Compression Behavior Of Randomly Formed Wood Flake Mats

Authors

  • Chunping Dai
  • Paul R. Steiner

Keywords:

Model, transverse compression, compression, Poisson distribution, flake, random flake mat, void volume, bonded area, pressing, composites

Abstract

A theoretical model for the prediction of compression response of a randomly formed flake mat is developed. The model rigorously relates the overall mat response to local mat structure and individual flake properties. The compression behavior of single flakes, flake columns, and random flake mats is experimentally determined. Satisfactory agreement is found between the predicted and experimentally obtained results. Equations are also derived for the calculation of the relative volumetric change of between- and inside-flake voids in a mat and the change of relative flake-to-flake bonded area during the course of mat densification. Typical predictive outputs are presented and discussed.

References

Beech, J. C. 1975. The thickness swelling of wood particleboard. Holzforschung 29:11-18.nBodig, J. 1963. The effect of anatomy on the initial stress-strain relationship in transverse compression. Forest Prod. J. 15(5): 197-202.nBolton, A. J., P. E. Humphrey, and P. K. Kavvouras. 1989. The hot pressing of dry-formed wood-based composites. Part VI. The importance of stresses in the pressed mattress and their relevance to the minimisation of pressing time, and the variability of board properties. Holzforschung 43:406-410.nDai, C., and P. R. Steiner. 1994a. Spatial structure of wood composites in relation to processing and performance characteristics. Part II. Modelling and simulation of a randomly-formed flake layer network. Wood Sci. Technol. (in press).nDai, C., and P. R. Steiner. 1994b. Spatial structure of wood composites in relation to processing and performance characteristics. Part III. Modelling the formation of multi-layered random flake mats. Wood Sci. Technol. (in press).nEllis, E. R., K. B. Jewett, W. H. Ceckler, and E. V. Thompson. 1982. Dynamic compression of paper. III. Compression equation for cellulose mats. AIChE Symposium Series 232(80): 1-7.nGibson, L. J., and M. F. Ashby. 1988. Cellular solids: Structure and properties. Pergamon Press, New York. 357 pp.nHarless, P. E., F. G. Wagner, P. H. Short, R. D. Seale, P. H. Mitchell, and D. S. Ladd. 1987. A model to predict the density profile of particleboard. Wood Fiber Sci. 19:81-92.nHumphrey, P. E., and A. J. Bolton. 1989. The hot pressing of dry-formed wood-based composites. Part II. A simulation model for heat and moisture transfer, and typical results. Holzforschung 43(3):199-206.nHumphrey, P. E., and S. Ren. 1989. Bonding kinetics of thermosetting adhesive systems used in wood-based composites: The combined effect of temperature and moisture content. J. Adhesive Sci. Technol. 3(5):397-413.nJones, R. L. 1963. The effect of fiber structural properties on compression response of fiber beds. Tappi 46(1):20-27.nKamke, F. A., and M. P. Wolcott. 1991. Fundamentals of flakeboard manufacture: Wood-moisture relationships. Wood Sci. Technol. 25:57-71.nKasal, B. 1989. Behavior of wood under transverse compression. Master's thesis, Virginia Polytechnic Institute and State University, Blacksburg, VA.nKennedy, R. W. 1968. Wood in transverse compression: Influence of some anatomical variables and density on behaviour. Forest Prod. J. 18(3):36-40.nKunesh, R. H. 1961. The inelastic behavior of wood: A new concept for improved panel forming process. Forest Prod. J. 9:395-406.nLiu, J. Y., and J. D. McNatt. 1991. Thickness swelling and density variation in aspen flakeboards. Wood Sci. Technol. 25:73-82.nMeincke, E. A., and R. C. Clark. 1973. Mechanical properties of polymeric foams. Technomic Publishing, Westport, CT. 105 pp.nRusch, K. C. 1969. Load-compression behavior of flexible foams. J. Appl. Polymer Sci. 13:2297-2311.nSmith, D. C. 1980. Waferboard press closing strategies. Forest Prod. J. 32(3):40-45.nSuchsland, O. 1959. An analysis of the particleboard process. Michigan Quarterly Bulletin 42(2):350-372.nSuchsland, O. 1962. The density distribution in flake boards. Michigan Quarterly Bulletin 45(1):104-121.nSuchsland, O. 1973. Hygroscopic thickness swelling and related properties of selected commercial particleboards. Forest Prod. J. 23(7):26-30.nSuda, H., S. Kawai, and H. Sasaki. 1987. Production technology for low-density particleboard. III. Effect of particle geometry on board properties. Japan Wood Res. Soc. J. 33(5):376-384.nVan Wyk, C. M. 1946. Note on the compressibility of wool. J. Textile Inst. 37:285-292.nWolcott, M. P. 1990. Modelling viscoelastic cellular materials for the pressing of wood composite. Ph.D. dissertation, Virginia Polytechnic Institute and State University, Blacksburg, VA.nWolcott, M. P., F. A. Kamke, and D. A. Dillard. 1990. Fundamentals of flakeboard manufacture: Viscoelastic behavior of the wood composite. Wood Fiber Sci. 22(4):345-361.nWolcott, M. P., B. Kasal, F. A. Kamke, and D. A. Dillard. 1989. Testing small wood specimens in transverse compression. Wood Fiber Sci. 21(3):320-329.n

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Published

2007-06-22

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Research Contributions