窯乾條件對琉球松木材強度與滲脂之影響

Effect of Kiln Conditions on the Strength and Resin Exudation of Luchu Pine

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

《林業試驗所研究報告季刊》 9卷1期 (1994/03) Pp. 1-9

https://doi.org/10.7075/BTFRI.199403.0001

摘要

為探討不同窯乾條件對琉球松之強度性質與滲脂具有何種影響，並藉以製訂一最適當之窯乾基準，提供業界參考，特就3.5cm厚之琉球松以高溫窯乾(A)；低～高溫窯乾(B)；與傳統窯乾(C)三種處理進行試驗。結果顯示：A處理具有節省能源與時間之功效；A與B處理對琉球松之強度性質均無減弱影響：A與B處理可促使松脂大量滲出，此當可減低使用後之滲脂困擾；琉球松之乾燥處理，以高溫窯乾最具經濟效益。

關鍵字

高溫乾燥 ； 低～高溫窯乾 ； 傳統窯乾 ； 琉球松 ； 滲脂

並列摘要

The objectives of the study reported here were to examine the effect of kiln conditions on the strength and resin exudation of 3.5cm Luchu pine (Pinus luchuensis), and then to develop a proper drying schedule for this wood. Twenty-eight 150cm-long bolts, ranging from 25.5 to 36.4cm in diameter, cut from twenty 30-year-old trees in northern Taiwan, were used for this study. The cutting size of the test boards was 3.5cm (T)×l5cm (W)×150cm (L). During cutting, each three consecutive test boards were divided into three groups and then stored in a refrigerator until the time of kiln drying.
The initial average moisture content of the test boards was 121.30%, and the specific gravity based on ovendry weight and green volume was 0.483. Each group of the test boards was dried in an automatically controlled experimental kiln by different drying process listed below:
A=High-temperature kiln drying (mixture of steam and air process).
B=Low～high-temperature kiln drying (Table 2.).
C=Conventional-temperature kiln drying (Table 3.).
The moisture content of the test boards during drying was monitored by standard sample board technique.
The results of this study show that:
1. High-temperature kiln drying can reduce both drying time and power consumptions. Treatment A reduces drying time more than 71%, and saves power and oil consumptions more than 31% and 81% respectively, as compared with treatment B; and reduces drying time more than 76%, and saves power and oil consumptions more than 34% and 83% respectively, as compared with treatment C (Table 4.).
2. The A treatment only shows significantly (0.05 level) higher strength values in gardness on the end and tangential surfaces, as cmpared with treatment C. As shown in Tables 6 and 7, however, there is no significant difference among the treatments in overall strength properties. This indicates that high-or low～hightemperature drying of Luchu pine does not affect its strength.
3. Both treatment A and B (high-and low～high-temperature drying) cause large quantity of resin-exudation during drying, this should reduce or eliminate the occurance of resin-exudation problem during service.
4. The most effective and economic drying process for 3.5cm Luchu pine is High-temperature Kiln Drying.

並列關鍵字

high-temperature kiln drying ； low～high-temperature kiln drying ； conventional-temperature kiln drying ； Pinus luchuensis ； resin-exudation