VCI FAQs

VCI is an acronym for Volatile Corrosion Inhibitor. VCI chemicals are a class of corrosion inhibiting compounds, which have sufficient vapor pressure to release molecules from the compound into the air. Armor Protective Packaging® VCI products are packaging products, which contain ARMOR’s proprietary VCI Nanotechnology™ chemicals directly in the packaging. Our packaging products include papers, films, foams, nettings, chipboards and many other packaging components, which safely prevent corrosion on protected metals without the need for messy grease, oils, protective coatings or other ineffective methods.

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Corrosion begins when an electrolyte (water, oxygen, humidity) is present on the surface of a metal. When this happens, electrons then flow from high-energy areas of the metal to low energy areas in a loop, through the electrolyte. The corrosion process results in the formation of oxidation on the metal surface. ARMOR VCI Nanotechnology™ retards this reaction by passivating the surface and inhibiting or depressing the electro-chemical mechanism that triggers oxidation, i.e. the current flow from anode to cathode. Electrical current attempts to flow from the anode through the electrolyte into the cathode but cannot, because of the VCI’s presence. VCI molecules attach themselves to a metal surface to form an invisible, thin film, possibly only a few molecules or even one molecule thick, to protect metal from attack. ARMOR VCI products can work for several years to prevent corrosion from occurring on the metal surface.

When using ARMOR VCI products properly, protection will last for years. ARMOR offers a range of VCI products to protect a variety of metals for specific packaging requirements. Typical protection periods of a normal steel panel wrapped properly in ARMOR WRAP® VCI paper can remain protected for over two years.

Corrosion is the natural mechanism by which metal returns to its original state of ore. Corrosion of metal is an electro-chemical process. The flow of electrons from high-energy areas of metal to low energy areas through a solution on the surface of the metal, capable of supporting corrosion. Corrosion will not take place without a conducting solution. The solution is called an electrolyte, caused by water, rain, moisture, and humidity. As little as 65% relative humidity will form an electrolyte, which can cause corrosion.

Nitrites are used in VCI in the form of sodium nitrite. Sodium nitrite has been used as a food preservative for over 100 years. It is found in the bacon you eat for breakfast and the salami you eat for lunch. It has been approved as a food additive for over two-thirds of a century. In fact, over 85% of the sodium nitrite present in our body is produced by our own body. In order to consume the MSDS reported hazardous dosage of sodium nitrite, for a normal VCI at 1.0 g/sq. ft. a person would have to EAT all of the sodium nitrite present in 31 sq. ft. of VCI treated paper. Not only does a person not ingest VCI paper, but rarely comes into contact with it, given the fact that workers should wear gloves to avoid the acidity that our fingerprints give off on the metal surfaces.

Similar to most ordinary household chemicals, sodium nitrite is not without risk. It simply must be handled in the same judicious fashion as such ordinary chemicals as household bleach, windshield washer fluid, floor wax, and several others. None of these components would be considered as “hazardous” within normal usage; however, sodium nitrite is often singled out as if it is. While sodium nitrite in VCI Paper should not be construed in the same light as a food preservative, it is not the lethal enemy that some make it out to be. It is used in the VCI industry because it is an excellent inhibitor of rust, especially for steel products. Armor Protective Packaging® manufactures several different VCI products, with and without sodium nitrite. Please contact an ARMOR representative for information and help in specifying the correct product(s) for your application.

From strictly a corrosion inhibitor standpoint, paper has been a better inhibitor of rust due to the way that the VCI is impregnated into the paper, and is released into the air and onto the product. VCI papers have been in existence for over 50 years, first adopted by the United States Military. VCI because of paper characteristics is able to protect a part quicker coming off of a paper, than it is off of polyethylene. This is not to say that VCI poly is not an excellent product or that it does not have its place. However, from a pure rust inhibitor issue, paper has proven over the long haul to be slightly more effective.

Ferrous metals are all metals which contain iron. Steel would be an example of a ferrous metal. Metals which contain other elements such as zinc, magnesium, copper, etc. are classified as non-ferrous.

