Optimization of Wood Drying Criteria for Michelia macclurei Wood based on Baidu Test Method and Kiln Drying Test Method
In order to fully understand and reasonably utilize the timber properties of Michelia mac-clurei,a world rare and excellent tree species and the major tree species for afforestation and timber in southern China,and to provide a more scientific and comprehensive drying benchmark for the timber drying industry,this study focuses on the 48-year—old plantation of Michelia macclurei.The Baidu experimental method was adopted to develop the preliminary drying benchmark and timber drying kiln.After conducting a small-scale kiln drying test on Michelia macclurei timber and optimizing the drying benchmark,the drying defects of the timber were measured and analyzed.The results showed that the drying defects of Michelia macclurei timber were mainly manifested as initial cracking,twis-ting,and cross—section deformation,without internal cracking.The initial cracking and twisting were of Grade 2,while the internal cracking and cross—section deformation were of Grade 1.The de-gree of initial cracking and twisting was moderate,and the degree of cross—section deformation was relatively light,making it unlikely to produce serious drying defects such as internal cracking.The dr-ying speed was of Grade 3,indicating a moderate drying speed and belonging to a species that is easy to dry.The basic conditions for the small—scale kiln drying process were:the initial drying tempera-ture was 60～70 ℃,the initial temperature difference between dry and wet bulbs was 3～7 ℃,and the final drying temperature was 80～85 ℃.Based on these conditions,no internal cracking or shrink-age occurred during the drying process of Michelia macclurei timber.The average final moisture con-tent was 7.9％,the deviation in moisture content on the thickness was 2.1％,the drying uniformity was 0.6％,and the residual stress was 1.4％.All drying quality indicators met the first—level re-quirements of the national standard for sawn timber drying quality.The thickness of the timber was 25～30 mm.
Michelia macclurei100 ℃ test methodkiln dry testdrying qualitydrying schedule
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