Sodium carboxymethyl cellulose (CMC) plays several important roles in ceramics manufacturing, particularly in ceramic processing and shaping. Here’s how CMC is utilized in various stages of ceramics production:

1. Binder in Ceramic Bodies: CMC is commonly used as a binder in ceramic bodies or greenware formulations. Ceramic powders, such as clay or alumina, are mixed with water and CMC to form a plastic mass that can be shaped or molded into desired forms, such as tiles, bricks, or pottery. CMC acts as a temporary binder, holding the ceramic particles together during shaping and drying stages. It provides cohesiveness and plasticity to the ceramic mass, allowing for easy handling and forming of intricate shapes.
2. Plasticizer and Rheology Modifier: CMC serves as a plasticizer and rheology modifier in ceramic slurries or slips used for casting, slip casting, or extrusion processes. CMC improves the flow properties and workability of ceramic suspensions, reducing viscosity and enhancing fluidity. This facilitates the casting or shaping of ceramics into molds or dies, ensuring uniform filling and minimal defects in the final products. CMC also prevents sedimentation or settling of ceramic particles in suspensions, maintaining stability and homogeneity during processing.
3. Deflocculant: In ceramic processing, CMC acts as a deflocculant to disperse and stabilize ceramic particles in aqueous suspensions. CMC molecules adsorb onto the surface of ceramic particles, repelling each other and preventing agglomeration or flocculation. This leads to improved dispersion and suspension stability, enabling uniform distribution of ceramic particles in slurries or casting slips. Deflocculated suspensions exhibit better fluidity, reduced viscosity, and enhanced casting performance, resulting in higher-quality ceramics with uniform microstructures.
4. Binder Burnout Agent: During the firing or sintering of ceramic greenware, CMC serves as a binder burnout agent. CMC undergoes thermal decomposition or pyrolysis at elevated temperatures, leaving behind carbonaceous residues that facilitate the removal of organic binders from ceramic bodies. This process, known as binder burnout or debinding, eliminates organic components from green ceramics, preventing defects such as cracking, warping, or porosity during firing. CMC residues also contribute to pore formation and gas evolution, promoting densification and consolidation of ceramic materials during sintering.
5. Porosity Control: CMC can be used to control the porosity and microstructure of ceramics by influencing the drying kinetics and shrinkage behavior of greenware. By adjusting the concentration of CMC in ceramic suspensions, manufacturers can tailor the drying rate and shrinkage rate of green ceramics, optimizing pore distribution and density in the final products. Controlled porosity is essential for achieving desired mechanical, thermal, and electrical properties in ceramics for specific applications, such as filtration membranes, catalyst supports, or thermal insulation.

sodium carboxymethyl cellulose (CMC) plays a crucial role in ceramics manufacturing by serving as a binder, plasticizer, deflocculant, binder burnout agent, and porosity control agent. Its versatile properties contribute to the processing, shaping, and quality of ceramics, enabling the production of high-performance ceramic products with tailored properties for various industrial applications.