The comparison of strength property between kraft pulp(KP)and Alkaline Sulfite-Anthraquinone(AS-AQ)pulp for thicker cell wall fiber materials Larch and Quercus as examples was studied. The average coefficient of flexi...The comparison of strength property between kraft pulp(KP)and Alkaline Sulfite-Anthraquinone(AS-AQ)pulp for thicker cell wall fiber materials Larch and Quercus as examples was studied. The average coefficient of flexibility of Larch and Quercus are 0.6-0.7 and 0.45-0.50, respectively. The results showed that the strength property of thicker cell wall pulp is some what different from those reported earlier. The strengths of AS-AQ are all higher than those of KP for Larch and Quercus. For Larch, under same beating degree the breaking length of AS-AQ is 8-16% higher than that of KP , burst index 3-14% higher, folding endurance 30% higher, tear index slightly higher. For Quercus, the breaking length of AS-AQ is 5-10% higher then that of KP, burst index 10-15% higher, folding endurance 30-50% higher, tear index 5-15% higher. Under the same breaking length the tear index of AS-AQ pulp is significantly higher than that of KP for both Larch and Quercus.展开更多
The paper is to study the TCF bleaching of high-yield chemical pulp of NS-AQ aspen(digester yield 63.7%, Kappa number 37.3, brightness 50.0%ISO, intrinsic viscosity 1,340ml/g). Under the suitable conditions(oxygen pre...The paper is to study the TCF bleaching of high-yield chemical pulp of NS-AQ aspen(digester yield 63.7%, Kappa number 37.3, brightness 50.0%ISO, intrinsic viscosity 1,340ml/g). Under the suitable conditions(oxygen pressure 0.6MPa, 85℃, 80min., NaOH 5%, MgSO4 0.3%, consistency 11%), oxygen delignification, can increase the brightness of pulp to 64.9%ISO, substantially decrease Kappa number to 9.11. Before the oxygen delignification pretreating pulp by acidic chelant(Qa)under conditions of pH 3.0, 30min, 40℃, DTPA 0.25%, consistency 15%, and after the Qa strengthening oxygen delignification by H2O2(Op, H2O2 2%)can increase the brightness of pulp to 77.1%ISO, decrease Kappa number and intrinsic viscosity to 6.36 and 984ml/g, respectively. After the Op, pretreat pulp by chelant once again(pH 6.0, 60℃, consistency 12%, other as the Qa), and following this pretreatment do bleach with 1% H2O2, namely using Qa-Op-Q-P bleaching sequence, resulting in the brightness 84.8%ISO, Kappa number 5.01, intrinsic viscosity 792ml/g, total bleaching loss 12.17% for bleached pulp.展开更多
A study on alkaline sulfite anthraquinone pulping of wheat straw indicated that the addition of formaldehyde could improve fine pulp yield effectively, enhance brightness of unbleached pulp, and decrease kappa number....A study on alkaline sulfite anthraquinone pulping of wheat straw indicated that the addition of formaldehyde could improve fine pulp yield effectively, enhance brightness of unbleached pulp, and decrease kappa number. Finally, the optimum conditions of this process were formed.展开更多
Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated l...Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated liquor and pulp of every cycles are analyzed respectively. Result shows that the content of lignin and organism in recycle black liquor and separated liquor increases faster in the first three cycles and then continues to increase slowly till four or five times, after that it trends to a stable state. The main organism separated from waste liquor of AS-AQ treated by sulfur dioxide is alkali-lignin, above 50% of total lignin in black liquor. The yield of pulp made from recycle cooking is steady, the hardness of pulp has a great improvement with recycle cooking. The brightness of pulp reduces correspondingly before bleaching, and after bleaching the brightness of pulp is relatively high and steady at the same sodium hypo chlorite dosage.展开更多
文摘The comparison of strength property between kraft pulp(KP)and Alkaline Sulfite-Anthraquinone(AS-AQ)pulp for thicker cell wall fiber materials Larch and Quercus as examples was studied. The average coefficient of flexibility of Larch and Quercus are 0.6-0.7 and 0.45-0.50, respectively. The results showed that the strength property of thicker cell wall pulp is some what different from those reported earlier. The strengths of AS-AQ are all higher than those of KP for Larch and Quercus. For Larch, under same beating degree the breaking length of AS-AQ is 8-16% higher than that of KP , burst index 3-14% higher, folding endurance 30% higher, tear index slightly higher. For Quercus, the breaking length of AS-AQ is 5-10% higher then that of KP, burst index 10-15% higher, folding endurance 30-50% higher, tear index 5-15% higher. Under the same breaking length the tear index of AS-AQ pulp is significantly higher than that of KP for both Larch and Quercus.
文摘The paper is to study the TCF bleaching of high-yield chemical pulp of NS-AQ aspen(digester yield 63.7%, Kappa number 37.3, brightness 50.0%ISO, intrinsic viscosity 1,340ml/g). Under the suitable conditions(oxygen pressure 0.6MPa, 85℃, 80min., NaOH 5%, MgSO4 0.3%, consistency 11%), oxygen delignification, can increase the brightness of pulp to 64.9%ISO, substantially decrease Kappa number to 9.11. Before the oxygen delignification pretreating pulp by acidic chelant(Qa)under conditions of pH 3.0, 30min, 40℃, DTPA 0.25%, consistency 15%, and after the Qa strengthening oxygen delignification by H2O2(Op, H2O2 2%)can increase the brightness of pulp to 77.1%ISO, decrease Kappa number and intrinsic viscosity to 6.36 and 984ml/g, respectively. After the Op, pretreat pulp by chelant once again(pH 6.0, 60℃, consistency 12%, other as the Qa), and following this pretreatment do bleach with 1% H2O2, namely using Qa-Op-Q-P bleaching sequence, resulting in the brightness 84.8%ISO, Kappa number 5.01, intrinsic viscosity 792ml/g, total bleaching loss 12.17% for bleached pulp.
文摘A study on alkaline sulfite anthraquinone pulping of wheat straw indicated that the addition of formaldehyde could improve fine pulp yield effectively, enhance brightness of unbleached pulp, and decrease kappa number. Finally, the optimum conditions of this process were formed.
文摘Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated liquor and pulp of every cycles are analyzed respectively. Result shows that the content of lignin and organism in recycle black liquor and separated liquor increases faster in the first three cycles and then continues to increase slowly till four or five times, after that it trends to a stable state. The main organism separated from waste liquor of AS-AQ treated by sulfur dioxide is alkali-lignin, above 50% of total lignin in black liquor. The yield of pulp made from recycle cooking is steady, the hardness of pulp has a great improvement with recycle cooking. The brightness of pulp reduces correspondingly before bleaching, and after bleaching the brightness of pulp is relatively high and steady at the same sodium hypo chlorite dosage.
