酵素前處理對雁皮與構樹纖維紙漿性質之效應

Abstract

雁皮 (Wikstroemia sikokiana Franch.et Sav.) 與構樹 (Broussonetia papyrifera (L.) Hert. ex Vent.) 纖維屬韌皮纖維(bast fiber)，為永續可再生材料，長久以來作為東方藝術用紙的原料。本研究以蘇打法 (soda process) 及蘇打添加草酸法 (soda/oxalate process)，對雁皮與構樹韌皮纖維進行製漿，探討紙漿卡巴值 (Kappa number)、白度 (brightness)、紙力 (hand sheet strength properties) 之特性。並進行雁皮與構樹次氯酸鈉 (sodium hypochlorite) 及二氧化氯 (chlorine dioxide) 漂白，其後添加木聚醣酶 (xylanase)、果膠酶 (pectinase complex)、果膠酶 (pectinase BL11) 三種酵素預處理二氧化氯漂白紙漿。雁皮漿蘇打法可獲致較高收率 47.57 %，高於蘇打加草酸鹽法製漿收率 44.30 %。構樹則是以蘇打加草酸法製漿收率較高 38.37 %，高於蘇打法製漿收率 37.81 %。雁皮與構樹添加草酸法製漿時，紙力整體上較蘇打法所得紙漿為高。 本研究並以次氯酸鈉及二氧化氯對以上四種紙漿進行漂白，以探討漂白藥劑對紙漿白度及紙力性質的影響。添加草酸法紙漿經次氯酸鈉漂白後，在部分紙力性質可得比蘇打法紙漿較高紙力。添加草酸法紙漿經二氧化氯漂白後，所有紙力皆高於蘇打法紙漿。比較在同為 0.3 Kappa factor的有效氯 (Active chlorine multiple, ACM) 用量下，二氧化氯漂白紙漿所得紙力，高於次氯酸鈉漂白紙漿。 本研究並以木聚醣酶、pectinase complex、pectinase BL11 酵素，對紙漿二氧化氯漂白序列進行前處理，以探討酵素前處理對節省漂白藥劑的效益。蘇打法及添加草酸法雁皮漿經木聚醣酶處理，在達到同一目標白度 47.5 % 時，每克絕乾漿可節省有效氯用量 33.33 % 和 14.29 %，經 pectinase complex處理可節省有效氯用量 66.67 % 和 33.73 %，經pectinase BL11 處理蘇打加草酸漿可節省有效氯用量 14.29 %。蘇打法及添加草酸法構樹漿經木聚醣酶處理，在達到同一目標白度 59 %時，每克絕乾漿可節省有效氯用量33.33 % 和 25.00 %，經 pectinase complex 處理可節省有效氯用量50 % 和60.11 %，經pectinase BL11處理蘇打加草酸漿可節省有效氯用量33.33 %。 以上之紙漿並以濕熱加速劣化，試驗返黃情形，並計算白度留存率 (brightness retention)。添加草酸製漿法紙漿較蘇打法所製紙漿，均可得較高白度留存率。兩種雁皮漿經次氯酸鈉漂白後，紙漿白度留存率65.65-79.42 %，經二氧化氯漂白後86.91- 99.38 %，木聚醣酶預處理及二氧化氯漂白後85.26-103.06 %，pectinase complex預處理及二氧化氯漂白後101.30-109.80 %，pectinase BL11 預處理及二氧化氯漂白後100.05-105.72 %。兩種構樹漿經次氯酸鈉漂白後，紙漿白度留存率 77.03-88.61 %，經二氧化氯漂白後71.47-95.88 %，木聚醣酶預處理及二氧化氯漂白後95.60-104.86 %，pectinase complex 預處理及二氧化氯漂白後95.74-104.97 %，pectinase BL11 預處理及二氧化氯漂白後99.86-109.18 %。本研究發現，酵素預處理，可減少後續二氧化氯漂白時，有效氯的用量，並可協助生產不易變黃的藝術用及古蹟修護用紙。

