The Role of Sodium Carboxymethyl Cellulose (CMC) in Ceramic Production

CMC can improve the plasticity of ceramic raw materials. When added to the ceramic body mixture, it helps the clay - like substances to become more pliable. This is crucial during the shaping process as it allows for more complex and precise forms to be created. For example, in the production of delicate ceramic figurines, the enhanced plasticity due to CMC enables the artisans to mold fine details such as the facial features and delicate ornaments more easily.

It acts as a binder, strengthening the connection between different ceramic particles. This binding effect is beneficial for maintaining the integrity of the ceramic body. In the case of making large - sized ceramic products, like ceramic vases or sculptures, CMC helps to hold the particles together, reducing the risk of cracking or crumbling during the drying and firing processes.

CMC can adjust the viscosity of the ceramic slurry. By adding an appropriate amount of CMC, the flow characteristics of the slurry can be optimized. In the process of slip - casting, for instance, the right viscosity is essential for the slurry to evenly coat the mold and produce a smooth - surfaced ceramic product. If the viscosity is too high, the slurry may not flow properly and result in an uneven coating; if it's too low, it may not adhere well to the mold.

It forms a kind of film - like structure on the surface of the ceramic body during drying. This film slows down the evaporation of water, which helps to prevent the formation of cracks caused by rapid drying. When producing thin - walled ceramics, such as ceramic cups or plates, this property of CMC is particularly important as these products are more susceptible to cracking due to uneven drying.

The addition of CMC can increase the strength of the green body (the unfired ceramic body). A stronger green body is more resistant to damage during handling and transportation before firing. This is significant for the mass production of ceramics, as it reduces the number of defective products due to breakage in the pre - firing stage.