Analysis of glue line and correlations between anatomical characteristics of Eucalyptus grandis x Eucalyptus urophylla glued-laminated timber

Abstract

The main goal of this study was to analyze glue line on eucalyptus wood. In order to do that, thickness of main and secondary glue lines were measured as well their interaction with apparent density of elements glued with resorcinol-formaldehyde (RF) and castor polyurethane (CP) adhesives. Anatomical wood characterization of Eucalyptus grandis x Eucalyptus urophylla was performed by correlating glue line thickness. According to normative instruction, specimens were produced for delamination tests. The experiment was conducted in a completely random 2 x 2 design factorial scheme (two classes of apparent density and two adhesives). Pearson correlation (t < 0.01) was performed among variables. It was found that there was adhesive penetration into wood pots and rays. Glue line thickness was higher in woods with density higher than 0.58 g cm-3 glued with RF adhesive. There was low correlation among density, vessel diameter, main and secondary glue lines (t < 0.01).