Electrophoretic enameling and electrostatic enameling are both methods of enameling enamel products, and they have many similarities and differences. Electrophoretic enamelling is suitable for one-pass enamelling of ground coat or highly opaque antimony cover coat. The product with good electrophoresis coating has good adhesion, fine porcelain surface and good gloss. The net blank is clamped by a special anode clamp. There are two cathode electrode nets on both sides of the clamp. When the DC power supply is turned on, the negatively charged powder particles will be deposited on the iron. A uniform powder layer is formed on the surface of the blank, which can be dried and fired.

Electrostatic dry powder spray enamel is a new enameling process developed in the 1990s. The method is as follows: the enamel powder is transported through the pipeline to the negatively charged high-voltage spray gun by compressed air, so that it is sprayed with a negative charge, and is adsorbed on the positively charged net blank to form a uniform sub-layer, which is fired. After that, products with fine porcelain surface and good gloss can be obtained. Because it can use the process of spraying the base powder first, then spraying the flour, and finally co-firing, which shortens the process flow, greatly improves labor efficiency and saves energy.

The main points of electrophoretic coating are:

1. The clamping contacts should be small and clamped on non-main surfaces;

2. The density of the electrode mesh and the distance between it and the iron billet directly affect the thickness of the powder layer. If the density is high or the distance is close, the powder layer is thick; otherwise, the powder layer is thin.

3. During the electrophoresis process, the enamel slurry concentraation decreases, the pH value increases, the temperature increases, the iron ion concentration increases, and the quality of the powder blank becomes worse. After firing, the porcelain surface shows point and linear defects, and the color turns yellow. Therefore, it is necessary to frequently replenish new powder, and add buffers (such as borax, etc.) to stabilize the pH value; at the same time, measures such as cooling and iron removal are used to improve the quality of electrophoresis.

Technical requirements for electrostatic dry powder spraying:

1. Porcelain powder particle size: 10~60 microns, 50% of which are 20~30 microns;

2. Specific gravity of porcelain powder: 2.3~2.4g/cm³;

3. Moisture content of porcelain powder: <1%;

4. Gun voltage: 60~100kV.

Nolifrit is a supplier of enamel frits and inorganic pigments, if you have any questions, please contact us!