VCI Poly has several advantages as a corrosion inhibiting packaging medium. The three main advantages are:

• Provides moisture barrier in addition to a corrosion inhibitor
• Offers ease of usage by simply placing a product into a treated ARMOR POLY® VCI bag
• Often a customer is already using a poly bag for moisture, dust and containment reasons and an ARMOR POLY® VCI bag can give them these same benefits with the addition of corrosion inhibiting protection. Disadvantages of VCI poly are that from a purely corrosion inhibiting standpoint, paper has a slight edge in overall protection. However, this is slight and usually the advantages will weigh more favorably over the disadvantages.

VCI products and desiccants work in a completely different way. ARMOR’s proprietary VCI Nanotechnology™ prevents corrosion by an electro-chemical process that forms a thin molecular layer of protection on a metal surface. This layer of protection is microscopic and does not alter the metal in any way, nor require removal of the VCI after being removed from the package. A desiccant is simply a moisture absorber. Desiccants absorb moisture but do not satisfactorily protect a metal surface from other electrolytes that cause corrosion such as oxygen. In fact, if a desiccant packet absorbs moisture as it should, it can actually cause rust wherever a metal part touches the desiccant packet. Our recommendation is that in most applications, if a customer uses a desiccant packet, that it be placed in an area that will not touch the parts.

While some VCI papers in the marketplace are only coated on one side of the paper, ARMOR WRAP® papers are impregnated on both sides of the paper. This avoids confusion on the plant floor as to what side to place against the part as well as offering true interleaving capability of the paper within a pallet of parts. The result: less paper, less waste; a cost savings for you and your customer. Since ARMOR WRAP® papers are impregnated, and not coated, the VCI is actually suspended within the fibers of the paper. This process allows for greater control of the amount of protectant found in the paper as well as the ability to put more VCI additive into the product compared to a standard coated product.

Corrugated is generally acidic by nature and acts as a sponge absorbing moisture due to its characteristics. Corrugated absorbs water/moisture even within a normal distribution environment. When metal or metal parts are placed directly on or near corrugated moisture and/or acidity transfer occurs, which will directly cause corrosion on a metal surface. It is important to place ARMOR VCI packaging between metals and acidic and hygroscopic materials such as corrugated and wood to prevent corrosion at contact points. These materials include boxes, trays, sheets and pallets.

Diverse needs call for diverse solutions. That is why ARMOR offers over 12 types of ARMOR WRAP® papers to choose from for your specific VCI needs. Some VCI manufacturers incorrectly claim that a single formulation will protect everything from steel to copper, others are vague or cannot tell you how much VCI is actually in the product. The fact is no single VCI formulation for paper can provide true corrosion-free protection for all metals and applications.

Due to the abundance of metals available, as well as the numerous coolants, washes, rust preventative oils and other substances used within a manufacturing process, it is important to check VCI compatibility with these substances ARMOR VCI products rarely react with any of these elements, occasionally there may be factors that either react adversely with a particular VCI formula or react to diminish the VCI performance.

Metals are composed of many different elements. Due to the vast differences in metal composition, one cannot attempt to protect varying metals with one formulation without a sacrifice in performance, or worse yet, failure. That is why ARMOR offers over 12 types of ARMOR WRAP® papers to choose from for your specific metal needs.

The answer to this question isn’t as definitive as a “yes” or “no” answer. While absolute airtight packaging is ideal for VCI rust protection, it is not required for a VCI product to work. What is critical in all uses of VCI is that the VCI vapors must be enclosed in some fashion – the more airtight the enclosure the more effective the VCI protection. Conversely, if the packaging is not airtight the strength of the VCI vapors will be diminished as they are able to escape the packaging.

For example, metal parts can be placed onto a sheet of ARMOR WRAP® paper for protection. With ARMOR WRAP®, parts should be completely wrapped or enclosed for maximum protection or it can be used to interleave between layers of parts. To further protect metal parts from corrosion, place the ARMOR WRAP® packaged part into an airtight package such as an ARMOR POLY® bag and seal it. The combination of the two products, combined with the airtight packaging, would offer the most effective, longest protection, and best results over time.

