气相硼法木材防腐处理的研究

STUDY ON VAPOR-PHASE BORATE PRESERVATIVE TREATMENT OF WOOD

对马尾松及花旗松木材试样进行了气相硼法木材防腐处理的研究。考察了马尾松木材试样的含水率、防腐处理温度、处理压力及进料温度等因素对防腐处理后试样中硼酸含量的影响。得到了气相硼法防腐处理的优选工艺条件:木材试样的含水率10%,防腐处理温度75℃,防腐处理真空度97.325kPa,进料温度32℃。防腐处理1h,马尾松试样中硼酸的含量为6.13%。对花旗松心材气相硼法防腐处理实验结果表明:对难渗透的木材渗透效果也很好。电子显微镜观察的结果表明:经气相防腐处理和液体浸泡防腐处理试样的细胞壁上均沉积了硼酸固体物质,但硼酸沉积量前者的远远大于后者的。对防腐处理前后试样的机械性能及尺寸变化测试结果表明,木材试样的冲击强度与抗弯弹性模量下降很小,而抗弯强度反而提高了4.6%;木材尺寸变化很小。

Studies on vapor-phase borate preservative treatment of Masson pine ( Pinus massoniana ) and Douglas fir[ Pseudotsuga menziesii (Mirbel) Franco]wood samples had been carried out.The optimum preservative treatment conditions were investigated by using orthogonal experiment as follows: wood sample moisture content 10 %, preservative treatment temperature 75 ℃, reduced-pressure treatment 97.325 kPa, preservative temperature 32 ℃. Boric acid content of Masson pine sample was 6.13 %. Test results of vapor-phase borate preservative treatment on Douglas fir heartwood samples that can hardly be treated indicated: permeability was good. Using electronic microscopy ,it was found that boric acid was deposited in both samples by vapor-phase treatment and by liquid treatment . However, boric acid content of samples of the former was higher than that of the later in wood cells. Testing results on mechanical properties and dimensional change of Masson pine samples indicated that impact strength and modulus of elasticity of the treated wood decreased insignificantly. Bending strength of the treated wood was elevated by 4.6 %. Dimensions of wood samples changed very small.