Under-utilized Canadian wood species for strand based products

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Canada has very large resources of trees such as Balsam Poplar (Populus balsamifera), Black Cottonwood (Populus trichocarpa), Jack Pine (Pinus banksiana), that are only minimally used in the strand-based product industry for a variety of reasons. Many of these other wood resources may be potentially suitable and close to some production facilities but are currently not or underutilized for composite board production. Since they are not as ubiquitous as Aspen (P. tremuloides), and there is less experience and information available to industry as to how this species converts to strands, flows through the blending and mat forming processes, and translates into board physical and mechanical properties. In some cases, such as Balsam Poplar, there are well-known problems experienced in conversion and utilization for OSB. The goal of this project is to generate data on stranding and OSB production from selected readily available but underutilized hardwoods and softwoods. This information will be used to produce a set of guidelines as to optimal stranding parameters as well as guidelines on differences in the pressing schedules between these species and Aspen for producing OSB with the optimum density profile and mechanical properties. Key project components include: (a) Material characterization - density, wood structure and moisture content, as it affects strander set up and strand quality outcomes; (b) Conversion to strands - target thickness 0.5 to 0.7 mm, width 18-25 mm, and length between 60 and 120 mm. Adjustable strander parameters include operating speed, knife protrusion (coupled with feed rate) and counter knife angle; (c) Strand behavior in key OSB processing stages: blending with resin, mat-forming, hot pressing; (d) Performance with different resin types and quantities. The two major resin systems used in OSB manufacture, either singly or in combination are Phenol Formaldehyde (PF), and Polymeric Methylene Di-Isocyanate (pMDI). OSB boards will be fabricated using both these resins, either singly, or in tandem (PF surfaces, pMDI core).