Company News

In the field of mold manufacturing, galvanization is a common and effective surface treatment technology. It forms a zinc metal coating on the mold surface to enhance the mold's corrosion resistance, wear resistance, and make the surface smoother and more flat.

The basic principle of galvanization is to use zinc metal to react with the surface of the mold steel, forming a zinc-iron alloy protective layer. This protective film can effectively isolate the mold substrate from contact with oxygen, moisture, and other corrosive media in the air, thereby preventing the mold from rusting and corroding. Zinc is very stable in dry air, so the galvanized layer is particularly suitable for protecting molds in atmospheric conditions.

There are two main methods for mold galvanization.

— Hot galvanization: The mold is immersed in molten zinc liquid. This method results in a uniform, strong adhesion, and high wear resistance coating. However, the high-temperature treatment may affect the size and hardness of the mold.

— Electro-galvanization: The zinc layer is deposited on the mold surface through electrolysis. This method is simple to operate, has a low temperature, has little impact on the mold performance, and allows precise control of the coating thickness. It is currently the most widely used method.

The benefits brought by galvanization treatment to molds:

1. It can effectively prevent oxidation and corrosion of the mold, significantly extending the mold's service life.

2. The surface after galvanization is smoother and more flat, reducing the friction resistance between the mold and other materials, and improving work efficiency.

3. The galvanized layer also has good metallic luster, making the mold more beautiful and durable.

Of course, galvanization treatment also has some limitations. The processing cost is relatively high, and specialized equipment and processes are required. The formation of the zinc layer changes the mold's size, increasing processing difficulty. At the same time, the galvanization process generates wastewater and exhaust gas, requiring corresponding environmental protection treatment measures. Additionally, it should be noted that if the mold works in environments containing strong corrosive media such as sulfuric acid, hydrochloric acid, or caustic soda, zinc coating is not recommended because zinc will react chemically with these substances and be corroded.

Galvanization treatment is widely used in various types of molds such as injection molds, die-casting molds, stamping molds, and zinc-based alloy molds. The key to process control lies in the pH value of the galvanizing solution (generally controlled at 2.5-3.0), current density (16-20A/dm² is suitable), and the stability of the galvanizing solution components. As long as the control is appropriate, galvanization can provide long-term and reliable surface protection for the mold.