Impregnation of Southern Pine Wood and Strands With Low Molecular Weight Phenol-Formaldehyde Resins for Stabilization of Oriented Strandboard
Keywords:
PF resin impregnation in wood, oriented strandboard, dimensional stabilization of wood composites, wood compositesAbstract
Low molecular weight phenol-formaldehyde (PF) resins were impregnated into southern pine wood using a vacuum/pressure method and the specimens were hot-pressed in the radial direction. Anti-swelling efficiency (ASE) values of treated specimens were up to 26% and 45%, respectively, for 1.0% and 5.0% resin solids loading levels in the first water-soak/dry cycle. The high ASE values were due to reduction in the irreversible swelling in radial and tangential directions of wood in spite of some negative effects that occurred in the reversible swelling. In the second and third water-soak/dry cycles, the ASE values were reduced mostly due to increased swelling of irreversible components in the radial direction with the tangential direction components little affected. Vacuum impregnation of southern pine/hardwood strands with 1.0% or 2.0% PF resin solids levels and hot-pressing gave strandboards with ASE values up to 45% in 24-h water-soak tests. ASE and board strength values of boards were higher for 2.0% resin solids loading level, higher hot-pressing temperatures, and longer press times. The high ASE values of boards arose from both irreversible and reversible swelling components and also increased adhesive bonds due to impregnating PF resins. The results would be useful for manufacturing oriented strandboard with reduced swelling if a low-cost resin impregnation process can be found.References
Farmer, R. H. 1967. Chemistry in the Utilization of Wood. Vol 9. Pergamon Press. New York, p. 193.nFPL 1999. Wood handbook-wood as an engineering material. Forest Products Laboratory. USDA Forest Service. Madison, WI.nHaygreen, J. G. and R. O. Gertjejansen. 1971. Improving the properties of particleboard by treating the particles with phenolic impregnating resin. Wood Fiber Sci3(2): 95-105.nHaygreen, J. G. and R. O. Gertjejansen. 1972. Influence of the amount and type of phenolic resin on the properties of a wafer-type particleboard. Forest Prod. J.22(12):30-34.nHujanen, D. R. 1973. Comparison of three methods for dimensionally stabilizing wafer-type particleboard. Forest Prod. J.23(6):29-30.nKim, M. G., L. W. Amos, and E. E. Barnes. 1990. Study of the reaction rates and structures of a phenolformaldehyde resol resin by carbon-13 NMR and gel permeation chromatography. Ind. Eng. Chem. Res.29(10): 2032-2037.nNicholas, D. D. and J. Siau. 1973. Factors influencing the treatability of wood. Pages 299-343 in Wood deterioration and its prevention by preservative treatments. Edited by D. Nicholas and W. E. Loos. Syracuse University Press. Syracuse, NY.nRowell, R. M. 1999. Specialty treatments. Page 463 in Wood handbook-Wood as an engineering material. Chapter 19. Gen. Tech. Rep. FPL-GTR-113. Forest Products Laboratory, USDA Forest Service, Madison, WI.nRyu, J. Y., Y. Imamura, M. Takahashi, and H. Kajita. 1993. Effects of molecular weight and some other properties of resins on the biological resistance of phenolic resin treated wood. Mokuzai Gakkaishi39(4):486-492.nSeborg, R. M., H. Tarkow, and A. J. Stamm. 1953. Effect of heat upon the dimensional stabilization of wood. Forest Prod. J.3(3):59-67.nSeborg, R. M., H. Tarkow, and R. M. Seborg. 1936. Minimizing wood shrinkage and swelling—treating with synthetic resin-forming materials. Ind. Eng. Chem.28(10):1164-1169.nSeborg, R. M., H. Tarkow, and R. M. Seborg. 1939. Resin-treated plywood. Ind. Eng. Chem.31(7):897-902.nSeborg, R. M., H. Tarkow, and R. M. Seborg. 1951. Resin-treated laminated, compressed wood (COMPREG). FPL-RP-1381. Forest Products Laboratory, USDA Forest Service, Madison, WI.nSeborg, R. M., H. Tarkow, and R. M. Seborg. 1955. Resin-treated wood (IMPREG). Res. Pap. FPL-1380, Forest Products Laboratory, USDA Forest Service, Madison, WI.nStamm, A. J. 1959. Dimensional stability of wood by thermal reactions and formaldehyde cross-linking. Tappi42(1):39-43.nStamm, A. J. and E. H. Elwin. 1953. Chemical processing of wood. Chemical Publishing Co. Inc., New York. 595 pp.nStamm, A. J. and R. H. Baechler. 1960. Decay resistance and dimensional stability of five modified woods. Forest Prod. J.10(1):22-26.nTalbott, J. W. 1959. Flapreg flakeboard, resin-impregnated, compressed wood flakes. Forest Prod. J.9(2):103-106.nWan, H. 2000. Ph.D. Dissertation. Stabilization of strand-board by impregnating low molecular weight PF resins and butanetetracarboxylic acid. Mississippi State University, Mississippi State, MS.nWan, H. and M. G. Kim. 2005. Southern pine wood and strands impregnated with low levels of butanetetracarboxylic acid as stabilizing agent for oriented strand board. Wood Fiber Sci. (in press).n
Downloads
Published
Issue
Section
License
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.
