Clay Used in Porcelain Enamel
In the process of enamel production, the preparation of enamel frit powder and enamel slurry is a very important link. Different enamel products have different enamel frit formulas due to different product materials, shapes and quality standards. In the selection of enamel slurry grinding additives, clay must be added, so what role does clay play in enamel and enamel slurry?
The clay used in the enamel industry is mainly kaolin (chemical formula: Al2O3•2SiO2•2H2O), and a small amount of montmorillonite bentonite (chemical formula: Al2O3•4SiO2•nH2O), which are all natural minerals with suspension properties. , is the main suspending agent, which can prevent the precipitation of enamel particles, enhance the strength of the dry powder layer, and help to adhere to the metal body.
If you want to improve the quality of enamel products, enamel factories must pay attention to the following points when choosing clay:
First, the content of iron and mica in the clay composition should be low, and the viscosity should be stable at the same time.
Second, the clay selected for the ground coat has better suspension properties, and the impurities that cause coloration are not so important.
Third, if it is the clay used for surface glazing, it should have good suspension performance and low impurity content. For example, iron oxide in clay affects the whiteness of titanium dioxide enamel, and if pyrite is contained in clay, it will cause "copper heads" in the ground coat layer, or pits and black spots in the cover coat layer.
In addition to clay, there are a variety of macromolecular organics that can also act as suspending agents. In the ground coat enamel slurry of two enamels and one firing by wet method, a small amount of macromolecular organic substances can be used to replace part of the clay, especially when there is a special requirement for the strength of the powder layer, the introduction of these organic substances can significantly increase the enamel powder blank. Strength of.
The above is about the application of clay in enamel, I hope it can be helpful to you, remember to pay attention and collect. Nolifrit has been focusing on enamel frit and inorganic pigments for 26 years, providing customers with one-stop service!