Abstract:

 Investigating the moisture migration during the process of wood drying can enhance the optimal utilization of wood. Using the advantage of one-dimensional measurement along different directions of wood by single-sided NMR technology, the variation of different heights in the process of moisture transfer along the axial and transverse directions during wood drying was discussed. This research focused on Pinus sylvestris var.mongolica wood, and a glue sealing technique was employed to ensure that the moisture only transfer along the axial or transverse axis, and the T_2app was utilized to investigate the alterations in moisture content at various heights during the drying procedure. The results showed that at the first 2 hours of the drying process, there was a scarcity of free water near the evaporation surface of Pinus sylvestris var.mongolica wood, and a noticeable difference in moisture content was evident near the evaporation surface. When the moisture transfer along the axial direction, the farther away from the evaporation surface, the more uniform the moisture distribution was. When the moisture transfer along the tangential direction, the farther away from the evaporation surface, the more obvious the moisture difference in each layer was. By utilizing single-sided NMR technology, it is possible to ascertain the moisture content of wood at various heights, thereby offering a theoretical framework for investigating the migration mechanism of water within wood.

Key words: single-sided NMR, wood drying, moisture migration, apparent transverse relaxation time (T2app), migration mechanism