Specific gravity and shrinkage of wood of three species of eucalypts for furniture

Abstract

A utiliza\ue7\ue3o da madeira de \ue1rvores de esp\ue9cies de reflorestamento pela ind\ufastria moveleira tem apresentado tend\ueancia de crescimento nos \ufaltimos anos. Nesse sentido, no presente trabalho foram determinadas a massa espec\uedfica b\ue1sica e varia\ue7\ue3o dimensional da madeira de \ue1rvores de Eucalyptus grandis , Eucalyptus dunnii e Eucalyptus urophylla , de 18 anos, para a aplica\ue7\ue3o como componentes de madeira maci\ue7a em movelaria. Os ensaios laboratoriais para a avalia\ue7\ue3o da massa espec\uedfica b\ue1sica e da varia\ue7\ue3o dimensional da madeira nos sentidos radial e longitudinal do tronco das \ue1rvores de eucaliptos foram realizados de acordo com a NBR 7190/96. Os resultados da an\ue1lise da madeira das esp\ue9cies de eucalipto foram submetidos ao Teste de Homogeneidade, An\ue1lise de Vari\ue2ncia, Teste de Tukey e Correla\ue7\ue3o de Pearson e comparados com o desempenho da madeira de sucupira ( Bowdichia nitida ) e de cumaru ( Dipteryx odorata ) utilizadas na ind\ufastria moveleira. Verificou-se para a madeira de Eucalyptus grandis menor valor de varia\ue7\ue3o dimensional, sendo a mais indicada para componentes de m\uf3veis que exigem elevada estabilidade dimensional, al\ue9m de pe\ue7as de maior superf\uedcie. A madeira dessa esp\ue9cie apresentou \uedndice de varia\ue7\ue3o dimensional compat\uedvel com o de esp\ue9cies nativas utilizadas na ind\ufastria moveleira. Verificou-se, ainda, varia\ue7\ue3o radial das propriedades da madeira, com alta correla\ue7\ue3o entre a massa espec\uedfica b\ue1sica e a varia\ue7\ue3o dimensional. No sentido longitudinal, a base do tronco das \ue1rvores de eucalipto mostrou-se com a regi\ue3o de madeira de maior estabilidade dimensional.The utilization of wood from reforested species by the furniture industry is a recent trend. Thus, the present study determined the specific gravity and shrinkage of wood of 18-year-old Eucalyptus grandis , Eucalyptus dunnii and Eucalyptus urophylla , for use as components in solid wood furniture making. The tests to evaluate the specific gravity and shrinkage of wood in the radial and axial variation of the eucalyptus trees were performed according to NBR 7190/96. The results of the analysis of wood from eucalypt species were subjected to the Homogeneity Test, ANOVA, Tukey and Pearson correlation and compared to the performance of sucupira wood ( Bowdichia nitida ) and cumaru wood ( Dipteryx odorata ), often used in the furniture industry. The following results were found: Eucalyptus grandis had a lower value of shrinkage, being more suitable for furniture components that require high dimensional stability, as well as parts of larger surface. The wood of this species showed a rate of dimensional variation compatible with the native species used in the furniture industry. The radial variation of the wood was also verified, and a high correlation between specific gravity and shrinkage was found. Longitudinally, the base of the trunk of the eucalyptus trees was shown to be the region of greatest dimensional stability