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

Antônio José Vinha Zanuncio,Bráulio Da Silva De Oliveira,Amélia Guimarães Carvalho,Jorge Luiz Colodette,Renato Augusto Pereira Damásio,Angélica De Cassia Oliveira Carneiro

doi:10.1590/0100-67622016000400016

Antônio José Vinha Zanuncio, Bráulio Da Silva De Oliveira + Show 4 more

Open Access

https://doi.org/10.1590/0100-67622016000400016

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Journal: Revista Árvore	Publication Date: Aug 1, 2016
Citations: 8	License type: cc-by

Affiliation: Universidade Federal de Viçosa

Abstract

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.

Highlights

The wood moisture content reduces the calorific value and carbonization yield (SWITHENBANK et al, 2011; ZANUNCIO et al, 2013a), worsens the mechanical properties (ENGELUND et al, 2013; BELTRAME et al, 2013), increases the transport costs (ZHU et al, 2011) and can cause defects such as cracks and warping (REBOLLEDO et al, 2013), making wood drying an essential process.Drying is more intense in wood having high humidity, with free water loss, which is held by weak intermolecular bonds (SKAAR, 1972)
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

Summary

Introduction

The wood moisture content reduces the calorific value and carbonization yield (SWITHENBANK et al, 2011; ZANUNCIO et al, 2013a), worsens the mechanical properties (ENGELUND et al, 2013; BELTRAME et al, 2013), increases the transport costs (ZHU et al, 2011) and can cause defects such as cracks and warping (REBOLLEDO et al, 2013), making wood drying an essential process.Drying is more intense in wood having high humidity, with free water loss, which is held by weak intermolecular bonds (SKAAR, 1972). The wood reaches the fiber saturation point (FSP) between 20 and 35% (KOLLMANN; CÔTÉ, 1968; BAL; BEKTAS, 2012; ZANUNCIO et al, 2014). This moisture range indicates that all free water has been removed, remaining the water of adsorption. This water is held in the wood by hydrogen bonds which require higher energy expenditure for its removal, reducing the drying process until the wood reaches the equilibrium moisture content (REZENDE et al, 2010; ENGELUND et al, 2013). The water of constitution, which is an essential part of the wood structure, can only be removed by wood degradation (SIAU, 1971)

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