ARMOR WRAP® paper is approved on the Qualified Products List for Military specification MIL-P-. This is a legitimately approved product and is not simply a “conforming” product, as some manufacturer’s may mislead you to believe is the same.

It is extremely important that all workers wear gloves to protect not only their hands but also to eliminate acidity and moisture from transferring onto the part. This is a very real and legitimate problem in many manufacturing facilities. A person’s hands have moisture and acidity that is directly transferred onto metal. This transfer of moisture and acidity will lead to corrosion at some point. In conditions of more severe temperature and/or humidity the problem arises much quicker. In situations where a metal part is more susceptible to rust due to machined surfaces, metal composition or the like, the problem is exponentially greater.

Armor Protective Packaging® offers full-service, in-house, accelerated corrosion testing at NO CHARGE to its customers. We have two distinct methods to subject parts to accelerated conditions including a 100% humidity chamber and the traditional method of ovens with humidity features.

Contact us to discuss your requirements of vci bag. Our experienced sales team can help you identify the options that best suit your needs.

• Cost effective protection
• VCI vapors replenish inside contained package
• Easy to apply
• No grease, messy oils, surface preparation
• No need to remove VCI protection before using or welding product
• Vapors penetrate recessed, inaccessible areas
• Provides up to 2 years of corrosion protection

Armor Protective Packaging® offers a variety of stock ARMOR WRAP® papers which are normally available for next day shipment. These sizes include 18”, 36”, and 48” x200 yard rolls. In addition, ARMOR has an ARMOR POLY® VCI stock program which includes a variety of small size bags ranging from 3”x5” to 24”x36” and also includes rolls or single wound sheeting up to 60” wide. Please contact an ARMOR representative for a complete stock sheet.

• Your parts should be clean and free from corrosion before packaging
• Package clean parts as soon as possible after processing, manufacturing or cleaning
• Use gloves when handling parts to eliminate corrosion caused by fingerprints.

In over 35 years, ARMOR has never been contacted regarding an issue with VCI compatibility to non-metallic surfaces such as plastics, rubbers or wood. However, since there are so many possible combinations of ingredients, processes and types of these substrates it is impossible to guarantee anything regarding their suitability with ARMOR VCI. Other rust prevention methods such as oils, greases and other liquid RPs (rust preventatives) pose a much higher likelihood of reacting with plastics, rubbers and wood. However, it is important for each customer to check VCI compatibility themselves with these substances due to the complexity and number of plastics, rubber materials and woods in the marketplace.

ARMOR can tell you exactly how much VCI is contained in our products to give your products the added insurance they need to remain corrosion free. For example, our papers contain a specified and measured amount of VCI additive, as measured in grams/square foot. This ability to monitor and control the amount is a testament to our quality and continued improvement. If a company cannot specify and consistently meet a given coating weight of VCI on a substrate, one runs the risk of having too little VCI to get the job done.

Armor Protective Packaging® corrosion management products provide approximately three years of protection for metal parts and surfaces when used properly in normal warehouse conditions. To ensure successful results, parts must be completely wrapped or enclosed – airtight packaging is the most effective for best results and longest protection time. Variable conditions such as temperature and humidity extremes, airflow, production and process methods, surface conditions of metal to be protected, customer employee training and other factors are impossible for ARMOR to control so it is impossible to guarantee a specific length of protection. Contact your ARMOR representative for details related to your specific application.

Armor Protective Packaging® uses a special mathematical formula for calculating the size VCI bag needed to serve as a box liner or pallet cover. When determining the proper bag size, special consideration is given to allow for a large enough surplus for the bag to fit inside the box or over the pallet while still allowing ample overage for tie-off and proper sealing. Key points to be addressed when determining the size of a bag include: bag must completely cover parts; it is crucial that bag must be large enough to provide ample excess to allow for proper tie off and sealing; insufficient overage can result in faulty seals which can allow air and moisture to enter the bag while at the same time allowing VCI to escape; and bag sizing and proper seals are especially important in export where temperature fluctuations and transport handling can be extreme. Contact ARMOR’s Customer Service at (800) 365- for assistance in calculating the size of your liner/bag/ pallet cover.

