When exposed to moisture and oxygen, metals such as iron, steel, and copper naturally react with those elements in a process called corrosion. When used in humid or wet environments, the propensity for corrosion increases because these conditions cause metallic surfaces to oxidize and erode faster than normal; this environment also creates small amounts of dust made of iron oxide because of the corrosion process.
Manufacturers use volatile corrosion inhibitors to protect against this damage during metal coating processes. These additives help prevent oxidation, tarnishing, and exposure to air that can lead to corrosion.
Volatile, corrosive inhibitors are liquids that evaporate quickly when applied to metal surfaces. As they escape from the surface, they take most of the moisture and oxygen with them so that there’s no remaining supply left on the surface that could promote corrosion. Here is more information about how an inhibitor works as a protective metal coating.
How Volatile Corrosion Inhibitors Work
The factors contributing to a volatile corrosion inhibitor’s (VCIs) corrosion inhibition are complex and interconnected: chemicals, formulation ratios, compatibility, and film coating weight. Because these elements work together to produce an effective VCI, the best VCI on the planet will not provide a 3- to 5-nm barrier unless the film or paper has sufficient VCI content (coat weight). The metal will rust, even if a highly effective VCI formulation is present.
Volatile corrosion inhibitors prevent oxidation and tarnishing, which can lead to corrosion. A chemical reaction called corrosion begins when exposing metals to moisture and oxygen. As this reaction occurs, oxygen combines with the metal to create rust. Moisture from the surrounding air or water in the environment combines with the metal to form a corrosive electrolyte. The natural result of this reaction is an uncoated metal surface that turns from shiny to dull and becomes flaky.
Manufacturers use VCIs during metal coating processes to prevent oxidation, tarnishing, and exposure to air that can lead to corrosion. The inhibitors evaporate quickly as they go onto the metal surface, taking most of the moisture and oxygen with them so that there’s no remaining supply left on the surface that could promote corrosion. During the process, the VCI creates a protective coating that prevents oxidation while the metal is in use.
VCI Benefits
Traditional methods of metal finishing often result in an uneven coating. To ensure a consistent thickness, an operator must manually coat each surface, leading to operators applying too much or too little coating to different parts of a machine, reducing its lifespan. Volatile corrosion inhibitors solve these issues by naturally creating a consistent coating each time they’re applied.
Businesses can also benefit from the fact that VCIs leave no residue, and they’re ideal for coating tools and equipment that operators must be cleaned thoroughly. VCIs naturally evaporate quickly from metal surfaces to prevent corrosion, allowing the coating to protect the metal for longer.
What is the Difference Between a Volatile Corrosion Inhibitor & an Epoxy Coating?
An epoxy corrosion inhibitor protects against corrosion and acts as a protective coating. Unlike VCIs, epoxy corrosion inhibitors form a hard, brittle coating and remain on the metal surface until they’re washed off. A volatile corrosion inhibitor evaporates quickly, leaving behind a thin, uniform protective coating. VCIs are also referred to as synthetic oil, fluid, varnish, finish, sealer, lacquer, coating, or preservative. The most common volatile corrosion inhibitors are synthetic oils and synthetic lacquers.
Using VCIs in Manufacturing
Manufacturers first sand or grind the metal surface during the coating process to remove existing coatings. Next, they apply a primer that is used to bring out the natural color of the metal. From there, the coatings manufacturer sprays on the VCI, which becomes a protective coating. The last step is to apply a top coat that gives the equipment its final color.
As the VCI evaporates, it takes most of the moisture and oxygen with it, leaving behind a thin and uniform protective coating that prevents oxidation while the metal is in use. The protective coating also prevents rust and stops the flaking that oxidized metals often experience. Compared with other methods of coating metals, applying a volatile corrosion inhibitor creates a thin, smooth coating that is easier to apply to complex shapes and surfaces.
VCIs are corrosion-inhibiting compounds with sufficient vapor pressure to release molecules into the air. When these substances come into contact with metal surfaces, they form a thin molecular barrier that prevents corrosion by keeping air and moisture away from the surface. Corrosion inhibiting vapors can reach into hard-to-reach areas of surfaces, unlike other rust prevention materials.
Manufacturers must use VCI packaging to keep metal parts rust-free during transit, as avoiding corrosion is critical for maintaining rust-free products upon delivery.
In Sum
Manufacturers can avoid losing business because of corrosion using VCI Packaging. This method is an effective way to eradicate rust on metal parts. Parts of a machine can remain rust-free for up to three years using this technique. Some VCI packaging techniques can keep moisture out completely. It is better to wrap parts before shipping them than to risk them rusting while in transit.
Using VCI is a great approach to preventing corrosion. It offers long-term protection against rust and benefits manufacturers who want to ship components and prevent rust and other forms of corrosion. VCI protection may help businesses prevent corrosion and is an excellent example of modern technology.