If there is a risk of corrosive attack to the whole or part of the goods, each individual packing and the complete pallet unit must be protected. The use of rust inhibitors requires that the goods and spacers are “dry” and “clean”.
- Check that the VCI is compatible with the process liquids that are used.
- Check that there is no contamination or detergent residues on the surface.
- Use the correct type of VCI for the respective types of metal to be protected.
- Use the correct quantity of VCI depending on the size of the packing material in accordance with the VCI supplier’s recommendations.
- Select the barrier material depending on the required protection time.
- Pack only clean and dry parts.
- When packing, the parts and the ambient air should have the same temperature.
- Use clean gloves and avoid fingerprints.
- Do not let the parts come into direct contact with wood, paper, cardboard or cellular plastic.
- Put a further dose of VCI in the middle of tightly packed parts.
- Combine paper, bags, boxes. In the event of more serious cases of corrosion (special packing instruction), consult the VCI supplier.
- If a water-soluble anti-corrosion agent is used to enhance the VCI, the water must be allowed to evaporate before packing with the VCI is started.
- Seal the packing material properly with waterproof tape or by welding.
- The finished package should not be subjected to a temperature below +20 degrees C during the first hour after packing.
- Allow the package to assume the temperature of the ambient air before opening it, to avoid condensation.
- Try and keep the package unopened until the articles really are needed.
- When unpacking secure good ventilation and protect against skin contact.
- When the package is opened, the corrosion protection is active for a further 1 to 2 hours.
- If metal surfaces are moist when the package is opened, they must be wiped dry.
- VCI material. Store the VCI material in accordance with the manufacturer’s instructions.
- Use a packet of VCI material as quickly as possible.
- Paper gives fast protection but a short protection time, min. 6 months.
- Plastic film gives slow protection and a long protection time.
- Only VCI materials free from nitrite may be used.
Inform/train all users of the VCI
Corrosion protection according to the VCI method
The corrosion protection comprises a Volatile Corrosion Inhibitor (VCI) instead of grease, wax, rust inhibiting oil, liquids, etc.
How does VCI work?
VCI is a group of substances that slowly vaporises at room temperature. The vapour saturates the atmosphere in the packing material and is absorbed by the metal. In some cases it can protect metals up to a distance of 300 mm. The protection time is at least 6 months and up to 10 years, depending on how well the packing materials are sealed.
Advantages of using the VCI method
The vapour protects against various types of atmosphere that occur, e.g. industrial emissions, water vapour, sea air, and other types of air pollution. The corrosion protection is easy to apply and easy to remove. The articles are ready for assembly or machining directly after delivery without any degreasing, cleaning, etc.
VCI products can be used for iron, steel, cast iron, and aluminium.
Metal surface condition
The surface of the metal must be free from fingerprints, machining chips and oils, corrosion, scale, and oxides. If alkaline cleaning is used, the flushing water should be somewhat basic to avoid the risk of corrosion attack during the drying process. The parts are packed directly after cleaning and drying in accordance with the VCI method.
For the corrosion protection to function properly, it is important that the packing is done as described in the instructions from the VCI supplier, but generally certain rules can be applied.
- That the packing materials are dry.
- That the packing materials are sealed as tight as possible
- That the longest distance between the VCI and the metal surface to be protected does not exceed 300 mm.
- That there are no shielding spacers etc. between the VCI and the part.
- That spacers and supporting blocks are covered with a VCI paper or VCI plastic to prevent the metal surfaces coming in contact with the wood.