Canadian Forest Service Publications

Improving value recovery of OSB from post-mountain pine beetle wood. 2005. Feng, M.W.; Knudson, R.M. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, B.C. Mountain Pine Beetle Initiative Working Paper 2005-13. 74 p.

Year: 2005

Available from: Pacific Forestry Centre

Catalog ID: 25487

Language: English

Series: Mountain Pine Beetle Working Paper (PFC - Victoria)

CFS Availability: PDF (download)


This project examined methods of log hydration and strander operation for OSB manufacture using mountain pine beetle (MPB)-killed wood. The results are potentially beneficial to all kinds of wood product manufacture involving log conditioning (lumber, plywood, OSB, etc.).

The grey stage MPB logs used in this study had little bark and were heavily checked and had relatively even moisture gradients (15%-25%). Their average dry density (0.447) was about the same as that of green pine, but about 23% higher than the dry density of aspen.

Water sprinkling was an effective method for reducing the production of fines and increasing the proportion of larger strands from MPB logs. The generation of fines during stranding was reduced by 28% after 10 days sprinkling, by 30% after 20 days sprinkling and by 35% after 30 days sprinkling. To restore physical properties of dry MPB wood, the optimal hydration appeared to be close to the fibre saturation point.

Similar to vat conditioning, water sprinkling is effective in increasing moisture content in only the outer sections of the logs. There is high potential for improvement of log conditioning to increase moisture uptake in the inner portions of MPB wood. Further development of industrially viable log hydration methods (industrial scale-up of sprinkled log storage, changes to log pond operation, etc.) is strongly recommended.

Strander knife package set-up can have a significant impact on strand size distribution. However, the differences between the outcomes of 50º, 60º and 70º counter knife angles were unexpectedly small in this study.

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