Skip to main content

Advertisement

Official Journal of the Japan Wood Research Society

Journal of Wood Science Cover Image
We’d like to understand how you use our websites in order to improve them. Register your interest.

Effects of mat moisture content and press closing speed on the formation of density profile and properties of particleboard

Abstract

Isocyanate resin-bonded 0.5 and 0.7 g/cm3 lauan (Shorea sp.) particleboards were produced from mats with uniform and distributed moisture content (MC) distributions, using three hot press closing speeds. The effects of these processing variables on the formation of density profile in particleboard and board properties were analyzed statistically. A definition of the density profile was introduced, and the correlations among the various defining factors were established. The results are summarized as follows. (1) The peak density (PD) of particleboard could be increased, with a slight reduction in the core density (CD), using mats with different MC distributions. (2) In a conventional density profile, CD and PD are highly dependent on the board mean density (MD); and the gradient factor (GF), peak distance from the faces (Pdi), and peak base (Pb) are significantly correlated to each other, at the 99% significance level. (3) Greater press closing speed reduces Pdi and Pb, with an increase in GF. (4) Greater press closing speed could increase the PD in board of low MD, with minimal effect on CD. (5) The modulus of elasticity (MOE) of particleboards from mats with high MC near the faces were consistently higher than those from mats with uniform MC, irrespective of the press closing speed, whereas their modulus of rupture (MOR) became indifferent at higher MD under slow and fast closing speeds. (6) Sanding does not improve the MOR and MOE of particleboard significantly.

References

  1. 1.

    Humphrey PE, Bolton AJ (1989) The hot pressing of dryformed wood-based composites. Part II. A simulation model for heat and moisture transfer, and typical results. Holzforschung 43:199–206

  2. 2.

    Bolten AJ, Humphrey PE, Kavvouras PK (1989) The hot pressing of dry-formed wood-based composites. Part III. Predicted vapour pressure and temperature variation with time, compared with experimental data for laboratory boards. Holzforschung 43:265–274

  3. 3.

    Bolton AJ, Humphrey PE, Kavvouras PK (1989) The hot pressing of dry-formed wood-based composites. Part IV. Predicted variation of mattress moisture content with time. Holzforchung 43:345–349

  4. 4.

    Humphrey PE, Bolton AJ (1989) The hot pressing of dryformed wood-based composites. Part V. The effect of board size: comparability of laboratory and industrial pressing. Holzforschung 43:401–405

  5. 5.

    Humphrey PE (1991) Pressing issues in panel manufacture: internal behavior during pressing and its impact on time minimization, properties, and profit. In: Maloney TM (ed) Proceedings of the 25th International Particleboard/Composite Material Symposium, Washington State Univ., Pullman pp 99–108

  6. 6.

    Shuo S, Bowyer JL (1994) Simulation modeling of particleboard density profile. Wood Fiber Sci 26:397–411

  7. 7.

    Wong ED, Zhang M, Wang Q, Kawai S (1997) Formation of the density profile and its effects on the properties of particleboard. Wood Sci Technol (in press)

  8. 8.

    Kelly MW (1977) Critical literature review of relationships between processing parameters and physical properties of particleboard. US Department of Agriculture, Frorest Products Laboratory, Wisconsin pp 37–44

  9. 9.

    Strickler MD (1959) Effect of press cycles and moisture content on properties of Douglas-fir flakeboard. For Prod J 7:203–215

  10. 10.

    Stevens RR (1978) Slicing apparatus aids in determination of layer-density of particleboard. For Prod J 28(9):51–52

  11. 11.

    Nearn WT, Bassett K (1968) X-ray determination and use of surface-to-surface density profile in fiberboard. For Prod J 18(1):73–74

  12. 12.

    Laufenberg TL (1986) Using gamma radiation to measure density gradients in reconstituted wood products. For Prod J 36(2):59–62

  13. 13.

    Steiner PR, Jozsa LA, Parker ML, Chow S (1978) Application of x-ray densitometry to determine density profile in waferboard: relationship of density to thickness expansion and internal bond strength under various cycles. Wood Sci 11(1):48–55

  14. 14.

    Kawai S, Sasaki H (1986) Production technology for low-density particleboard. I. Forming a density gradient and its effect on board properties. Mokuzai Gakkaishi 32:324–330

  15. 15.

    Winistorfer PM, Depaula EVCM (1993) Measuring the density profile during pressing: the method, the equipment, and the results. In: Maloney TM (ed) Proceedings of the 27th International Particleboard/Composite Material Symposium, Washington State Univ., Pullman pp 45–53

  16. 16.

    Kollman FFP, Kuenzi EW, Stamm AJ (1975) Principles of wood science and technology. Vol II. Wood based materials. Springer, Berlin, Heidelberg, New York pp 415–417

  17. 17.

    Schulte M, Fruhwald A (1996) Some investigations concerning density profile, internal bond and relating failure position of particleboard. Holz Roh Werkstoff 54:289–294

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Ee Ding Wong.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Wong, E.D., Zhang, M., Wang, Q. et al. Effects of mat moisture content and press closing speed on the formation of density profile and properties of particleboard. J Wood Sci 44, 287–295 (1998). https://doi.org/10.1007/BF00581309

Download citation

Key words

  • Particleboard
  • Mat moisture content
  • Press closing speed
  • Density profile
  • Board properties