This project presents the results of a computer simulation of the recovery obtained from six bucking optimization systems equipped with different scanner and conveyor combinations.
Forty sample stems were scanned and stem models developed to provide input for Forintek’s sawing simulation program, OPTITEK®. Input files of both sawmill machinery and their products were developed based upon the operation of a typical sawmill in the Interior of B.C. Optimized bucking solutions were generated, and sample stems were sawn accordingly. Lumber value and volume recovery data were obtained and enabled a performance evaluation of the six bucking optimization systems.
In this project the affect of both the log conveying system and the type of scanner was considered. Both lineal and transverse conveyor systems were studied and the effects of true shape, partial true shape and XY scanners were modelled. Various combinations of parameters were studied and the annual dollar production for such combinations were computed.
Recommendations are made relating to the different systems studied and how the results may be of benefit to mill optimization.
Le rapport présente une carte routière traçant les grandes lignes d'une stratégie d'innovation technologique, de recherche et de développement, ainsi que de transfert technologique pour les opérations forestières canadiennes au cours de la prochaine décennie. La carte identifie les points de départ et d'arrivée, discute des forces motrices, décrit les occasions favorables à des améliorations technologiques et donne des recommandations sur la meilleure route à choisir pour l'avenir.
The report presents the verification of two truss analysis computer programs developed at Forintek. Validation consisted of comparing the computed truss deflections with the deflections measured from full scale truss tests conducted at Forintek. Issues which should be considered when modeling parallel chord trusses using either of the two computer models are discussed. A strategy for estimating lateral load sharing and composite action in flat roof and floor systems using these models with the Floor Analysis Program (FAP) is discussed.
Trusses - Computer simulation
Joints and fastenings - Strength - Computer simulation
Laminated Veneer Lumber (LVL) and plywood are the two major veneer-based wood composite products. During LVL/plywood manufacturing, the hot pressing process is crucial not only to the quality and productivity, but also to the performance of panel products. Up to now, the numerical simulation of the hot-pressing process of LVL/plywood products is not available.
To help understand the hot-pressing process of veneer-based wood composites, the main objective of this study was to develop a computer simulation model to predict heat and mass transfer and panel densification of veneer-based composites during hot-pressing. On the basis of defining wood-glue mix layers through the panel thickness, a prototype finite-element based LVL/plywood hot-pressing model, VPress®, was developed to simulate, for the first time, the changes of temperature, moisture and vertical density profile (VDP) of each veneer ply and glueline throughout the pressing cycle. This model is capable of showing several important characteristics of the hot-pressing process of veneer-based composites such as effect of glue spread level, veneer moisture, density, platen pressure and temperature as well as pressing cycles on heat and mass transfer and panel compression. Experiments were conducted using several different variables to validate the model. The predicted temperature profiles of the veneer plies and gluelines (especially at the innermost glueline) by the model agree well with the experimental measurements. Hence, the model can be used to evaluate the sensitivity of the main variables that affect hot-pressing time (productivity), panel compression (material recovery) and vertical density profile (panel stiffness). Once customized in industry, the new model will allow operators to optimize the production balance between productivity, panel densification and panel quality or stiffness. This hot-pressing model is the first step in facilitating the optimization of the pressing process and enhanced product quality.
