Steel parts, machined components, or marine spares shipped by sea or stored long-term often rust before reaching the customer, because container humidity and temperature swings cause condensation. VCI (vapor corrosion inhibitor) packaging releases an inhibitor that coats the metal in a thin molecular layer inside sealed packaging — protecting it with no oil to apply and no wash-off before use. Choose: VCI film (wrap/cover plate, coil, structures), VCI bag (small-to-medium parts, reaches bores/threads/recesses), desiccant (a second moisture layer). SAHA supplies quote-only, with sizing and export-packing guidance included.
Metal parts shipped by sea or stored long-term face the same enemy: humidity. Inside a container where temperature swings day to night, airborne moisture condenses onto the metal surface, producing rust or oxide staining before the goods reach the destination customer — well-made parts spoiled in transit. VCI (Vapor Corrosion Inhibitor) packaging solves this without applying any oil. This article explains how it works and how to choose between VCI film, VCI bags, and desiccants.
How VCI works
VCI material (film or bag) releases a corrosion-inhibiting compound as a vapor inside sealed packaging. The vapor settles on the metal as an extremely thin molecular layer, suppressing the electrochemical reaction that causes rust. Advantages over rust-preventive oil:
- No application — just wrap or bag and seal; the vapor distributes itself
- No wash-off — unwrap and assemble/use immediately (critical for machined parts)
- Reaches where oil can't — bores, threads, internal recesses
- Nitrite-free — the formulation SAHA supplies uses no nitrites
Standards note: VCI performance depends on packaging tightness, duration, and inhibitor quantity per surface area/volume. We advise on sizing and packing method to suit the actual part and transport — grade-specific specs and certificates are available on request when you ask for a quote.
Choosing film / bag / desiccant
| Product | Best for | How it's used |
|---|---|---|
| VCI Anti-Corrosion Film | Steel plate, coil, structures, large/flat parts | Wrap, cover, or line container interiors / cover pallets |
| VCI Anti-Corrosion Bag | Machined/turned parts, marine spares, molds, export sets | Place the part inside, seal the bag; vapor surrounds the surface |
| Desiccant Moisture Absorber | Every export/humid-storage job (add-on) | Place in the packaging with VCI; pulls humidity below the rust point |
Quick rule: large/flat part → film · small-to-medium with bores/recesses → bag · sea freight / very humid → always add a desiccant.
A fit for Thai exporters
Thailand's 2025 exports hit a record high (+12.9%, led by electrical goods, machinery, and automotive) — a large volume of metal parts travels weeks by sea through humid conditions. VCI is a standard way to cut rust-claim risk without adding an oil-removal step at the destination.
Ordering
It's a made-to-order (quote-only) item — tell us (1) part type + size/weight, (2) volume per shipment, (3) transport mode and storage duration. We'll help select the right VCI film/bag and desiccant plus export packing method. VCI is part of SAHA's complete metal-protection approach — supplied alongside anti-rust coatings and sacrificial anodes from one source.
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Frequently Asked Questions
1How is VCI different from applying rust-preventive oil?
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2Should I use VCI film or VCI bags?
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3Do I also need a desiccant?
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4How do I order, and is there a sizing service?
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