How Stretch Wrap Supports Safe Transportation of Goods

How Stretch Wrap Supports Safe Transportation of Goods

Quick answer: Stretch wrap keeps goods safe in transit by turning a stack of separate boxes into one unit that moves together. The film is stretched as it goes on, then tries to pull back, which squeezes the load and ties it to the pallet. That’s what stops cartons sliding off when a lorry brakes, takes a bend or hits a pothole. It works best with firm turns at the base, even tension all the way up, and a film that’s strong enough for the load.

A pallet can look perfectly solid standing in the warehouse and still come apart on the road. The forces it meets in the back of a vehicle are very different from the ones it meets on the floor. Here’s what those forces are, how stretch wrap resists them, and how to wrap so your loads arrive the way they left.

What a pallet goes through on the road

Every journey puts the load through the same few things:

• braking, which throws the load forwards
• pulling away, which pushes it backwards
• bends and roundabouts, which push it sideways
• bumps and vibration, which slowly work loose anything that isn’t held
• handling at each end, as the pallet is lifted, carried, set down and sometimes stacked

A pallet sent through a pallet network may be loaded and unloaded several times before it arrives, often at hubs overnight. Each lift is another chance for a loose load to shift.

How stretch wrap holds a load

Stretch film is made to be pulled longer as it goes on. Once it’s wrapped round the load, it tries to recover to its original length. That pull back is what does the work. It presses every carton inwards and holds them against each other, so the whole stack behaves like one block.

Each turn adds to that hold. One loose layer does very little, but several layers applied under tension add up to a firm grip. The film also clings to itself, so the tail stays put without tape.

That’s why film put on slack, at full width with no stretch, does so little. It covers the load, but it doesn’t hold it. Our guide on what “up to 500% stretch” means explains how much stretch you actually get when wrapping by hand.

Tie the load to the pallet

A tightly wrapped stack that isn’t joined to the pallet can still slide off it in one piece. The first turns are the most important. Start with three or four turns round the base, with the bottom edge of the film catching the pallet itself, not just the bottom row of boxes. Some people twist the film into a rope for the first turn, so it sits low and tight on the pallet deck.

Where wrapped loads fail

Most loads that fail in transit fail for the same few reasons:

• the film doesn’t reach the pallet, so the load slides off in one block
• the film went on loose, so it held nothing
• too few turns at the top, so the top layer moves
• sharp corners cut the film, and the tear runs once the lorry is moving
• the stack overhangs the pallet edge, so the film can’t pull it in
• the film was too thin for the weight or shape of the load

Our guide to six signs your wrap isn’t holding the load shows what each of these looks like before the pallet leaves.

A simple wrap pattern for transport

• Stack square and tight, heaviest at the bottom, nothing over the edge.
• Three or four turns round the base, catching the pallet.
• Work up with each turn overlapping the one below by about half.
• Keep the tension even by keeping the film tight as you walk round.
• Two or three turns round the top, folding the film over the top edge if you can.
• Work back down if the load is tall, heavy or travelling a long way.
• Press the film on each side. It should feel firm, with no slack.

Our step-by-step guide to wrapping a pallet goes through this in more detail.

Wrap holds the pallet together, straps hold it in the vehicle

Stretch wrap and load restraint do different jobs. The film keeps the pallet as one unit. Straps, bars and the vehicle body keep that unit in its place in the vehicle. The DVSA’s guidance on securing loads on HGVs and goods vehicles says a load securing system should be able to hold the full weight of the load forwards, and half of it backwards and to each side. Straps can only do that if the pallet under them stays in one piece.

Choosing film for transport

For light, square loads on short trips, 17 micron is usually enough. For heavy pallets (over about 500kg), tall loads, sharp or uneven shapes, pallet networks and long journeys, 23 micron is the safer choice. If the contents are valuable or shouldn’t be seen, use black film. Our 17 vs 23 micron guide helps you pick, and our pallet wrap rolls come in both.

FAQs

How many times should I wrap a pallet for transport?

Three or four turns at the base, half-overlapping turns up the load, and two or three at the top is a good starting point. Add more for heavy, tall or long-distance loads.

Can stretch wrap replace straps?

No. Stretch wrap holds the pallet together. Straps or other restraints hold it in the vehicle. You usually need both.

Why did my wrapped pallet lean in transit?

Usually because the film didn’t catch the pallet at the base, went on loose, or there weren’t enough turns at the top. Sharp corners that cut the film are another common cause.

Does black stretch wrap hold as well as clear?

Yes, at the same thickness. The colour only changes whether you can see the goods through it.

For a quick check before each pallet goes out, use our printable pallet load security checklist. For more on choosing the right roll, see our complete guide to stretch wrap film.

Related guides: safe packaging for transport, wrapping pallets for shipping and export, pallet stability testing (EUMOS 40509).