Dyeing With Reactive Dyes Without Salt And Alkali

With a great progress of people’s view, human’s consciousness to environmental protection is improving day by day. Amounts of polluted waste water springing from textile dyeing and finishing process, is not only dark color, but high salt and alkali content. It is so difficult to deal with the high concentration of inorganic salts and soda in the waste water and cost is so expensive to solve the problem. Therefore, it is a excellent way for dyeing and finishing researchers to made repeated efforts to radically reduce the dosage of inorganic salt and soda.Oxygen anions on cotton fibers in the effect of soda can react with reactive groups of reactive dyes, which is a substitution reactive, so reactive dye can be connected to cotton fibers by chemical bond. In the article, bridging molecule is envisaged to play a role between reactive dyes and cellulose, so reactive dye was fixed to fibers by a reactive linking group between dye and fiber. Batch or gas steam step was pluged in traditional dyeing or finishing process in order to increase the diffusion rate of dye to the fiber interior. three processes have been designed:pad→ dry→ cure, pad →dry→steam →cure. pad→batch→dry →cure.Compared with fabric dyed in tradition process,different types of reactive dyes should be screened through the above three processes.Thinking about reagents with more than two active groups-durable press finishing agent, DM-3510 resin that is more suitable to fabric has been screened from NDF,SDP-1, DM-3510, 980, ECO finishing agents. Optimum catalyst type and concentration of catalyst for DM-3510 resin finishing agent have been obtained by the orthogonal analysis:catalyst C-8, concentration 30g/L.Fabric dyed by pad→ batch→ry→ure process own best performance after comparing with fabrics dyed separately with different reactive dyes by three designed experimental processes and traditional dyeing process. And performance of fabric treated with pad→ batch→ dry→ cure process could be comparable with one treated with traditional dyeing process.14 kinds of reactive dyes which are more suitable to one bath dyeing and finishing process without adding salt and alkali have been screened out from more than 70 kinds of reactive dyes. After that, this article has analysed the effect of concentration of dye added to the finishing bath on fabric physical properties and comes out that 20 g/L concentration bring good effect.This article also analyse single factor in pad→batch→ dry →cure process, finally the best factors have been obtained. catalyst C-8 concentration:30g/L, finishing agent concentration: 190g/L, cure temperature:160℃, cure time:3.5min. As well known, softener can not only improve feel of fabric, but also increase fabric tear strength retention. This article also trys to add 5 kinds of softeners respectively, T831, T 606,T689, T819, T602 into dyeing and finishing bath, and concludes that softener T689 has shown good stability and not only improve 54 degrees of fabric wrinkle recovery angle, and also make weft tear strength retention of fabric increase from 45% to 60%, and warp tear strength retention rate from 37%to 52%.ECO n 980 resin finishing agents also are used in dyeing and finishing bath, but effects of them are less than one of DM-3510. Then in order to optimize the wet rubbing fastness of Kromazol red RFT, Kromazol yellow RFT, Kromazol blue RFT fabric, fabric could have better fastness,after DM-2588 wet rubbing fastness improver deal with dyed fabricsSelect six fabrics dyed with different kinds of reactive dyes, then the six fabrics.respectively,were extracted in 50% DMF (dimethylformamide) solvent under conditions of 100℃ for 30 min, then fabrics treated by DMF before and after could be found out that surface color of these fabrics almost have no change. So chemical bonds between fiber and reactive dyes may exist.Finally, several acid dyes are respectively added into dyeing and finishing baths so as to analyze the feasibility of that dyeing cotton with acid dyes. Performances of cotton dyed with acid dyes, such as color depth, fixing rate,are not better than ones of cotton dyed with reactive dyes.