Resumo de Potential Use Of Wood From Eucalyptus Grandis X Eucalyptus Urophylla Hybrid Clones For Veneer And Pl

The main objective of this work was to evaluate the potencial ofeucalyptus grandis x Eucalyptus urophylla hybrid clones wood forplywood and veneer production. Five (5) trees were collected for eachclone (I and II) and 2 logs of each tree, being one from base (A) andother subsequent one (B), totaling 20 logs. The logs after debarked andheated in hot water were processed in rotary cutting lathe generatingveneers of 2,00 mm nominal thickness. The peeling yield was evaluatedand mean values were 51,74% from clone I logs and 56,81% from the IIone. The veneer quality graded was conduced following Norma de Controlede Qualidade e Classificação de Compensados, Brazilians standards. Theclone I generated veneers of better quality: 11,94% of grade A veneer;32,84% of B; 54,48% of C and 0,75% of grade D veneer, while the cloneII generated: 1,20% of grade A veneer; 8,40% of B; 67,47% of C and22,89% of grade D veneer. 5 layers plywood was manufactured with gradeC veneers. The plywood manufacture treatment factors were: clone (I andII), glue amount (320 and 360 g/m2) and press time (8 and 12 minutes).From manufacture plywood were obtained specimens to evaluate thephysical properties - apparent specific mass, superficial absorption ofwater, total absorption of water, thickness swelling more thicknessrecovery and thickness recovery, and the mechanical properties -parallel and perpendicular static bending (MOR and MOE) and bondingline shear test in the dry and wet conditions. The result obtainedduring the physical and mechanical assessments of plywood were analyzedusing a variance analysis, executed by SAS (Statistical AnalysisSystem). There was not significant interaction among the factors clone,glue amount and press time, considering all the appraised variables.Significant differences were detected for factor clone in relation tothe variables apparent specific mass (clone I higher than clone II),superficial and total absorption of water (clone I smaller than cloneII); bonding line shear test (dry condition) and static bending -parallel and perpendicular MOR (clone I higher than clone II). To thefactor glue amount there was not significant difference among thetreatments for none of the appraised variables. There was significantdifference for the factor press time in relation to the variablessuperficial absorption of water (12 minutes smaller than 8 minutes),thickness swelling more thickness recovery and thickness recovery (8minutes smaller than 12 minutes). It's concluded that Eucalyptusgrandis x Eucalyptus urophylla hybrid clones wood have a high potencialfor phywood and veneer production.vvz

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