Introduction of Decorative Enamel Coating

There are generally three types of decorative enamel coating in enamel factories: inner white and outer color enamel, pearl enamel, and spot enamel.
The first type of inner white and outer color enamel coating. There are many inner white and outer color products in enamel pots and pots. If spray enamel is required for cast iron utensils, the white enamel slurry in the inner cavity of the blank can be sprayed first, and then the blank is turned over and released to spray the external colored enamel slurry. When spraying, something needs to be properly covered to prevent heterochromatic pollution. If it is steel plate utensils, enamel is usually used, that is, white enamel slurry is poured into the cavity of the vessel, and then the excess enamel slurry is removed by the method of dipping enamel. After drying (sometimes without drying), the external colored enamel slurry is soaked.

The second type of pearl enamel coating, the cross section of pearl powder particles has a physical structure similar to that of pearls, which is a high refractive index metal oxide, such as titanium dioxide or iron oxide, wrapped around mica with a low optical refractive index. The pearl powder is evenly dispersed in the ceramic layer and forms a multilayer distribution parallel to the surface. The incident light will produce pearlescent effect through multiple reflections and interference.
Pearl powder cannot be ground together with enamel frit. When in use, mix the pearl powder into the ground transparent enamel ground coat, stir evenly, dip the enamel and spray it onto the fired cover coat, and then fire it again after drying. The pearlescent enamel has low hiding power and cannot be used as a top coat enamel alone. The product needs three tangs and three firings of the ground coat-top enamel-pearl enamel.
The color of the product is mainly determined by the color of the enamel. Typical pearlescent enamels include silver-white pearlescent enamels on black and dark blue enamels; golden pearl enamels on purple-red and brown-red enamels. Pearlescent enamel is mostly used for oven shells and architectural decorative enamel panels.
The third type of spot enamel coating, and the decoration similar to pearl enamel is spot enamel. This decoration method appeared much earlier than pearl enamel. Spot enamel is generally made by adding white enamel particles to the black and dark blue enamel surface enamel slurry, stir evenly, soak the enamel on the bottom enamel, and then dry and fire it.
The white particles are made by dry grinding for a short time, sieving, and selecting 40~60 mesh particles or 60~80 mesh particles as needed. The amount of white particles added is generally 1% to 3% of the mass of the enamel slurry. Black with white dots and blue with white dots are mostly used for wild tableware exported to Europe and the United States.
Another method of applying spot enamel is to reduce the compressed air pressure and properly enlarge the nozzle diameter during manual spraying, so that the enamel slurry of one color can splash onto the cover coat of another color in dots. Hemp spray method".