VCI is the abbreviation of Volatile Corrosion Inhibitor in English, and we call it VCI. This method was researched in the United States in the 1940s and began to be used. At present, VCI is used in storage, transportation, and packaging in various ways in Germany.
Its principle is to prevent the metal and the medium from reacting. Through the sublimation phenomenon, the corrosion inhibitor gas can fill the entire enclosed space and form a protective film on the metal surface in the form of molecules, thereby separating the water and the metal and preventing the occurrence of electrochemical reactions.
It can also be soluble in water, and only when the concentration in the water is high enough, can it effectively protect the metal surface from corrosion caused by water droplets.
The conditions of use of this vapor phase rust prevention method are:
- the surface area of gas-phase antirust material should be as large as possible;
- the material is as close as possible to the metal to be protected (no more than 30cm);
- closed cover;
- this material is less affected by water and other corroded materials;
- the metal surface should be as clean as possible (processing tools, sweat, and other stolen goods will affect the anti-rust effect);
- he antirust package formed before the formation of solidified water should be kept for a period of time as far as possible.
In Germany, the carrier of this kind of corrosion inhibitor gas mainly uses paper and polyethylene film, which are often referred to as VCI paper and VCI film.
In addition, there are also carrier forms such as foam and corrugated cardboard.
The advantages of the vapor phase rust prevention method are low cost, simple packaging process, fast speed, sealing requirements are not as strict as desiccants, and there is no need to clean grease like the coating method when opening the package.
VCI anti-rust method is mainly used in the packaging of electromechanical products and auto parts in Germany.
The anti-rust packaging of electromechanical equipment is mainly completed by using the vapor phase anti-rust film combined with wooden boxes.
The anti-rust film can be spread on the base of the wooden box, and then heat-sealed with another anti-rust film hanging on the equipment.
If the equipment is large, the space in the film cavity can also be hung with some vapor phase anti-corrosion foam materials. For some products with low anti-rust requirements, general plastic film can be spread on the base and anti-rust film on the top, and they are nailed to the box board with special tools.
