木素含量和纤维回用次数对漆酶改善纸浆强度的影响

取未漂和漂白硫酸盐浆进行浆料复配和纤维回用实验，考察木素含量和纤维回用次数对漆酶处理改善纸浆性能的影响．漆酶处理后复配浆的强度性能提高，尤其湿强度提高明显，随着漂白浆比例的增加，浆中木素含量减少，经漆酶处理后纸浆强度增幅逐渐降低．漆酶处理后未漂浆的湿抗张指数提高33．45％，当漂白浆含量为40％时湿强的增幅减小为2．72％，说明适宜的木素含量是漆酶催化提高纸浆强度的必要条件．回用浆经漆酶处理后纤维性能得到改善，但随着纤维回用次数的增加，漆酶增强幅度呈降低趋势．纤维性能测试结果表明纤维回用过程中纤维长度和宽度降低，针叶木细小纤维含量略有减少，阔叶木细小纤维含量变化与此相反，漆酶处理后纤维性能无明显变化．扫描电镜检测说明漆酶处理后纸浆纤维间产生“黏合”现象．

Effects of Lignin Content and Fiber Recycling Times on Pulp Strength Improvement under Laccase Treatment

Experiments on mixed pulp and fiber recycling of unbleached and bleached kraft pulp were carried out to esti- mate the effects of different lignin content and the fiber recycling times on pulp laccase treatment. The strength properties, especially the wet strength of the mixed pulp were improved under laccase treatment. The increase rate of strength properties reduced gradually with the decrease of lignin content. After laccase treatment, the wet tensile strength of the unbleached kraft pulp improved by 33.45%,but the increase rate decreased to 2.72% when the bleached kraft pulp content reached 40%, indicating that the proper lignin content was necessary for laccase catalysis. The recycled fiber properties were improved after being treated with laccase, but the increase rate decreased with increasing fiber recycling times. The fiber test results showed that the length and width of the fiber decreased, the fines of softwood pulp decreased slightly while those of the hardwood pulp increased and the fiber properties had no significant changes after laccase treatment in the process of fiber recycling. The SEM result showed that adhesion between fibers occurred after laccase treatment.