高级检索

    热处理温度和时间对杉木质量损失和静曲强度的影响

    Effects of thermal treatment temperature and duration on mass loss and rupture modulus of Cunninghamia lanceolata

      摘要
    • 摘要:
        目的  热处理可以改善木材的尺寸稳定性，同时会降低木材质量并影响木材力学性能，有必要探明热处理对木材质量和力学性能的作用机制。
        方法  本研究选用人工林杉木薄片作为试验材，在160、180、200、220℃及氮气环境下分别处理1、2、3、4、5、6 h，测试处理后木材的质量损失率（mL）和静曲强度（MOR），采用ATR-FTIR、TGA进行表征，并建立热处理杉木质量损失率和静曲强度的预测模型。
        结果  热处理温度低于200 ℃时，温度比时间对杉木质量损失率和力学性能的影响更显著。当热处理温度高于200 ℃时，温度和时间对质量损失率和力学性能均有显著性影响。热处理杉木的质量损失率随热处理温度升高和时间延长呈非线性增加，质量损失率范围在0.2% ~ 17.6%之间，其预测模型为lnmL = 0.8lnt + 9.35lnT – 53.67（t为时间，T为温度），R2为0.99，试验测试值与模型预测值基本一致。杉木的MOR随热处理温度升高和热处理时间延长线性降低，与未处理杉木相比，MOR降低了4.4% ~ 74.8%，其预测模型为MOR = −2.57t – 0.82T + 220.44，R2为0.93，该模型总体预测效果较好。热处理杉木MOR随质量损失率增加呈指数下降，两者关系模型为MOR = 65.4\rme^ - 20m_\rmL + 16.4，R2为0.95，此模型能够预测MOR随质量损失率的非线性变化趋势。
        结论  通过试验数据建立了杉木的质量损失率与热处理条件，MOR与热处理条件，质量损失率与MOR之间的经验方程，可预测热处理木材质量损失和MOR的变化趋势，为木材热处理工艺的优化和热处理木材性能预测提供参考和依据。

       

      Abstract:
        Objective  Heat treatment can improve the dimensional stability of wood, but it will simultaneously reduce its mass and affect its mechanical properties. So it is necessary to explore the mechanism of heat treatment on wood mass and mechanical properties.
        Method  In this study, flakes of Chinese fir plantation were used as the test material, and they were treated at 160, 180, 200, 220 °C and nitrogen atmosphere for 1, 2, 3, 4, 5 and 6 hours, respectively. The mass loss rate (mL) and static bending strength (MOR) of treated wood were tested, characterized by ATR-FTIR and TGA. And the prediction model of mass loss and MOR during heat treating process was established.
        Result  When the heat treating temperature didn’t exceed 200 ℃, it had a more significant impact on the mass loss and mechanical properties of wood than the heat treating time. When the heat treating temperature exceeded 200 °C, heat treating temperature and time had significant effects on wood mass loss and mechanical properties. The mass loss rate of Chinese fir wood showed a non-linear increase with the increase of heat treating temperature and heat treating time, and when the range of mass loss rate was between 0.2% and 17.6%, a model can be established, lnmL = 0.8 lnt + 9.35 lnT – 53.67 (t is time, T is temperature), R2 was 0.99. And the tested values were basically consistent with the predicted values. The MOR of Chinese fir wood decreased linearly with the increase of heat treating temperature and heat treating time. Compared with untreated wood, MOR decreased by 4.4%−74.8%, and a model which had a better forecast can be established, MOR = −2.57t – 0.82T + 220.44, R2 was 0.93. The MOR of heat-treated wood decreased exponentially with the increase of mass loss, and a model that accurately predict the changing trend of MOR with mass loss can be established, MOR = 65.4\rme^ - 20m_\rmL + 16.4, R2 was 0.95.
        Conclusion  This study establishes the empirical equations between mass loss and the heat treating conditions, the MOR and the heat conditions, the mass loss and MOR of Chinese fir wood through the experimental data, which can provide reference and basis for optimization of wood heat treating process and prediction of heat-treated wood performance.

       

      • HTML全文
      • 参考文献(40)
      • 相关文章
      • 施引文献
    • 资源附件(0)

    /

    返回文章
    返回