DENSIDADE BÁSICA E ESTABILIDADE DIMENSIONAL DE MADEIRAS TROPICAIS MODIFICADAS POR TRATAMENTOS TÉRMICOS

O objetivo deste estudo foi avaliar as modificações de propriedades físicas das madeiras de três espécies tropicais de interesse comercial por tratamentos térmicos conduzidos com diferentes temperaturas e tempos de exposição ao calor. Amostras de madeira de Pouteria caimito, Protium altissimum e Jacaranda copaia foram submetidas a modificações térmicas a 180 e 240 °C, ambas por 1 e 2 h. Foram avaliadas redução de massa, densidade básica e contração volumétrica das madeiras. O tratamento de 2 h a 240 °C causou maior redução de massa para todas as espécies. Pouteria caimito e Protium altissimum não apresentaram diferença significativa na densidade básica e contração volumétrica entre os tratamentos térmicos. A redução de massa, que confirma a efetividade dos tratamentos térmicos, aliada à manutenção da densidade é básica, é benéfica para a qualidade das madeiras. Jacaranda copaia apresentou maior estabilidade dimensional, mas foi mais afetada pelas variações dos tratamentos com diminuição da densidade básica da madeira quando submetida a 180 ºC por 1 h e 240 ºC por 2 h. A secagem das madeiras não tratadas, assim como os tratamentos térmicos, diminui a capacidade de adsorção de água e o volume saturado, resultando em contrações volumétricas similares às das madeiras termicamente tratadas. Palavras-chave: secagem da madeira; hornificação; densidade básica; contração volumétrica. Basic density and dimensional stability of tropical woods modified by thermal treatments ABSTRACT: This study aimed to evaluate the wood physical properties’ modifications from three commercially interesting tropical species by thermal treatments carried out with different temperatures and heat exposure times. Wood samples of Pouteria caimito, Protium altissimum, and Jacaranda copaia were submitted to thermal modifications at 180 and 240 °C, both for 1 and 2 h. The mass reduction, basic density, and volumetric contraction were evaluated. The treatment of 2 h at 240 °C caused the highest mass reduction for all species. Pouteria caimito and Protium altissimum did not significantly differ in basic density and volumetric contraction of wood among thermal treatments. The mass reduction, which confirms the effectiveness of thermal treatments, allied to the maintenance of basic density, benefits the wood quality. Jacaranda copaia showed the greatest dimensional stability, but it was the most affected species by the variations of thermal treatments with decreases in basic wood density when submitted to 180 ºC for 1 h and 240 ºC for 2 h. The drying of the samples, as well as the thermal treatments, may decrease the water adsorption and saturated volume, resulting in volumetric contractions similar to those of thermally treated samples. Keywords: wood drying; hornification; basic density; volumetric contraction.

Download Full-text

ANÁLISE DA MASSA ESPECÍFICA E DA RETRATIBILIDADE DA MADEIRA DE Tectona grandis NOS SENTIDOS AXIAL E RADIAL DO TRONCO

FLORESTA ◽

10.5380/rf.v45i4.31991 ◽

2015 ◽

Vol 45 (4) ◽

pp. 671 ◽

Cited By ~ 1

Author(s):

Ghislaine Miranda Bonduelle ◽

Setsuo Iwakiri ◽

Rosilani Trianoski ◽

José Guilherme Prata ◽

Vinicius Yurk Rocha

Keyword(s):

