The adhesion of CMC ceramic grade in the slurry is manifested by a strong network structure formed by macromolecules or macromolecules based on hydrogen bonds and van der Waals forces. When water penetrates the CMC block, the part with less hydrophilic groups will swell, and the part with more hydrophilic groups will be separated from the block immediately after swelling. Due to the uneven hydrophilic groups in the production of CMC ceramic grade, the dispersed particle size of micelles is inconsistent. The inside of the micelle is hydrated and swelled, and the outside is bound with a layer of hydrate, that is, the bound water layer. In the early stage of dissolution, micelles are free in the colloid. Due to the asymmetry of size and shape, and the regular proximity to each other under the action of Van der Waals force, the combined water layer gradually forms a network structure. Because CMC ceramic grade is fibrous, the network structure formed is larger in volume and strong in adhesion, which can lower glaze defects.
2. Suspension effect
If no additives are added, the glaze slurry will precipitate over time due to gravity. When preparing the glaze, even if a certain amount of clay is added, the precipitation cannot be prevented. However, after adding a certain amount of CMC, a network structure is formed to support the gravity of the glaze molecules. The molecules or ions of CMC extend in the glaze and occupy a certain space, preventing the glaze molecular particles from contacting each other and improving the dimensional stability, especially through belts. The repulsion between the negatively charged CMC anions and the negatively charged clay particles increases the suspension of the glaze slurry, so the CMC ceramic grade has a good suspension in the glaze slurry.
1. See the model and specifications clearly when purchasing, and select the CMC ceramic-level specifications that are suitable for production.
2. When the glaze is milled, please add CMC at the same time because it is helpful to improve the milling efficiency. To achieve maximum efficiency, please pay attention to the ingredients when pouring water: water = 1%: 0.5% is appropriate.
3. It is best to let the glaze rot for a day or two so that the glaze slurry can be stable enough and CMC can exert the best effect.
4. Please adjust the addition amount of CMC ceramic grade appropriately according to the changes of the seasons. When it is summer, the amount is the largest, the winter is the smallest, and the spring and autumn are middles. The general variation range is between 0.05% and 0.1%. If it stays the same in winter, it will cause glaze flow, slow drying, and cause glaze sticking. On the contrary, if the materials are not enough, the dense and smooth glaze will not be made. Due to the high temperature in summer, CMC is affected by bacteria, and the viscosity will reduce. Therefore, please take corresponding measures in summer to add suitable additives to improve the corrosion resistance of CMC.
5. When using, the glaze is best sieved with a sieve of more than 100 mesh, so it will not affect the glaze surface by the residual CMC during firing.