Properties of Hardboards Made From Acetylated Aspen and Southern Pine
The effects of fiber acetylation, resin content, and wax content on mechanical and physical properties of dry-process hardboard made from aspen and southern pine were investigated.
Test results indicate that the modulus of rupture (MOR) and modulus of elasticity (MOE) of the hardboard specimens were decreased due to the fiber acetylation. Tensile stress parallel to face and internal bond (IB) were generally higher for untreated boards than for acetylated boards. Water absorption (WA) and thickness swelling (TH.S) were both reduced markedly by acetylation. In general, increasing resin content from 3% to 7% brought increases in MOR, MOE, tensile stress, and IB and improved WA and TH.S. Addition of the 0.5% wax content usually caused reductions in these mechanical properties, but improved WA and TH.S in some cases. Linear expansion (LE) in the dimensional stability test (from 30% to 90% RH) was significantly reduced by acetylation and influenced by wood species. Neither resin nor wax contents significantly affected the LE value of hardboard specimens in this study.
American Hardboard Association (AHA). 1988. Basic hardboard. ANSI/AHA A135.4. 1988. American National Standard/American Hardboard Association. Palatine, II. 5 pp.nAmerican Society For Testing and Materials (ASTM). 1993. Standard methods of evaluating the properties of wood-base fiber and particle panel materials. ASTM D 1037. Philadelphia, PA.nCanadian Standard Association (CSA). 1975. Matformed wood particleboard. Can 3-0188. 0-M-78. Canadian Standard Association, Ontario, Canada.nChow, P. 1978. Phenol adhesive bonded medium-density fiberboard from Quercus rubra L. board and sawdust. Wood Fiber 11(2):92-98.nChow, P., J. Q. McNatt, and Y. L. Xiong. 1987. Effects of accelerated weathering on some physical and mechanical properties of wood-based building panels. Pages 97-103 in Proc. Fourth International Conference on Durability of Building Materials Components, Singapore.nHsu, W. E. 1987. Steam pretreatment of wood fibers. Pages 65-71 in Wood Science Seminar 1: Stabilization of the Wood Cell Wall. Michigan State University, East Lansing, MI.nHsu, W. E., W. Schwald, J. Schwald, and J. A. Shield. 1988. Chemical and physical changes required for producing dimensional stable wood-base composites. Wood Sci Technol. 22:281-289.nRowell, R. M. 1986. Chemical modification of wood substance. Proc. Wood Technology, Chemistry, and Construction. USDA, Forest Serv., Forest Prod. Lab., Madison, WI.nRowell, R. M. 1987. Can the cell wall be stabilized? Pages 53-64 in Wood Science Seminar 1: Stabilization of the Wood Cell Wall. Michigan State University. East Lansing, MI.nRowell, R. M. and W. B. Banks. 1987. Tensile strength and toughness of acetylated pine and lime flakes. Br. Polymer J. 19:478-482.nRuffin, E. T. 1960. Exterior durability of hardboard. Forest Prod. J. 10:336-341.nStamm, A. J. 1964. Wood and cellulose science. The Ronald Press Co., New York, NY. 549 pp.nSuchsland, O. 1965. Swelling stresses and swelling deformations in hardboard. Michigan State Univ. Agric. Exp. Sta. Quart. Bull. 47(4):591-605.nSuchsland, O. and G. E. Woodson. 1986. Fiberboard manufacturing practices in the United States. USDA Forest Serv. Agric. Handbook No. 640. U.S. Government Printing Office, Washington, DC. 263 pp.nSuzuki, H., H. Takahashi, and K. Endoh. 1976. On water absorbability of dry process fiberboard. J Japan Wood Res. Soc. Mokuzai Gakkaishi. 22(10):557-563. Hokkaido Forest Products Research Institute, Asahikawa, Hokkaido, Japan.nYounoquist, J. A., J. Muehl, A. Krzysik, and T. Xin. 1990a. Mechanical and physical properties of wood/ plastic fiber composites made with air-formed dry-process technology. Pages 159-162 in Proc. Joint International Conference on Processing and Utilization of Low-grade Hardwoods and International Trade of Forest-Related Products. June 11-13, 1990, Taipei, Taiwan.nYounoquist, J. A., R. Rowell, N. Ross, A. M. Krzysik, and P. Chow. 1990b. Effects of steam and acetylated fiber treatment, resin content and wax on the properties of dry-process hemlock hardboard. Pages 254-257 in Proce. Utilization of Low-grade Hardwoods and International Trade of Forest-related Products. June 11-13, 1990, National Taiwan University, Taipei, Taiwan.n
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