Pallet Wrapping Best Practices to Prevent Load Collapse: Gauge, Wraps, Containment Force
Why pallets collapse and how to stop it: stacking rules, film gauge by load weight, base/body/top wrap counts, containment-force targets and a method for unstable loads — with the numbers to write into a dispatch SOP.
Short answer
To prevent pallet load collapse, stack cartons in a column pattern with zero overhang, wrap three to five turns at the base so the load is bonded to the pallet, spiral up and down with 50% overlap, finish with two or three top wraps, and use 20 micron film for ordinary loads or 23 micron and above for export, sharp-cornered or unstable loads. Check containment force with a pull gauge, not by feel.
Key takeaways
- Most collapses start before wrapping: 25 mm of carton overhang can cut compression strength by roughly a third, and an interlocked stack loses 10–30% of the strength of a column stack.
- The base wraps are the load-to-pallet bond: three to five turns, with the film catching the pallet deck edge, are the single most skipped step.
- Use 20 micron cast film (18.4 g/m²) for mixed loads up to about 500 kg and 23 micron (21.2 g/m²) for export, tall and sharp-cornered pallets.
- Target containment force of about 2–3 kgf for light stable loads, 3–5 kgf for medium loads and 5–7 kgf or more for heavy or unstable ones, measured at mid-height.
- A 1200 × 1000 × 1500 mm pallet takes roughly 79 m of applied film; at 200% machine pre-stretch that is about 240 g of 20 micron film against about 485 g by hand.
A pallet collapses for one of three reasons: the stack was unstable before the film went on, the film was the wrong gauge or applied with too few layers for the load, or the wrap never bonded the load to the pallet. Stretch film cannot fix the first; it only hides it until the truck brakes hard on NH-48. The practices below are the ones that hold a load together, with the numbers to write into a dispatch SOP.
Why pallets collapse: the six causes in order of frequency
When a load arrives leaning, the film gets the blame; in our experience it is the root cause less than half the time.
| Cause | What you see at the receiving end | Fix |
|---|---|---|
| Overhang or a stack that leaned before wrapping | Bottom carton corners crushed, lean visible in the first 50 km | Column stack, zero overhang, tier sheets, level top |
| No load-to-pallet bond | Whole stack has slid on the pallet deck during braking; film intact | Three to five base wraps with film catching the pallet edge |
| Under-gauge film or too few layers | Film torn at carton corners, cartons have walked outward | 23 micron or above, corner boards, extra passes |
| Wrong tension | Loose: film lifts easily by hand. Tight: carton side panels bowed inward | Measure containment force; set machine pre-stretch and force-to-load |
| Wet or weak cartons | Bottom tier bulging, top tiers sagging into it | Check ECT, store cartons off the floor in monsoon, reduce pallet height |
| Film tail not secured or cling lost | Film unwound mid-transit, load loose but standing | Press the tail onto a flat carton face; store film at 15–35 °C, away from dust |
Build the stack before you touch the film
A corrugated carton carries almost all of its compression load at its four vertical corners. Column stacking, where every carton sits exactly on the one below, keeps those corners aligned and retains the most stacking strength. Interlocked or brick stacking resists shear better but moves load from corners to panel centres, typically costing 10–30% of stacking strength. Our rule: column stack anything heavy or tall and rely on film and corner boards for shear; interlock only light, uniform cartons under about 1.2 m total height.
Overhang is the most damaging stacking fault. A carton hanging 25 mm beyond the pallet edge has no support under its strongest corner, and the loss in compression strength is commonly put at around a third. Underhang has its own cost: if the load sits 50 mm inside the pallet edge, the film has no corner to grip and the base wraps hold the pallet but not the cartons. The footprint should fill the deck exactly, which is why the 1200 × 1000 mm export pallet should decide your carton sizes and not the other way round. The palletizing glossary entry lists the standard sizes, and our guide to palletization patterns and pallet sizes in India works through the layer arithmetic.
Heaviest cartons go in the bottom tiers, every tier level, an uneven top capped with a 3-ply sheet. Between tiers of slippery goods place a 200 GSM kraft or 3-ply tier sheet. Keep the finished height to 1.6–1.8 m for road freight.