Physical Properties ◽

Wood Density ◽

Dimensional Stability ◽

Radial Direction ◽

Wood Quality ◽

Basic Density ◽

Tectona Grandis ◽

Axial Direction ◽

Tree Trunk ◽

The City

O objetivo deste trabalho foi avaliar a massa específica e a retratibilidade da madeira nos sentidos axial e radial do tronco. Foram coletadas cinco árvores com 18 anos, provenientes do município de Brasnorte, MT, as quais foram seccionadas nas posições da base, meio e topo, para avaliação das propriedades no sentido axial. Da parte diametral das toras foram obtidos pranchões onde foram controladas as posições radiais. A avaliação da massa específica e da retratibilidade da madeira seguiu as recomendações da norma panamericana. Os resultados demonstraram que a teca possui massa específica aparente a 12% de 0,606 g.cm-3, massa especifica básica de 0,524 g.cm-3 e fator anisotrópico de 2,271. Não foram observadas grandes variações de propriedades tanto no sentido axial quanto no radial. As propriedades físicas demonstram que a madeira possui média estabilidade dimensional, podendo ser indicada para aplicações em laminação, lambris, portas, decoração e movelaria. AbstractAnalysis of wood density and shrinkage of Tectona grandis wood in axial and radial direction of the tree trunk. This research aimed to evaluate density and shrinkage of wood in axial and radial directions of the tree. We collected five trees aged 18, from the city of Brasnorte, MT, which were cut at the base, middle and top, for evaluation of the properties in axial direction. We obtained planks from the diametric part of the logs, from which we controlled radial positions. The evaluation of density and shrinkage of wood followed the panamerican standard recommendations. The results revealed that teak has apparent density at 12% of 0.606 g.cm-3, basic density 0.524 g.cm-3, and anisotropic fator of 2,271. There were no major variations in properties both in axial and radial direction. The physical properties demonstrate that the timber has medium dimensional stability, and it could be used in peeling, sidings, doors, decorating and furniture industry.Keywords: Teak; anisotropy; dimensional stability; wood quality.

Download Full-text

Influence of Heat on Seed Germination of Cistus Laurifolius and Cistus Ladanifer

International Journal of Wildland Fire ◽

10.1071/wf9920015 ◽

1992 ◽

Vol 2 (1) ◽

pp. 15 ◽

Cited By ~ 47

Author(s):

L Valbuena ◽

R Tarrega ◽

E Luis

Keyword(s):

Seed Germination ◽

High Temperatures ◽

Exposure Time ◽

Germination Rate ◽

Heat Exposure ◽

Cistus Ladanifer ◽

Different Temperatures ◽

Petri Dishes ◽

Germinated Seeds

The influence of high temperatures on germination of Cistus laurifolius and Cistus ladanifer seeds was analyzed. Seeds were subjected to different temperatures for different times, afterwards they were sowed in plastic petri dishes and monitored for germinated seeds over two months.The germination rate observed in Cistus ldanifer was greater than in Cistus laurifolius. In both species, heat increased germination percentages. For Cistus laurifolius higher temperatures or longer exposure times were needed. Germination percentages of Cistus ladanifer were lower when heat exposure time was 15 minutes.It must be emphasized that germination occurred when seeds were not treated, while seeds exposed to 150�C for 5 minutes or more did not germinate.

Download Full-text

Hygroscopic properties of thermally modified false Iroko [Antiaris toxicara (Lesch)]

Journal of Agriculture Forestry and the Social Sciences ◽

10.4314/joafss.v18i1.7 ◽

2021 ◽

Vol 18 (1) ◽

pp. 51-57

Author(s):

F.A. Faruwa ◽

K. Duru

Keyword(s):

Weight Loss ◽

Dimensional Stability ◽

Thermal Process ◽

Colour Change ◽

Wood Properties ◽

Thermal Modification ◽

Hygroscopic Properties ◽

Different Temperatures ◽

Thermally Modified Wood ◽

Modified Wood

The study investigated the use of thermal modification to improve the hygroscopic properties of False Iroko [Antiaris toxicaria (Lesch)]. Samples of Antiaris toxicara Lesch wood were subjected to thermal modification in a furnace at temperatures of 160, 180 and 200°C for 30 and 60 minutes. Results showed that wood properties were improved with exposure to different temperatures. Subsequent to the thermal process, a colour change from pale yellow to darkish brown was observed progressively with increase in temperature, accompanied by a weight loss in the range of 12.08% to 23.67%. The outcome of these treatments resulted in a decrease in volumetric swelling and increase in dimensional stability of modified wood; this can be attributed to observed decrease in moisture intake. The thermal modification of Antiaris toxicara Lesch wood affected the dimensional stability properties. Thus, due to significant changes via modification carried out on the selected species which is classified as lesser utilized wood species, lesser utilized wood,Antiaristoxicara Lesch wood is recommended for use due to its efficient dimensional stability after modification . keywords:, Thermally modified wood ;False Iroko

Download Full-text

QUALITY OF REACTION WOOD IN Eucalyptus TREES TILTED BY WIND FOR PULP PRODUCTION

CERNE ◽

10.1590/01047760201723032286 ◽

2017 ◽

Vol 23 (3) ◽

pp. 291-297

Author(s):

