The impacts of panel density and strand alignment, and their synergistic effect, on bending strength and stiffness of strand-based wood composites were investigated experimentally. Fifteen unidirectional strand panels with a range of densities were manufactured. Bending specimens were cut at an angle with respect to the alignment direction at 15-degree increments from 0 to 90 degrees. Bending strength and stiffness with extended ranges of density (480 to 672 kg/m3) and strand alignment (0 to 90 degrees) enabled these production factors to be simultaneously investigated. The response of the bending properties to changes in density greatly depended on strand angle. A smaller strand angle exhibited a greater rate of bending property change with density. This synergistic effect provided a supplementary basis for focusing efforts in improving strand alignment on the thin layers near the high-density surfaces to enhance bending properties. The data presented in this article should be especially useful when dealing with unidirectional wood strand/veneer products, such as oriented strand lumber, where strand alignment and density are crucial for the intended application.
Contributor Notes
The authors are, respectively, Associate Professor, Shunde Polytechnic, Shunde, Guangdong, China (ysliuxiaohong@sdpt.com.cn); and Senior Scientist and Program Manager (siguo.chen@albertainnovates.ca) and Manager (rob.wellwood@albertainnovates.ca), Forest Products Business Unit, Alberta Innovates–Technology Futures, Edmonton, Alberta, Canada. This paper was received for publication in January 2010. Article no. 10730.