Sea Freight and Moisture: What Film and Foam Can (and Cannot) Do

Ocean containers sweat. Warm days and cold nights move water onto cartons and metal. Bubble film and stretch wrap are not ship-grade vapour barriers by themselves. Treating them as waterproof is how rust claims start.

What polymers do

LDPE and LLDPE slow liquid splash and dust. They do not make a carton hermetic. EPE foam can trap moisture against a surface if you wrap wet wood or undried metal. Dry the part first.

Metal

Anti-rust / VCI film is for clean, dry ferrous parts in a reasonably closed wrap. Combine with desiccant in the carton when your QC requires it. We quote the film; we do not sell a full climate-control system.

Fragile non-metal

For glass and electronics, moisture is secondary to shock and ESD. Use the right bubble or antistatic grade, then a carton that can take a wet floor without collapsing. That carton spec is the box plant’s job.