An introduction to the basics of VpCI corrosion protection productAnna Lee
VpCI stands for Vapor Phase Corrosion Inhibitors; it comprises a unique family of corrosion protection products made by Cortec. The generic name for VpCI is VCI which stands for Volatile Corrosion Inhibitors. VpCI molecules react with metal in a way that prevents corrosion; it forms a thin barrier on the surface of the metal.
Corrosion is a chemical reaction that slowly degrades the metal. In order for this chemical reaction to occur there are three critical elements needed: Moisture, oxygen and electrolytes. Electrolytes are substances that contain free ions such as salts, acids or bases. In order to retard corrosion one must prevent one or all of three of the critical elements from reacting with the metal.
High temperature and humidity or the presence of salt, sulfur or corrosive gases can accelerate the corrosion process.
While VpCI is actually a variety of different chemical formulations, they all work the same way in terms of preventing corrosion. VpCI are molecules that contains both positive and negative charge ions that deposit themselves on the metal surface forming a one-molecule ionic-bonded film which prevents oxygen in the surrounding atmosphere from interacting with the metal. The VpCI is essentially a vapor that disperses through the air. Because of its small molecular size VpCI can attain very high concentration levels. This allows it to vaporize and saturate the air as it disperses. It has a very high affinity for metal so when the surrounding air reaches a saturation point, the molecules attach themselves to metal. VpCI works best in a fully sealed environment as a certain vapor pressure is required for the molecules to effectively disperse.
Cortec has chosen to designate some of its contact corrosion inhibitor products as VpCI. Vapor phase is a very different process than contact where the product is applied by spray, foam or immersion. The actual corrosion protection is similar in that molecules are bonding to the metal to form a barrier. However with vapor phase, the molecules are dispersed in the air around the metal.
Cortec has created a large variety of VpCI corrosion inhibitor products that work with a variety of metal types. There is no one product that works in every situation. For more information on VpCI products, please go to Packnet’s corrosion inhibitor products page.