Sodium Carboxymethyl Cellulose – A Valuable Additive in the Ceramic Industry
Sodium carboxymethyl cellulose (CMC) has made significant contributions to the ceramic industry, playing a critical role in key processes such as green body formation, glaze preparation, and performance optimization.
Application in Green Body Formation
Enhancement of Plasticity
When incorporated as a binder into ceramic green bodies (e.g., mixtures of clay, quartz, and feldspar), CMC significantly improves the plasticity and toughness of the unfired body, thereby facilitating press molding and slip casting operations.
In the manufacturing of daily-use ceramics—such as tableware and tea sets—the addition of CMC helps minimize cracking during forming and enhances overall molding efficiency.
Improvement of Drying Strength
CMC forms hydrogen bonds with particles in the green body, effectively reducing shrinkage stress during drying and preventing cracks. For instance, in tile production, the inclusion of CMC increases green strength by over 30% and substantially lowers the rate of damage during handling and transportation.
Application in Glaze Preparation
Suspension Stabilization
CMC acts as an effective suspension stabilizer, ensuring uniform dispersion of solid particles within the glaze suspension. This prevents sedimentation and maintains consistent glaze composition, which is essential for achieving high-quality surface finishes. In the production of architectural ceramic glazed tiles, the use of CMC eliminates issues related to glaze stratification.
Adjust rheological properties
CMC optimizes the viscosity of glaze, making it easy to spray or dip, while reducing glaze defects (such as pinholes and sagging). For example, when glazing sanitary ceramics, CMC helps achieve a smooth and flawless surface effect.
Other key applications
Enhance the strength of the green body
The molecular chains of CMC interact with ceramic particles, effectively enhancing the mechanical strength of green bodies prior to sintering. This property makes CMC particularly suitable for the production of large-sized or complex-shaped ceramic products. For instance, in the manufacturing of ceramic insulators, the incorporation of CMC has significantly reduced the rate of breakage during the pre-sintering stage.
Environmentally friendly alternative solution
As a valuable eco-friendly substitute, CMC can partially replace conventional polyvinyl alcohol (PVA), thereby reducing emissions of volatile organic compounds (VOCs). One ceramic manufacturing facility successfully replaced 20% of its PVA usage with CMC, resulting in a notable decrease in environmental compliance costs.