【作者】 蓝家良；

【导师】 马乐凡；

【作者基本信息】 长沙理工大学 ， 应用化学， 2011， 硕士

【摘要】 纸袋纸是重要的商品包装材料。随着社会的进步和人们生活水平的提高,对纸袋纸的需求数量越来越大,质量要求越来越高。打浆是提高纸袋纸质量的主要措施,国内纸袋纸生产多采用低浓打浆,有关研究的报道也很少,国外纸袋纸的打浆主要采用高浓或者高浓后接着低浓的打浆方式。国产纸袋纸的质量与进口产品相比有一定差距。为此,本研究以未漂马尾松硫酸盐浆和马尾松KP浆配加一定比例的桉木KP浆为原料,探索纸袋纸高浓、低浓及高浓后接着低浓打浆工艺及其机理。研究内容主要包括:不同配比的马尾松KP浆和桉木KP浆的高浓打浆工艺、低浓打浆工艺和高浓后接着低浓打浆工艺,手抄片性能对比分析,打后浆纤维表面形态及表面电荷的变化情况。研究结果如下:1. 100%马尾松KP浆采用高浓打浆有利于保持纤维长度,成纸的透气度、伸长率、撕裂指数和TEA指数较高,在打浆度15-24oSR的较宽范围内成纸都可以满足《伸性纸袋纸》(GB/T 24287-2009)的质量要求。2. 100%马尾松KP浆采用低浓打浆,可获得较高的抗张指数和耐破指数。在打浆度15-18oSR的狭窄范围内成纸有可能满足《伸性纸袋纸》(GB/T 24287-2009)的质量要求。3. 100%马尾松KP浆采用高浓后接着低浓的打浆方式,其合适的工艺条件为:先用高浓打浆至打浆度14~15oSR,接着低浓打至打浆度16~17oSR;在此条件下打浆,成纸透气度可达5.0μm/Pa.s以上,TEA指数可达2.37J/g以上,其它指标均较好。4. 100%马尾松KP浆高浓打浆后,接着进行消潜处理,可提高成纸抗张、撕裂和耐破指数,但会降低透气度、TEA指数和伸长率。5.配加15%的桉木浆时,采用高浓后接着低浓打浆生产纸袋纸合适的打浆度为20oSR;配加30%的桉木浆时,采用高浓、低浓和高浓后接着低浓打浆合适的打浆度均为23oSR左右;随着桉木浆的配比增加,其合适的打浆度也相应增加;随着桉木浆配比增加,纸袋纸的抗张、伸长、TEA、撕裂、耐破和透气性能指标整体下降。6.马尾松KP浆和桉木KP浆混合,用低浓打浆成纸可获得较好的抗张和耐破指数;用高浓打浆成纸可获得较好的伸长率、撕裂度和透气度;用高浓后接着低浓打浆成纸性能可兼顾高低浓打浆的优点。7.打浆可使纤维表面电荷增加,且随打浆度升高而增加,两者呈线性关系;低浓打浆纤维表面电荷的增值要高于高浓打浆。8.与高浓打浆相比,100%马尾松KP浆采用低浓打浆使纤维表面产生更多的酸性基团,纤维更易于吸水润胀,纤维之间接触面积更大,纤维结合更紧密,表现为抗张和耐破强度较高,透气性能较差。本研究提出了马尾松KP浆和马尾松KP浆配一定比例的桉木KP浆生产纸袋纸合适的打浆工艺条件,探索了其高浓打浆和低浓打浆机理,可为纸袋纸的生产和研究提供指导。更多还原

【Abstract】 Sack paper is a very important material for goods packaging and the quality demand for sack paper is getting higher. With the development of society as well as the improvement of living conditions, refining is one of the main methods for quality improving of sack paper. Low consistency refining (LCR) is used in sack paper making in China, and few reports on it are available. High consistency refining (HCR) or HCR followed by LCR is widely used in sack paper making worldwide, and the quality of the paper is much better than that produced in China. For this reason, unbleached Masson’s Pine kraft pulp and its mixed pulp with eucalyptus pulp were chosen as the raw materials for the study of the refining, technology and mechanism of HCR, LCR for sack paper. Processes of HCR, LCR, and LCR following HCR with different ratios of Masson’s Pine and Eucalyptus mixed pulps were studied. The comparison of handsheets properties of different refining processes, the change of fibre surface morphology, fibre surface chemical composition and fibre surface charge were carried out. The results are as following.1. HCR had the advantage of maintaining the fibre length for 100% Masson’s Pine kraft pulp. The properties of handsheets, such as the air permeability, tensile stretch, tear index and Tensile Energy Absorption (TEA) index were higher than that of LCR. And the characteristics of handsheets could meet the standard GB/T 24287-2009 in a wide range of beating degree 15-24oSR.2. The properties of handsheets, such as the tensile index and burst index were better with LCR for 100% Masson’s Pine kraft pulp. The characteristics of handsheets could meet the standard GB/T 24287-2009 in a narrow range of beating degree 15-18oSR.3. The optimal parameters of HCR followed by LCR were as follows: the pulp was refined to a beating degree of 14~15 oSR with HCR, followed by LCR to a beating degree of 16~17oSR for 100% Masson’s Pine kraft pulp. Under this condition, air permeability and TEA index was higher than 5.0μm/Pa·s and 2.37 J/g, respectively. The other properties of handsheets also could meet the standard requirements.4. Delatency treatment following HCR process of Masson’s pine kraft pulp could improve the handsheets properties of tensile index, tear index and burst index, but decrease the air permeability, TEA index and tensile stretch.5. The appropriate beating degree was 20±2oSR by using HCR followed by LCR for sack paper with Masson’s Pine kraft pulp and 15% eucalyptus kraft pulp, and the appropriate beating degree by using HCR, LCR, and HCR followed by LCR was 23±2oSR if 30% eucalyptus kraft pulps was added. The optimal beating degree increased with the increase of the ratio of eucalyptus pulp and Masson’s pine pulp. The properties of the handsheets decreased with the increase of the ratio of eucalyptus pulp.6. The properties of handsheets, such as the tensile index and burst index were better with LCR for Masson’s pine and eucalyptus mixed pulps, and the tensile stretch, tear index and air permeability were better with HCR. HCR followed by LCR had the advantages of both HCR and LCR.7. Fibre surface charge of refined pulp increased as beating degree increased. A linear relationship was obtained between surface charge and beating degree. The surface charge of LCR fibres was higher than that of HCR at the same beating degree.8. There were more acidic groups concentrating on the fibre surface with LCR for 100% Masson’s pine kraft pulp, and greater degree of fibre-fibre bonding could be obtained due to the swelling fibre and the higher contact areas between fibres. It meant that, tensile index and burst index were better with LCR, but the air permeability, which is very important for sack paper, was poor.The refining processes were optimized and it’s mechanism of Masson’s kraft pulp and its mixed pulps with eueucalyptus kraft pulp for sack paper was studied which offered a guidance for sack paper producing and studying.更多还原