1. Sodium Carboxymethyl Cellulose
Reactive printing paste is a derivative with ether structure obtained through chemical modification of natural cellulose. It is a water-soluble glue that can be dissolved in cold water and hot water. Its aqueous solution has the functions of bonding, thickening, dispersing, suspending and stabilizing.
Reactive printing paste is a product of sodium carboxymethyl cellulose with a high degree of etherification. The special process makes its primary hydroxyl group completely replaced, so as to avoid reaction with reactive dyes.
As the thickener of printing paste, reactive printing paste can stabilize the viscosity, improve the fluidity of the paste, enhance the hydrophilic ability of the dye, make the dyeing uniform and reduce the color difference; at the same time, in the washing process after printing and dyeing, the washing rate is higher, The fabric feels soft to the touch.
2. Comparison of the characteristics of reactive printing paste and sodium alginate
2.1 Paste rate
Compared with sodium alginate, reactive printing paste has a higher viscosity, whether it is used alone or in combination with other thickeners, it can effectively reduce the cost of the paste; usually, the active printing paste The dosage is only 60-65% of sodium alginate.
2.2 Color yield and feel
The color yield of the printing paste prepared with reactive printing paste as thickener is equivalent to that of sodium alginate, and the fabric feels soft after desizing, which is equivalent to that of sodium alginate paste products.
2.3 Paste stability
Sodium alginate is a natural colloid, which has poor tolerance to microorganisms, short storage time of color paste, and is easy to spoil. The stability of ordinary sodium carboxymethyl cellulose products is far superior to that of sodium alginate. Reactive printing paste products have been improved by a special process, and their electrolyte resistance is better than ordinary sodium carboxymethyl cellulose products. At the same time, they have good compatibility with chemical auxiliaries and dyes, and are not easy to be corrupted and deteriorated during storage. Chemical stability is much better than sodium alginate.
2.4 Rheology (complementary)
Both sodium alginate and CMC are pseudoplastic fluids, but sodium alginate has low structural viscosity and high PVI value, so it is not suitable for round (flat) screen printing, especially high-mesh screen printing; reactive printing paste products have high structural viscosity , PVI value is about 0.5, easy to print clear patterns and lines. The combination of sodium alginate and active printing paste can meet more rheological requirements of printing paste