Walter Torezani Neto Boschetti ◽

Juarez Benigno Paes ◽

Graziela Baptista Vidaurre ◽

Marina Donária Chaves Arantes ◽

João Gabriel Missia da Silva

Keyword(s):

Chemical Composition ◽

Chemical Constituents ◽

Wood Quality ◽

Basic Density ◽

Kraft Pulping ◽

Normal Wood ◽

Reaction Wood ◽

Opposite Wood ◽

Holocellulose Content

ABSTRACT This study aims to evaluate the quality of normal, tension and opposite wood of eucalyptus trees lengthwise, in straight and inclined stems, affected by wind action. It also aims to explain the pulping parameters resultant from the quality of the wood. The trees were grouped into four tilt ranges, ranging from 0 to 50º, and the basic density, chemical composition of the wood, and performance in kraft pulping were assessed. Normal and tension wood had similar basic densities; while for opposite wood, the density was lower, being responsible for a decrease in reaction wood density. The chemical composition of the wood was influenced by the presence of reaction wood in the stem. Tension and opposite wood showed lower levels of extractives and lignin and higher holocellulose content when compared to normal wood, with favorable wood quality for pulping. The increase in holocellulose content and the reduction of lignin and extractives content contributed positively to a more delignified pulp and reduction of the Kappa number. However, after cooking the reaction wood under the same conditions as those of normal wood, reaction wood pulping tends to have a lower screen yields. Due to differences in basic density and chemical constituents between opposite and normal wood, it is recommended not to designate the opposite wood as normal wood.

Download Full-text

Growth performance and wood quality of white jabon (Neolamarckia cadamba) progeny testing at Parung Panjang, Bogor, Indonesia

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d200826 ◽

2019 ◽

Vol 20 (8) ◽

Author(s):

Nurul Chaerani ◽

DEDE J SUDRAJAT ◽

ISKANDAR Z SIREGAR ◽

ULFAH J SIREGAR

Keyword(s):

Specific Gravity ◽

Moisture Content ◽

Growth Performance ◽

Wood Density ◽

Block Design ◽

Wood Quality ◽

Basic Density ◽

Progeny Testing ◽

Pilodyn Penetration

Abstract. Chaerani N, Sudrajat DJ, Siregar IZ, Siregar UJ. 2019. Growth performance and wood quality of white jabon (Neolamarckia cadamba) progeny testing at Parung Panjang, Bogor, Indonesia. Biodiversitas 20: 2295-2301. The aim of this study was to evaluate the genetic parameters of growth and wood quality in white jabon progeny test at 54 months old in Parung Panjang, Bogor. The 105 half-sib families obtained from 12 provenances were evaluated in a randomized complete block design with five replications. Wood quality was assessed both in a non-destructive way using a pilodyn and by destructive method using wood sample taker. Results indicated that the mean value ranged from 5.10 to 10.15 m for height, 6.67 to 15.30 cm for diameter, 2.30 to 3.62 cm for pilodyn penetration, 0.66 to 0.82 g/cm3 for wood density, 0.33 to 0.50 for specific gravity, and 66 to 111 % for moisture content, respectively. There were significant differences among 105 families for all traits except moisture content. The high heritability estimate was found for height (0.4-0.69) and basic density (0.27-0.59). Applying 80% selection intensity on diameter and leaving 84 best families in each block will produce a high total genetic gain. Pilodyn penetration had negative correlation with diameter, wood density, and specific gravity.

Download Full-text

QUALITY OF TROPICAL HARDWOOD FLOORS

Revista Árvore ◽

10.1590/1806-908820210000003 ◽

2021 ◽

Vol 45 ◽

Author(s):

Ana Carolina Silva Costa ◽

Aylson Costa Oliveira ◽

Bárbara Luísa Corradi Pereira ◽

José Reinaldo Moreira da Silva ◽

Mônica Bezerra de Oliveira ◽

...

Keyword(s):

Basic Density ◽

Tropical Species ◽

Steel Sphere ◽

Hymenaea Courbaril ◽

Small Areas ◽

Tropical Hardwood ◽

Wood Flooring ◽

Rolling Load ◽

Dipteryx Odorata

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.

