How to use Zerust VCI products correctly

For close to 50 years, industries worldwide have used Zerust VCI (Volatile corrosion inhibitor) products for packaging metal parts to prevent rust and corrosion during transport and storage. Still, not everyone knows exactly how VCI works and how to achieve the best possible result. Follow these procedures when using Zerust VCI products:

VCI comes in many different shapes and formats; VCI plastic bags, kraft paper , capsules , powders, liquids, etc. Regardless of the type you use, they have one thing in common: they evaporate VCI molecules that form an invisible protective film that prevents metal from corroding. It is important to know this when choosing which VCI product to use, because the VCI molecules must be locked in a closed container (bag, box, cupboard, etc.) - otherwise they will simply evaporate away. The container must be properly closed and the metal parts you are going to protect must be inside this container. VCI bags, or ordinary plastic bags with other VCI products in them must be welded again, stripped or folded and taped.

VCI works best to prevent rust and corrosion on metal that is clean and free of contamination. Often in the metal industry we see manufacturers, without knowing it, pack metal parts that contain chlorides, bacteria or other known corrosion-causing ions left on the surface. This can be due to several reasons such as contamination from fingerprints, dirty work areas or poor maintenance of metalworking fluid. In addition to having clean parts, VCI is optimized when the parts are completely dry before packing. If metal parts are packed wet or damp, the corrosion cycle can start before the VCI has sufficient time to spread out and do its job.

Another thing to consider when using VCI is to make sure the metal parts are at room temperature before closing the packaging. If metal parts are packed and

sealed warmer than room temperature, they run the risk of causing a greenhouse-like effect that can lead to immediate dampness due to condensation. Similarly, when you pack up cold parts inside a warm warehouse, the warm moist air will condense on the cold parts. At the same time, the VCI molecules will evaporate, leaving behind unprotected metal. Therefore, ensure that the parts are at the same temperature as the room before unpacking.

As VCI products are often used in packaging, you also need to consider what other packaging materials you use. You want to make sure your metal parts are never in direct contact with cardboard, non-VCI paper or wood as they can be sources of moisture and acid. If dividers or interleaved sheets are required, ensure they do not block the path of the VCI source to the metal. In layered or bulk packaging configurations, ensure that there are multiple VCI materials to protect each layer of metal parts inside a case.

Zerust VCI plastic products can be recycled or disposed of in the same way as other similar LDPE products you handle. Kraft VCI paper is also fully recyclable, made from responsibly managed forest products.

Read more articles about VCI products on the Zerust website.

Download our Package Instructions. It is also available as a poster to hang over the parcel counter. Click on the image to go to the download page