熱壓乾燥材吸濕與脫濕性質之研究

Study on the Adsorption and Desorption Behaviors of Press-Dried Wood

熊如珍(Ju-Chen Hsiung) ； 翟思湧(Sy-Yung Jai)

《林業試驗所研究報告季刊》 10卷4期 (1995/12) Pp. 513-524

https://doi.org/10.7075/BTFRI.199512.0513

摘要

本研究旨在探討木材在不同高低濕度條件下之吸脫濕性質，除就2cm木荷之小同熱壓乾燥條件進行探討外，並對不同齡級(6、11、15、21)之台灣杉比較氣乾材與熱壓乾燥材間吸脫濕性質之差異。
研究結果顯示：木荷、台灣杉熱壓乾燥材及台灣杉氣乾材其吸脫濕過程均發生遲滯現象(hysteresis)；其中，熱壓乾燥材之遲滯現象較烈於氣乾材。熱壓乾燥處理可降低木材之吸脫濕率及吸濕速度；熱板溫度越高，其吸脫濕率減少之程度亦越高，吸脫濕速度亦越慢。此外，熱壓乾燥處理減少木材徑弦向吸、脫濕速度之差異。

關鍵字

熱壓乾燥材 ； 吸濕 ； 脫濕 ； 遲滯現象

並列摘要

This study investigates the adsorption and desorption behaviors of press-dried wood. Chinese guger-tree (Schima superba) and Taiwania (Taiwania cryptomerioides) were used for this study.
Treatment combinations of press drying for Chinese guger-tree were: T1P1 (174℃and 3.5kgf/cm^2), T1P2 (174℃ and 4.5 kgf/cm^2) T2P2 (150℃ and 4.5 kgf/cm^2), T2P3 (150℃ and 2.5 kgf/cm^2). Treatments of drying for Taiwania were air drying at 30℃ and 56% R. H. and press drying at 174℃ and 3.5 kgf/cm^2.
The results of this study indicate that:
1. For Taiwania, the amount and the rate of adsorption and desorption for each treatment of press drying were smaller than those with treatment by drying. The results proves that the application of press drying reduces the sorption capacity.
2. For Chinese guger-tree, it was found that the higher the platen temperature, the smaller the amounts and the rates of adsorption and desorption. The results mean that the higher the temperature, the greater the reduction of sorption capacity.
3. The phenomenon of sorption hystersis was also obtained from the application of press drying and this phenomenon was stronger than that obtained from the application of air drying.
4. The application of press drying reduced the difference of the rate of adsorption and desorption between the tangential and radial faces.

並列關鍵字

press-dried wood ； adsorption ； desorption ； hysteresis