Using acoustic wave velocity to select fibre-managed plantation Eucalyptus nitens logs for laminated veneer lumber products
Blackburn, D and Vega, M and Nolan, G, Using acoustic wave velocity to select fibre-managed plantation Eucalyptus nitens logs for laminated veneer lumber products, Southern Forests pp. 1-12. ISSN 2070-2620 (2019) [Professional, Refereed Article]
The aims and objectives of this study were to: Investigate the potential to predict LVL stiffness from wood properties measured on trees and logs; determine variation in log, wood, and veneer properties as a function of tree height and age.
Log selections were made from trees in three stands that were planned for harvesting at 14, 20 and 21 years of age. Rotary peeled veneer recovery from the logs was on average 65 percent. After drying, Metriguard testing showed over 50 percent of the veneer had an estimated dynamic modulus of elasticity (MOEdyn) above 12 Gigapascals (GPa), with 20 percent above 14 GPa, and that veneer from the second log by tree height had higher MOEdyn values. In visual assessment to the AS/NZS 2269.0:2012 Standard, no veneer could be utilised in a panels face or sub-face positions and older-age stand provided almost four times the volume of usable veneer. Standing tree AWV explained a moderate amount of variance in log MOEdyn and Pearson correlation coefficients between the (Metriguard) veneer MOEdyn, log AWV, log MOEdyn, and disc basic density were significant, positive and strong, with log AWV explaining most of the observed variance in log stiffness. A moderately strong and positive linear regression existed between log AWV and veneer MOEdyn, supporting the use of log AWV tools for the ranking of stiffness in fibre grown plantation E. nitens logs. Mechanical strength testing of LVL studs extracted from panels manufactured from the trialís veneer, indicated they equalled, and for some tested parameters exceeded, the characteristic design strength values previously published by commercial LVL manufacturers for equivalent size pine products.