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本文就两种不同的纤维素酶对纸浆纤维角质化损伤的影响(干燥处理会降低纸浆打浆度和机械性能)进行了研究。实验所采用的两种纤维素酶分别是ComC商品纤维素酶(来自汽巴公司Per-galaseA40)和实验室自制纤维素酶CelB(由地衣芽孢杆菌发酵制得)。将未经过干燥处理的工业级桉木漂白硫酸盐浆分成两部分:一部分不经过任何干燥处理;另一部分在一定温度下进行干燥处理。我们对纤维素酶处理对这两种纸浆在PFI磨浆前后的影响进行了比较研究。酶处理能够提高未经干燥纸浆打浆度和保水值,但对纸浆物理性能没有提高。相反,酶处理干燥纸浆在提高纸浆打浆度和保水值的同时,也能够提高纸浆物理性能。这是因为酶处理使得纸浆经干燥处理所产生的负面影响得以缓解。干燥纸浆经过CelB纤维素酶处理之后,纸浆的抗张强度和耐破度得以提高,但是撕裂度降低。CelB纤维素酶所产生的影响可以被认为是“生物磨浆”效应。实际上,通过CelB纤维素酶处理能够使得干燥纸浆所抄纸页的性能和湿纤维所抄纸页相当,但是撕裂指数例外。酶处理使得纤维表面形态发生变化,从而产生碎片和去皮现象。纤维表面改性使得纤维间的结合力增加、纸张结构更加紧密。最终得出结论:纤维素酶处理能够缓解纤维角质化影响,并且能够节约磨浆能耗。新型CelB商品酶在提高纸页性能、缓解纤维干燥角质化损失方面非常有效。
In this paper, the effects of two different cellulases on the keratinization of pulp fibers were studied (drying treatment will reduce pulp beating and mechanical properties). The two cellulases used in the experiment were ComC commercial cellulase (Per-galase A40) and laboratory self-made cellulase CelB (fermented by B. licheniformis), respectively. The industrial grade eucalyptus bleached kraft pulp without drying is divided into two parts: one part without any drying treatment and the other part under a certain temperature for drying treatment. We compared the effects of cellulase treatment on the pulp before and after PFI refining. Enzymatic treatment can improve the undried pulp beater and water retention, but did not improve the physical properties of the pulp. In contrast, enzymatic treatment of dried pulp increases pulp pulping and water retention while also improving pulp physical properties. This is because enzyme treatment relieves the negative effects of pulp drying. After the dried pulp was treated with CelB cellulase, the tensile strength and burst resistance of the pulp were improved, but the tear was reduced. The effect of CelB cellulase can be considered as a “bio-refining” effect. In fact, the performance of dried paper pulp by CelB cellulase treatment is comparable to that of wet fiber paper, except for the tear index. Enzymatic treatment causes changes in fiber surface morphology, resulting in debris and peel. Fiber surface modification makes the binding force between the fibers increased, the paper structure is more compact. The final conclusion: cellulase treatment can reduce the fiber keratinization, and can save refining energy consumption. The new CelB commercial enzyme is very effective in improving sheet properties and alleviating the loss of keratin dryness.