• Title/Summary/Keyword: log cross section of softwoods

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Determination of Trend of a Radial Distribution of Moisture Content within a Log Cross Section by Oven-Drying of Circumferential Slices(II) - For some of domestic softwoods - (원주상(圓周狀)슬라이스의 오-븐건조법에 의한 함수율의 원반(圓盤)내 방사방향분포 추이 평가 (II) - 주요 국산 침엽수재를 중심으로 -)

  • Lee, Nam-Ho;Li, Chengyuan;Choi, Jun-Ho;Hwang, Ui-Do;Jin, Young-Moon
    • Journal of the Korean Wood Science and Technology
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    • v.32 no.2
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    • pp.19-25
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    • 2004
  • This study was carried out to investigate a radial distribution of moisture contents (MCs) within a log cross section (LC) during oven-drying of 3 mm-thick circumferential slices cut from several domestic softwoods LCs.For Korean red pine, drying rate of sapwood slices during oven-drying represented much higher values than that of heartwood slices, and so sapwood with higher green MC early reached below fiber saturation point (FSP) rather than heartwood did. However, this distribution of moistures did not last for long duration. For Japanese larch, green MC of sapwood was approximately three times higher than that of heartwood. This similar distribution in MC was lasted until about 20% average MC. The MC was around uniform throughout the sapwood of Ginkgo when green and during oven-drying, although it was somewhat fluctuated. For Japanese cedar, the heartwood with so low moistures around FSP would begin to shrink from the beginning stage of drying, but the sapwood above hygroscopic MC prevents the heartwood from shrinking, and consequently, the heartwood or the transition wood goes into tension stress. The results for Japanese cypress showed that the green MCs of the sapwoods were much lower than those for heartwoods, and then this trend was continued until about 20% in average MC. For Chinese thuja, the green MCs of sapwoods were about 2 times as high as those of heartwood, but this along the radial gradient in MC rapidly became gentle during oven-drying.