The Application Of Ultrasonic Technology In The Desizing And Scouring Processes Of Cotton Fabric

Most of the dyeing and finishing processes are chemical processes, which have the characteristics of long technical flow and working hours, high energy and water consumption, and producing pollution badly. Nevertheless, our country is short of water resource, so we must actualize high-efficiency and ecotypic process, and develop energy and water saving, consumption and contamination reducing technology as soon as possible if we want to realize the sustainable development in dyeing and finishing industry. Ultrasonic has been paid much attention because of its convenience, speediness, safety and efficiency. In order to meet the requirements of sustainable development and efficient eco-process, and solve the problems of high energy and water consumption and pollution brought by traditional alkali desizing and scouring processes, the application of ultrasonic in the desizing and scouring processes of cotton fabrics was studied in this paper.Two ways were adopted to study the effect of ultrasonic in this paper. One is the cotton fabrics were pretreated with ultrasonic, which means the cotton fabrics were pretreated by ultrasonic before alkali desizing and scouring; the other is the cotton fabrics were washed with ultrasonic, which means the cotton fabrics were firstly processed of desizing and scouring, and then washed with ultrasonic.The impacts of frequency, processing time, temperature and ultrasonic power on desizing effect with pretreatment process and cleanout effect after desizing were studied, and contrast of the two ways was made, lastly pretreatment technology of desizing with ultrasonic was optimized by orthogonal experiment. The results showed that pretreatment process could impart cotton fabrics certain desizing percentage in a short time which can only be accomplished in a long time in traditional desizing process, and whiteness of cotton fabrics was improved. So ultrasonic can be used to reduce the time of desizing, enhance the efficiency of processing and achieve the aim of saving energy.The impacts of frequency, processing time, temperature and ultrasonic power on scouring effect with pretreatment process and cleanout effect after scouring were studied, and contrast of the two ways was made, lastly pretreatment technology of scouring with ultrasonic was optimized by orthogonal experiment. The results showed that pretreatment process could impart cotton fabrics certain weight loss rate in a short time which can only be accomplished in a long time in traditional scouring process, and capillary effect and whiteness of cotton fabrics were improved. It proves that ultrasonic can reduce the time of scouring, and enhance the efficiency of processing, it is a feasible way to be used to scouring process of cotton fabrics.One bath method of desizing and scouring on cotton fabrics can reduce the time of processing and save chemicals. On the basis of studying the application of ultrasonic in each process, the application of ultrasonic in one bath method was studied, and the optimal process was concluded through orthogonal experiment. Properties of fabrics processed with ultrasonic desizing and scouring and traditional desizing and scouring were compared through dyeing experiment, the results showed that the wet rubbing fastness of samples processed by ultrasonic was higher than that of traditional process, but the K/S value had little decrease and there was no obvious difference of soaping fastness and dry rubbing fastness between samples processed by theultrasonic and traditional process.The impacts of ultrasonic on configuration and crystallinity of cotton fabric were studied by SEM and XRD. The results showed that, after ultrasonic processing, the fiber’s crude twist disappeared, degree of orientation enhanced, the fiber became round and full and its crystallinity had little decrease.