (DBH and commercial height). The use of the dymethil yellow compound was indispensable in defining the heartwood and sapwood regions in the samples from 50% of the stem height. The heartwood permeability was low in all evaluated clones, suggesting vessel obstruction by tyloses or other deposits, while sapwood permeability reached 405.4 cm3/cm.atm.s.

scholarly journals Quality of Eucalyptus Wood Grown in Rio de Janeiro State for Bioenergy

2016 ◽  
Vol 23 (3) ◽  
pp. 435-442 ◽  
Author(s):  
Ananias Francisco Dias Júnior ◽  
Djailson Silva da Costa Júnior ◽  
Azarias Machado de Andrade ◽  
Elisabeth de Oliveira ◽  
Artur Queiroz Lana ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Rio De Janeiro ◽  
Energy Use ◽  
Pearson Correlation ◽  
Eucalyptus Grandis ◽  
Basic Density ◽  
Principal Component ◽  
Component Analysis ◽  
Eucalyptus Wood ◽  
Janeiro State

ABSTRACT This study aimed to evaluate the Eucalyptus grandis and Eucalyptus saligna, from production areas of Rio de Janeiro State, intended for energy use. The selection consisted of six trees per specie, at six years old. The wood samples had its basic density determined, then, was subjected to the pyrolysis process with 500 °C of final temperature. Charcoal, pyroligneous liquid and non-condensable gases yields were determined. In addition, the charcoal had its immediate analysis performed to determine the levels of volatiles matter, fixed carbon and ash content. Data were analyzed using descriptive statistics, Pearson correlation and principal component analysis. The correlation analysis and principal component analysis were effective to predict recommended species. Based on the results, the most recommended specie for energy purposes was the Eucalyptus grandis.

scholarly journals Effect of growth stress and interlocked grain on splitting of seven different hybrid clones of Eucalyptus grandis×Eucalyptus urophylla wood

Holzforschung ◽  
2020 ◽  
Vol 74 (10) ◽  
pp. 917-926
Author(s):  
Frederico José Nistal França ◽  
Tâmara Suely Filgueira Amorim França ◽  
Graziela Baptista Vidaurre
Keyword(s):  
Cross Section ◽  
Eucalyptus Grandis ◽  
Growth Stress ◽  
Eucalyptus Urophylla ◽  
Stress Indicator ◽  
Eucalyptus Wood ◽  
Standing Trees ◽  
Interlocked Grain ◽  
Hybrid Clones ◽  
Selection Of

AbstractTrees with high levels of growth stress begin to show log end splits (LES) immediately after harvesting, usually reaching its maximum end split in a week, and these tensions also create splits during lumber manufacturing. Interlocked grain is another characteristic that impacts the properties of eucalyptus wood. The aim of this study was to evaluate the effect of growth stress and interlocked grain patterns on log end splitting of seven different hybrid clones of Eucalyptus grandis × Eucalyptus urophylla planted in Brazil. The growth stress indicator (GSI) was measured in standing trees before harvesting. Splits were measured on logs in three different stages, and interlocked grain from wood blocks was obtained across the center of the cross-section. The results showed that LES occurred as soon as the trees were harvested; however, for better selection of clones, LES should be evaluated after a week of harvesting. There were statistically significant correlations for GSI with LES. Clones that presented higher values of interlocked grain tended to develop lower values of GSI and LES. Using GSI and interlocked grain measurements, it was possible to select the most indicated eucalyptus clones for lumber production.

scholarly journals Maintenance of the Economic Performance of Eucalyptus in Competition With Weeds

2019 ◽  
Vol 11 (7) ◽  
pp. 60
Author(s):  
Kaléo D. Pereira ◽  
Jonas E. C. Rocha ◽  
Norberto C. Noronha ◽  
Rafael G. Viana ◽  
Dênmora G. Araújo ◽  
...  
Keyword(s):  
Economic Performance ◽  
Weed Management ◽  
Chemical Control ◽  
Eucalyptus Grandis ◽  
Economic Loss ◽  
Volume Estimation ◽  
Continuous Control ◽  
Eucalyptus Urophylla ◽  
Base Diameter ◽  
Eucalyptus Wood

The aim of this study was to evaluate the growth of the hybrid clone Eucalyptus grandis &times; Eucalyptus urophylla submitted to competition with weeds and determine the period prior to economic loss (PPEL). The experiment was carried out in Ulian&oacute;polis, Par&aacute; State, Brazil, and consisted of the treatments continuous control and no control of weeds. Weed management was carried out by integrating both mechanical and chemical control. Stem base diameter, height, canopy diameter of eucalyptus plants were measured on the 16th month after planting. Wood volume was estimated by means of a volumetric equation. The treatments continuous control and no control of weeds were compared using the Hotelling&rsquo;s T2 test and the parameters for PPEL calculation were defined from volume estimation. The treatment continuous control promoted significant gains in eucalyptus growth. PPEL tended to be reduced by 3.8287 and 0.2393 units with the increase of a unit in the price of wood and the increase of planting yield, respectively. For different eucalyptus wood prices, the calculated PPEL ranged from 40 to 161 days of coexistence with weeds.

scholarly journals Eucalypt Clonal Hybrid Influences the Carbon Amount of Below-Ground Biomass in Oxisol, Brazil

2020 ◽  
Vol 3 (1) ◽  
pp. 53
Author(s):  
Grasiele Dick ◽  
Humberto J. Eufrade-Junior ◽  
Mauro V. Schumacher ◽  
Gileno B. Azevedo ◽  
Saulo P. S. Guerra
Keyword(s):  
Carbon Concentration ◽  
Eucalyptus Grandis ◽  
Eucalyptus Camaldulensis ◽  
Eucalyptus Urophylla ◽  
Ground Biomass ◽  
Homogeneity Of Variances ◽  
Below Ground ◽  
Hybrid Eucalyptus ◽  
Carbon Determination ◽  
Hybrid Clones

The objective of this study was to evaluate whether there is an influence of different clonal hybrids of Eucalyptus urophylla on the carbon concentration and amount in below-ground biomass in trees cultivated in Oxisol, Brazil. Stumps and roots of three different eucalypt hybrid clones, AEC 0144, AEC 0223, and VM01, were selected, weighed immediately after being removed from the ground, and sampled for carbon determination and moisture content at the laboratory. The Shapiro-Wilk and Bartlett tests were used to evaluate data distribution and the homogeneity of variances, respectively. Analysis of variance (ANOVA) complemented by the Scott-Knott test was used to evaluate the effects of specie/hybrid on the below-ground biomass (dry matter) and carbon amount per stump. The hybrid type of Eucalyptus urophylla does not influence the carbon concentration; however, there is a difference in below-ground biomass production and carbon amount with it being higher for Eucalyptus urophylla × Eucalyptus camaldulensis when compared to the species Eucalyptus urophylla and hybrid Eucalyptus urophylla × Eucalyptus grandis.

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