Palletised cargo looks secure when it is loaded. The problem starts in transit: braking, cornering, vessel motion and vibration let pallets creep into any empty space beside them. Once one pallet has room to move, it gains momentum, leans, and can topple or crush its neighbour. A dunnage bag removes that room. Inflated in the void, it presses evenly against both pallet faces and turns a loose row of pallets into one braced block. The six steps below show how to do it correctly.

Step 1: Arrange the pallet layout before you reach for a bag

Dunnage bags work best on a tidy load, so start with the layout. Load pallets in straight, even rows with their faces aligned, heaviest pallets at the bottom and towards the centre of the container or truck. Keep each pallet load unitised first — cartons strapped with cord strap or wrapped — because a bag braces whole pallets, not loose cartons sliding off a pallet. Avoid leaving several small scattered gaps: it is better to consolidate empty space into one or two clean voids that a bag can fill properly than to chase five narrow slivers.

Step 2: Measure the void and choose the bag size

With the pallets in their final position, measure the void width at several heights — pallet loads are rarely perfectly vertical, and the widest point decides the size. Tezheng dunnage bags are made for voids of 10 to 50 cm, in six sizes; choose the size whose range covers your measured void, and check that the bag height covers most of the pallet stack height so pressure spreads over a broad contact area. If you are unsure between two sizes, run the numbers in our packaging calculator or see what size dunnage bag do I need. Never stretch one bag across a void wider than 50 cm — use two bags side by side, or fill part of the space and brace the rest with lashing.

Step 3: Protect the bag from pallet edges and nails

Before the bag goes in, run a hand along both pallet faces that will touch it. Exposed nail heads, splintered deck boards, sharp carton corners and protruding strap buckles are the most common cause of punctures — not the weight of the cargo. Cover anything sharp with a sheet of cardboard or a board, or turn the pallet so a flat face meets the bag. This takes a minute and prevents the most avoidable failure in pallet securing.

Step 4: Place the uninflated bag upright in the gap

Unfold the bag and slide it flat and upright into the void, centred so it will press evenly on both sides once inflated. The priority positions are between two pallet rows, and between the last row and the container doors or wall — the places where a pallet can build up sideways or lengthwise movement. Keep the bag off the floor where possible so it bears on the cargo, not the deck, and keep the valve facing out where the inflation gun can reach it. Do not fold or twist a bag to force it into a gap; a folded bag inflates unevenly and the crease becomes a weak point.

Step 5: Inflate slowly to the rated pressure — maximum 0.3 bar

Connect a standard air compressor or pump with an inflation gun and inflate slowly, watching the bag expand against both pallet faces. Inflate to the bag's rated working pressure and never above 0.3 bar. Judge the result by feel as well as by gauge: the bag should be firm and springy, filling the void completely without bulging out of it, and the pallet should no longer rock when pushed. If the load still moves, the answer is a correctly sized or higher-rated bag — not more pressure in the same bag. Over-inflation is the fastest way to burst a bag, during loading or later in transit.

Step 6: Check the brace, then re-check after a few minutes

Push each braced pallet firmly by hand: there should be no loose play. Check that no sharp edge has pressed into the bag during inflation, and that the valve sealed when the gun was removed. Wait a few minutes and check again — a bag that softens in that time has a slow leak and should be replaced now, while the doors are still open. Finally, look at the load as a whole: bags handle the voids, but if cartons can still slide on their own pallet, add strapping before you close up.

Common mistakes with pallet cargo

• Sizing from the pallet instead of the void — the gap width and stack height decide the bag, not the pallet footprint.
• Leaving scattered small gaps instead of consolidating space into fillable voids during loading.
• Skipping edge protection — pallet nails and splinters puncture more bags than cargo weight ever does.
• Over-inflating past 0.3 bar to compensate for an undersized bag, instead of fitting the right size.
• Expecting the bag to unitise the load — bags brace pallets; strap or wrap still holds each pallet's cartons together.

Frequently Asked Questions

How do you use dunnage bags to secure pallet cargo?

Arrange the pallets in even rows with flat, stable faces, measure the void between pallets or between pallets and the container wall, choose a bag sized for that void, slide the uninflated bag upright into the gap, inflate slowly to no more than 0.3 bar and the bag's rated working pressure, then push-test the pallets and re-check the bag after a few minutes.

What size dunnage bag do I need for pallet cargo?

Size by the measured void, not by pallet size alone. Tezheng's range covers voids of about 10 to 50 cm across six sizes, and the bag should cover most of the pallet stack height. For a void wider than 50 cm, use two bags side by side or combine bags with lashing straps.

What pressure should I inflate a dunnage bag to for pallets?

To the bag's rated working pressure, and never above 0.3 bar. The bag should feel firm and springy and the pallet should no longer rock when pushed. Under-inflation leaves play; over-inflation risks a burst bag.

Do I still need strapping if I use dunnage bags between pallets?

Often, yes. Dunnage bags stop pallets shifting into a void, but they do not unitise cartons on a pallet. Keep each pallet load together with cord strap or wrap, use bags for the gaps between pallets, and add lashing straps where lengthwise movement is a risk.

Where should dunnage bags be placed on a pallet load?

In the voids where movement is most likely: between two pallet rows, between the last row and the container doors or wall, and in any crosswise gap in the loading pattern. Place the bag upright and centred, covering most of the stack height, with the valve accessible.

Related reading: see the dunnage bag product page for sizes and specifications, and check your void against the packaging calculator before ordering. Ordering note: Tezheng's export MOQ for dunnage bags is 5,000 pieces, with a lead time of about 20 days from production to port; our SGS report covers chemical safety testing (TPCH) only and is not an AAR railway performance certification.