【作者】 许伟；

【导师】 张宗才；

【作者基本信息】 四川大学 ， 皮革化学与工程， 2005， 硕士

【摘要】 当前制革工业面临着严重的环境污染问题,它严重地阻碍了制革工业的发展,而只有实行绿色清洁生产才是皮革工业实现可持续性发展的必由之路。皮革脱毛工序所用的传统灰碱法脱毛污染十分严重,而酶法脱毛是一种清洁的脱毛方法,但由于酶质量不稳定,酶系组分多作用复杂,操作控制难度大且容易产生松面、烂面、小毛不易脱净等缺陷。本文采用酶活力较高的两种脱毛酶制剂,研究了它们的脱毛工艺,而针对不易脱净的小毛,再用少量的硫化物或双氧水辅助完成。该论文主要包括三个部分,第一部分首先对两种蛋白酶的性能进行研究,结果表明:2709 碱性蛋白酶的最适pH 值为9 左右,且当pH 值大于12 时其活力就降至很低,A.S1398 蛋白酶的最适pH 值为8 左右,当pH 值大于11 时其活力几乎为0;两种蛋白酶的活力均在55℃时达到最大值,温度再升高其酶活就急剧下降;金属离子Mn2+、Ca2+对酶活具有激活作用,而Cu2+、Cr3+、Fe2+、Zn2+等离子对这两种酶的酶活具有抑制作用;另外,表面活性剂对这两种酶的活力具有轻微的激活作用。第二部分从酶活力的影响因素出发,对2709 碱性蛋白酶和A.S1398 蛋白酶的应用条件进行了研究,优化工艺实验,得到两种酶法脱毛工艺:(1)2709 碱性蛋白酶堆置脱毛工艺:温度25℃,pH值控制为9,背脊部酶浓度250u/g,边腹部酶浓度为150u/g;(2)A.S1398 蛋白酶堆置脱毛工艺:温度25℃,pH 值控制为7.5,背脊部酶浓度300u/g,边腹部酶浓度为200u/g。对酶脱毛实际生产过程中的短小绒毛分别采用硫化物和双氧水处理后的脱毛效果良好,两种方法都大大减少更多还原

【Abstract】 Nowadays leather industry is facing severely environmental and pollutional issues which badly block continual development of leather industry,thus green and clean production is the only way to implement continual development of leather industry. Traditional liming method in unhairing procedure was highly contaminative, enzymatic unhairing was a cleaner method in contrast. However, it was not widely used due to instable quality, complex components and difficult control in the operation. So two sorts of enzyme with higher energy in this paper were introduced to research their depilatory technology, short hair was treated with a few sulfides or peroxides according to hardly dehairing hair. The paper was involved into three parts. Firstly two kinds of proteinase 2709 and A.S1398 were chosen to research their performances, results showed that optimal pH value of 2709 proteinase was about 9, it’s energy would drop to low when pH value was greater than 12 and that of 1398 proteinase was 8,it was almost zero when pH was greater than 11. They reached their maximum at 55℃and their energy would sharply drop with temperature elevated; their energy was activable by ions Mn2+ and Ca2+ but restrained by ions Cu2+、Cr3+、Fe2+ and Zn2+. In addition that was slightly activable by detergent.Based on influencing elements of enzyme energy, application conditions of 2709 and A.S1398 proteinases were researched and optimized. Two enzymatic unhairing technologies were obtained including (1) 2709 proteinase pile dehairing technology: 250u/g enzyme 2709 in back parts and 150u/g in belly parts under pH value 9 and (2) A.S1398 proteinase pile dehairing techonolgy: 300u/g enzyme A.S1398 in back parts and 200u/g in belly parts under pH value 7.5, their pile temperatures were all under 25℃. Sulfides and peroxides managed short hairs during process of enzymatic unhairing. Those two methods all reduced environmental pollution. The physical testing of finished leather showed that tearing strength of enzyme treated leather was slightly lower than lime-sulphide treated leather and other indexes were of no difference to conditional method treated leather, but breaking elongation was higher than that of lime treated leather. Through analysis of protein, glucose and hydroproline in waste liquors produced by unhairing procedure and observation of hair and skin during dehairing procedure, results showed that degree of depilation could be expressed by contents of protein and glucose in waste liquors and that of hydrolysis of collagen by contents of hydroproline. Obtained results were consistent to determination of preceding enzyme energy. Otherwise, principle of different unhairing methods and effect of latter procedure on hide could be indirectly explained by observation of hair and skin. Two kinds of enzymatic unhairing methods could not only obtain favorable effect, but also greatly reduce the pollution of sulfide. Physical and mechanical properties of resultant leather were not different from those of liming leather. So it is an effective cleaning unhairing technology method.更多还原