WLS Additives Modified Cotton Yarn And Its Application In The Active Dyes Salt-Free Dyeing

This paper studied on the application of the cationic additives WLS used in cottonyarn reactive dyes salt-free dyeing, the purpose is to solve the environment pollutionproblems of waste water with excessive salt, low dyes utilization in traditional dyeingways and to realize salt-free dyeing in reactive dyeing.At the first, the modification process of cotton yarn with the cationic modifier WLSwas studied, the influence of the conditions, the added order,dosage, processing time andprocessing temperature of WLS additives and NaOH, to the dyeing method of cottonyarn without salt was discussed, and the modified cotton yarn reactive dyes salt-freedyeing effect was assessed. The results show that when the modified cotton yarn dyeswithout salt, the dye uptakes and the fixation were significantly increased,at the sametime, compared with unmodified cotton yarn dyeing with traditional ways, fastness torubbing, washing and cotton taking of modified cotton yarn salt-free dyeing has changeda little, which also conform to the industry standard, and realize the cotton yarn reactivedyes salt-free dyeing.Then, through the study of dyeing dynamics and thermodynamics propertieschanges of the modified cotton yarn, the dyeing mechanism of the modified cotton yarnwas discussed. The results show that, compared with the unmodified cotton yarn dyeingwith salt, dyeing rate and equilibrium dye uptake of modified cotton yarn were increased,dyeing depth even deeper, and adsorption studies revealed that the process fits well withthe Langmuir isotherm model.The principle was changed into chemical positioningadsorption.Finally, the IR spectrometry and SEM of modified and unmodified cotton yarnswere measured to characterize the structure of modified cotton yarns.The result Showsthat the WLS agent has really been crosslinked into the modified cotton yarn, and thebasic structure of cotton yarns does not be changed.The investigation of the influence on the performance of cotton yarn, shows that onebath method of refineding-bleaching and cationic modification is feasible, and evenshorten processing process, the application of thus modification technique is promoted in practical.In this study, cotton yarn was modified with cationic agent WLS, which could bedyed with reactive dyes without salt addition, and the dyes could be saved.The purposeof cleaning dyeing drainage and reducing the environment pollution can be reached.So itis favorable to the environment protection and this is a meaningful research.