Published by BENZ Packaging Technical Team | Last Updated: March 2026
Why Do Metal Parts Corrode During Export Shipping?
Metal corrosion during ocean freight is primarily caused by container rain — condensation that forms inside shipping containers when warm, humid air meets cold container walls during temperature swings at sea. A single 20-foot container can generate up to 8–10 liters of condensation per voyage. This water drips directly onto packaged goods, penetrating standard cardboard packaging and triggering rapid rust formation on unprotected metal surfaces.
Additional corrosion risks during export shipping include:
- Salt-laden coastal air during port storage and loading operations
- Extended transit times (4–8 weeks for India-to-Europe ocean voyages)
- Tropical humidity during trans-equatorial shipping routes
- Uncontrolled warehouse storage at destination before final delivery
Which VCI Paper Type Should You Use for Export?
BENZ Packaging manufactures four types of VCI paper. The right choice depends on the transit conditions, part geometry, and required protection duration:
| VCI Paper Type | Best For Export When... | Protection Duration |
|---|
| VCI Plain Paper | Air freight or short domestic transit in dry conditions | Up to 2 years |
| Poly Coated Laminated VCI Paper | Ocean freight, high humidity, container rain risk — the primary export VCI paper | Up to 5 years |
| VCI Crepe Paper | Complex-shaped export parts: engine blocks, castings, bearings | Up to 3 years |
| VCI HD Reinforced Paper | Heavy parts with sharp edges: castings, forgings, defense equipment | Up to 5 years |
BENZ Expert Recommendation: For standard ocean freight, always use Poly Coated Laminated VCI Paper as the minimum. The polyethylene layer blocks moisture from penetrating the paper during container rain events, keeping the VCI active on the metal surface.
The Multi-Layer Export Packaging System
For high-value metal components traveling by sea, BENZ Packaging recommends a four-layer corrosion protection system:
Layer 1: Direct Contact — VCI Paper
Wrap the metal part directly with the appropriate VCI paper type. This provides the primary corrosion protection through vapor-phase inhibition. Ensure minimum 50 mm overlap at seams and complete coverage of all metal surfaces.
Layer 2: Moisture Control — Desiccants
Place BENZ Desiccants inside the sealed package to absorb humidity that enters during container loading or through minor seal gaps. This extends VCI effectiveness significantly by controlling the internal humidity.
Layer 3: Vapor Barrier — Aluminium Barrier Foil
Enclose the VCI-wrapped, desiccant-protected parts in BENZ Aluminium Barrier Film. This metallic barrier provides near-zero moisture and oxygen permeability — the outermost shield against container rain and salt air.
Layer 4: Physical Protection — Wooden Box or Crate
Place the barrier-sealed package into a properly braced wooden crate for physical protection during handling, stacking, and forklift operations at ports and warehouses.
5 Common Mistakes in Export VCI Packaging
- Using plain VCI paper for ocean freight: Plain paper is breathable — it has no moisture barrier. Container rain will wet the paper, dilute the VCI, and cause corrosion. Always use laminated VCI paper for sea shipments.
- Placing foam or plastic between VCI paper and metal: Non-VCI barriers block vapor contact. The VCI paper must have an unobstructed air path to the metal surface to work effectively.
- Packaging warm parts: Metal parts that are warm from machining release moisture as they cool inside the sealed package, creating condensation. Always allow parts to reach ambient temperature before VCI wrapping.
- Oversized packages with insufficient VCI: VCI molecules have an effective working distance of approximately 30 cm. For large voids, add additional VCI paper strips or VCI Diffusers.
- Reusing torn or contaminated VCI paper: Damaged VCI paper loses protective capacity. Always use fresh material for every shipment.
Export Packaging Checklist
- Parts cleaned and dried to ambient temperature
- VCI paper type selected based on transit mode and duration
- Metal wrapped with VCI paper (50 mm overlap minimum)
- Desiccant packets placed inside sealed package
- Aluminium barrier foil heat-sealed or taped
- Temperature and humidity indicator placed on outer package
- Wooden crate with proper bracing and cushioning
- Packaging specification documented for customer quality audit
Industries That Rely on BENZ VCI Export Packaging
- Automotive CKD Kits — Mixed-metal assemblies shipped from India to assembly plants in Africa, South America, and Southeast Asia
- Heavy Machinery OEMs — CNC machines, industrial pumps, and turbines exported to Europe and Middle East
- Defense — MIL-PRF-3420H compliant preservation for military equipment exports
- Steel and Metal Traders — Cold-rolled coils, galvanized sheets, and precision tubes exported globally
For export packaging specifications, corrosion testing, and custom VCI solutions, contact BENZ Packaging. We supply to 20+ countries from our ISO-certified manufacturing facility in India. Call +91-124-4148831.