This project explores a new and economical way to improve the properties of BC softwood lumber, generally not considered by the industry. Surface and vacuum pressure polymer treatments of Lodgepole Pine, Subalpine Fir, and White Spruce (SPF) from Northern BC were investigated to assess the effectiveness of polyurethanes of different molecular weights, and several epoxy products. Penetration depth, density, and growth rate were evaluated in relation to treatment efficacy. The low molecular weight polymer generally gave the better penetration and results. Vacuum pressure application was found to be impractical and unsuccessful due to the moisture-reactive nature of the polyurethanes. Results show that a new composite with a useful combination of properties including high MOR, flexibility, hardness, and abrasive resistance could be obtained. The properties are dependent on the polymer interaction with wood species, wood components (sapwood/heartwood) and treatment face (tangential, radial, and longitudinal). The findings are valuable in the designing of new products and utilization of BC softwood lumber (e.g. the underutilized Subalpine Fir species) for value-added products by exploiting these treated product properties. Products with more flexible nature such as flooring and wall panel applications could be developed with underutilized species such as Subalpine Fir. A recommendation of this study is to transfer the findings into the industrial area by examining applications of the modified wood, as well as to investigate further property enhancement through the optimization of penetration and the examination of water soluble thermosetting polymers. As the results with SPF were promising, it would be of value to examine a greater range of BC wood species such as Douglas-Fir, Cedar, and Hemlock, found in coastal forests, as their growth rates would generally be much greater than those of the Northern SPF group. Suezone Chow, Alice Obermajer, Alison Hack .
Chow, Suezone, Obermejer, Alice; Hack, Alison. 2003. Quality and surface modification of BC softwood for value-added products. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2003MR244