Shrinkage stress of wood during drying under superheated steam and its mechanism

木材过热蒸汽干燥收缩应力及其机理

• 批准号: 14560135
• 负责人: MOROOKA Toshiro
• 金额: $ 2.24万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14560135/
• 关键词: Wood; drying stress; shrinkage stress; su; superheated steam; Viscoelasticity; compressive deformation; chemical analysis; 応力緩和; 水蒸気処理; セルロース系繊維; 乾燥; 高温; 木材横方向

In order to reduce the internal stress of wood during drying, an attempt was made to dry wood with superheated steam above 100℃. Sugi (Cryptomeria japonica D.Don) wood specimens were dried with radial restraint using superheated steam at up to 180℃ and the resulting restrained shrinkage stress was examined. A load cell capable of measuring shrinkage stress inside an autoclave was developed and the shrinkage stress was measured at temperatures from 80 to 180℃ and a relative humidity of 0 to 80%. It was found that the shrinkage stress decreased dramatically with drying above 140℃ and above 60 percent relative humidity. It was also found that the shrinkage stress above 140℃ occurred even at 100%RH and was ascribed to the structural change of cell wall components.

为了降低木材干燥过程中的内应力，尝试了用100℃以上的过热蒸汽干燥木材。对日本柳杉（Cryptomeria japonica D.Don）木材进行了径向约束干燥，并对径向约束干燥产生的约束收缩应力进行了研究。研制了一种能测量高压釜内收缩应力的测力传感器，并在温度为80 ~ 180℃、相对湿度为0 ~ 80%的条件下测量了收缩应力。结果表明，当干燥温度高于140℃，相对湿度高于60%时，干缩应力显著降低。140℃以上的收缩应力在100%RH下也能产生，这是由于细胞壁组分的结构变化引起的。

项目成果

Cheng, W.: "Shrinkage stress of wood during drying under superheated steam above 100C."Holzforshung. (in press).

Cheng, W.：“木材在 100°C 以上的过热蒸汽干燥过程中的收缩应力。”Holzforshung。

Morooka, T.: "On a master curve for strain recovery vs.steaming time obtained under superheated steam"Proceedings of the fourth international wood science symposium-Sustainable utilization of Tropical Forest Resources. 2-5 (2002)

Morooka, T.：“在过热蒸汽下获得的应变恢复与蒸煮时间的主曲线”第四届国际木材科学研讨会论文集 - 热带森林资源的可持续利用。

高原貴志: "水蒸気処理および熱処理による木材の化学変化と圧縮変形固定の関係"木材学会誌. 50. 159-167 (2004)

Takashi Takahara：“木材的化学变化与蒸汽处理和热处理引起的压缩变形之间的关系”日本木材学会杂志 50. 159-167 (2004)。

Cheng, W.: "Shrinkage stress of wood during drying under superheated steam above 100C."Holzforschung. (印刷中). (2004)

Cheng, W.：“100°C 以上过热蒸汽干燥过程中木材的收缩应力”。Holzforschung（出版中）。

Higashihara, T.: "Mechanism of permanent fixation of radially compressed wood by steaming or heating"Proceedings of the fourth international wood science symposium-Sustainable utilization of Tropical Forest Resources. 58-63 (2002)

Higashihara, T.：“通过蒸汽或加热永久固定径向压缩木材的机制”第四届国际木材科学研讨会论文集-热带森林资源的可持续利用。