Avaliação das caracteristicas da madeira e da polpa de Eucalyptus mediante e aplicação de método não destrutivo na árvore viva

Abstract

The eucalyptus wood is the main raw material used for bleached kraft pulp production in Brazil. The conventional methods to evaluate the wood quality for cellulose production include slow and expensive laboratorial methods of production and determination of the wood quality. The quality evaluation of the wood for simpler and faster techniques is a fundamental need in the qualification of Eucalyptus forests destined to the cellulose production. The objective of this study was characterizing six Eucalyptus clones and studying different wood non-destructive techniques and to correlate them with the conventional methods of laboratorial analysis. The samples were collected from commercial plantations (3,0 x 3,33m line spacing) in the areas of Cocais, Guanhães, Rio Doce-Ipaba and Santa Bárbara, in the state of Minas Gerais, with five three-year-old sample-trees by clone being used. The clones were characterized by different non-destructive methods (extensometer, resistograph, pilodyn, stress waves time and NIRS), using living trees at 1,3 m from the ground (DAP) and by destructive methods (basic density, morphology of the fibers, wood chemical composition and pulping), carried out in a laboratory on the whole chipped trees. The results showed that the extensometer and pilodyn methods are viable for the prediction of wood basic density. The value of longitudinal residual strain (DRL), obtained through the extensometer, presented good correlation with the pulping yield and the cellulose content. Among the characteristics evaluated for characterization of the cellulose pulp, it was the basic density and the lignin syringyl/guaicyl (S/G) ratio that influenced the pulp quality the most. The kappa number and the pulping yield showed significant correlations with the S/G ratio. The spectroscopy near infrared (NIRS) showed viable for estimation of lignin S/G ratio and wood basic density.