VCI 2000 Technology
VCI 2000 Technology
Our technology is based on enclosing the protected product in a sealed bag that contains VCI2000, consisting of aminocarboxilates, a volatile compound that is attracted to the surface metal. This compound forms a protective layer that prevents oxygen and water vapor from making contact with the metal surface. The protective layer does not change the properties of the product, even highly sensitive electronic products.
Protection of multiple metal types.
Wide range of applications.
VCI products produce no residue and can be applied during the manufacturing, packaging and/or operational stages of a product.
- Nitrite free, environmentally safe.
How does VCI work?
VCI generally comes in solid form, for convenience in handling. Volatility is simply a means of transport. Protective vapors disseminate within an enclosed space until equilibrium–determined by the partial vapor pressure–is attained. The inhibiting process starts when the vapors contact the metal surface and condense to form a thin barrier of micro-crystals. In the presence of even minute traces of moisture, the crystals dissolve and develop strong ionic activity.
The result of such activity is adsorption of protective ions onto metal surfaces, with the concurrent formation of a molecular film that fosters a breakdown of contact between the metal and an electrolyte. The presence of an invisible monomolecular film does not alter any of the important properties of the metal, even in precise electronic applications, where properties such as conductivity or dimensional tolerances are critical, and where even minute deviations could cause malfunction.
VCIs migrate to distant metallic surfaces. This ability enables VCIs to protect metals without coming into direct contact with them. VCIs need only to be placed in the vicinity of the metals to provide protection. VCIs will migrate to metallic surfaces through the vapor phase, and the inhibitor will be adsorbed on the surface. The protective vapors will disseminate within the enclosed space until equilibrium is reached. Equilibrium is determined by the compound’s partial vapor pressure.
Excessive vapor pressure will cause the inhibitor to be released to such an extent that a protective concentration cannot be maintained over time. On the other hand, a low-vapor-pressure inhibitor is not used up as quickly and can thus assure more durable protection; however, more time is needed to generate the desired degree of protective vapor concentration. This time-gap raises the risk of corrosion during the initial saturation period, and if the space is not sealed in a timely fashion, a protective concentration may never be attained.
Selection of VCI’s
Proper selection of volatile compounds enables controlled and dependable volatilization. The higher the temperature, the stronger the tendency of the metal toward corrosion. The volatilization rate of VCIs has a similar function-dependence upon temperature, so that more inhibitive material is evaporated at higher temperatures. VCIs can thus self-adjust to the aggressiveness of the environment, over a wide temperature range.
Volatile corrosion inhibitor development
Volatile corrosion inhibitors were originally developed for protection of ferrous metals in tropical environments, an approach that soon proved limiting because of its incompatibility with nonferrous metals. Recent developments are based on the synthesis of compounds that provide satisfactory “general” protection, i.e., they protect most commonly used ferrous and nonferrous metals and alloys. Investigations of electrochemical behavior show that these compounds belong to a family of mixed or “ambiodic” inhibitors capable of slowing both cathodic and anodic corrosion processes. Active ingredients in VCIs are usually products of reaction between a volatile amine or amine derivative and an organic acid. The product obtained as a result of this reaction, ‘amino-carboxilates’, are the most commonly used VCIs. Cyclohexylamine, dicyclohexylamine, guanidine, amino-alcohols, and other primary, secondary and tertiary amine salts represent the chemical nature of VCIs. VCI compounds, although ionized in water, undergo a substantial hydrolysis that is relatively independent of concentration. This independence contributes to the stability of the film under a variety of conditions. The VCI’s absorbed film on the metal surface repels the water molecules away from the surface. This film also provides a diffusion barrier for oxygen, which decreases the oxygen concentration, thereby reducing the cathodic reaction. Strong inhibition of the anodic reaction results from the inhibitor’s having two acceptor-donor adsorption centers that form a chemical bond between the metal and the inhibitor. Adsorption of these compounds alters the energy state of metallic surface, thus leading to rapid passivation that diminishes the metal’s tendency to ionize and dissolve. In addition to preventing a general ”attack” on ferrous and nonferrous metals, mixed VCIs are found to be effective in preventing galvanic corrosion of coupled metals, pitting attack and, in some cases, hydrogen embrittlement.
