頁籤選單縮合
題名 | 南洋材製漿適性之研究(第二報)--柳桉材硫酸鹽紙漿之漂白性及漂白紙漿回色之研究=Pulping Potentials of Tropical Woods(PartⅡ)--Bleachability and Brightness Stability of Kraft Pulps from Shorea Woods |
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作者 | 蘇裕昌; 粘青藍; 陳鴻財; | 書刊名 | 臺灣林業科學 |
卷期 | 12:1 1997.03[民86.03] |
頁次 | 頁81-93 |
分類號 | 476.2 |
關鍵詞 | 南洋材; 柳桉材; 製漿適性; 漂白性; 難漂性; 紙漿回色; Tropical woods; Shorea woods; Pulping potentials; Bleaching ability; Hard-to-bleach pulps; Color reversion; |
語文 | 中文(Chinese) |
中文摘要 | 評估南洋材三種柳桉材 - 黃柳桉 ( Shorea polita ),淺紅柳桉( Shorea richetia ),紅柳桉( Shorea albida )硫酸鹽紙漿之漂白性及漂白紙漿白度安定性,並 探討各影響因子對紅柳桉硫酸鹽紙漿難漂白性及漂白紙漿回色之影響,同時檢討其解決方法 。綜合試驗結果如下: 1. 三硫酸鹽漿紙漿漿料經傳統 C-E-D-E-D 五段漂白後白度,黃柳桉,淺紅柳桉紙漿漂白後 白度可達 83% ISO 以上具難漂性。 紅柳桉紙漿漂白後白度,黃柳桉,淺紅柳桉紙漿漂白後 白度可達 83% ISO 以上不具難漂性。 紅柳桉紙漿漂白後白度僅 73%-78%,白度偏低具相當 難度之漂白性,隨未漂漿卡巴值之升高而難漂性增高,未漂漿卡巴值在 20 以下則無難漂性 之問題。三種漂白紙漿之白度安定性,黃柳桉,淺紅柳桉之 PC 價低,白度安定性佳。紅柳 桉之 PC 價較高( 1.91 - 4.65 ),其值隨未漂漿卡巴值之升高而升高, 白度安定性不佳 。 2. 影響紅柳桉硫酸鹽紙漿漂白性的因子有白度低下其及其白度不安定原因,可推論如下: ( 1 )就醇苯抽出物而言, 先抽除樹脂後再蒸煮之漿料, 其漂白漿白度大量提升達 83% ISO,PC 價也降低至 1.39,故本片中樹脂對白度及白度安定性有相當程度之影響。 未處理 木片煮漿後脫脂,漂白後其白度提升較少,其 PC 價降低也較小,顯示木片中醇苯抽出物在 蒸解反應有某些變性,大部份溶出後殘存之小部分不易被醇苯抽出,而影響其白度及白度安定 性。在醇苯抽出物中影響漂白度因子,經添加試驗之結果,推論為酚性成分為最大,影響白 度安定性之因子為乙酸乙酯不溶部及酚性部。 ( 2 )依逐次抽出(苯、醇苯、甲醇及丙酮 / 水)抽出物之再添加試驗結果,顯示各抽出 成分對漂白性及漂白漿白度安定性之影響程度, 以極性較優者, 即甲醇抽出物、丙酮 / 水 抽出物有較大的影響。全抽出物對漂白性與 PC 價之影響程度依其逐次抽出物,佔整個抽出 物含量百分比相乘之計算值,有類似的結果。 ( 3 )就木片冷熱水抽出物而言,木片抽除熱水溶物後蒸煮漂白,白度較高。 若以 PC 價 影響度而言,熱水處理後能降低 22.97% 之 PC 價,冷水只降低 10.21%。 ( 4 )半纖維素對漂白漿之白度影響極大, 經冷鹼萃處理將其除去後白度約提升 4%。 對 PC 價之影響亦很大,冷鹼萃取處理後 PC 價減少 37% ∼ 42%,可見漂白漿中之半纖維素 為造成難漂白性及白度安定性之一重大因子。並推論此原為蒸煮後未漂漿中有較高木質素 - 碳水化合物之錯合物含有率所導致。 ( 5 )經鹽酸處理除去金屬離子後,白度皆提升了 3%,PC 價也減少了 10.22% ∼ 12.34% ,可見金屬離子亦為影響白度及白度安定性之一因子。 3. 以二氧化氯取代部份的氯氣的 C-E-D-E-D 漂白流程,能改善紅柳桉紙漿的最終白度及白 度安定性。 以臭氧段( Z )段取代氯氣( C )段的無氯元素漂白流程 Z-E-D-E-D 及 Z-E-C/D-E-D,及無氯漂白流程如 O-Z-E-P-Y 以臭氧添加量 1% 即可達到傳統五段漂白的水 準,超過此量更可改善難漂漿的漂白性。 |
英文摘要 | The main purpose of this study was to eluclidate the bleachability and brightness stability of kraft pulps from 3 Shorea wood species (Shorea polita, Shorea richetia and Shorea albida).Factors which influence the bleachability and brightness stability of those pulps are also discussed. The results are summarized as follows. 1.Kraft pulps from Shorea polita and Shorea richetia were easy to bleach, and after the conventional 5-stage C-E-D-E-D belaching sequence, the brightness of the resulting pulps reached 83% ISO, but kraft pulp of Shorea albida only reached 73%-78% ISO in brightness. Kraft pulps of this latter species have bleaching problems. In comparison, the PC numbers of pulps from Shorea polita and Shorea richetia were small, indicationg good brightness stability of bleached pulps. Those from Shorea albida (red shorea) had high PC numbers indicating unstable brightness characteristics. 