| Summary: | 碩士 === 大葉大學 === 環境工程學系碩士班 === 104 === ABSTRATC
This study mainly investigated the effects of fiber morphologies of six bleached softwood pulps, seven bleached hardwood pulps, five wastepaper pulps and a bamboo pulp from Thailand on the water absorbance and strength properties of the resulting handsheets in a three-stage experiments. Through blending of different pulp ratios (BSKP/BHKP: 0/100, 25/75, 50/50, 25/75, 0/100) and treatment with enzymes (dosage at 0, 125, 250, 500, 1,000 ppm), we also endeavored to improve water absorbance and strengths of the resulting paper.
In the first stage, pulp freeness, fiber coarseness and fiber length of the bleached softwood pulps were found to be proportional to water absorbance performances; number of fibers and fiber length, meanwhile, exerted positive correlation with the strength properties. For the bleached hardwood pulps, similar correlations were also found. In the case of wastepaper pulp, pulp freeness and fiber length exerted positive effect on water absorbance; whereas pulp freeness negatively correlated with the strength properties; with increasing paper grammage, the wastepaper pulp having the higher coarseness also showed the higher water absorbance.
In the second stage of blended pulp experiments, when Arauco N pulp is blended with Fibera pulp (25/75), the resulting handsheets had 1.8% higher water absorbance; tensile and burst indices gained 34%, and 1.7% respectively. When it was blended with Arauco L pulp (75/25), the handsheet water absorbance, tensile and burst indices increased 3.5%, 29%, and 15%, respectively. When Pacifico pulp was blended with Fibera pulp (50/50), the water absorbance increased 5.2%, tensile index increased 11%, and burst index increased 10%. In the blended group involving Canfor pulp, when blended with Fibera pulp (25/75), the water absorbance, tensile and burst indices increased respectively 5.5%, 9%, and 38%; when it was blended with Arauco L pulp (25/75), the water absorbance, tensile and burst indices gained respectively 6.4%, 6%, and 45%. In the blended deinking pulp (DIP) or recycled mealbox with bleached pulps (Arauco N and Arauco L) groups, the water absorbance has positive correlation with bleached pulps ratio increased.
Cellulase enzyme at doses of 0~1,000 ppm were added to bleached wood pulps of Canfor, Acauco N, Arauco L, Pt. Tel and DIP at 50℃ for 1 h, in a bid to increase the resulting water absorbance. Among the enzyme 6599 experimental sets, at the dosage of 250 ppm, the Arauco L pulp showed increases in water absorbance, tensile and burst indices of 0.8%, 7%, and 45%, respectively. The treated Pt. Tel pulp showed gains in the same traits of 5.1%, 43%, and 49%, respectively. The treated DIP showed gains in water absorbance, and burst index of 3.0% and 10%, except drops in tensile index of 1%. In the enzyme 7300 experimental sets, at the dosage of 125 ppm, the Arauco L pulp showed gains in water absorbance, tensile and burst indices respectively of 3.4%, 1% and 22%; the treated DIP in the same traits of 6.8%, 10% and 16%, respectively. At the dosage of 250 ppm, the Pt. Tel pulp showed gains in water absorbance, tensile and burst indices of 15.4%, 45% and 52%, respectively. At the dosage of 500 ppm, the Arauco N pulp, meanwhile showed increases of 5.3%, 16% and 6% for these traits, respectively.
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