Which film gauge for which load
Gauge decides puncture resistance and how much tension the film carries before it necks down and tears. It also decides grams per pallet, because stretch film is sold by net weight. The table is the cast LLDPE range we supply and where each gauge belongs.
| Gauge | Film weight | Load it suits | Application |
|---|---|---|---|
| 17 micron | 15.6 g/m² | Stable, regular loads under about 300 kg, no sharp corners | Hand, light bundling |
| 20 micron | 18.4 g/m² | Mixed warehouse loads up to about 500 kg | Hand or machine; the Indian default |
| 23 micron | 21.2 g/m² | Export container loads, tall pallets, carton and crate corners | Machine preferred |
| 25 micron | 23.0 g/m² | Unstable, very heavy or irregular loads | Machine |
| 30 micron | 27.6 g/m² | Unprotected metal, sharp fabricated assemblies, long multimodal journeys | Machine |
Check the gauge you are paying for: a 500 mm × 1000 m roll of true 20 micron cast film weighs close to 9.2 kg net of core.
The wrap pattern that holds: base, body, top
- Tie on. Twist the first 300 mm of film into a rope and tuck it round a pallet corner block. The wrap must start anchored, not held by cling alone.
- Base wraps: three to five turns. Position the film so its lower edge covers the top of the pallet deck and its upper edge covers the bottom carton. This is the load-to-pallet bond.
- Spiral up with 50% overlap. Each turn covers half of the previous one, giving two layers over the body. With 500 mm film that is a rise of 250 mm per turn.
- Top wraps: two to three turns. The film should extend no more than about 100 mm above the top tier unless a top sheet is fitted; beyond that it is holding air and will loosen.
- Spiral back down with 50% overlap. Where the passes cross, the body now has four layers.
- Two more base turns, then cut and press the tail flat onto a carton face, not over a corner where it will lift.
| Load type | Base turns | Body layers | Top turns | Extras |
|---|---|---|---|---|
| Stable cube, under 500 kg, under 1.5 m | 3 | 2 (one pass up, one down) | 2 | None |
| Tall or light, over 1.6 m | 3 | 3–4 | 3 | Rope band at one-third and two-thirds height |
| Mixed SKU, uneven top | 4–5 | 4 (two full passes) | 3 | Cap sheet, tier sheets, corner boards |
| Heavy, sharp corners (machined parts, crates) | 4–5 | 4 | 3 | 25–30 micron, corner boards, PET strapping through the pallet |
Tension and containment force: measure, do not guess
Containment force is the inward force the film exerts on the load, and it is the number that predicts whether a pallet survives. It is measured with a pull-plate gauge hooked under the film at mid-height on the long face. Typical targets are 2–3 kgf for light stable loads, 3–5 kgf for medium loads and 5–7 kgf or more for heavy or unstable ones. Container loads bound for Mundra or Nhava Sheva belong at the upper end of their band: weeks of vibration, not hours.
Containment force is film tension multiplied by layers, so you can pull harder or add layers. Pulling harder has a ceiling: beyond it the film crushes carton corners and destroys the stacking strength you are protecting. The lever that improves both is pre-stretch: a powered carriage elongates the film 200–250% before it reaches the load, so each metre from the roll becomes three metres on the pallet, applied at a consistent holding force. Hand wrapping seldom exceeds 50–70% stretch.
The grams matter because film is bought by weight. A 1200 × 1000 mm pallet loaded 1500 mm high has a perimeter of 4.4 m. Three base turns, six turns up at 250 mm rise, two top turns, six down and one closing turn make 18 turns, about 79 m of film on the load. A machine at 200% pre-stretch draws 79 ÷ 3 = 26.3 m from the roll, which at 500 mm width and 18.4 g/m² is about 242 g of 20 micron film. A hand wrapper at 50% stretch draws 52.7 m, about 485 g, for a less consistent result. Our post on pre-stretch film and cost per pallet takes this calculation across gauges.
Wrapping unstable and awkward loads
Most collapse enquiries involve a load that was never going to stand on its own; the fixes are mechanical before they are film-related.
- Mixed cartons with an uneven top. Build the tallest cartons in the centre, level the top with a cap sheet and wrap the cap in.
- Tall, narrow loads. Add roping: at one-third and two-thirds height, twist the film into a 50 mm rope for two full turns.
- Sharp or abrasive edges. Fit vertical corner protectors on all four edges before wrapping and move to 25 micron.
- Bags and sacks. Interlock in a 5-bag pattern, wrap after the sacks have settled, and strap as well as wrap.
- Monsoon dispatch. Corrugated board at 85–90% relative humidity can lose up to half its compression strength. Store cartons off the floor, wrap the same day they are stacked, and drop the pallet a tier rather than adding film.
