Tectona grandis L. f. (teak) is highly valued in the international market, but its volume and properties vary depending on its genetic material and planting site. Evaluating these factors is crucial ...for promoting new plantations. Therefore, this study aimed to assess the impact of genetic material (clones TG1 and TG3 and seminal material) and planting site (Nova Maringá and Água Boa, Mato Grosso, Brazil) on morphological parameters (heartwood, sapwood, bark, pith proportions, and pith eccentricity), physical properties (shrinkage and air-dry density), and mechanical properties (static bending strength—fm, compressive strength—fc0, Janka hardness—fH90, and shear strength—fv0). For this purpose, we sampled five trees aged 13 years per genetic material from commercial plantations. In Nova Maringá, trees exhibited, on average, 56.07% heartwood, while in Água Boa, this value was less than 50%. Seminal material showed the lowest percentage of heartwood (49.2%). The pith percentage was significantly greater in Água Boa than in Nova Maringá, regardless of the genetic material. We observed the highest standard deviation (5.61) in pith eccentricity for the seminal material. Both the planting site and genetic material influenced the air-dry density (~12% moisture content), which ranged from 0.535 to 0.618 g·cm−3. Trees grown in Nova Maringá produced wood with higher dimensional stability than those from Água Boa, exhibiting a 14% lower radial shrinkage and a 6% lower volumetric variation. In Nova Maringá, the wood from the seminal material exhibited greater resistance. On the other hand, in Água Boa, that material showed lower resistance (fv0, fm, and fc0), or there was no significant difference (fH90) compared to the clonal materials. When comparing the clonal materials (TG1 and TG3) at each planting site, they demonstrated similar mechanical properties. The variability in physical and mechanical properties among different genetic materials and planting locations highlights the need to select appropriate teak genetic materials for each region. We concluded that more productive teak clones can be selected without compromising the physical and mechanical properties of the wood.
The clonal materials of Tectona grandis L. f. in fast-growing plantations exhibit faster growth than the seminal materials. Therefore, it is necessary to investigate the differences in wood drying to ...ensure the quality and yield of the final product. This study evaluated the outdoor drying behavior of three genotypes of teak lumber. Two clonal genotypes (G1 and G2) and one of seminal origin (G3) were assessed. Boards measuring 30 × 150 × 1000 mm (thickness × width × length) were produced from the basal logs. The average moisture content (79.3, 64.9, and 60,1%), final moisture content (10.8, 9.8, and 11.6%), and mean drying rate (1.2, 0.97, and 0.85%.day-1) were observed in the wood from genotypes G1, G2 and G3, respectively. The clonal material crooked and bowed below 5 mm.m-1, which is considered the tolerance limit for both warpings. The seminal material had a greater incidence of splitting. The clonal genotypes G1 and G2 had similar qualities and presented higher drying rates, final moisture contents below 11% and a lower incidence of defects, especially splitting, compared to the naturally seeded material.
ABSTRACT The objectives of the present work were to determine the properties of wood and charcoal from Eucalyptus clones and assess impacts of charcoal features on the CO2 gasification reactivity and ...to compare with coke reactivity. Gasification reactivity was performed using charcoal particles in a furnace setup at 820 °C, under CO2 atmosphere. The results show that there is wood variability among evaluated clones and strong correlations between wood and charcoal properties. All charcoals had higher reactivity in comparison to coke. The decrease in porosity and increase in apparent density in Eucalyptus wood led to a slight decrease of CO2 gasification reactivity. In addition, strong positive correlation between charcoal reactivity and potassium concentration (K) was found.
Drying is an indispensable process for the industrial use of wood because it results in greater stability, durability, quality, and value of the final product. However, pre-established programs for ...tropical species have been poorly evaluated. The objective of this study was to formulate and evaluate drying programs for tropical species. The woods of Astronium lecointei (muiracatiara), Dinizia excelsa (faveira-ferro) and Hymenolobium heterocarpum (angelim-pedra) were used. The anatomical characteristics and physical properties of these species were evaluated. The drying programs for each wood were elaborated based on the drying potential to estimate the initial and final temperatures. The programs were executed in a laboratory oven with forced air circulation and afterward, the drying rates and defects were evaluated. The highest values of basic density were observed for faveira-ferro (0.92 g cm
-
³) followed by muiracatiara (0.70 g cm
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³), and angelim-pedra (0.59 g cm
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³). As for the volumetric shrinkage, the values were increased in the following order: angelim-pedra (9.87%), faveira-ferro (12.70%), and muiracatiara (14.23%). The anisotropy coefficient of the three wood evaluated was less than 1.5. The density and vessel diameter influenced the drying rate of the woods. The application of the drying programs in this work resulted in a high rate of top and surface cracking, which can compromise the use of wood for more demanding purposes. The woods were classified as first-class because the warping did not exceed the allowed limits.
