Studies On Alkaline Dyeing And Printing Of Disperse Dyes And Rheological Properties Of Paste

Shortening the dyeing procedures is one of the important developing direction of energy saving and emissions reduction in the future. Compared with conventional dyeing of disperse dye, alkaline dyeing showed advantages in rationalizing technological process and improving dyeing quality. Alkaline dyeing enables pretreatment, dyeing and reduction clearing to be carried out at the same time, which is conducive to simplify the technology, reduce the time of processing polyester fabric, and decrease the cleaning times of polyester fabric. Therefore, it increase production efficiency, save energy and reduce emmisions. Regarding printing, there is no need to conduct reduction clearing when using alkaline printing for polyester fabric, which decrease consumption of water and energy, and is significant for saving energy and reducing emissions.This paper analyzes six alkaline-stable disperse dyes which were sorted out finally, and investigate on their strong alkaline resistance and oxidation resistance during the dyeing process of polyester fabric, the additive’s influence on dyeing performance in pretreatment, as well as the basic performances of dye, such as, dye migration performance, levelness, improving performance, the dyeing rate and dyeing fastness. The result shows that: these six alkaline-stable disperses have excellent strong alkali resistance and oxidation resistance and good dyeing rate. The additive used in pretreatment doesn’t influence the K/S value and color shade of dyes. There is no influence in dyeing K/S value and final uptake percentage on acidic conditions dyeing and alkaline conditions dyeing. Among which, O-SE-3RLN, R-GS, P-H-FRL, and Y-SA-GL have great dye migration and levelness performance; R-SA-6B have good levelness performance but the migration is poor.And the levelness and migration of the B-SA-GBL are poor.The application of these leveling agents included M-1、N-1, can singnificantly improve the levelness and migration, and at the time,they have no singnificant effect in K/S value. And they are suitable for alkaline dyeing. By comparing one bath of refining, bleaching, and dyeing technology with conventional dyeing of polyester fabric, there is no obvious difference in K/S value, color shade and fastness. This technologh is suitable for one bath of refining, bleaching and dyeing polyester fabric, and increase production efficiency and the success rate of right-first-time.The original paste in priting is mainly made up of sodium alginate paste, mixed with synthetic thickening agent and sodium carboxymethyl cellulose. This paper discusses the relationship between rheological properities and printing performance, influence reasons of paste. It also tests the influence on printing quality by changing the dosage of sodium alginate. Meanwhile, the printing quality under different printing conditions, rheological properties and analyzing the relevant reasons that influences printing quality were studied. The research shows that: by mixing synthetic thickening agent and sodium alginat, paste viscosity is larger in acidic conditions than that of alkaline conditions, which is more similar Newtonian fluid. And with increasing addition of synthetic thickening agent, it’s more similar Newtonian fluid, and PVI of paste would rise. Printing K/S value increases with the portion of synthetic thickening agent. It is found that the mixed thickener of synthetic thickening agent and sodium alginate(7:3) is suitable for alkaline printing. The mixture of sodium carboxymethyl cellulose and sodium alginate is good rheological properties than sodium alginate, which shows that paste viscosity of alkaline conditions than acid conditions. With the increasing proportion of sodium carboxymethyl cellulose, paste pseudoplasticity, PVI and K/S value decreased. And it’s suitable for rotary screen printing and printing delicate that the mixed paste of sodium alginate and carboxymenthyl cellulose sodium(6:4). As for mixed paste, it has the same storage stability both in acid and alkaline conditions. Paste viscosity will decrease along with the time, and temperature has significant influence on paste viscosity. With the rising of temperature, the viscosity of paste decreased.Comparing alkaline printing with conventional printing of these six alkali resistant disperse dyes in, there is no obvious difference in K/S value and L*、a*、b* value, and these dyes are suitable for alkaline printing of polyester fabric. With the paste viscosity of printing increasing, printing K/S value decreased, which reflects that 50%-60% of paste viscosity is suitable. It found that the experiment of these six dyes printing on polyester fabric had good permeability.