Determination of Percentage of Broken Fiber Pieces in Macerated Brittleheart Material


  • Jun Li Yang
  • Edward F. Dougal


Percentage of broken fiber pieces (PBFP), brittleheart, <i>Eucalyptus regnans</i> F.v. Muell


A method to determine the number of slides that need to be examined in order to estimate the mean percentage of broken fiber pieces (PBFP) of macerated brittleheart samples within 10% error is described. The macerated samples were prepared from brittleheart wood chips of Eucalyptus regnans F.v. Muell. measuring approximately 2 x 2 x 15 mm in size. Temporary wet slides were prepared from one macerated sample that contained a moderate amount of broken fiber pieces. Each slide was covered with a 22 x 22-mm cover slip on which thin lines were drawn dividing the cover slip into sixteen equal areas. There were in total 400 to 600 whole fibers and broken fiber pieces within the cover slip area for each slide. It was found that examination of one slide would be sufficient to estimate within 10% error the mean PBFP of the macerated sample from which the slide was prepared. The same result was also found for macerated samples containing high or low amounts of broken fiber pieces.


Chudnoff, M., and K. Tischler. 1963. Fiber morphology of Eucalyptus camaldulensis Dehn. and the relation of wood anatomy to certain physical and mechanical properties. La-Yaaran Supp. 1: 3-23.nDadswell, H. E., and I. Langlands. 1934. Brittle heart in Australian timbers: A preliminary study. J. CSIR, Australia 7: 190-196.nFranklin, G. L. 1945. Preparation of thin sections of synthetic resins and wood resin composites, and a new macerating method for wood. Nature 155: 51.nHillis, W. E., A. D. K. Hardie, and Y. Ilic. 1973. The occurrence of brittle heart in Eucalyptus grandis grown in Zambia. IUFRO-5 Republic of South Africa 2: 487-493.nShiokura, T. 1981. Distribution and morphology of the compression failure observed within tropical small tree trunks. J. Agric. Sci. Tokyo Nogyo Daigaku O (Special issue): 74-84.nWardrop, A. B., and H. E. Dadswell. 1947. Contribution to the study of the cell wall 5. The occurrence, structure, and properties of certain cell wall deformations. CSIR Bulletin, Australia 221: 5-31.nWilkins, A. P. 1986. Factors affecting the occurrence of broken fibers in macerated wood: A research note. Wood Fiber Sci. 18(1): 208-210.nWilkins, A. P. 1989. Relationship between broken fibers in macerated eucalypt wood and the abundance of cell wall deformations. IAWA Bulletin n.s. 10(1): 77-81.nYang, J. L. 1990. The occurrence of brittleheart in Eucalyptus regnans and its effect on various wood properties. Ph.D. thesis, The University of Melbourne, Australia. 241 pp.n






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