Sorting Logs and Lumber for Stiffness Using Director HM200

Authors

  • Peter Carter
  • Shakti Chauhan
  • John Walker

Keywords:

Director HM200, acoustic velocity, density, stiffness, radiata pine

Abstract

Acoustic tools such as the Director HM200 are able to sort logs and boards according to their intrinsic stiffness. Here, some uses of such tools are demonstrated. First, six logs are analyzed before sawing into cants and individual boards. Second, the same approach is reconsidered from basic principles, emphasizing the variety of investigative projects to match the species-specific responses to acoustics and the need to match local resources to local markets. In both instances, correlations between acoustic properties measured in logs are related to those from cants and boards. The offsetting effects of changes in stiffness and density in determining acoustic velocity are discussed. The intention is to emphasize future possibilities for commercial application.

References

Addis Tsehaye, A. H., Buchanan, And J. C. F. Walker. 1995. Stiffness and tensile strength variation within and between radiata pine trees. J. Inst. Wood Sci.13(5):513-8.nAddis Tsehaye, A. H., Buchanan, And J. C. F. Walker. 2000. Sorting of logs using acoustics. Wood Sci. Technol.34(4):337-344.nAndrews, M. 2000. Experiences in New Zealand: Where are we with sonics? WTRC Workshop-2000: Capturing the benefits of forestry research, University of Canterbury, Christchurch, New Zealand. Pp. 57-61.nAndrews, M. 2002. Which acoustic speed? Pages 159-166 in Proc. 13th Internat. Symp. On Non-destructive Testing of Wood. FPRS, Madison, WI.nArima T., N. Nakamura, S. Maruyama, And S. Hayamura. 1990. Natural frequency of log and lumber hit with hammer and application for production processing. Pages 527-533 in Proc. International Timber Engineering Conference, 23rd-25th Oct 1990.nChauhan, S. S. 2004. Selecting and/or processing wood according to its processing characteristics. Ph.D. thesis, University of Canterbury, New Zealand.nHarris, P., And M. Andrews. 1999. Tools and acoustic techniques for measuring wood stiffness. Proc. 3rd Wood Quality Symposium: Emerging Technologies for Evaluating Wood Quality for Wood Processing, Rotorua, New Zealand.nHarris, P., R. Petherwick, And M. Andrews. 2002. Acoustic resonance tools. Pages 195-201 in F. C. Beall, ed. Proc. International Symposium on Nondestructive Testing of Wood. Forest Products Research Society.nPellerin, R. F., And R. J. Ross. 2002. Nondestructive evaluation of wood. Forest Product Society. 201 pp.nRoss R., K. McDonald, D. Green, And K. Schad. 1997. Relationship between log and lumber modulus of elasticity. Forest Prod. J.47(2):89-92.nWang, X., R. J. Ross, M. McClellan, R. J. Barbour, J. R. Erickson, J. W. Forsman, G. D. McGinnis, And X. P. Wang. 2000. Strength and stiffness assessment of standing trees using a non-destructive stress wave technique. Research Paper Forest Products Laboratory, USDA Forest Service (FPL-RP-585). 9 pp.n

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Published

2007-06-05

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Section

Research Contributions