台灣主要經濟樹種材質之基礎研究（VII）長尾尖櫧、光腊樹及台灣櫸之比重、收縮率、纖維飽和點之變異性

Abstract

The variations in the transversal and axial direction of physical properties of Longleaf evergreen chinkapin, Griffith's ash and Taiwan zelkova in a single trunk were investigated. The experimental results are summarized as follows: (I) The variation in the specific gravity in the transversal direction can be classified into four types. However, there are two types of variation in the axial direction. (2) The variation of radial and tangential shrinkage % in the transversal direction can be grouped into four types. However, there are two types of variation in the axial direction. (3) The variation of longitudinal shrinkage % in the transversal direction can be expressed by five types. However, there are two types of variation in the axial direction. (4) The variation of Fiber saturation point in the transversal direction can be divided into three types. However, there are two types of variation in the axial direction. (5) The valves of the average shrinkage % in the radial and tangential direction increased linearly with increasing bulk density values. However, the values of anistropy of total shrinkage (αt/αr) showed the contrary trend. Their relationships could be represented by the linear regression equation (7)-(8) and (11).