Download Full-text

Relationship between Growth and Wood properties in Agathis sp. Planted in Indonesia

Wood Research Journal ◽

10.51850/wrj.2012.3.1.1-5 ◽

2017 ◽

Vol 3 (1) ◽

pp. 1-5

Author(s):

Futoshi Ishiguri ◽

Kazuko Makino ◽

Imam Wahyudi ◽

Jun Tanabe ◽

Yuya Takashima ◽

...

Keyword(s):

Wood Quality ◽

Basic Density ◽

Tree Breeding ◽

Wood Properties ◽

Stem Diameter ◽

Breeding Programs ◽

Significant Difference ◽

Pilodyn Penetration ◽

The Mean ◽

The Relationship

The present study clarified the relationship between the growth and wood properties of 54-year-old Agathis sp. trees planted in Indonesia. Stem diameter, pilodyn penetration, and stress-wave velocity (SWV) were measured for all trees (35 trees) in a plot (30  30 m) located almost at the center of a stand. Based on the mean stem diameter, 10 standard trees in a plot were selected for measuring the basic density (BD) and compressive strength parallel to grain (CS). Core samples (5 mm in diameter) were collected from the 10 selected trees to determine BD and CS. The mean stem diameter, pilodyn penetration and SWV in the plot were 40.2  11.3 cm, 23.4  2.1 cm, and 3.85  0.43 km/s, respectively. No significant correlation coefficeint (r = -0.327, no significance at 5% level) was obtained between stem diameter and SWV. The mean BD and CS in the 10 trees were 0.42  0.03 g/cm3 and 28.1  2.7 MPa, respectively. A significant positive correlation was observed between BD and CS. Analysis of variance (ANOVA) revealed a significant difference between BD and CS values of the 10 trees, indicating that wood properties may differ among trees with the same standard growth in a stand. From these results, we concluded that wood quality improvement in this species could be achieved by selecting trees with high density and strength in tree breeding programs.

Download Full-text

Numerical Study of Heat and Mass Transfer during the Thermal Drying of Tropical Woods

International Journal of Thermal and Environmental Engineering ◽

10.5383/ijtee.08.01.002 ◽

2014 ◽

Vol 08 (1) ◽

Keyword(s):

Water Content ◽

Thermophysical Properties ◽

Numerical Study ◽

Wood Quality ◽

Central Africa ◽

Industrial Process ◽

Self Control ◽

Heat Equations ◽

Wood Drying ◽

Tropical Woods

A sector of utilization and transformation of wood give much money at the countries of the central Africa region. If we want to increase these advantages, it is important to do locally the first and second transformations of wood. Self-control of the wood drying is necessary to ameliorate a wood quality and to preserve an art work doing in wood. In this article, we are modeling a drying of one piece of bete wood (Mansonia altissima) with dimensions are 1m of length and thickness is no more than 25cm. We have used a literature to obtain a mass and heat equations and the thermophysical properties of the present wood. We have considered some thermophysical properties that we are unkempt in the precedent work [1]. We have experimentally obtained a relationship between a density of this wood with a water content. The others thermophysical properties come from the literature [1,2]. We have simulated a wood drying in the constant conditions and in the conditions of the bete drying table established by CIRAD Organization. A sensibility study is doing to validate a modeling. Then, the present modeling explains temperature, mass fraction of the vapor in air and water content evolutions during the industrial process of drying. This modeling can to be used for to overhaul a drying table of bete wood and the others of tropical woods. This work uses a gaseous pressure can be used to explain the drying with the high temperatures conditions.

Download Full-text

VARIAÇÃO LONGITUDINAL E EFEITO DO ESPAÇAMENTO NA MASSA ESPECÍFICA BÁSICA DA MADEIRA DE Mimosa scabrella E Ateleia glazioveana

FLORESTA ◽

10.5380/rf.v43i2.29266 ◽

2013 ◽

Vol 43 (2) ◽

pp. 327 ◽

Cited By ~ 2

Author(s):

Elder Eloy ◽

Braulio Otomar Caron ◽

Rômulo Trevisan ◽

Denise Schmidt ◽

Magda Lea Bolzan Zanon ◽

...

