Properties and Decay Resistance of Preservative-treated Douglas-fir Flakeboard


  • Asghar Jeihooni
  • Robert L. Krahmer
  • Jeffrey J. Morrell


Flakeboard, Douglas-fir, CCA, borate, azaconazole, physical properties, durability


The effect of pretreatment of Douglas-fir flakes with CCA-C, borate, and azaconazole on properties of flakeboard was studied. Flakes had higher retention levels of CCA-C and borate in their ends than in their centers. The distribution of chemicals was uniform in panels, which indicates that the chemicals did not migrate during hot-pressing. Treatment markedly enhanced resistance to brown rot (Postia placenta). Borate-treated panels had large thickness swelling and often delaminated when exposed to hot, wet conditions. In static bending and internal bond tests, strength reduction for borate- and CCA-C-treated panels was evident. Azaconazole showed no deleterious effect on strength.


American National Standards Institute (ANSI). 1979. Mat-formed wood particleboard. ANSI A208.1. ANSI, New York, NY.nAmerican Society For Testing and Materials (ASTM). 1993. Standard methods of evaluating the properties of wood-base fiber and particle panel materials. D 1037-93. In Annual book of ASTM standards. ASTM. Philadelphia, PA.nAmerican Wood-Preservers' Association (AWPA). 1992a. Determining the leachability of wood preservatives. Standard E 11-87. In Book of standards. AWPA, Woodstock, MD.nAmerican Wood-Preservers' Association (AWPA). 1992b. Testing wood preservatives by laboratory soil block cultures. Standard E 10-91. In Book of standards. AWPA, Woodstock, MD.nAmerican Wood-Preservers' Association (AWPA). 1992c. Lumber and plywood for permanent wood foundations, pressure processes. Standard C 22-92. In Book of standards. AWPA, Woodstock, MD.nAmerican Wood-Preservers' Association (AWPA). 1992d. Lumber, timbers, bridge ties, and mine timbers, pressure treatment. Standard C2-92. In Book of standards. AWPA, Woodstock, MD.nArsenault, R. D. 1975. CCA treated wood foundations: A study of permanence, effectiveness, durability, and environmental considerations. Proc. Am. Wood Preservers' Assoc. 71:126-149.nASOMA Instruments, Inc. 1988. ASOMA manual. Model 8620 X-ray fluorescence analyzer S/N 1306. Austin, TX.nBarnes, H. M., T. L. Amburgey, L. H. Williams, and J. J. Morrell. 1989. Borates as wood preserving compounds: The status of research in the United States. IRG/WP/3542. International Research Group on Wood Preservation. Stockholm, Sweden.nBoggio, K., and R. Gertjejansen. 1982. Influence of ACA and CCA waterborne preservatives on the properties of aspen waferboard. Forest Prod. J. 32(3):22-26.nHartford, W. H. 1986. Practical chemistry of CCA in service. Proc. Am. Wood Preservers' Assoc. 82:28-43.nJeihooni, A. 1992. Distribution of preservative chemicals in flakeboard and its effect on board properties and fungal deterioration. Ph.D. thesis, Oregon State University, Corvallis, OR. 131 pp.nLaks, P. E., B. A. Haataja, R. D. Palardy, and R. J. Bianchini. 1988. Evaluation of adhesives for bonding borate-treated flakeboards. Forest Prod. J. 38(11/12): 23-24.nLee, A. W. C., and C. B. Stephens. 1988. Comparative shear strength of seven types of wood composite panels at high and medium relative humidity conditions. Forest Prod. J. 38(3):49-52.nLittle, T. M., and F. J. Hills. 1978. Agricultural experimentation: Design and analysis. John Wiley and Sons, New York, NY. 350 pp.nNurmi, A. J. 1990. Leachability of active ingredients from some CCA treated and creosoted poles in service. A progress report after 10 years' testing. IRG/WP/3627. International Research Group on Wood Preservation, Stockholm, Sweden.nSAS Institute. 1987. SAS/STAT guide for personal computers. Version 6 Edition. SAS Institute, Inc., Cary, NC.nSchmidt, E. I., and R. O. Gertjejansen. 1988. Trials of two powdered preservatives for phenol-formaldehyde bonded and polymeric-isocyanate-bonded aspen structural composite board. Forest Prod. J. 38(3):19-21.nValcke, A. R., and W. R. Goodwine. 1985. Azacon-azole, a new wood preservative. Proc. Am. Wood Preservers' Assoc. 81:196-202.nWilson, W. J. 1958. The determination of boron in treated wood. Anal. Chim. Acta 19(6):509-512.nWinandy, J. E., and R. S. Boone. 1988. The effects of CCA preservative treatment and redrying on the bending properties of 2 x 6 southern pine lumber. Wood Fiber Sci. 20(3):350-364.n






Research Contributions