CMC for Textile Dyeing

[Physicochemical Properties]

Sodium carboxymethyl cellulose is generally a powdery solid, sometimes also appearing as granules or fibers. It is white or pale yellow in color, has no special odor, and is a macromolecular chemical substance with strong hygroscopic properties.

It is soluble in water, forming a highly transparent, viscous solution. It is insoluble in common organic solvents such as ethanol, ether, chloroform, and benzene, but soluble in water. Direct dissolution in water is relatively slow, but the solubility is still quite high, and the aqueous solution has a certain viscosity. The solid is relatively stable under normal conditions. Due to its hygroscopic properties, it can be stored for a long time in a dry environment.
 

Application Background

In recent years, the textile industry has widely adopted sodium carboxymethyl cellulose (CMC) as a sizing agent to replace starch. Practice has proven that CMC sizing not only saves significant amounts of grain and oil but is also far superior to using starch, animal glue, etc. Using CMC as a binder on cotton, silk, wool, chemical fibers, synthetic fibers, or blended fabrics and warp yarns has the following advantages:

- CMC aqueous solutions are clear, transparent, uniform, and have good stability. They remain unchanged even with pump circulation or stirring and can be used as needed for production.

- CMC aqueous solutions are viscous and have film-forming properties, forming a smooth, abrasion-resistant, and flexible film on the warp yarn surface that can withstand the high strength of the loom, providing favorable conditions for high-speed production.

- Yarn treated with CMC aqueous solutions dries easily, has a glossy finish, and a soft hand feel.
 

Textile Grade CMC is used as a thickener and emulsifier in printing pastes. It is particularly suitable for silk printing pastes. Printing pastes for synthetic fiber fabrics such as cellulose acetate should contain high-boiling-point solvents, dyes, water, and sufficient thickeners. CMC acts as both a thickener and an emulsifier, and has the following advantages for Textile Dyeing:

(1) Significantly improves the vibrancy of the print. Since general printing pastes use water as a medium, and Textile Printing and Dyeing CMC has strong hygroscopicity, it can increase the color mixing rate and improve vibrancy.
(2) Good permeability. CMC paste has better permeability than starch paste, reducing labor intensity.
(3) Easy to desizing, resulting in a soft texture.
(4) Improves the stability of the paste. CMC Textile Printing and Dyeing Grade is less prone to mold and deterioration, making the paste more stable than those using starch.
(5) Strong adhesion. In hand printing, it is difficult to make it adhere firmly to the plate using ordinary adhesives, but Textile Printing Grade CMC can make it lie flat and adhere firmly to the plate, which is convenient for operation.