AAR-Approved Dunnage Air Bags for Freight Protection

Dunnage air bags are inflatable bracing tools used to fill void gaps between freight and container, trailer, or railcar walls. When inflated to the correct working pressure, they apply lateral support that helps prevent load shift, stabilizes pallets, and reduces in-transit damage caused by vibration, braking, cornering, and impact.

Most standard dunnage air bags operate at a low working pressure, often in the 2–3 PSI range, but the correct PSI depends on the specific bag rating and application. Always follow the manufacturer’s working pressure specification. Over-inflation can increase burst risk and can transfer damaging force into the load, especially if the bag contacts sharp edges or uneven surfaces. Use a regulated inflator with a gauge, not an uncontrolled air line.

Start by measuring the void gap at its widest point, then confirm the bag will cover as much of the vertical height of the load face as practical. Bags perform best with full, flush surface contact on both sides. If the void is inconsistent, the load face is uneven, or you have irregular freight geometry, you may need additional dunnage materials to create a consistent contact surface, or use a different configuration. If you’re unsure, share the gap dimensions and load details with Sunrise and we’ll help match the right bag.

Neither is universally better; it depends on the shipment.

• Paper (kraft) dunnage air bags are commonly used for dry, controlled environments and many domestic over-the-road applications with predictable handling.
• Polywoven dunnage air bags are typically preferred for rough handling, moisture exposure, heavier loads, intermodal moves, and ocean freight due to higher durability and puncture resistance.
  When in doubt, choose based on the worst-case conditions the load may encounter, not the best-case.

Some dunnage air bags are AAR approved for rail use, but approval depends on the specific bag type and rating, not the category as a whole. Rail shipments can involve higher shock forces (coupling/braking) than many over-the-road shipments, so it’s important to confirm that the exact bag you’re using is approved for your rail application and installed according to best practices. If you’re shipping by boxcar or rail-intermodal, Sunrise can help confirm the right specification.

Most failures come down to a few preventable issues:

• Over-inflation beyond the rated working pressure
• Sharp edges or protrusions (strapping, fasteners, rough timber) contacting the bag
• Poor surface contact, where force concentrates on a small section of the bag
• Using a bag rated below the force requirements of the application
• Inflating to “push freight into place” instead of stabilizing a load that’s already positioned
  Correct sizing, edge protection, full contact, and inflation to rated PSI prevent the majority of failures.

It depends on the bag type and the application. Many paper dunnage air bags are designed for single use. Polywoven bags may be suitable for reuse in some over-the-road contexts if they pass inspection for punctures, valve wear, or abrasion. For higher-risk environments (especially rail), reuse policies can be stricter. The safest approach is to inspect any bag before reuse and replace it if there’s any doubt about integrity.

In freight shipping, these terms often refer to the same thing. Dunnage air bags are pneumatic (air-inflated) bags used to brace loads by filling void gaps and preventing shifting during transit. Some companies use “pneumatic air bags” as a general phrase, while “dunnage air bags” is the more specific industry term tied to shipping and load securement.