Ceramic grade cmc carboxymethyl cellulose is used in the ceramic industry as an excipient, plasticizer and reinforcing agent for blanks. It is used for the base glaze and top glaze of ceramic tiles, which can keep the glaze in a stable dispersion state. It is mainly used in printing glaze to thicken, bond and disperse.
CMC has a unique linear polymer structure. When CMC is added to water, its hydrophilic group is combined with water to form a solvation layer, so that CMC molecules are gradually dispersed in water. CMC polymers rely on hydrogen bonds and van der Waals forces to form a network structure, thus showing adhesion.
Cmc carboxymethyl cellulose for ceramic embryos can be used as excipients, plasticizers, and enhancers for embryos in the ceramic industry. When the dosage is small, the flexural strength of the green body increases significantly.
(1) Improve the green processing speed and reduce production energy consumption;
(2) Good loss on ignition; no residue after burning; does not affect the green color;
(3) It is convenient for process operation and prevents defects such as rolling glaze and lack of glaze;
(4) It has the effect of decoagulation, which can improve the fluidity of glaze slurry and facilitate the operation of glaze spraying;
(5) As a blank excipient, it can increase the plasticity of the sediment material, and carboxymethyl cellulose is convenient for blank molding;
(6) Strong resistance to mechanical wear; less molecular chain damage during ball milling and mechanical stirring;
(7) As a blank reinforcing agent, it can increase the flexural strength of the green blank, improve the stability of the blank, and reduce the breakage rate;
(8) Strong suspension and dispersibility; CMC ceramic grade can prevent the coagulation of barren raw materials and color paste particles, so that the slurry is evenly dispersed;
(9) Evaporate the moisture in the blank evenly to prevent drying and cracking; it is especially used in large-sized floor tile blanks and polished tile blanks, and the effect is obvious.
CMC belongs to the polyelectrolyte class, and it is mainly used as a binder in the glaze slurry, and also plays a role in suspension. When CMC is added to the glaze slurry, water penetrates into the CMC glue block, and the hydrophilic group combines with water, resulting in water swelling.
At the same time, the inner part of the micelle is hydrated and swollen, and the outer part forms a bound water layer. The micelles are free in the glue solution in the initial dissolution stage. Due to the asymmetry in size and shape, and regularly approaching each other through van der Waals force, a network structure is gradually formed in combination with the water layer. Due to its large size, it has strong adhesion:
(1) Under the condition of low dosage, carboxymethyl cellulose can effectively adjust the rheology of glaze slurry, which is convenient for glazing;
(2) Improve the bonding performance of the blank glaze, significantly improve the glaze strength, and prevent deglazing;
(3) The glaze surface has a high degree of fineness, the glaze slurry is stable, and pinholes on the glaze surface after sintering can be reduced;
(4) The dispersibility and the performance of protective colloid are excellent, which can make the glaze slurry in a stable dispersion state;
(5) Effectively improve the surface tension of the glaze, prevent water from diffusing from the glaze to the body, and cmc carboxymethyl cellulose increases the smoothness of the glaze;
(6) Avoid cracking and printing breakage during transportation due to the decrease in the strength of the green body after glazing.
CMC has good solubility, high solution transparency, and almost no insoluble matter. It has excellent shear thinning and lubricity, which can greatly improve the printing adaptability and post-processing effect of printing glaze.
At the same time, CMC has good thickening, dispersing and stabilizing effects in ceramic printing glaze:
(1) The printing rheology is good, and the carboxymethyl cellulose ensures smooth printing;
(2) The printed pattern is clear and the color is consistent;
(3) The solution has high fineness, good lubricity and good use effect;
(4) The carboxymethyl cellulose has good water solubility, has almost no insoluble matter, does not stick to the net, and does not block the net;
(5) The carboxymethyl cellulose solution has high transparency and good mesh penetration;
(6) The carboxymethyl cellulose has superior shear dilution, which greatly improves the printing adaptability of printing glaze.
Infiltration glaze contains a lot of soluble salts and is acidic. CMC for oozing glaze has excellent acid and salt resistance stability, which keeps the viscosity of oozing glaze stable during use and placement, prevents chromatic aberration due to changes in viscosity, and greatly improves the stability of oozing glaze:
(1) The carboxymethyl cellulose has good solubility, does not block the mesh, and has good mesh penetration;
(2) The carboxymethyl cellulose has a good match with the glaze, which makes the glaze stable;
(3) The carboxymethyl cellulose has good acid resistance, alkali resistance, salt resistance and good stability, and can keep the viscosity of the seepage glaze stable;
(4) The solution has good leveling performance and good viscosity stability, which can prevent chromatic aberration from being affected by viscosity changes.