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林业科学 ›› 2006, Vol. 42 ›› Issue (11): 93-96.doi: 10.11707/j.1001-7488.20061117

• 论文及研究报告 • 上一篇    下一篇

不同加热方式下白桦小径木锯材的表层应力

郭明辉 赵西平   

  1. 东北林业大学生物质材料科学与技术教育部重点实验室,哈尔滨150040
  • 收稿日期:2005-04-15 修回日期:1900-01-01 出版日期:2006-11-25 发布日期:2006-11-25

Stress of Surface Layer of Small-Diameter Birch Timber with Different Heating Methods

Guo Minghui,Zhao Xiping   

  1. Key Laboratory of Bio-Based Material Science and Technology of Ministry of Education,Northeast Forestry University Harbin 150040
  • Received:2005-04-15 Revised:1900-01-01 Online:2006-11-25 Published:2006-11-25

摘要:

研究小径木白桦锯材在连续加热方式和间歇加热方式(间歇2h和间歇6h)干燥过程中表层应力的产生、发展变化规律。结果表明:3种加热方式下锯材表层应力的变化趋势基本一致,但无论是干燥前期或干燥中期,间歇加热锯材的表层应力明显小于连续加热锯材的表层应力,间歇6h锯材的表层应力最小。间歇阶段使干燥过程中木材的干燥应力得到了释放,延长间歇时间有利于降低锯材表层应力。同一含水率水平下,弦切板的表层应力比径切板的表层应力大。

关键词: 白桦小径木, 锯材, 表层应力, 加热方式

Abstract:

The stress of surface layer of small-diameter Asian White Birch(Betula platyphylla)timber with consecution-heat and intermittent-heating(intermittent 2 h and intermittent 6 h)was discussed.The results showed that the change of tress of surface layer with three kinds of heating methods were in a similar way.However,during either prophase drying or metaphase drying,the stress with intermittent-heating was smaller than that with consecution-heat,the stress was least with intermittent 6 h.The drying stress was loosed during intermittent,intermittent time more long,the effect of loosen more remarkable.At the same moisture content level,the stress of surface layer of tangential timber was larger than that of radial timber.

Key words: small-diameter Asian White Birch, timber, surface layer stress, heating methods