ARMOR VCI packaging, such as ARMOR WRAP® paper, ARMOR POLY® film and ARMOR SHIELD® products, is reusable, provided it is stored properly, it is not exposed to any extreme environmental conditions and that it is in good condition. For a full list of proper storage recommendations, contact ARMOR’s Customer Service at (800) 365-.

Moisture is enemy number one in the fight against corrosion – it promotes corrosion and has the potential to accelerate it as well. To eliminate the presence of moisture, be sure that parts are dry before wrapping them in ARMOR VCI packaging, such as ARMOR WRAP® paper and ARMOR POLY® film. We have identified four key factors within a manufacturing process that help to increase the effectiveness of ARMOR VCI packaging and reduce corrosion:

• Parts should be clean and free from corrosion before packaging.
• Parts should be thoroughly dry to eliminate moisture in the packaging.
• Package clean parts as soon as possible after processing.
• Use gloves when handling parts to eliminate corrosion caused by fingerprints.

Oil, lubricants, and/or transmission fluids typically do not have any adverse effects when used together, other than they would inhibit the full potential of the VCI. ARMOR VCI was developed to be used on parts that are clean and dry (free of RPs and oils). If parts are coated with these types of liquids, the VCI may not be able to penetrate through the coatings to get to the metal surfaces. ARMOR VCI, will however, protect recessed areas or other areas where the oil/lubricant/transmission fluid is not, thereby guarding against corrosion in that regard. ARMOR recommends lab testing if there is concern regarding compatibility.

ZERUST® VCI products prevent corrosion in several ways:

1. By acting as a protective barrier from external corrosive atmospheric elements such as abrasion, water, dirt, and acid gas pollutants.
2. By emitting Volatile Corrosion Inhibitors that passivate the electron flow between the anodic and cathodic areas on metal surfaces and interrupt the electrochemical corrosion process.
3. By adding water repulsion properties to the metal surface, which inhibit water from permeating the metal surface and providing the electrolyte for corrosion reactions.

The vapor corrosion inhibitor portion of ZERUST® VCI products is made of proprietary chemical formulations that are invisible, odorless, non-toxic, non-reactive, non-flammable, and non-allergenic. These chemical formulations release a corrosion inhibiting vapor that diffuses throughout an enclosure that either contains VCI formulations or is made from VCI materials and settles on exposed metal surfaces to form a microscopic corrosion inhibiting layer.

This protective layer will remain on the surface of the metal if there is no significant, continuous exchange of air within the enclosure. Ideally, there should be less than one air exchange per day (for example, when an electrical cabinet or package is opened briefly and occasionally). Once the metal part is removed from the enclosure, the corrosion inhibiting layer is no longer kept in place by equilibrium with the VCI source, and it dissipates from metal surfaces (typically within about an hour), leaving the metal part clean, dry, and corrosion-free.

The vapor diffusing properties of our corrosion inhibiting formulations offer an important advantage over conventional inhibitor coatings since the traces of these gas molecules penetrate hard-to-access crevices, gaps, and slots. They also cover the surfaces of complex-shaped articles that are difficult to coat. They are adsorbed onto the surface of the metal to form a corrosion inhibiting protective layer that is just a few molecules thick. ZERUST® VCI products may also include acid gas absorbing chemicals in the packaging material to act as a barrier and add another dimension to the protection of the metal content. These “scavenging” chemicals react and neutralize the polluted air that may diffuse through the ZERUST® VCI material. Also used are various combinations of physical barrier properties that optimize the corrosion prevention and physical protection needs of our customers. These may range from plain low-density polyethylene (LDPE) material to combinations of higher strength, higher tear resistance, higher resistance to sunlight or UV, static charge dissipation, and lower diffusion for moisture or acid gas molecules.

ZERUST® VCI products offer corrosion protection without having to be in direct contact with or coated onto the parts that are being protected. Metal parts merely need to be enclosed in or with a ZERUST® VCI product (where airflow is minimized) for protection to occur. With ZERUST® VCI packaging, it is no longer necessary to apply messy oils, greases, and other corrosion protection compounds and incur the cost of their removal.

