Moisture Content-Water Potential Relationship of Sugar Maple and White Spruce Wood From Green to Dry Conditions
Keywords:
Water potential, sugar maple, white spruce, pore size distributionAbstract
The moisture content-water potential relationship was determined at 40°C and 60°C for sugar maple (Acer saccharum Marsh.) sapwood and at 60°C for white spruce (Picea glauca (Moench.) Voss.) heartwood from green to dry conditions. The pressure membrane technique was used for high moisture contents and equilibration over salt solutions for low moisture contents. The results show that at high moisture contents, the equilibrium moisture contents obtained from the green condition are lower than those obtained from full saturation (boundary desorption). It is recommended that the sorption history must be taken into account when modeling wood drying. Water potential at a given moisture content increases with temperature. There is a characteristic plateau in the green moisture content-water potential relationship obtained for sugar maple at water potentials between -2,000 and -6,000 J kg-1, which can be attributed to its heterogeneous capillary structure. The maximum concentration of effective pore radius occurs at 0.02 μm in the case of sugar maple, corresponding to the size of the pit membrane openings.References
Babbit, J. D. 1950. On the differential equations of diffusion. Can. J. Res. Sect. A. 28:449-474.nBarkas, W. W. 1936. Wood-water relationship. 2. The fiber saturation point of beech wood. Proc. Phys. Soc. 48:576-588.nChahal, R. S. 1965. Effect of temperature and trapped air on matric suction. Soil Sci. 100:262-266.nCloutier, A., and Y. Fortin. 1991. Moisture content-water potential relationship of wood from saturated to dry conditions. Wood Sci. Technol. 25:263-280.nCloutier, A., and Y. Fortin. 1994. Wood drying modelling based on the water potential concept: Hysteresis effect. Drying Technol. 12(8):1793-1814.nCloutier, A., Y. Fortin. and G. Dhatt. 1992. A wood drying finite element model based on the water potential concept. Drying Technol. 10(5):1151-1181.nCloutier, A., Y. C. Tremblay, and Y. Fortin. 1995. Effect of specimen structural orientation on the moisture content-water potential relationship of wood. Wood Sci. Technol. 29:235-242.nComini, G., and R. W. Lewis. 1976. A numerical solution of two dimensional problems involving heat and mass transfer. Int. J. Heat Mass Transfer 19(12):1387-1392.nCunningham, M. J., R. B. Keey, and C. Kerdemelidis. 1989. Isothermal moisture transfer coefficients in Pinus radiata above the fiber saturation point, using the moment method. Wood Fiber Sci. 21:112-122.nFortin, Y. 1979. Moisture content matric-potential relationship and water flow properties of wood at high moisture contents. Ph.D. thesis, The University of British Columbia, Vancouver, BC. 187 pp.nFortin, Y. 1981. Relationships between water potential and equilibrium moisture content of sugar maple wood. Unpublished data.nGoulet, M. 1968. Phénomènes de second ordre de la sorption d'humidité dans le bois au terme d'un conditionnement de trois mois à température normale. Seconde partie: Essais du bois d'érable à sucre en compression radiale. Note de recherche n° 3, Département d'exploitation et utilisation du bois. Univ. Laval, Québec, Canada. 29 pp.nHart, C. A. 1984. Relative humidity, EMC, and collapse shrinkage in wood. Forest Prod. J. 34(11/12):45-54.nHeizmann, P. 1970. Die Bewegung von flüssigem Wasser in kapillarporösen Körpern unter dem Einfluss kapillarer Zugkräfte sowie dem Einfluss von Zentrifugalkräften. Holz Roh-u Werst. 28(8): 295-309. Also: Movement of liquid water in capillary porous bodies under the influence of capillary tension forces and centrifugal forces. Transl. No. 10466, CSIRO, Australia.nHernández, R. E., and M. Bizoň. 1994. Change in shrinkage and tangential compression strength of sugar maple below and above fiber saturation point. Wood Fiber Sci. 26(3):360-369.nIrudayaraj, J., K. Haghighi, and R. L. Stroshine. 