Assessing the Effect of Swelling Pressures in Particleboard and MDF Using Acoustic Emission Technology
Keywords:
Acoustic emissions, nondestructive testing, wax, particleboard, resin, medium density fiberboardAbstract
The interaction of moisture with wood-based composites leads to the development of swelling pressures that cause the failure of resin bonds and the dislocation of fibers within the composites. These bond failures and dislocations can result in abrupt stress changes that trigger vibrations and create acoustic emissions (AE). Resin and wax levels within the composites effectively limit the interaction of wood and water and affect the level of AE. In this research, acoustic emissions were used to measure the effects of resin and wax levels in both particleboard and medium density fiber-board (MDF).
Two resin levels and three wax levels in the composites were tested. Samples were immersed in distilled water for 120 min during which cumulative AE were recorded. In addition, the density and moisture content gains of the samples were determined.
The results provide evidence that both resin and wax levels significantly affect the number of acoustic emissions and the failure of internal bonds within the samples. Increasing the percentage of wax reduced the level of acoustic emissions in both the MDF and particleboard. Increasing the percentage of resin significantly affected the levels of AE in both MDF and particleboard, although in different ways because of the differences in internal structure within the composites. Acoustic emission technology could be a useful tool in assessing the quality and consistency of the composites.
References
American Society for Testing and Materials. 1994. Standard terminology for nondestructive examinations. E 1316-94. ASTM, Philadelphia, PA.nBeall, F. C. 1986. Effect of resin content and density on acoustic emission from particleboard during internal bond testing. Forest Prod. J.36(7):29-33.nBeattie, A. G. 1983. Acoustic emission, principles and instrumentation. J. Acoustic Emission2(11):95-128.nBennet G. A. 1969. An investigation of some properties of medium hardboard. Timberlab Paper No. 4. Forest Products Research Lab., Princes Risborough, Bucks., England.nBrown, F. L., D. L. Kenaga, and R. M. Gooch. 1966. Impregnation to control dimensional stability of particleboard and fiberboard. Forest Prod. J.16(11):45-53.nGeneralla, N. C., E. J. Biblis, and H. F. Carino. 1989. Effect of two resin levels on the properties of the commercial southern OSB. Forest Prod. J.39(6):64-68.nHaygreen, J., 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.nMiller, D. G. 1963. Sounds generated by wood when under stress. Can Dep. Forest. Forest Products Res. Bulletin. Res. News 6:6-7.nPorter, A. W. 1964. On the mechanics of fracture in wood. Ph.D. thesis, State University College For., Syracuse University, Syracuse, NY.nRice, R. W., and F. R. A. Kabir. 1992. The acoustic response of three species of wood while immersed in three different liquids. Wood Sci. Technol.26:131-137.nRice, R. W., and E. Peacock. 1992. Acoustic emissions resulting from cyclic wetting of southern yellow pine. Holz Roh- Werkst.50:304-307.nSchneider, M. H., Ying H. Chui, and Stefan B. Ganev. 1996. Properties of particleboard made with a polyfur-furyl-alcohol/urea-formaldehyde adhesive. Forest Prod. J.46(9):79-83.nSuchsland, O. 1973. Hygroscopic thickness swelling and related properties of selected commercial particle-boards. Forest Prod. J.23(7):26-30.nSkaar, C. 1988. Wood-water relations. Springer-Verlag, New York, NY.nStillinger, J. R., and W. G. Coggan. 1956. Relationship of moisture content and flexural properties in 25 commercial hardboards. Forest Prod. J.6(5):179-186.nTarkow, H., and H. D. Turner. 1958. The swelling pressure of wood. Forest Prod. J.8:193-197.nWang, C. 1999. Evaluating the effects of resin level, wax level and refiner plated sharpness using acoustic emission technology. M.S. thesis, University of Maine, Orono, ME.nWinistorfer, P. M., Wei Xu, and Christopher M. H. 1996. Influence of three wax formulations and three application rates on thickness swell performance of southern pine flakeboard. Forest Prod. J.46(3):63-67.n
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