The fibers of gampi (Wikstroemia sikokiana Franch.et Sav.) and paper mulberry (Broussonetia papyrifera (L.) Hert. ex Vent.) belong to the genre of bast fiber. They are sustainable and reproducible materials and applied as a conventional oriental art paper material source. Soda pulping process and soda/oxalate pulping process were employed to prepare the above two fibers, with their Kappa number, brightness, physical strength properties analyzed. This study also employed sodium hypochlorite and chlorine dioxide to bleach the pulps, and were employed xylanase, pectinase complex and pectinase BL11 for the pretreatments of chlorine dioxide bleaching sequences. The yield of gampi soda pulping was 47.57 %, higher than 44.30 % after soda/oxalate pulping. The yield of paper mulberry soda pulping was 38.37 %, higher than 37.81 % after soda/oxalate pulping. Physical strength properties of soda/oxalate pulps were superior to the strength values of soda pulps for both gampi and paper mulberry fibers. This study also employed sodium hypochlorite and chlorine dioxide to bleach the above four pulps, and investigated the impact of bleaching agents on brightness and physical strength properties of resulting pulps. After sodium hypochlorite bleaching, some superior physical strength properties were observed for soda/oxalate pulps than the values for soda pulps. After chlorine dioxide bleaching, all superior physical strength properties were observed for soda/oxalate pulps than the values for soda pulps. Under an identical Kappa factor as 0.3 active chlorine multiple (ACM), pulp physical strength properties after chlorine dioxide bleaching were higher than values after sodium hypochlorite bleaching for both gampi and paper mulberry pulps. Xylanase, pectinase complex and pectinase BL11 three enzymes were employed for the pretreatments of chlorine dioxide bleaching sequences. The efficacies of bleaching agent saving for enzymatic pretreatments were investigated. Xylanase pretreatments for soda and soda/oxalate gampi pulps save 33.33 % and 14.29 % active chlorine. Pectinase complex pretreatments for soda and soda/oxalate gampi pulps save 66.67 % and 33.73 % active chlorine. Pectinase BL11 pretreatments for soda/oxalate gampi pulps save 14.29 % active chlorine. The above comparisons were set at a target of 47.5 % brightness level. Xylanase pretreatments for soda and soda/oxalate paper mulberry pulps save 33.33 % and 25 % active chlorine. Pectinase complex pretreatments for soda and soda/oxalate paper mulberry pulps save 50 % and 60.11 % active chlorine. Pectinase BL11 pretreatments for soda/oxalate paper mulberry pulps save 33.33 % active chlorine. The above comparisons were set at a target of 59 % brightness level. Accelerated aging by heat-humid treatment were conducted to evaluate yellowing phenomena and to estimate brightness retention. Better brightness retention values were observed for soda/oxalate pulps than the values of soda pulps. For two gampi pulps, brightness retention levels were: 65.65-79.42 % after sodium hypochlorite bleaching; 86.91- 99.38 % after chlorine dioxide bleaching. For two gampi pulps with chlorine dioxide bleaching, brightness retention levels were: 85.26-103.06 % after xylanase pretreatment; 101.30-109.80 % after pectinase complex pretreatment; 100.05-105.72 % % after pectinase BL11 treatments. For two paper mulberry pulps, brightness retention levels were: 77.03-88.61 %after sodium hypochlorite bleaching; 71.47-95.88 % after chlorine dioxide bleaching. For two paper mulberry pulps with chlorine dioxide bleaching, brightness retention levels were: 95.60-104.86 % after xylanase pretreatment; 95.74-104.97 % after pectinase complex pretreatment; 99.86-109.18 % after pectinase BL11 treatments. This study found that the enzymatic treatments were able to reduce the active chlorine usage of chlorine dioxide, and to assist producing photo-stable paper materials for art and artifact-repairing applications.