@article{oai:nagoya.repo.nii.ac.jp:00007010,
 author = {金川, 靖 and KANAGAWA, Yasushi and 服部, 芳明 and HATTORI, Yoshiaki},
 journal = {名古屋大学農学部演習林報告},
 month = {Dec},
 note = {In this paper, shrinkage properties of some Sulawesian woods were investigated. The shrinkage behavior consisted the shrinkage in cell wall thickness below the fiber saturation point and the cell deformation, socalled “Cell Collapse”, cuased by liquid tension above the fiber saturation point. Cell collapse was generally understood as “abnormal shrinkage of wood”. However, in this study and other works, cell collapse was not so abnormal phenomenon in the shrinkage of wood. To make clear this fact, shrinkage proceedures of woods from Sulawesi were measured in detail, specially in moisture content range of 20-40%. Because, in this range, cells were collapsed by liquid tension and then tended to recover to its original forms. This phenomenon was observed in ray cells typically. Furthermore, cell collapse was depended on the drying temperature. Therefore, measurement of shrinkage was carried out under tow drying conditions of room temperature (22℃) and about 70%RH, and of 60℃ in dry bulb temperature and depression of wet bulb temperature of 2℃.  As mention above, shrinkage phenomenon was observed as sum of shrinkage in cell wall thickness and cell deformation. Therefore, in order to estimate the cell collapse only, basic shrinkage proceedures were measured in following manners. At first, a wood specimen in green condition was freezed in liquid nitrogen and then dried under vacuum. Furthermore, after reaching near oven dry condition, it was moistened and swelled in a seasoning chamber step by step. Then dimensions of specimen measured in radial and tangential direction were converted to shrinkage coefficients. These values were meaning the shrinkage of specimen caused by the shrinkage in cell wall deformation (collapse) could be estimated by the subtraction of normal and basic shrinkage.  Results obtained were as follows; (1) All of shrinkage curves was classified into four groups by degree of cell collapse in drying. The degree of cell collapse was estimated by a shape of shrinkage curve and a shrinkage coefficient at 30%MC from green condition. The class I was meaning the cell collapse free species, and the class Ⅱ was cell collapse species. Furthermore, the class Ⅱ was classified into three groups, i.e. species in class Ⅱ-1 showed a slight cell collapse, in class Ⅱ-2, a typical cell collapse was observed and in class Ⅱ-3, a recovery of cell deformation by collapse was not recognized (see table 1). (2) Comparing to Japanese, North American and other tropical species, shrinkage coefficient of species from Sulawesi had lower values in tangential and almost same in radial. And a average of the balk density was slightly higher than Japanese species and a average of the shrinkage coefficient was almost same to Japanese species. (3) Generally it was said that the shrinkage in near parts to pith showed higher value than in sap wood. However, about half of species measured was not showed above tendency. And also, it was not recognized a higher corelationship between existence of brittle heart in pith parts and a high value in the shrinkage coefficient. (4) The cell collapse phenomenon was observed in almost species at drying temperature of 60℃. Only Gonystylus sp. and Duabanga sp. (2) were not observed cell collapse in both parts of sap and heart wood (class Ⅰ). Cell deformations caused by the collapse were found in ray tissue typically and it was observed as increment of shrinkage coefficient at 30%MC. Therefore, it was found that the shrinkage coefficient at 30%MC was a good indicator for the degree of cell collapse (see Fig. 10 and Table 4)., 農林水産研究情報センターで作成したPDFファイルを使用している。},
 pages = {54--78},
 title = {2.1 収縮特性 (2. スラウェシー産材の物理特性)},
 volume = {8},
 year = {1984}
}