Longitudinal and Transverse Permeability of Balsam Fir Wetwood and Normal Heartwood
Keywords:Intrinsic permeability, <i>Abies balsamea</i> L. Mill, wetwood, wood drying, wood anatomy, SEM
AbstractThe occurrence of wetwood in balsam fir is a problem in the drying of sawn lumber: drying time increases and moisture content of dried lumber is heterogeneous. Permeability may be used as an indicator of drying rates. Longitudinal, radial, and tangential intrinsic permeability of balsam fir wet-wood and normal heartwood was measured in this study. The longitudinal intrinsic permeability was about 2,000 times and 9,000 times higher than the tangential and the radial intrinsic permeability, respectively. Wetwood had a higher longitudinal permeability than normal heartwood, but no significant difference was found between the radial and tangential directions. Sampling height in the tree, basic density, and growth ring width had no effect on the intrinsic permeability. An increase of latewood percentage in the growth rings resulted in an increase in longitudinal intrinsic permeability and a decrease in tangential intrinsic permeability. Radial flow seemed to be controlled by ray blockage in wetwood and normal heartwood, which may result in radial impermeability of wood. A poorly drained stand seemed to favor wetwood formation.
Arganbright, D. G., and W. W. Wilcox. 1969. Comparison of parameters for predicting permeability of white fir. Proc. Am. Wood-Preserv. Assoc. 65:57-62. Cited in J. C. Ward, 1986. The effect of wetwood on lumber drying times and rates: An exploratory evaluation with longitudinal gas permeability. Wood Fiber Sci. 18(2): 288-307.nDokken, M., and R. Lefebvre. 1973. Drying veneer peeled from seven New Brunswick balsam fir logs. Can. Dep. Environ. Inf. Rep. OP-X-60. 20 pp.nEriksson, K. E. L., R. A. Blanchette, and P. Ander. 1990. Microbial and enzymatic degradation of wood and wood components. Springer Verlag, New York, NY. 407 pp.nEtheridge, D. E., and L. A. Morin. 1962. Wetwood formation in balsam fir. Can. J. Bot. 40(10): 1335-1345.nFlynn, K. A. 1994. A review of the permeability, fluid flow, and anatomy of spruce (Picea spp.). Wood Fiber Sci. 27(3):278-284.nGarrahan, P. A., M. Savard, and D. A. Cane. 1994. Sorting and drying eastern SPF on the basis of initial moisture content. Forintek Canada Corp. Rep., project no. 3743K441. 118 pp.nKelso, W. C., R. O. Gertjejansen, and R. L. Hossfeld. 1963. The effect of air blockage upon the permeability of wood to liquids. Univ. of Minnesota Agric. Exp. Sta. Tech. Bull. 242. 40 pp.nMarkstrom, D. C., and R. A. Hann. 1972. Seasonal variation in wood permeability and stem moisture content of three Rocky Mountain softwoods. USDA For. Serv. Res. Note RM-212, Rocky Mountain For. Range Exp. Sta., Fort Collins, CO. 7 pp. Cited in J. C. Ward, 1986. The effect of wetwood on lumber drying times and rates: An exploratory evaluation with longitudinal gas permeability. Wood Fiber Sci. 18(2):288-307.nOsnach, N. A. 1961. The permeability of wood. Derev. Prom. 10(3): 11-13. Cited in G. L. Comstock, 1970. Directional permeability of wood. Wood Fiber 1:283-289.nPerng, W. R. 1980. Studies on flow in wood II. Mokuzai Gakkaishi 26(4):219-226.nPerré, P. 1987. Le séchage convectif de bois résineux: choix, validation et utilisation d'un modèle. Thèse de doctorat, Université Paris VII. 251 pp.nRice, R. W., and M. D'Onofrio. 1996. Longitudinal gas permeability measurements from eastern white pine, red spruce, and balsam fir. Wood Fiber Sci. 28(3):301-308.nSchink, B., J. C. Ward, and J. G. Zeikus. 1981. Microbiology of wetwood: Importance of pectin degradation and clostridium species in living trees. Appl. Environ. Microbiol. 42(3):526-532.nSchneider, M. H., and L. Zhou. 1989. Characterization of wetwood from four balsam fir trees. Wood Fiber Sci. 21(1):1-16.nSchroeder, H. A., and C. J. Kozlik. 1972. The characterization of wetwood in western hemlock. Wood Sci. Technol. 6(2):85-94.nShaw, D. C., R. L. Edmonds, W. R. Littke, J. E. Browning, and K. W. Russel. 1995. Incidence of wetwood and decay in precommercially thinned western hemlock stands. Can. J. For. Res. 25:1269-1277.nSiau, J. F. 1995. Wood: Influence of moisture on physical properties. Virginia Polytechnic Institute and State University Press, Blacksburg, VA. 227 pp.nSPSSTM 7.0. 1996. SPSS Inc., Chicago, IL.nTesoro, F. O., E. T. Choong, and O. K. Kimbler. 1974. Relative permeability and the gross pore structure of wood. Wood Fiber Sci. 6(3):226-236.nVerkasalo, E., R. J. Ross, A. TenWolde, and R. L. Youngs. 1993. Properties related to drying defects in red oak wetwood. For. Prod. Lab. Res. Pap. FPL-RP-516, USDA, Forest Serv. Forest Prod. Lab. Madison, WI. 10 pp.nWard, J. C. 1986. The effect of wetwood on lumber drying times and rates: An exploratory evaluation with longitudinal gas permeability. Wood Fiber Sci. 18(2):288-307.nWard, J. C., and W. Y. Pong. 1980. Wetwood in trees: A timber resource problem. USDA For. Serv. Gen. Tech. Rep. PNW 112, Pacific Northwest For. Range Exp. Sta. Portland, OR. 56 pp.nWinCAM™. 1998. Instruments Regent Inc., Québec, Canada.n
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