关键词: 柚木, 纤维长度, 比重, 标准物理力学性质

Abstract: Twenty 11-13-year-old trees and seven 17-19-year-old trees of Tectona grandis L. f. were taken from Hainan Island to study some characteristics of wood specific gravity and fibre length, and to test the standard physical and mechanical properties.With the weighted mean of the breast height disc as the unit, specific gravity varied from 0.466 to 0.588, averaging 0.516, and fibre length varied from 0.878 to 1.230 mm, averaging 1.063 mm. A slight negative relationship was observed between ring width and specific gravity (r=-0.029), also and fibre length (r=-0.108). There were significant correlations between the 1st ring and the ninth ring for both properties.Variations in the two properties among sample plots were insignificant while those between trees within sample plot were highly significant.Radial variation Fibre length increased rapidly outward from the pith in the few rings; after the eighth ring the rate of increase slowed down. Specific gravity showed similar increasing trend to that of fibre length at first and more fluctuations after the eighth ring.Axial variation This analysis was based on seven trees, from each of which discs at 0.2, 1.3, 3.6, 5.6 and 7.6m height levels of the trunk were removed, then every growth ring in the southern and northern radii from each of these discs were further sampled. 1. Core sequence (six growth rings from the pith outward) In the ring nearest the pith, fibre length varied very little up the tree, and in the outer rings, either it decreased gradually or showed some fluctuations. Specific gravity in the six rings at the base were the greatest, then decreased rapidly to the 1.3m height, after which they varied differently up the trunk. 2. Sheath sequence (six growth rings from the bark inward) Fibre length and specific gravity in the six rings all decreased rapidly from the base upward. The main factors affecting the two sequences of axial variation in fibre length were discussed.The result of the standard physical and mechanical properties tested was presented.

Key words: Teak, Fibre length, Specific gravity, Standard physical and mechanical property