2.The major factors responsible for lower brightness and higher PC numbers of kraft pulps from red shorea wood are summarized as follows: (1)The alchol-benzene extractives in the chips didn't show much influence on belachability.Brightness of resulting pulp from extractive-free chips after conventional C-E-D-E-D belaching reached 83%, and the PC number was quite low. After bleaching the extractive-free unbleached pulps the brightness and PC number showed little improvement. Assuming the solvent extractable extractive didn't affect bleachability and brightness stability to an apperciable extent, the presence of some polyphenol compounds which are diffecult to extract should be one of the factors responsible for bleachability and brightness stability. (2)The readdition experiment using extractives from the sequential extraction (benzenealcohol/benzene-methanol-acetone/water) indicated the effect of each fraction on bleachability and brightnes stability of the pulps. The more polar componenets, such as methanol and acetone/water extractives showed greater influences. The entire extractives exerted comparable effects on the bleachability and brightness stability as the sum of the products of individual fractions and the fraction's percentage. (3)Removing the cold and hot water soluble extractives of chips increased the bleachability of the resulting kraft pulps. Hot-water-soluble extraction of wood chips decrease the ratio to 22.97%. Cold-water-soluble extraction of wood chips decreased the PC number 10.21% in the resulting pulp. (4)Hemicellulose in pulps showed great influence in brightness and PC number. Using the alkaline extraction to remove hemicellulose resulted in a gain of 4% ISO in brightness, and a decrease in the PC number of 37%-42%. (5)Removal of metal ions in the unbleached pulp increased brightness by 3% compared to untreated pulp, and decreased the PC number by 10.22%-12.34%, suggesting that metallic ions are also a factor responsible for bleachability and brightness stability. 3.Partial replacement of chlorine with chlorine dioxide in the C-E-D-E-D sequence improved the final brightness and brightness stability of the red shorea pulps. Substitution of chlorine with ozone in the elemental-chlorine-free sequences, Z-E-D-E-D or Z-E-C/D-E-D sequence, or total chlorine-free bleaching sequence, e.g. O-Z-E-P-Y at an ozone dosage of 1% with respect to o.d. pulp, reached the same brightness as that of the traditional 5-stage bleaching sequence. Exceeding this charge level, the hard-to-bleach characteristic of this species can be overcome. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。