熱壓條件對杉木乾燥之影響

The Effect of Press Conditions on Wood Drying of China Fir

熊如珍(J. C. Hsiung)

《林業試驗所研究報告季刊》 1卷2期 (1986/12) Pp. 45-54

https://doi.org/10.7075/BTFRI.198612.0045

摘要

本所蓮花池分所35年生杉木，平均直徑24.3cm，比重0.367，初期含水率67.36%，鋸製為3cm厚板材，以3.5/2、3.5及3.5×2 kgf/平方公分之熱板壓力，熱板溫度174℃，樣板中心溫度163℃為乾燥終點，對不同長度（40及120cm）、不同鋸製方式（象鋸或平鋸）之試材，行熱壓乾燥試驗。結果顯示：樣板中心溫度達163℃，平均含水率應已在6%之關係，不適用於杉木之乾燥。熱壓乾燥時，熱板壓力增大，乾燥速率亦增加。製材方式影響乾燥材品質，象鋸板之乾燥缺點較輕微。

並列摘要

The objective of this study was to evaluate the effect of press conditions on drying for 3 cm of China fir in thickness. Press drying was at 174℃ platen temperature, at three (3.5/2, 3.5 and 3.5×2 kgf/cm^2) platen pressure, and boards in two common sawing patterns (flat- and quartersawn). Boards were edged to the closet cm in width, surfaced to 3 cm in thickness, and end trimmed to 40 cm and 120 cm in length.
The material were tested to evaluate the effect of platen pressure on drying rate for different length, then the experiment was conducted in two parts. In the first part (40 cm in length), drying defects compared in press-dried quartersawn versus flatsawn lumber. The second part of the study (120 cm in length), determined the mechanical properties of press-dried material.
The results of this research are shown as follows:
1. Increasing platen pressure increased drying rate.
2. The drying defects of quartersawn press-dried lumber is slighter than flatsawn press-dried lumber.
3. The midthickness of the specimen in a temperature 163℃ (platen temperature 174℃) indicated that the average moisture content of the specimens was below 6%. This condition was suited for hardwoods, but not for softwoods.