| 摘要 |
PROBLEM TO BE SOLVED: To scatter a stress developing along the circumferential direction of the annual ring boundary of a log or a pith-containing squared log discontinuously and, in addition, retard the evaporation speed of the water content of the log slow down the change of the stress, resulting in developing neither crack nor warpage by a method wherein the log is cut oblique to its pith by a required tilt angle in a required thickness. SOLUTION: This wooden piece (a) is produced by cutting a log 1 oblique to a vertical line 9 in the symmetrical plane passing through the pith 2 of the log 1 by a required tilt angle (θ) in a required thickness. In the wooden piece (a) cut obliquely as mentioned above, the shrinkage developing along the circumference of an annual ring boundary in a same plane is broken up. As a result, the tensile stress in this piece becomes smaller as compared with that in a wooden piece which is produced by being cut normal to the pith. Further, the crossectional area and thickness concerning to this tensile stress become larger. Furthermore, the opening area of a tracheid 3 also becomes larger. As a result, the evaporation speed of a water content becomes slow and consequently no abrupt change of the stress develops, resulting in remarkably reducing the development of crack. In addition, this wooden piece is provided as a flooring material by properly working its peripheral edge.
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