How Do You Test Stretch Wrap Containment Force on Export Pallets?

Why can a neatly wrapped pallet still shift in transit?

A pallet can look tightly wrapped at dispatch yet arrive with shifted cartons or a leaning top layer. Appearance does not tell the shipping team how consistently the film holds the load together. A heavy base may remain intact while a lighter top layer moves, or tight film may hide carton damage. Exporters need to compare actual loads and repeatable measurements rather than judge a wrap recipe by the number of turns alone.

Begin by recording the carton layout, pallet condition and handling route. Film is only one part of the system. A damaged deck, unsupported carton edges or an unstable stack cannot reliably be corrected by adding more wraps. Agree on acceptable load construction before comparing machines, film grades or operating recipes.

What does a stretch wrapper control?

On a turntable stretch wrapper, the loaded pallet rotates while a carriage moves along a fixed mast. The carriage feeds film toward the load, and its vertical travel determines how adjacent bands overlap. The machine can apply different numbers of turns near the base and top. A rotary-arm design instead moves the film delivery assembly around a stationary load. In either design, the material path must remain consistent from the carriage to the carton stack.

Pre-stretch and force applied to the load are different settings. The first changes the film as it passes through the delivery system; the second affects how tightly it is applied. Changing film, carriage speed or overlap can change the measured result even when the operator does not touch the force setting. Record the complete recipe rather than one display value.

How should an export team measure containment force?

Use a suitable containment-force tool according to its instructions and measure comparable points on comparable loads. Lantech's published guidance uses readings near the top, middle and bottom. Establish the precise measurement positions, instrument and timing before the trial. Compare readings taken by the same method; two different instruments or procedures may not yield interchangeable results. Carry out checks only when the load is stationary and safely accessible.

Repeat the trial with representative pallets rather than relying on one ideal sample. Note carton deformation, punctures, loose tails and weak film coverage alongside the readings. A higher reading is not automatically better if the film crushes a fragile carton or the stack becomes distorted. Set acceptance criteria with the packaging team using real shipment requirements and suitable handling or transport validation.

Illustrative calculation: is the lower-film recipe worth testing?

This is a planning example, not a measured result or an equipment guarantee. Suppose a factory wraps 300 pallets per week. Recipe A uses 0.42 kg of film per pallet, while Recipe B uses 0.36 kg under the same weighing procedure. The difference is 0.06 kg per pallet, or 18 kg each week if both recipes perform equally well on the same shipment mix.

Now assume Recipe B takes eight seconds longer per cycle. At 300 pallets, that adds 2,400 seconds, or 40 minutes of wrapper occupation. Whether that matters depends on spare line capacity and the timing of dispatch peaks. The film difference is not a saving until Recipe B also passes the agreed containment, damage and handling checks. Compare actual material consumption, including breakage and rewraps, during the trial.

How would this work on a mixed export line?

Consider a hypothetical exporter shipping dense hardware cartons and lighter household products on separate pallets. A single recipe is convenient, but the lighter cartons may be more sensitive to squeezing. The trial team can create two load families, test a representative pallet from each and log the film used, cycle time, three force readings and visible damage. These are planning steps, not claims about a customer installation.

Keep the pallet layout unchanged while comparing the first wrap settings. Later, test different layouts separately. This avoids crediting a film change for an improvement caused by a better carton pattern. Retain the accepted recipe and its limits, including any carton height or board changes that require another trial.

How does pallet wrap testing fit into packaging automation?

Start with the output from the palletizer. Confirm the load dimensions and pattern before releasing it to wrapping. For an integrated line, define what happens when the wrapper is occupied, the film breaks or the completed pallet cannot leave the station. A half-wrapped pallet should not be silently released as finished. Plan a safe recovery procedure with the supplier and ensure operators know when a pallet requires inspection.

Recipe storage and production reporting are useful when several load families share one wrapper. Ask whether recipes record the actual film and machine settings, and whether the system logs alarms and incomplete cycles. An automatic recipe does not replace physical measurements. As an operation expands, a modest number of validated recipes may be easier to maintain than a large list of poorly distinguished formats.

FAQ: stretch wrapper settings and pallet wrap testing

Is there one correct containment force for every export pallet?

No. Load weight, carton strength, pattern and distribution conditions affect the target. Use a documented target for each relevant load family, confirmed through representative testing rather than a generic number from another line.

Will more film wraps always improve load stability?

Not necessarily. Additional turns may help in a weak zone, but they can also add material, increase cycle time or damage susceptible cartons. Check where the problem occurs and verify the effect of each change.

Can I change film thickness without retesting the wrap recipe?

Do not assume that a new film will behave like the old one. Check compatibility with the carriage and repeat the force, appearance and handling checks on real loads before adopting it for production.

What should I ask a stretch wrapper supplier to demonstrate?

Request a trial using your pallet, cartons and proposed film. Compare the completed load, recorded film consumption, elapsed cycle time and recovery after a normal interruption. Document the accepted settings and test limits before signing off. A practical trial should also show how operators identify an incomplete wrap, change film and return the line to normal production.

Technical reference: Lantech guidance on containment-force measurement. The images are illustrative, not photographs of a customer installation.