Optitek©, a sophisticated sawing simulator co-developed by FPInnovations - Forintek Division and Université Laval and used intensively by the wood industry across Canada will be used to simulate product recovery for each stem. Using the 3-D stem geometry data, each stem will be “processed” by Optitek© using the two types of sawmills (stud and random length mills) to obtain simulated sawmilling product recovery. Various product recovery parameters in relation to stand/tree/stem characteristics will be examined to develop tree-level sawmilling product recovery models. A virtual-shape stem will be reconstructed for each stem using both the CroBas model and our taper model, and the stems will be processed using Optitek©. The product recovery from the real-shape and virtual-shape stems will be compared to develop a product recovery correction model for stem deformations. Models will be developed to describe the lumber recovery difference between the two types of stems in relation to the stand and tree characteristics. The scanned stems will be divided into two comparable groups for lumber conversion studies at the two types of sawmill to validate the tree-level sawmilling product recovery models. The lumber, chip, plannings and sawdust samples from each stem will be used for Theme 4 studies.

Theme 3 also provides an excellent opportunity to quantify the impact of sawing/optimization strategies on chip volume and quality. Similarly, tree-level primary product recovery in relation to stand/tree/stem characteristics will be examined to develop the tree-level primary product recovery models. To evaluate the potential of the lumber samples for value-added wood products, the samples will be divided into two groups: structural products and appearance-based applications. For structural products major mechanical properties will be evaluated, and MSR yield will be determined for each stem. The mechanical properties and MSR yield in relation to various stand/tree/stem characteristics will be examined to develop tree-level mathematical models to predict the properties and MSR yield in relation to stand/tree/stem characteristics.

Researchers and students associated to this theme are :