Study Of Cellulose Enzyme Washed Indigo Denim Based On The Ultrasonic Environment

It is an important link in enhancing the additional value of the products that denim finishing washing.In order to improve the denim garment washing way of traditional stirring process,this paper study on the changes of denim surface color "worn out" and the microstructure after treatment by the lights of extensive application of ultrasonic technology in textile with assisted the cellulose washed indigo denim.At first,the activity of cellulase for best technological conditions were screen out thorough orthogonal test. The best process conditions were pH value is4.5, the temperature is60℃, enzyme concentration is3.0g/L and substrate concentration (CMC)is2.5g/Lrespectively. Meanwhile,based on the above process conditions, the best activity of cellulase under the ultrasonic were studied with the ultrasonic power is60W at50℃for5-6min, duty ratio of0.4and pH value of4.5. The molecular structure of the enzyme before and after processing by the ultraviolet and infrared spectrum were further analyzed.It was found the molecular structure of cellulose not affected at the appropriate ultrasound power.In addition, the changes of surface K/S and CIE L*value for indigo denim under the ultrasonic-assisted cellulase washing were tested by single factor and orthogonal experiment,respectively,and compared with traditional stirring washing process. The results show that ultrasonic technology is superior to the traditional process under the bio-washing at a certain degree. And the factors of affecting order, the optimal process parameters combination and its significance were determined by using analysis of range and variance.The significance order from big to small of the effects of each process parameters on "worn out" effect was pH value6.5,ultrasonic power400W,ultrasonic time25min,enzyme concentration5g/Land temperature50℃; and these factors are equally important.At last,the microstructure of denim were characterized before and after processing. SEM showed that the denim fabric surface was polishing and etching after ultrasonic-assisted cellulase washing process;elements analysis indicated ultrasonic technology is helpful to more enzyme catalysis molecular adsorption on the fabric surface; FTIR demonstrated no new functional groups generated and without destroyed the chemical genes and molecular configuration after finishing; X-ray diffraction diagram showed that the cellulose enzymatic hydrolysis in the crystalline region,but fabric crystallinity increased, in other words, its amorphous region area was relatively reduced after ultrasonic cavitation, mechanical vibration and thermal effect.It also indirectly proved the cellulose enzymatic hydrolysis occurred both the amorphous and crystalline area simultaneously.The particle size analysis proved solid cellulose were easily dispersed and is contributed to the enzyme catalysis.