Dispatch checklist
- Zero overhang on all four sides; footprint fills the pallet deck.
- Heaviest cartons at the bottom, every tier level, top capped if uneven.
- Corner boards on export, tall or sharp-cornered loads.
- Film anchored, then at least three base turns catching the pallet edge.
- 50% overlap up and down; extra pass for unstable loads; roping on tall loads.
- Two or three top turns, film not more than 100 mm above the load.
- Pull-gauge reading at mid-height meets the target band for the load.
- Push test: the top tier moves as one block with the pallet.
- Total height within 1.8 m for road, and within container clearance for export.
Specify film by the pallet, not by the roll
The cheapest roll per kilogram is rarely the cheapest film per pallet. Send us your pallet size, typical load weight and height, whether you wrap by hand or machine, and where the load is going, and we will recommend a gauge, a wrap pattern and an expected grams-per-pallet figure so you can compare suppliers on the number that matters. Cast film in 17–30 micron and 250–750 mm widths ships from Rajkot across India; dispatch lanes are on our stretch film supply page.
Frequently asked questions
How many times should you wrap a pallet with stretch film?
A stable load under about 500 kg needs three base wraps, one pass up and one pass down at 50% overlap (two layers on the body, four where the passes cross) and two wraps at the top. Unstable or mixed-SKU loads need two full up-and-down passes, giving four layers on the body, plus corner boards. Tall loads over 1.6 m benefit from a roped band at one-third and two-thirds height.
How do you wrap an unstable pallet load?
First make the stack itself stable: level the top with a cap sheet, put a tier sheet between slippery layers and remove any overhang. Then fit vertical corner boards, wrap the base four to five times so the load is bonded to the pallet, run two full passes up and down at 50% overlap, and rope the film at mid-height. Use 23 or 25 micron film so the extra tension does not tear it, and strap through the pallet if the load is heavy.
What causes stretch wrap to fail to stabilise a load?
The usual causes are film that is too light for the load (17 micron on a 600 kg pallet), no base wraps catching the pallet, tension so low that containment force is under 2 kgf, tension so high that carton corners crush, punctures from sharp corners without corner boards, a film tail left loose, and wet cartons that lose stacking strength in monsoon humidity. Film cannot correct a stack that leans before wrapping.
Should heavy items go at the bottom of a pallet?
Yes. Place the heaviest and most rigid cartons in the bottom tiers and keep each tier the same height so the column stays vertical. Mixed weights on one pallet should be arranged so the centre of gravity is low and central. If light crushable cartons must sit under heavy ones, insert a 3-ply tier sheet to spread the load and keep the total pallet height under about 1.8 m.
Is machine wrapping better than hand wrapping for load stability?
A machine with a powered pre-stretch carriage applies the film at 200–250% elongation with consistent tension on every turn, which gives higher, repeatable containment force and uses roughly half the film of hand wrapping. Hand wrapping rarely exceeds 50–70% stretch and the tension varies with the operator. For under about 20 pallets a day hand wrapping with 20–23 micron film is acceptable if the pattern and base wraps are followed.
What is the maximum height for a wrapped pallet?
For Indian road freight, a total height of 1.6–1.8 m including the pallet keeps the centre of gravity manageable and fits standard truck bodies with headroom. A 20-foot or 40-foot container has about 2.39 m internal height, so two pallets cannot be double-stacked unless each is under about 1.15 m. Beyond 1.8 m the wrap needs extra layers and roping to stop the top tiers swaying.
Have a packaging requirement?
Get a customized solution and quote from our team.
Keep reading
Palletization Explained: Meaning, Stacking Patterns and Standard Pallet Sizes in India
What palletization (palletisation) means, the six ISO pallet sizes and which India uses, column vs interlock stacking, the overhang rule, load height limits and how to secure a unit load.
Pre-Stretch Film Explained: 200% vs 300% and the Real Film Cost per Pallet
What pre-stretch percentage means, hand vs machine vs factory pre-stretched film, and a worked cost-per-pallet calculation in grams of film: 23 micron hand wrap vs 17 micron at 250%.
Shrink Film vs Stretch Film: Which to Use, Materials, Gauges and Equipment
Shrink film contracts with heat; stretch film holds by elastic tension. Here is how each works, POF vs PVC vs PE shrink against LLDPE stretch, gauge ranges, the equipment each needs and a use-case table.