Radial Moisture Profiles of Cedar Sapwood During Drying: A Proton Magnetic Resonance Study
Keywords:Cedar, sapwood, drying, proton magnetic resonance, imaging, moisture profiles, moisture content
AbstractThe drying of 6 x 6 x 10 mm western red cedar (Thuja plicata Donn.) sapwood samples has been studied with proton magnetic resonance (1H-NMR) imaging. Bulk moisture content and one-dimensional radial moisture profiles have been observed as functions of time under controlled air flow rate and temperature conditions. The effects of these drying conditions on the behavior of bulk moisture content with time corresponded well to the effects observed in full-scale lumber drying, although typical observed drying rates were of the order of 100 times faster. Sub-millimeter resolution of the radial water distribution has been attained with moisture contents from the green state to as low as a few percent, and contrasting drying behavior has been observed in the carlywood and latewood regions of the growth rings.
Dedrick, D. S. 1968. Some observations of the kinetics of lumber drying in conventional kilns. Proc. 19 Annual Meeting, Western Dry Kiln Clubs. Pp. 5-11.nMenon, R. S., A. L. MacKay, J. R. T. Hailey, M. Bloom, A. E. Burgess, and J. S. Swanson. 1987. An NMR determination of the physiological water distribution in wood during drying. J. Appl. Polym. Sci. 33:1141-1155.nMenon, R. S., A. L. MacKay, S. Flibotte, and J. R. T. Hailey. 1989. Quantitative separation of NMR images of water in wood on the basis of T2J. Magn. Res. 82:205-210.nNelson, R. M., Jr. 1986. Diffusion of bound-water in wood, Part I: The driving force. Wood Sci. Technol. 20(2):125-135.nSalamon, M., and S. McIntyre. 1969. Manipulation of air velocity permits drying time savings. Report from Canadian Forest Industries (September 1969).nSiau, John F. 1984. Transport processes in wood. Springer-Verlag, Berlin, New York. 131 p.nSmith, D. M. 1954. Maximum moisture content method for determining specific gravity of small wood samples. Forest Products Laboratory, Madison, WI. Report No. 2014. 8 pp.nSternin, E. 1985. Data acquisition and processing: A systems approach. Rev. Sci. Instrum. 56(11):2043-2049.n
The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:
1. All proprietary rights other than copyright, such as patent rights.
2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.
3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.