Sodium carboxymethyl cellulose, an organic substance, is a carboxymethylated derivative of cellulose and is the predominant ionic cellulose gum. CMC-Na is a white fibrous or granular powder, odourless, tasteless, hygroscopic and easily dispersed in water to form a transparent colloidal solution.
CMC is widely used as slurry treatment agent for oil industry, synthetic detergent, organic detergent aid, textile printing and dyeing sizing agent, water-soluble gelatinous tackifier for daily-use chemical products, tackifier and emulsifier for pharmaceutical industry, thickener for food industry, adhesive for ceramic industry, industrial paste, sizing agent for paper industry, etc. It is used as a flocculant in water treatment, mainly for wastewater sludge treatment, and can improve the solid content of the filter cake.
CMC for Printing and Dyeing
CMC has been widely used in printing and dyeing, and has a very high cost performance compared with sodium alginate.
Disadvantages of Sodium Alginate:
1. Not resistant to strong acid, alkali and heavy metal ions; easy to mildew and poor storage stability;
2. The structural viscosity of the original paste is low, which is close to the rheological properties of Newtonian fluid, which is not conducive to circular (flat) screen printing, especially high-number screen printing;
3. It has high fluidity for flat screen printing, and has defects such as permeability, screen penetration, color yield, and brightness that are not ideal.
4. In recent years, the supply of sodium alginate has become tight and the price has risen.
CMC instead of Sodium Alginate has the following characteristics:
1. Super high degree of substitution and uniform distribution of substituents.
2. Stable viscosity, excellent salt and alkali resistance, and good dilution resistance.
3. Excellent filterability and fluidity of the solution.
4. Excellent colourability.
5. High efficiency in washing after printing and dyeing, good fabric feel and softness comparable to sodium alginate.
6. Good water holding capacity, fine patterns can be printed.
7. Very few gel particles, no blemishes in printing and dyeing.
8. No reducibility itself, little effect on the colour and light of the dye.