亚麻粗纱的超临界CO2煮漂工艺

针对亚麻粗纱传统煮漂工序的高耗水和环境污染问题,利用超临界CO₂代替水介质对亚麻粗纱进行煮漂。系统研究了复配生物酶(木聚糖酶和纤维素酶)质量分数、温度、压力和时间对亚麻粗纱白度的影响,并利用响应面分析法对粗纱煮漂工艺条件进行优化,通过Box-Behnken中心组合实验和响应面法研究了自变量及其交互作用对白度的影响,得到粗纱白度的二次多项式回归方程的预测模型。确定了亚麻粗纱超临界CO₂煮漂最佳工艺条件:复配生物酶质量分数为3%,温度为50 ℃,压力为13 MPa,时间为60 min。在最优工艺条件下,超临界CO₂煮漂亚麻粗纱与原样相比,白度达到40.8%、残胶率为16.68%、断裂强度为17.12 cN/tex、断裂伸长率为4.23%、分裂度为1 072 Nm。与传统煮漂效果相比,超临界CO₂煮漂工艺仍存在一定差距,需进一步提高。

Scouring and bleaching process for flax roves using supercritical CO2

In order to solve the problem of high water consumption and environmental pollution in conventional scouring and bleaching process of flax roves, scouring and bleaching technology for flax roves using supercritical CO₂ as the medium instead of water was proposed. The effects of mass fraction of compound biological enzymes (xylanase and cellulase), temperature, pressure and time on the whiteness of flax roves were systematically studied using supercritical CO₂, and the process conditions of scouring and bleaching were optimized by responsive surface analysis. The influence of the independent variables and their interaction on the whiteness was investigated using Box-Benhnken center composite design and responsive surface method, and the prediction model in a form of quadratic polynomial regression equation was obtained. An optimized process for scouring and bleaching of flax roves was recommended with a mass fraction of compound biological enzymes of 3%, a temperature of 50 ℃, a pressure of 13 MPa as well as a treatment time of 60 min in supercritical CO₂. Moreover, under the optimum technical conditions, the properties of scoured and bleached roves under the supercritical CO₂ condition were compared with that of original sample. The whiteness, the residual gum content, the breaking strength, the elongation at break and the split degree of the flax roves are 40.8%, 16.68%, 17.12 cN/tex, 4.23% and 1 072 Nm, respectively. However, there is still a certain gap in comparison with the traditional method, which needs to be further improved.