Teakwood from fast-growth plantations is commercialized at increasingly younger ages for economic reasons. However, wood features are influenced by the age of the tree. This study examined how age ...affects heartwood proportion, color parameters, chemical composition, and natural teakwood durability. Trees with 5, 10, 15, and 20 years of fast-growth at commercial plantations located in Mato Grosso, Brazil were evaluated. The base diameter of the trees ranged from 13.1 (5 years) to 28.3 cm (20 years), and the heartwood percentage increased from 16.3 to 60.0%, respectively. The color parameters in the CIELab system indicated that wood became darker and more saturated, and the predominance of yellow color decreased compared with red as age advanced. The total extractive content ranged between 7.4 (5 years) and 9.6% (15 years), without a clear trend of age affecting the extractive content. The extractives from five-year-old wood were mainly composed of tectoquinone (43.3%), phthalic acid (19.1%), and 1,3-indandione (9.2%), while those from 20-year-old wood were mainly composed of tectoquinone (60.7%), lapachol (13.8%), and phthalic acid (9.7%). Teakwood can be classified as resistant (5 years) to very resistant (20 years) after being submitted to an accelerated decay test.
Forestry companies have invested in genetic improvement to increase wood production in a shorter amount of time. Thus, studies are needed to compare the properties of clonal and seminal wood ...materials. The objective of this study was to analyze physical and mechanical properties of Tectona grandis from clonal (C1 and C2) and seminal (S) origin and evaluate the yield and quality of sawn wood subjected to outdoor and oven drying. Genetic material was collected from six, 15-year-old trees. Clone C2 presented the lowest amount of bark, and 51 % heartwood up to half the commercial height, while the heartwood of C1 and S went up to 25 % of the height. The three materials did not differ statistically for maximum angular deviation, pith eccentricity, basic density, Janka hardness, anisotropy, commercial income of sawn wood and the presence of knots. After the drying processes, the bowing and crooking indexes were less than 5 mm.m-1, however, the seminal material showed a higher cracking incidence after outdoor and oven drying. In conclusion, the wood properties of the three materials are similar. In addition, the oven drying process is recommended.
QUALITY OF TROPICAL HARDWOOD FLOORS Costa, Ana Carolina Silva; Oliveira, Aylson Costa; Pereira, Bárbara Luísa Corradi ...
Revista Árvore,
01/2021, Volume:
45
Journal Article
Peer reviewed
Open access
ABSTRACT This study aimed to determine the basic density of the wood and to simulate the performance of flooring produced with wood from five tropical species: Dipteryx odorata (Cumaru), Handroanthus ...spp. (Ipê), Hymenaea Courbaril (Jatobá), Astronium Lecointei (Muiracatiara), and Bowdichia virgilioides (Sucupira-Preta). Falling steel sphere, static and dynamic friction, indentation caused by loads applied in small areas, rolling load, and abrasiveness impact tests were simulated. The results were subjected to analysis of variance and Tukey’s test at 5% significance, and Pearson’s correlation was performed between the basic density and the indexes of each flooring. The basic density of the wood flooring made from the evaluated species ranged from 0.735 to 0.958 g.cm-3. D. odorata, Handroanthus spp. and H. courbaril woods were classified as heavy, while those of A. Lecointei and B. Virgilioides as moderately heavy. It was possible to indicate D. odorata, Handroanthus spp., H. courbaril, and B. Virgilioides flooring for environments with intense traffic where there is dragging or falling objects such as industries and companies. The A. Lecointei flooring can be used in residential environments with light traffic, where the loads exerted are low. There was a correlation between the basic wood density and the flooring use simulation tests.
