The Use of Acoustic Emission to Detect Fines for Wood Based Composites, Part Two: Use on Flakes

Oriented strand board (OSB) is commonly used for structural applications. Manufacturers of OSB want to minimize the presence of small particles or “fines” in the panels because fines increase the consumption of resins, leading to an increase in the weight of the board. Fines are produced when either a refiner or chipper blade becomes dull, or when the wood raw material becomes excessively dry. By accurately monitoring the presence of fines, manufacturers can help control their percentage within a product. Acoustic emission (AE) is an elastic or plastic wave generated when a surface is deformed or has an external force exerted on it. This research shows the feasibility of using AE to monitor the presence and percentage of fines in flakes. The study follows up on previous research conducted years ago by Lemaster (1994). The study also shows the effect of the flake geometry and flake moisture on the AE signal.