Export Packaging Methods — Wooden Crates, Vacuum Packing, and Desiccants

Damaged export cargo means claims, reshipping costs, and — worse — damaged trust with your buyer. Yet many teams stop at "put it in a box and tape it shut." This guide covers three packaging methods actually used in export operations — sealed wooden crates, vacuum (moisture-barrier) packing, and desiccants — and explains when, why, and how much of each you need.

Sealed Wooden Crates

Machinery and electronics that are shock-sensitive and high-value get crated rather than boxed in cardboard. Wooden crates serve two core purposes:

1. Structural strength — withstanding forklift forks, crane slings, and other handling impacts during loading and unloading
2. Buffer space — building the crate with margin (typically around 100mm) beyond the cargo's own dimensions so cushioning material fits inside

Panel thickness scales with cargo weight. Common practice uses 15mm for light cargo (up to ~300kg), 18mm for standard cargo (up to ~1,000kg), and 24mm or more for heavy cargo (1,000kg+). Heavier loads also need reinforced bottom skids (the base structure a forklift's forks slide under).

Note — ISPM-15 fumigation: Most countries require wooden packaging used in international shipping to be fumigated or heat-treated and certified under ISPM-15 (the International Standards for Phytosanitary Measures), marked with the IPPC stamp. Uncertified wood packaging can be rejected or destroyed at customs — always source from a certified wood packaging supplier.

Vacuum (Moisture-Barrier) Packing

Electronic components and precision machinery that are sensitive to moisture and oxidation get sealed in an aluminum moisture-barrier film with the air drawn out. Unlike crating, the goal here isn't shock protection — it's blocking moisture ingress and condensation during long ocean transits.

A common rule of thumb for film usage is the cargo's surface area × roughly 1.2 to account for seams and overlap. If the film tears or a seam opens, the moisture barrier is compromised entirely, so reinforcing corners is standard practice.

Desiccants

Even inside a sealed moisture-barrier package, residual moisture remains — so silica gel or other desiccants go inside the seal. Desiccant quantity is typically calculated using a recommended weight (g) per cubic meter (CBM) of sealed space, then converted into a count of standard sachets (usually 30–50g each).

Required desiccant weight (g) = Sealed volume (CBM) × Recommended weight per m³ (g)
Number of sachets = Required weight ÷ Standard sachet weight (rounded up)

Crucially, this calculation uses the volume of the cargo actually sealed inside the barrier film — not the outer volume of the wooden crate, since a crate is a breathable structure and isn't the sealed space itself.

Combining all three methods

For high-value, precision cargo on long ocean voyages, all three methods are often combined: ① seal the cargo in vacuum moisture-barrier packing with desiccant inside, then ② place that sealed unit — along with cushioning — inside a wooden crate for structural protection. Our Packaging Material Calculator takes your cargo dimensions and computes all three quantities (moisture-barrier film area, crate panel volume, and desiccant sachet count) in one step.

Practical checklist

• Match crate panel thickness to your cargo's weight class first.
• Always verify ISPM-15 certification on wood packaging — uncertified wood risks customs rejection.
• Prepare moisture-barrier film with roughly 20% margin over the surface area, and reinforce corners.
• Calculate desiccant based on the sealed cargo volume, not the crate's outer volume.
• Additional packaging increases CBM and can affect freight cost — check the volume impact with the CBM Calculator before finalizing your packaging plan.