The potential to recover higher value veneer products from fibre managed plantation eucalypts and broaden market opportunities for this resource. Part A and Part B
Tasmanian forests are predicted to produce over 2,000,000 cubic metres of pulp grade hardwood logs annually, largely from unpruned, unthined plantations currently managed for fibre production. However, variable world wood chip prices mean growers must breed and grow trees that could find more valuable uses in the future—particularly in rotary peeled veneers, plywood and LVL (laminated veneer lumber).
Part A of this project identified the genetic parameters and wood quality of Tasmanian plantation E. nitens—sampling trees aged 16 years and 26 years—and 33-year old E.globulus.
The results reveal a genetic correlation between pulpwood selection criteria and wood stiffness in E. nitens. Breeding programs that improved desired properties in pulpwood have also improved the veneer stiffness for veneered engineered wood products.
The 16-year E. nitens was not very useful for producing higher value veneer and ply because of low overall veneer recovery and a tendency to produce a relatively high proportion of low-grade (knotty) veneer, which is plentiful and cheap. The older E. nitens tended to deliver a higher recovery than the younger material and was higher in stiffness than the younger material. Although E. nitens veneers often failed to meet minimum visual grade standards, they could be used for structural products and for producing LVL.
The E. globulus produced veneer that was higher in stiffness to any of the E. nitens.
Researchers expect that further breeding and optimising peeling, drying, gluing and pressing processes will increase the use of younger E. nitens for higher value products. They also found that acoustic velocity measurements of logs enabled them to sort and select the best logs for value-added processing (i.e. some logs created better plywood panels)
Part B of the project investigated markets for products manufactured using rotary peeled veneer from native pulpwood and the potential to develop niche markets for these products.
The results show small-diameter or poor quality native forest eucalypt logs can be successfully peeled and dried, and the veneer used to produce LVL. This LVL can be re-sawn to produce a range of high-quality appearance-grade products such as flooring, furniture and framing. The researchers expect the strength, durability and stability of the LVL products to equal or surpass equivalent solid wood products. They also suggest plantation grown hardwoods and softwoods could be used in certain lower-strength applications.
The researchers recommend follow-up detailed technical assessment and economic analysis for both studies.