邓恩桉木材干燥特性初探

摘要

The wood drying characteristics of Eucalyptus dunnii were analyzed by using 100℃ test meth-od.The results showed that it was very difficult to dry E.dunnii wood,there were serious problems with cross-sectional deformation (grade 5),initial craze (grade 4)and internal craze (grade 4)、very slow dr-ying speed (grade 4),a large drying shrinkage with volume shrinkage and chordwise shrinkage,and a small drying shrinkage with longitudinal shrinkage.The initial drying temperature was 40℃.Depression of the wet bulb in the initial drying period was 2℃,and in the final period of wood drying the temperature was 70℃.Time needed to make 25 mm lumber dried to 10 % in forced circulation draught kiln was 20.5 days.Major defects of the wood drying of E.dunnii were the cross-sectional deformation and the early wood craze.In the actual production process,a soft schedule would be preferable,and humidifying treat-ment should be recommended in the middle and later stage of processing.%采用百度试验法对邓恩桉木材的干燥特性进行了初步研究。结果表明,邓恩桉属难干木材,截面变形较严重,为5级；初期开裂和内裂严重,均为4级；干燥速度慢,为4级；弦向干缩率和体积干缩率大,差异干缩小。邓恩桉的干燥初期温度为40℃,干燥初期干湿球温度差为2℃,干燥终期温度为70℃。25 mm 厚的邓恩桉板材在窑干至10%所需时间约为20.5天。邓恩桉主要干燥缺陷为截面变形,初期开裂发生较早,在实际干燥过程中要尽量使用软基准,干燥中、后期适时进行调湿处理。