Preparation Of Printing Mixture Pastes And Their Printing Properties For Cotton Fabrics With Reactive Dyes

Reactive dye printing for cotton fabrics relies mainly on the use of alginate thickeners. Because of the unreliable supply, high price, and environmental problems of alginate thickener, other natural polysaccharides and synthetic thickeners as an alternative have been developed. According to several explored experiments of present thickeners for reactive dye printing, three kinds of synthetic thickeners, compound of polypropylene, acrylic acid and carboxymethyl cellulose, were selected to mix with sodium alginate as mixture pastes.In order to compare the physical performance and printing effect among synthetic thickeners compound of polypropylene acrylic acid and CMC are tested on terms of their properties. The physical performance indexes include CMC DS, reaction between Paste and reactive dye, pasting rate, rheological properties of paste, printing viscosity index, hydrability, dilution, compatibility to chemical additives and storage stability, printing effect include dye yield of color paste printing, permeability, fixation rate,color yield, color yield uniformity, de-paste ratio as well as color fastness of printing. Experiment conclusions are as follows. Sodium alginate and synthetic thickeners are not reactive with reactive dye, CMC has a low reactivity with reactive dye. Sodium alginate and synthetic thickeners have a better pasting rate, printing viscosity index, and storage stability, but theirs compatibility to chemical additives is worse than that of sodium alginate. From the section of printing effect, sodium alginate has a better color yield and de-paste ratio, the synthetic thickeners and CMC have a better permeability, sodium alginate and synthetic thickeners have a better Printed color yield uniformity than CMC, all of them have good fixation rate and color fastness.Since a single paste printing production can’t meet the requirements of printing so a variety of mixed paste instead of a single paste is becoming a trend. There are some similar advantages and disadvantages between synthetic thickeners and CMC, so we choose sodium alginate to compound with3kinds of synthetic thickeners and CMC respectively to research physical performance and printing effect different proportions of compound paste. Experiment conclusions are as follows. After the compound of sodium alginate with synthetic thickeners and CMC. The viscosity and PVI of colorants decreased. Thus the paste’s rheology can be adjusted by different proportion of paste compounded. From the section of printing effect, sodium alginate-based’s surface color yield is very close to the surface color yield of sodium alginate. And to sodium alginate-EM610system, when its compound proportion is6:4, it have a even better surface color yield than sodium alginate. The permeability of compound increases with the decrease of sodium alginate. All compound pastes have high fixation rate. The sodium alginate-synthetic thickener system has a better color yield uniformity than sodium alginate-CMC system. The de-paste ratio decrease with sodium alginate’s proportion increase. And to sodium alginate-EM610system, when its compound proportion is6:4, it have a better Tread contour sharpness. All compound pastes have good good fixation rate and color fastness.Experiments showed that the synthetic thickening agent or CMC-sodium alginate system increased sodium alginate’s rheology and decreased synthetic thickening agent and carboxymethyl cellulose’s sensitivity to the electrolyte, and also increased synthetic thickening agent and carboxymethyl cellulose’s de-paste ratio. Through the compound of different thickeners the rheology was modified, the applied scope was enlarged, the end product properties were bettered and the cost was reduced. Also, the best thickeners can be chosen according to the printing apparatus, patterns to obtain the best product.