Influência das características anatômicas e do teor de extrativos totais da madeira de eucalyptus Grandis W. Hill ex maiden na qualidade da colagem

Abstract

The study aimed to anatomically characterize and to quantify the total extractives in different positions of the log of Eucalyptus grandis W. Hill ex Maiden with 18 years of age and to assess their influence on the shear strength and percentage of wood failure in adhesive bonded joints with thermosetting resorcinol-formaldehyde. Histological slides were prepared for an anatomical study and determined the total extractive content. The preparation of bonded joints was made according to ASTM D 2339-98(2000). It was used the correlation coefficient of Pearson, 1 % probability by t test to evaluate the correlation between the anatomical and extractives content with the quality of the glued joints. It was found that there was a correlation between the shear strength with the following characteristics: vessel diameter, wall width, length and width of the fiber, the width of the radius and total extractives content. For the percentage of wood failure, there was a correlation between this with the following characteristics: the frequency of vessels, thickness of the heat of fiber, and high frequency of lightning. Both the radial direction as in the longitudinal direction of the logs there was change in the values found for the measurement of the anatomical elements, the total amount of extractives, the shear test strength and the percentage of wood failure.