臭冷杉表面密实化及后期高温热处理工艺

Surface densification and high temperature hydrothermal post treatment of the Abies nephrolepis lumber

以35 mm厚臭冷杉气干光边板为试验材料,采用2种厚度压缩率,分别在160、180℃的热压温度下进行表面压密化处理;然后将表面压密材在温度分别为180、200℃的热湿环境下进行高温热处理,对表面压密化对比材与高温热处理材试件进行常温浸水处理;分析了表面压缩率、热压温度、热处理条件等因子对臭冷杉表面压密地板材厚度方向变形恢复的影响。结果表明:在实验所采用的开放热压工艺下,臭冷杉弦切板材的实际压密区位于上、下表面2 mm处,达到了表面压密强化的目的;表面压密试件在温度为200℃时经高温热处理1 h,其厚度方向变形恢复率为对比材的28.6%;高温热处理工艺是改善表面压密材尺寸稳定性的有效方法。

The objective of this article was to provide theoretical bases for the value.added processing technology of soft.wood plantation timbers, as well as to develop innovative wooden flooring materials. Abies nephrolepis sapwood lumbers with thickness of 35 mm was surface.densified to two degrees of compression at 160 ℃ and 180 ℃ by using a wooden composites heated press. The densified specimens were then hydrothermally post.treated at 180℃ and 200℃. To study the influence of the degree of compression, hot.pressing temperature and high.temperature hydrothermal post.treatment on the set.recovery of surface densified floorings, specimens were subjected to water soaking plus oven.drying cycles. The actual influential mechanisms of these factors over the recovery of surface compressive sets were discussed herein. Under these specified hot.pressing technique parameters, the actual densification areas of Abies nephrolepis sapwood lum.bers lies two millimeters below wood surfaces and the densification plus reinforcement of flooring surfaces has been a.chieved accordingly. Being hydrothermally treated at 200℃ for one hour, the deformation recovery ratios of surface.den.sified specimens was just 28.6% of that of control specimens, highlighting that the hydrothermal post.treatment was a ef.ficient technology, which could improve the deformation stability of surface.densified solid wood.