RESUMO O objetivo deste estudo foi determinar a densidade básica da madeira e simular o comportamento em uso de pisos maciços produzidos com madeiras de cinco espécies tropicais: Dipteryx odorata (cumaru), Handroanthus spp. (ipê), Hymenaea courbaril (jatobá), Astronium lecointei (muiracatiara) e Bowdichia virgilioides (sucupira-preta). Nos testes de simulação foram realizados os ensaios de impacto da esfera de aço cadente, de atrito estático e dinâmico, de endentação causada por cargas aplicadas em pequenas áreas, de carga rolante e de abrasividade. Os resultados foram submetidos à análise de variância e ao teste de Tukey, a 5% de significância, e realizou-se a correlação de Pearson entre a densidade básica e os índices de cada ensaio de simulação de pisos. A densidade básica dos pisos de madeira das espécies avaliadas variou de 0,735 a 0,958 g·cm-3, sendo as madeiras de D. odorata, Handroanthus spp. e H. courbaril classificadas como pesadas e as de A. lecointei e B. virgilioides como moderadamente pesadas. Foi possível indicar os pisos de D. odorata, Handroanthus spp., H. courbaril e B. virgilioides para ambientes com tráfego intenso, onde há o arraste ou a queda de objetos, como indústrias e empresas. Já o piso de A. lecointei pode ser utilizado em ambientes residenciais, com tráfego leve, onde as cargas exercidas sejam baixas. Houve correlação entre a densidade básica da madeira e os ensaios de simulação dos pisos em uso.
TORREFIED BRIQUETTES OF SUGAR CANE BAGASSE AND EUCALYPTUS Costa, Emylle Veloso Santos; Pereira, Matheus Perdigão de Castro Freitas; Silva, Carlos Miguel Simões da ...
Revista Árvore,
01/2019, Volume:
43, Issue:
1
Journal Article
Peer reviewed
Open access
ABSTRACT Torrefaction and briquetting are two techniques that improve the quality of the biomass and facilitate direct use as fuel. The objective was to evaluate the effect of torrefaction ...temperature on the properties of the compound briquettes made from sugar cane bagasse and Eucalyptus sawdust. After sample preparation and particle analyses, briquettes were produced with the mixture of the two biomasses, a total of five compositions (0, 25, 50, 75 and 100%) at 120 °C and pressure of 1500 PSI. Subsequently, the briquettes were torrefied at temperatures of 180, 220 and 260 °C, for a period of 15 minutes. According to the results, both biomasses of Eucalyptus sawdust and sugar cane bagasse showed potential for the production of briquettes. The torrefaction reduced hygroscopicity and increased the calorific value of compound briquettes. The ideal composition for the production of briquettes is 100% Eucalyptus. The composition of 50% Eucalyptus + 50% sugar cane bagasse is also a great option, as some bagasse parameters were excellent. 260 °C was the best temperature to promote energy savings.
RESUMO A torrefação e a briquetagem são duas técnicas que melhoram a qualidade da biomassa e facilitam seu uso direto como combustível. O objetivo do trabalho foi avaliar o efeito da temperatura de torrefação nas propriedades dos briquetes compostos produzidos com bagaço de cana-de-açúcar e serragem de eucalipto. Após o preparo das amostras e análises das partículas, produziram-se briquetes com a mistura das duas biomassas, totalizando cinco composições (0, 25, 50, 75 e 100%), na temperatura de 120°C e pressão de 1500 PSI. Posteriormente, realizou-se a torrefação dos briquetes nas temperaturas de 180, 220 e 260°, por um período de 15 minutos. De acordo com os resultados, tanto as biomassas de serragem de eucalipto como a de bagaço de cana apresentaram potencial para produção de briquetes. A torrefação reduziu a higroscopicidade e aumentou o poder calorífico dos briquetes compostos. A composição ideal para a produção de briquetes é a de 100% eucalipto. A composição de 50% eucalipto + 50% bagaço de cana também é uma ótima opção, já que alguns parâmetros do bagaço se sobressaíram. A temperatura de 260°C foi a que promoveu melhores ganhos energéticos.
Deterioration of Teak Wood in Accelerated Decay Test Oliveira, Weslley Candido de; Pereira, Bárbara Luísa Corradi; Goes, Leonora Stéfani de Assis ...
Floresta e Ambiente,
01/2019, Volume:
26, Issue:
2
Journal Article
Open access
ABSTRACT The present study aimed to evaluate the biological resistance of teak (Tectona grandis) heartwood and sapwood to the action of Trametes versicolor and Gloeophyllum trabeum fungi in ...laboratory accelerated decay assays. The mass loss evaluation of the samples was performed periodically. The heartwood presented a higher percentage of extractives and the sapwood of holocelluloses. The sapwood and heartwood subjected to the fungus Gloephyllum trabeum remained stable. For the Trametes versicolor fungus, there was an increasing loss of mass over time for both regions, presenting a mass loss of 40% for the sapwood and of 20% for the heartwood at the conclusion of the assay. Teak wood was classified as highly resistant to the fungus Gloeophyllum trabeum, and moderately resistant to Trametes versicolor.
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