The deterioration of recycled fibers especially unbleached kraft with high wet strength resin content due to the irreversible structural changes caused by drying and added chemicals makes the raw material difficult to...The deterioration of recycled fibers especially unbleached kraft with high wet strength resin content due to the irreversible structural changes caused by drying and added chemicals makes the raw material difficult to repulp.The mechanical effect in the pulper over time with chemical treatment has a negative impact on the recycled fibers.At lab scale,different compositions of enzymatic treatment C022L were under investigation to select the most efficient laccase Lacc1,Lacc2 or Lacc3 and to observe the impact of lipases during repulping at low and high consistencies.Pulp disintegration at different times was evaluated to define the level of rejects and to analyze the morphology of fibers after treatments.These results were more significant for Lacc2,by increasing the pulp consistency to 15%in the pulper.Combining lipases with CELODASE 022L appeared to decrease the efficiency of enzymes.The results showed a high reduction of energy power with the enzymatic treatment and a significant reduction of fines level in fibers’suspension.The most efficient version of C022L was used at industrial scale to compare directly with the standard conditions used in a paper mill.展开更多
The recycling of wet strength papers in a normal recycling mill is often troublesome due to the severe operating conditions required to defibre wet strength papers. The various methods are presented which will quickly...The recycling of wet strength papers in a normal recycling mill is often troublesome due to the severe operating conditions required to defibre wet strength papers. The various methods are presented which will quickly allow mills to determine the most effective pulping aids to use when repulping wet strength papers. The repulping of wet strength paper with inorganic chemicals was investigated in the laboratory. The effects of major variables, that is, repulping time, pulp consistency, soaking time, temperature, and reactant concentration in the repulping stage were examined using Plackett-Burman design. The repulping time was the most crucial & influential process variable affecting repulping characteristic and formation related properties. The more significant repulping process variables affecting pulp yield were repulping time, soaking temperature and pulp consistency whereas for formation index and feature size, repulping time, pulp consistency, soaking temperature and time were the more important variables. The formation index is increased by an increase in repulping time, pulp consistency and soaking time whereas the feature size is decreased by an increase in repulping time, soaking temperature and pulp consistency. The formation index and the rejects were more sensitive to changes in process variables than were the feature size or the pulp yield. The pulp recycled from wet strength waste paper had good physical strength properties.展开更多
以废旧短棉纤维为主要原料,并在抄造过程中添加一系列助剂制备出新型的高湿强型纸基功能性地膜。研究了废棉纤维打浆度、原纸定量及助剂加入量对地膜相关性能的影响。结果表明:制备该新型纸基地膜的最佳工艺条件为:棉纤维打浆度60°...以废旧短棉纤维为主要原料,并在抄造过程中添加一系列助剂制备出新型的高湿强型纸基功能性地膜。研究了废棉纤维打浆度、原纸定量及助剂加入量对地膜相关性能的影响。结果表明:制备该新型纸基地膜的最佳工艺条件为:棉纤维打浆度60°SR,原纸定量为30g/m 2,阳离子淀粉用量1.3%,增强剂阳离子聚丙烯酰胺用量0.7%,湿强剂P A E用量0.4%,经湿法抄造得到的纤维原纸在液体石蜡中浸渍以改善其透明度,该条件下制得的高湿强型纸基功能性地膜性能优良,撕裂指数为12.5m N.m2/g,干抗张指数为23.7N.m2/g,湿强度指数为7.9N.m2/g,湿强度保留率达到了33.4%,透明度为65.2%,透气量为1.8mm/s。展开更多
文摘The deterioration of recycled fibers especially unbleached kraft with high wet strength resin content due to the irreversible structural changes caused by drying and added chemicals makes the raw material difficult to repulp.The mechanical effect in the pulper over time with chemical treatment has a negative impact on the recycled fibers.At lab scale,different compositions of enzymatic treatment C022L were under investigation to select the most efficient laccase Lacc1,Lacc2 or Lacc3 and to observe the impact of lipases during repulping at low and high consistencies.Pulp disintegration at different times was evaluated to define the level of rejects and to analyze the morphology of fibers after treatments.These results were more significant for Lacc2,by increasing the pulp consistency to 15%in the pulper.Combining lipases with CELODASE 022L appeared to decrease the efficiency of enzymes.The results showed a high reduction of energy power with the enzymatic treatment and a significant reduction of fines level in fibers’suspension.The most efficient version of C022L was used at industrial scale to compare directly with the standard conditions used in a paper mill.
文摘The recycling of wet strength papers in a normal recycling mill is often troublesome due to the severe operating conditions required to defibre wet strength papers. The various methods are presented which will quickly allow mills to determine the most effective pulping aids to use when repulping wet strength papers. The repulping of wet strength paper with inorganic chemicals was investigated in the laboratory. The effects of major variables, that is, repulping time, pulp consistency, soaking time, temperature, and reactant concentration in the repulping stage were examined using Plackett-Burman design. The repulping time was the most crucial & influential process variable affecting repulping characteristic and formation related properties. The more significant repulping process variables affecting pulp yield were repulping time, soaking temperature and pulp consistency whereas for formation index and feature size, repulping time, pulp consistency, soaking temperature and time were the more important variables. The formation index is increased by an increase in repulping time, pulp consistency and soaking time whereas the feature size is decreased by an increase in repulping time, soaking temperature and pulp consistency. The formation index and the rejects were more sensitive to changes in process variables than were the feature size or the pulp yield. The pulp recycled from wet strength waste paper had good physical strength properties.
文摘以废旧短棉纤维为主要原料,并在抄造过程中添加一系列助剂制备出新型的高湿强型纸基功能性地膜。研究了废棉纤维打浆度、原纸定量及助剂加入量对地膜相关性能的影响。结果表明:制备该新型纸基地膜的最佳工艺条件为:棉纤维打浆度60°SR,原纸定量为30g/m 2,阳离子淀粉用量1.3%,增强剂阳离子聚丙烯酰胺用量0.7%,湿强剂P A E用量0.4%,经湿法抄造得到的纤维原纸在液体石蜡中浸渍以改善其透明度,该条件下制得的高湿强型纸基功能性地膜性能优良,撕裂指数为12.5m N.m2/g,干抗张指数为23.7N.m2/g,湿强度指数为7.9N.m2/g,湿强度保留率达到了33.4%,透明度为65.2%,透气量为1.8mm/s。