Nitrates (NO3 – one nitrogen and three oxygen molecules) are compounds that occur naturally in soil. Consequently, nitrates are also present naturally in root vegetables like carrots and potatoes, as well as leafy green vegetables. Nitrates are not generally harmful unless they are consumed in massive quantities. When we eat nitrates, they are converted into nitrites in our digestive system.

Nitrites are also compounds made up of nitrogen and oxygen, but instead of three oxygen molecules, they have only two (NO2). Nitrite compounds combine with other elements like sodium and potassium to make sodium nitrite or potassium nitrite, which are used as preservatives and color fixatives in cured meats. Nitrites are particularly good at preventing botulism – an anaerobic form of bacteria that causes paralysis and death – which is why small amounts of sodium nitrite are required by law to be added to cured meats. Nitrites too, on their own and in moderation, are also generally not harmful.

Sodium nitrite, however, isn’t just a good food preservative, it’s also an excellent corrosion inhibitor. That’s why, when NTIC developed and commercialized the first-ever VCI rust preventative plastic packaging, the active chemical protection system was formulated using common food additives, including sodium nitrite. Conservative chemists generally do not recognize sodium nitrite itself as a vapor corrosion inhibitor because, on its own, it has a vapor pressure so low that it is almost immeasurable. When used in combination with other additives in proprietary ZERUST® formulations, sodium nitrite can be effective “VCI activated”. The ZERUST® VCI effectiveness has been proven in commercial and military applications worldwide, as well as scientifically by recognized standard test methods for vapor corrosion inhibitors used by U.S. and NATO military organizations.

Nitrites in VCI products are a commonly misunderstood safety concern because of the historic use of the specific compound, dicyclohexylamine nitrite (or dicyclohexylammonium nitrite). Sometimes referred to by the brand name “Dichan”, dicyclohexylamine nitrite is a vapor corrosion inhibitor that was first used in VCI paper production in the ’s. Later, in the ’s, toxicologists started to become aware that compounds using both amines and nitrites in combination could lead to the formation of “n-nitroso amines”, which are believed to be both carcinogenic and genotoxic. It is for this reason that VCI products produced in most advanced industrialized nations no longer use dicyclohexylamine nitrite. ZERUST® VCI packaging has never contained dicyclohexylamine nitrite and, furthermore, does not use amines of any kind because they are known to be skin and respiratory irritants.

Depending on the design of the corrosion prevention solution, some ZERUST® VCI packaging products may be produced from low and high-density polyethylene resins that are resistant to vapor penetration. Some atmospheric moisture will eventually find its way into a closed package. The presence of moisture in a package can be expected during shipments across areas of high humidity.

When moisture permeates through the ZERUST® VCI plastic packaging products (flexible and rigid), the moisture is affected by the vapor corrosion inhibitors that are present in the VCI product. As a result, the ZERUST® VCI products inhibit corrosion despite a low level of moisture passing through the plastic. Corrosion problems arise when moisture can enter a package unimpeded by the packaging products, such as through an incorrect closure or a significant hole in the package. For example, when there is a significant breach in the package, the corrosion inhibiting molecules can escape, breaking up the protective corrosion inhibiting molecular layer that had formed on the surface of the metal. Therefore, an unimpeded airflow into the package must be avoided.

If you have any questions regarding the best VCI protection for your needs, we advise consulting a ZERUST®/EXCOR® representative. ZERUST®/EXCOR® possesses wide-ranging testing capabilities, which quickly enable us to determine the optimum method of protecting a given metal item. We also can send samples for customers to conduct their own tests. First, try packing identical parts simultaneously and under identical conditions, one part in a normal film or your current packaging and one in ZERUST®/EXCOR® film. Next, store these parts for several days in the most challenging conditions they will be in, such as high humidity, or move them from warm to cool places in your warehouse, similar to shipping conditions. If the part packed in normal packaging shows signs of corrosion, while the one packed in ZERUST®/EXCOR® VCI film shows none, it can be assumed that the part requires VCI protection.

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