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2022.3.11
Metal molds are tools that are used in blow molding, die casting, injection molding, and more forming methods to change the physical state of molding materials and finally create various parts based on the drawings. In this article, we’ll talk about the reasons or causes of metal mold corrosion, why do metal molds rust and how do you get rid of rust on die casting metal mods?
Metal mold includes moving mold and fixed mold (or male mold and female mold), which can be divided or combined. Metal molds are precision tools with complex shapes. In addition to strict requirements for their own performance, such as bearing expansion force, structural strength, surface hardness, surface roughness, and processing accuracy, in order to effectively ensure that metal molds are free from corrosion during production, maintenance, and storage, a complete set of metal mold rust prevention management is very important. The specific process includes metal mold cleaning, Rust prevention, neutral rust removal, gas-phase rust prevention packaging, using desiccant to control humidity, etc.
1. During vulcanization and high-temperature molding of plastic or rubber, chemical changes occur, and these residues and gas corrosives cause corrosion of metal molds
2. The storage temperature and humidity of metal mold are high, resulting in condensation on the surface of the mold cavity and metal corrosion
3. Before the metal anti-corrosion treatment, the metal mold was not thoroughly cleaned, and there were too many corrosive residues
4. Spraying metal mold rust inhibitor, the temperature is too high. If the mold is sprayed with metal anti-corrosion oil at a high temperature, it is easy to absorb the water in the anti-corrosion agent. If the water is absorbed, the metal may produce rust.
1. Avoid placing the mold in a humid environment
The ancients said that every drop of water wears away the stone. The mold is the same. If it is placed in a wet place for a long time, no matter how good the anti-corrosion agent is, it will eventually lead to the rust of the mold. Therefore, when we unload the mold from the machine, we must pay attention to the storage environment. It is best to put it on a dry and ventilated mold frame.
2. Avoid direct contact with the mold by hand
Workers’ hands will sweat, which is easy to get on the workpiece. It can be prevented by wearing gloves.
3. The anti-rust agent can be used only after the mold is cooled down
If the mould is sprayed with the anti-rust agent before cooling down, the mould will rust in a few days. The reason is that the mold will absorb the moisture in the anti-rust agent before rewarming, resulting in signs of rust. The best way is to wait for the mold to cool naturally, and then use the mold rust inhibitor after cooling.
4. Long term anti-rust agent shall be selected according to the anti-rust demand
At present, there are many anti-rust agents, anti-rust oil, and anti-rust powder on the market. However, the long-term anti-corrosion agent is a professional mold anti-corrosion agent, and the general anti-corrosion cycle is 1 ~ 3 years. It can effectively ensure the mold safety of the factory and reduce unnecessary losses.
5. In order to facilitate cleaning, anti-rust oil that is easy to clean shall be selected
Some anti-rust oils have thick oil film and high viscosity. After coating, they give customers the feeling of strictly protecting the mold, and the color with color (such as green and white) is too dark, which is not conducive to subsequent cleaning. In fact, as long as the anti-corrosion film covers the mold, the anti-rust oil with low viscosity and thin oil film is more conducive to cleaning. Too much oil can not play a better anti-corrosion effect but will increase the difficulty of subsequent cleaning.