In the era of rising living standards, the demand for high-quality paper has surged, propelling the rapid development of the papermaking industry. To meet these escalating standards, innovative and multifunctional green papermaking additives have emerged. While natural cellulose has limitations hindering its role in papermaking, carboxymethylcellulose, a product of various modifications, has emerged as a cutting-edge and efficient papermaking additive.

Through a series of modifications involving alkalinization and etherification reactions between natural cellulose molecules and chloroacetic acid under alkaline conditions, carboxymethylcellulose overcomes the limitations of natural starch, such as poor rheology and low viscosity. The introduction of hydrophilic carboxymethyl groups significantly enhances cellulose swelling, improving compatibility with pulp fibers and filler particles. This enhancement contributes to increased paper toughness and strength. Moreover, the negative charges carried by pulp and fillers repel each other, ensuring even dispersion in the pulp and enhancing paper uniformity.

Carboxymethylcellulose boasts excellent film-forming and rheological properties, making it a versatile additive for surface sizing, water retention, and paper reinforcement. Its safety, non-toxicity, and cost-effectiveness position it as a promising 21st-century papermaking additive with vast development potential.

1. Application as Papermaking Aid and Enhancer

Carboxymethylcellulose, functioning as a water-soluble anionic surfactant, forms a transparent viscous solution when dissolved in water. Adding it to pulp during paper sheet forming, drying, and dehydration enhances fiber bonding through hydrogen bonds, resulting in improved paper strength. This additive proves effective in high-filler paper, reducing raw material costs and addressing mechanical strength challenges associated with increased filler amounts.

In beating processes, carboxymethylcellulose demonstrates remarkable efficiency, increasing breaking length and reducing energy consumption. Its role in bamboo pulp beating aids lubricity between fibers, improving fiber filamentation, beating degree, water retention, bonding force, and paper strength.

2. Paper Machine Wet End Additives

Carboxymethylcellulose's presence in the wet end enhances chemical retention through electrostatic adsorption. Its negative charge contributes to fiber surface attachment, strengthening bonding forces between fibers. Combined with appropriate cationic additives, carboxymethylcellulose exhibits synergistic effects, improving the retention rate and overall additive efficiency of the paper machine.

As a wet end additive, it improves cardboard properties, forming a film on the surface and enhancing tensile and surface strength. Its combination with polyacrylamide yields synergistic effects, significantly improving various paper strength indicators.

3. Application as Surface Sizing Agent

Carboxymethylcellulose's film-forming properties and water retention make it a valuable surface sizing agent. It evens coating on paper or cardboard surfaces, adjusting paper humidity, improving strain caused by drying, and enhancing properties like friction resistance and smoothness. Surface sizing with carboxymethylcellulose proves crucial in preventing undesirable printing phenomena, such as edge warping and uneven color distribution.

4. Paint Water Retaining Agent

Carboxymethylcellulose enhances coating water retention by adjusting coating rheology, preventing adhesive migration, and improving coating effects. Coatings with carboxymethylcellulose exhibit good rheology, increasing coating solid content, reducing dispersion medium amounts, and enhancing water retention performance.

5. Applications in Different Paper Types

a. Packaging Paper:

• Carboxymethylcellulose aids in producing coated paper with strong hydrophobic properties, enhancing coating network structures and viscosity. It improves stability, surface roughening strength, and acts as an auxiliary adhesive for pearlescent pigment-coated paper.

b. Special Paper:

• Carboxymethylcellulose finds application in producing antibacterial paper, offering superior performance compared to acrylic resin. It enhances the antibacterial properties of shoes stored in boxes for extended periods.

c. Household Paper:

• Carboxymethylcellulose improves the beating degree and dispersion of fibers in paper towels, enhancing softness without compromising strength. In wet wiping paper, it contributes to sufficient retention, improving wet strength and water decomposability.

  

These diverse applications showcase the versatility and significant contributions of carboxymethylcellulose to advancements in papermaking across various paper types. As technology continues to evolve, the utilization of carboxymethylcellulose is likely to expand, offering sustainable solutions for the papermaking industry.