Explore Of New Dyeing Technology With Reactive Dyes To Reduce Consumption

Reactive dyes are widely used in fabric dyeing now.They don't only have complete chromatography and excellent color fastness of wet treatment,but also are very easy to put in use. So they have become the most important dyes for cellulose.But the problem is that the exhaustion of reactive dye is low in fabrics dyeing,and a large quantity of wastewater will be discharge into the environment.Recent years,improving the exhaustion of reactive dyes and enhancing the utilization rate,enhancing the color depth when using the same amount of dyes without increasing processing procedures,nor adding new additives have become a research hotspot.In this paper,a new technology called "alkaline bath drip dyeing technology" was studied by changing the sequence of adding reagents and dyes,in order to use less amount dyestuffs and get the same color depth in fabric dyeing.Some primary influence factors in the new designed dyeing process were analyzed,including the dyeing temperature,concentration of salt and alkali,the rate of adding dyes.Compared with the conventional process,when three kinds of textiles(the twill fabric,poplin,and knitted fabric) were dyed with three different series of commercial dyes(the LEVAFIX CA dyes,ARGUST and SANDAFIX)with the same color depth,the quantity of the saving dyestuffs was obtained and the degree of fixation and the fastness to rubbing and washing were also determined.The results of our experiment showed that the fabric dyed with the alkaline bath drip dyeing technology could get darker color.When getting the same color depth with conventional method, less reactive dyes would be required in the new method than the conventional.The average value of saving ratio is about 20%.From the considerations of dyeing time and the result of deep dyeing, the optimum dyeing conditions was investigated:the time of continuous adding dyes was 60min, the dyeing temperature was 60℃,the salt concentration was 50g/L,Na₂CO₃ concentration was 20g/L.With dyeing on the same fabric,the saving ratio of LEVAFIX CA dyes is the highest, ARGUST and SANDAFIX the lest,but the saving ratio of SANDAFIX can also reach 19%; When dyed with the same dyestuff,the saving ratio of dyestuff in dyeing twill fabric was highest, the poplin less,and the knitted fabric least,but the saving ratio can also reach 20%.The results of our experiment showed that the more dyes we used,the higher saving ratio we could get.When getting the same color depth,the fixation ratio of the poplin fabric dyed with ARGUST BF and SANDAFIX was higher than that dyed with conversational method,but when dyed with LEVAFIX CA,the fixation would be lower.While the fixation ratio of the twill fabric dyed with SANDAFIX was higher than that dyed with conversational method,but when dyed with ARGUST BF and LEVAFIX CA,the fixation would be lower.The fabric dyed with two methods had almost the same fastness to rubbing and washing.Only a little fastness of a few samples decrease by half one grade.Observed by microscope,the yarn dyed with the pre-alkali adding dyes continuously technology had good dyes penetration.There was not ring dyeing and white spot in the yarn.Blending dyeing and the production of bulk sample in laboratory were also studied.The results of our experiment showed that blending dyeing could get better results.Fabric could get more deeper color strength than that dyed with single dyes.When dyed with blending dyestuffs, the dye saving ratio could improve once than that dyed with single dyes.And the production of bulk sample in laboratory also received good results.All this provides the basis for actual production in the promotion of our process.The reason of deeper color with the new technology was also analyzed by studying the dyeing curves,the permeating situation of the dyes when dyeing with fabric clips and rolls.