1990. Nonlinear finite element analysis of coupled heat and mass transfer problems with an application to timber drying. Drying Technol. 8(4):731-749.nKawai, S., K. Nakato, and T. Sadoh. 1978. Moisture movement in wood below the fiber saturation point. Mokuzai Gakkaishi 24(5):273-280.nLinzon, S. N. 1969. Seasonal water content and distribution in eastern white pine. Forestry Chron. 45(1):38-43.nLuikov, A. V. 1966. Heat and mass transfer in capillary-porous bodies. Pergamon Press, New York, NY. 523 pp.nMoschler, W. W. Jr., and R. E. Martin. 1968. Diffusion equation solutions in experimental wood drying. Wood Sci. 1:47-56.nNadler, K. C., E. T. Choong, and T. M. Wetzel. 1985. Mathematical modeling of diffusion of water in wood during drying. Wood Fiber Sci. 17:404-423.nPanshin, A. J., and C. de Zeeuw. 1980. Textbook of wood technology. McGraw-Hill, New York, NY. 722 pp.nPenner, E. 1963. Suction and its use as measure of moisture contents and potentials in porous materials. Pages 245-252 in A. Wexler, ed. Humidity and moisture, Vol. 4. Reinhold Publ. Co. New York, NY.nPerré, P. 1987. Le séchage convectif des bois résineux. Choix, validation et utilisation d'un modèle. Thèse de Doctorat, Université de Paris VII, Paris, France. 251 pp.nPerré, P. and A. Degiovanni. 1990. Simulation par volumes finis des transferts couplés en milieux poreux anisotropes: séchage du bois à basse et à haute température. Int. J. Heat Mass Transfer 33(11):2463-2478.nPetty, J. A. 1970. Permeability and structure of the wood of Sitka spruce. Proc: Royal Soc. Lond. B. 175:149-166.nPlumb, O. A., G. A. Spolek, and B. A. Olmstead. 1985. Heat and mass transfer in wood during drying. Int. J. Heat Mass Transfer 28(9):1669-1678.nSaha, R. S., and R. P. Tripathi. 1981. Effect of temperature on the soil-water content-suction relationship. Indian Soc. Soil Sci. 29(2):143-147.nSebastian, L. P., W. A. Côté, and C. Skaar. 1965. Relationship of gas phase permeability to ultrastructure of white spruce wood. Forest Prod. J. 15:394-404.nSiau, J. F. 1983. Chemical potential as a driving force for nonisothermal moisture movement in wood. A model for unsteady-state gas flow in the longitudinal direction in wood. Wood Sci. Technol. 17(2):101-105.nSiau, J. F. 1992. Nonisothermal diffusion model based on irreversible thermodynamics. Wood Sci. Technol. 26(5):325-328.nSiau, J. F. 1995. Wood: influence of moisture on physical properties. Dept. of Wood Sci. and Forest Prod. Virginia Polytechnic Institute and State University. Blacksburg, VA. 227 pp.nSkaar, C. 1988. Wood-water relations. Springer-Verlag, New York, NY. 283 pp.nSkaar, C. and N. Kuroda. 1985. Application of irreversible thermodynamics to moisture transport phenomena in wood. Pages 152-158 in Proc. North American Drying Symposium. Mississipi Forest Products Utilization Laboratory.nStanish, M. A., G. S. Schajer, and F. Kayihan. 1986. A mathematical model of drying for hygroscopic porous media. AICHE J. 32(8):1301-1311.nStone, J. E., and A. M. Scallan. 1967. The effect of component removal upon the porous structure of the cell wall of wood II. Swelling in water and the fiber saturation point. Tappi 50(10):496-501.nThomas, H. R., R. W. Lewis, and K. Morgan. 1980. An application of finite element method to the drying of timber. Wood Fiber 11(4):237-243.nTremblay, C., A. Cloutier, and Y. Fortin. 1996. Moisture content-water potential relationship of red pine sapwood above the fiber saturation point and the determination of the effective pore size distribution. Wood Sci. Technol. 30:361-371.nViktorin, Z., and B. Čermák. 1977. Rozbor problematiky a urćování chemického potenciálu vlhkostidřeva. Drevársky Výskum 22:235-259.nWheeler, E. A. 1982. Ultrastructural characteristics of red maple (Acer rubrum L.) wood. Wood Fiber 14(1):43-53.nWhitaker, S. 1977. Simultaneous heat, mass and momentum transfer in porous media: a theory of drying. Pages 119-203 in J. P. Hartnett and T. F. Irvine Jr., eds. Advances in heat transfer, vol. 13, Academic Press, New York, NY.n
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