Moisture changes, climate and mold growth in spruce timber during storage : Calibration of finite elements model for moisture changes

A diffusion based Finite Element- model designed to calculate changes in moisture content distribution in packages of wood during storage has been calibrated by means of combined measurements of climate and moisture content in a test package. Moisture content distribution before and after storage has been determined by dry mass measurements and X- ray Computer Tomography (CT- scanning). CT- scanning was done on individual planks to reduce interference from surrounding material. As a complement to the measurements of climate and moisture content, the test material was inspected visually after storage to determine if mould growth had occurred.The results from the study show that the moisture flux within a package of wood is slower than the moisture flux theoretically estimated based on published diffusion coefficients of wood. The moisture flux from the interior of a plank to the surface is slower than the removal of moisture from the surface, also when the plank is within a closed package covered with plastic on five surfaces.The calibration of the Finite Element model makes it ready for calculations of changes in moisture content in wood with high accuracy