Magnetic Resonance Studies of Wood Log-Drying Processes

Abstract

Abstract Spatially resolved measurements of moisture content (MC) in black spruce (Picea mariana Mill.) logs were undertaken by unilateral magnetic resonance (UMR) and magnetic resonance imaging (MRI). The goal of this study was to understand drying behaviors of the different regions in black spruce wood logs. Results indicate that water is lost from the entire length of the log as drying progresses. Diffusive drying from both sapwood and heartwood was observed at the log ends. The most significant drying in the log interior was through the bark. The magnetic resonance signal has an amplitude that depends on water content and a lifetime that depends on the water environment, namely, cell wall or cell lumen. The UMR measurement distinguished signal from cell wall and lumen water. The MRI measurement spatially resolved, in 3D, total water content in the wood. This was important in order to differentiate the water content and drying behavior in sapwood and heartwood. The MC in the black spruce sapwood was si...