Evaluating Log Stiffness Using Acoustic Velocity for Manufacturing Structural Oriented Strand Board

Abstract

. Oriented strand board (OSB) is an engineered panel product formed by layering strands of res-inated wood in speci fi c orientations into a mat, then pressing the mat at a high temperature to form a panel of desired strength and stiffness. OSB manufacturing facilities utilize small diameter logs from thinning operations and waste from harvesting. Considerable variation exists in the wood properties of the raw material and ideally the OSB industry would take advantage of such variation, however, it lacks the technology required to rapidly assess log quality on-site. Nondestructive evaluation (NDE) techniques based on acoustics have the potential to rapidly segregate logs in the fi eld, however, the in fl uence of acoustic-based log segregation on OSB panel properties is unknown. The aims of this project were to determine whether log quality affects panel properties and if acoustic NDE technology is a satisfactory tool for determining log stiffness before entering the manufacturing process. It was found that low-velocity (stiffness) logs produced panels with low stiffness whereas high-and medium-velocity (stiffness) logs produced panels with similar properties. The Director HM 200 was a satisfactory tool for determining log stiffness. Further studies are required to determine how to incorporate NDE tools into the manufacturing process.