How to Remove Rust of Metal Substrate
The commonly used enamel substrate on the market is steel plate or cast iron. These metal materials often have grease, rust or oxide on the surface. If they are not treated, it will directly affect the quality of the enamel product. It will make it difficult to apply the enamel ground coat or It will fall off after drying, shrink during firing, and may also cause defects such as bubbles, pinholes, and poor adhesion. So, how to remove the rust stains on the enamel substrate?
There are three main methods for removing rust stains on the enamel substrate: degreasing and acid pickling, oil-burning and acid pickling and oil-burning and sandblasting. These three have their own advantages and disadvantages, and their characteristics are described in detail below.
1. Degreasing and acid pickling is a metal material surface treatment process widely used in the enamel industry. It has two kinds: manual operation and automatic operation. With the continuous upgrading of technology, manual operation has been gradually eliminated by the market. If there is no rust on iron billet, the acid pickling can be omitted. Which is beneficial to improve the operating environment, increase production efficiency and reduce production costs.
2. Oil-burning and acid pickling is mainly for the thick iron billet, with severe internal stress after rolling, or special grease on the surface of the iron billet, etc. The general iron billet does not require the oil burning process. Iron billets will form oxide scales on the surface after being burned. For the quality of enamel products, these oxide scales need to be removed by acid pickling.
3. The process of oil burning and sand blasting is mainly to spray sand on the iron billet with a machine to eliminate iron rust stains through force. It is generally used on products with thicker iron billets such as industrial enamel reactors, enamel water heaters, and enamel pipes .
The methods for removing the rust stains on the enamel substrate are mainly the three introduced above. However, with the continuous improvement of production technology, the current chemical degreasing technology is also continuously used in industrial production. It is mainly through the action of alkaline solution and the surface of the iron billet, remove oil stains from the surface of the metal body. Compared with the pickling process, it can improve the quality of enamel products, reduce production costs, and reduce energy consumption.