Evaluating the suitability of hybrid poplar clones for the manufacture of oriented strand boards

Abstract

Abstract Clonal trees from five different plantation-grown, industrially relevant hybrid poplar genotypes of the same age, grown on a common site in British Columbia, Canada, were tested for their performance in strand production and properties of oriented strand board (OSB). The results were compared against a benchmark mill-run OSB furnish derived from native aspen (Populus tremuloides). Variation in solid wood density among the hybrid poplar clones was shown to influence the compaction ratio and densification of the OSB, which in turn led to variation in board strength properties. After accounting for specimen density using co-variate statistical models, it was apparent that there were significant effects of genotype on bonding strength and thickness swell. Lower density wood from the fastest growing P. deltoides×P. trichocarpa (DTAC 7) clone resulted in better mat compaction and higher bond strength, whereas higher density wood from a P. trichocarpa×P. deltoides (TD 50-184) clone resulted in lower compaction and bonding strength. Flexural strength (rupture and elastic moduli) and nail pull through were not as significantly affected by either board density or genotype when adjusted for density. The study clearly demonstrates that fast grown, large diameter wood of lower initial wood density from hybrid poplar is highly suited for OSB production.