What are YOU doing to control YOUR corrosion problems?
Are you using 1940’s technology or 1990’s technology? Or worse yet, nothing at all…? Is corrosion eating away your bottom line, as well as your products??
By implementing a total corrosion control plan, you can reduce rejects, returns and malfunctions; while increasing productivity, customer satisfaction, and profitability.
VCI-2000 packaging products are nitrite-free, environmentally safe corrosion-preventing products that provide protection of multiple metal types for everything from steel rebar to electronic circuit assemblies.
VCIs produce no residue and can be applied during the manufacturing, packaging or operational stages of a product.
A brief history of vapor corrosion inhibitors
In the early 1900’s, it was discovered that a chemical could protect metal from corrosion by vaporizing and depositing on the metals.
These chemicals were nitrites, and the first useful one was Dichan (dicyclohexylammonium nitrite).
This compound was developed by Shell Oil Co. after the Second World War to protect military equipment.
Dichan was adapted by some companies as a powder and as a paper coating to protect metal parts. However, there were early problems . . .
Characteristics of nitrites
Nitrites protect iron and aluminum only.
Nitrites attack copper and bronze.
Nitrites are known to cause health problems – cancer, respiratory, visual.
The disposal of nitrites causes environmental problems.
Nitrites exhibit low vapor pressure.
It is difficult to calculate an exact “dose” for application.
Nitrites can cause corrosion.
Facts about the interaction between nitrates and VCIs:
Today, sodium nitrite is frequently used in Vapor Corrosion Inhibitor (VCI) paper coatings, and the same problems exist with this compound.
But since sodium nitrite is inexpensive a large quantity can be used in a coating without impacting cost significantly. Hence, nitrites continue to be sold and give VCIs a bad reputation.
In the 1950’s research began in earnest to overcome the problems associated with nitrite-based VCIs.
The goals of researchers were to:
Protect other metals besides iron and aluminum, especially copper.
Achieve higher vapor pressure to protect larger surfaces.
Develop products that are safe to use and cause no health problems.
Solve disposal problems – safe for water systems.
Facilitate calculating precise amounts for proper protection suited to the end product.
Results of the research
These research programs were largely successful. New and innovative methods were developed to deliver these new compounds; and improved products are now available. However, the workplace is still lenient on rules and regulations protecting workers’ handling of VCI products, and nitrates are still acceptable in most countries. The United States, Japan and Germany, to name a few, continue to produce sodium nitrite products. WHY? The low cost of sodium nitrite makes it difficult for environmentally safe products to compete. Additionally, sodium nitrite-based products have performed well in a number of tests (especially when health and environmental factors were disregarded).
Companies like yours that are health and environmentally conscious can make a difference, however. You can insist on VCIs that not only outperform sodium nitrite, but protect your company’s products without compromising the environment or your employee’s health!!
VCI2000 handling information
Packaging personnel should always wear gloves while handling metal parts.
Parts should be clean and free of fingerprints before wrapping.
Package your clean products as quickly as possible.
The VCI active side should face the metal.
The metal part should be no more than 300mm from the VCI product. The closer to the metal, the better the corrosion protection.
As a general rule, use 1 m2 (10 sq. ft.) of VCI film for every 1-2.5 m2.
(10-25 sq. ft) of metal surface. Use at least 1m2. of VCI for every 0.25 cubic meter of void space.
Use VCI to separate metal from acidic packing materials such as corrugated boxes and wooden pallets in order to prevent corrosion at the contact points.
The duration of protection depends on the VCI paper and packing method used.
Packages may be opened and resealed without affecting the corrosion protection. (Avoid touching metals during the inspection!).
VCI2000 recommends inventorying no more than a six-month supply of VCI packaging. Store unused VCI in a cool, dry place, away from direct sunlight.
For best results, we recommend testing the VCI product for compatibility prior to use.