Keyword(s):

Block Design ◽

Wood Quality ◽

Basic Density ◽

Technological Characteristic ◽

Diameter At Breast Height ◽

Breast Height ◽

Living Space ◽

Randomized Complete Block Design ◽

Axial Variation ◽

Set Up

Este trabalho teve como objetivo avaliar a variação longitudinal e o efeito do espaçamento de plantio na massa específica básica das árvores de Mimosa scabrella Benth e Ateleia glazioveana Baill, aos 36 meses de idade. Analisou-se um experimento instalado em delineamento de blocos completos casualizados, com três repetições. Os tratamentos foram definidos em função dos espaçamentos (2,0x1,0 m, 2,0x1,5 m, 3,0x1,0 m e 3,0x1,5 m). Foram avaliadas 72 árvores, sendo essas medidas e cubadas pelo método de Smalian. Em seguida, foram retirados discos nas posições do tronco: 0,10 m (base), 1,30 m do solo (DAP – Diâmetro a Altura do Peito), 25%, 50% e 75% da altura total da árvore, para determinação da massa específica básica. A massa específica básica em árvores de Mimosa scabrella apresentou um decréscimo até a região do DAP, seguido de acréscimo, sem tendência de estabilização com a altura. A Ateleia glazioveana apresentou uma tendência de decréscimo no sentido base-topo das árvores. Os espaçamentos influenciaram a variação da massa específica básica em árvores de Mimosa scabrella e Ateleia glazioveana, não sendo verificada uma variação sistemática positiva ou negativa em relação ao espaço vital proporcionado.Palavras-chave: Variação axial; característica tecnológica da madeira; qualidade da madeira; espaçamento de plantio. AbstractLongitudinal variation and effect of spacing on basic density wood of Mimosa scabrella and Ateleia glazioveana. This study aimed to evaluate the variation in length and effect of spacing of the basic density of Mimosa scabrella Benth e Ateleia glazioveana Baill, trees with 36 months of age. We analyzed an experiment set up in randomized complete block design with three replications. The treatments were defined by the spacing (2.0x1.0 m, 2.0x1.5 m, 3.0x1.0 m, 3.0x1.5 m). 72 trees were evaluated, and these measures and scaled by the method of Smalian. Then, the disks were removed from the trunk positions: 0.10 m (base), 1.30 m (DAP - diameter at breast height), 25%, 50% and 75% of the total height of the tree, determining the basic density. The basic density in trees of Mimosa scabrella showed a decrease to the region of the DAP, followed by addition, without a tendency to stabilize with time. The Ateleia glazioveana showed a decreasing trend towards bottom-up tree. The spacing influenced the variation of basic density in trees of Mimosa scabrella e Ateleia glazioveana not been verified a systematic positive or negative trend in relation to the living space provided. Keywords: Axial variation; technological characteristic of wood; wood quality; planting space.

Download Full-text

Genotypic variation in the basic density, dynamic modulus of elasticity and tracheid traits of Pinus elliottii in three progeny trials in southern China

Holzforschung ◽

10.1515/hf-2019-0046 ◽

2019 ◽

Vol 74 (1) ◽

pp. 1-9

Author(s):

Meng Lai ◽

Leiming Dong ◽

Chunhui Leng ◽

Lu Zhang ◽

Min Yi

Keyword(s):

Genetic Correlation ◽

Modulus Of Elasticity ◽

Dynamic Modulus ◽

Southern China ◽

Wood Quality ◽

Basic Density ◽

Pinus Elliottii ◽

Wood Properties ◽

Correlated Response ◽

Dynamic Modulus Of Elasticity

AbstractA firm understanding of the genetic relationships among wood properties is a prerequisite for breeding for higher wood quality in Pinus elliottii families. To examine and deal with such relationships, increment cores were sampled at breast height from 1260 trees in 42 open-pollinated families in three 27-year-old Slash pine progeny trials in southern China, and genetic variation, genotype-by-environment (G × E) interaction, genetic correlation and correlated response were investigated. The basic density (BD), dynamic modulus of elasticity (MOED) and tracheid traits were found to be under moderate to strong genetic control for the three locations combined, with individual narrow-sense and family mean heritability ranging from 0.28 to 0.44 and 0.52 to 0.69, respectively. Type B genetic correlation estimates indicated that the G × E interaction had a small-level influence on wood properties. Strong genetic correlations (rg) were found between BD and MOED at the three sites (rg = 0.46–0.85), and BD or MOED showed moderate to strong correlations with most tracheid traits at specific localities. In tree breeding programs, one possible strategy would be to improve pulpwood quality and the strength of structural wood through selection for different wood quality traits.

Download Full-text