Short answer: stretch film thickness is matched to the weight and shape of the load, the route and the stretch wrapper, not to the pallet weight alone. For hand wrapping, 10-15 µm is usually enough for light, even pallets, and 20-30 µm for mixed pallets and pallets with sharp edges. Thicker film is not always stronger: strength also depends on the film structure and the working stretch.
Stretch film thickness is given in microns (µm) and it is the first parameter buyers ask about. Many companies assume that thicker film means stronger load securing. In practice this is a simplification that ends either in overpaying for kilograms of film or in pallets that fall apart in transport. Whether stretch film holds the load depends on the thickness together with the film structure, the stretch on the stretch wrapper and the number of wraps.
Below we describe how we select the right stretch film for companies that wrap many pallets a day: in warehouses, logistics centres and on packing lines.
What thicknesses does stretch film come in and what does a micron mean?
A micron is one thousandth of a millimetre: 23 micron stretch film is 0.023 mm thick, and 17 micron stretch film 0.017 mm. The difference looks small, but from the same roll weight the thinner film gives noticeably more metres.
Thicknesses we produce:
- machine film: 10, 12, 15, 17, 20, 23 and 30 µm, width 450 or 500 mm, rolls up to 18.2 kg net,
- hand film: from 10 to 30 µm, rolls from 1 to 3 kg, for wrapping by hand or from a dispenser,
- pre-stretched film: from 6 to 11 µm, because most of its stretching has already been done during production.
You will find the thickness in the film specification and on the roll label. It is worth checking it, though, not just reading it: during a packaging audit we measure the actual film thickness with a micrometer at five points, because it happens that film described as 23 µm is in fact thinner.
What does the choice of stretch film thickness depend on?
We do not use rigid tables of the "so many kilograms of pallet, so many microns" kind. The same weight can mean even cartons or sacks with sharp corners, and these two pallets need different film. The right thickness depends on the weight and shape of the load, the transport conditions and the stretch wrapper.
Weight and height of the load
A heavy load presses harder on the film when braking and cornering, and a tall pallet has a longer lever arm on which the goods can tip over. The greater the weight and height, the larger the strength reserve the film needs: greater thickness or a stronger structure. With heavy pallets, resistance to tearing under vibration also matters.
Shape and edges of the goods
Even cartons spread the pressure of the film over the whole surface. Profiles, metal sheets, buckets with handles, furniture parts or the corners of pallets with building materials concentrate it at one point, and that is where thin film is most easily punctured. For mixed pallets and loads with sharp edges in hand wrapping, we usually select 20 to 30 µm, and for light and even pallets 10 to 15 µm is enough. The most often chosen hand film thickness is 23 µm, because it suits most loads.
Transport and storage conditions
A pallet that travels 20 km to the customer and a pallet that spends a week on an export route with several transhipments are two different tasks for the film. A longer route and longer storage require film that does not lose tension, does not tear under vibration and protects the goods against mechanical damage, dust, dirt and moisture. With long storage, the durability of the wrapping also matters: the film must not loosen on the cartons over time.
Stretch wrapper and wrapping method
In hand wrapping the stretch depends on the worker, so the film needs a reserve. In automatic pallet wrapping the stretch wrapper stretches the film repeatably, which is why machine film can often be thinner for the same result. Width also matters: the standard is 500 mm, and we select the 450 mm width for narrower guides and low pallets.
Is thicker stretch film stronger?
Not always. Two stretch films of the same thickness can behave completely differently on a stretch wrapper. What decides is the film structure and type: the number of layers, the polymers used, the adhesion between layers and the working stretchability. We write more about how the individual layers work in the article Five layers in stretch film.
An example from our range: standard machine film has a working stretch of 180%. Power film has five layers with reinforcing polymers and a working stretch of 220-350%. At a stretch of 300%, every metre of film from the roll extends on the stretch wrapper to four metres on the load. That is why with heavy pallets Power often lets you reduce the thickness instead of increasing it, while keeping the load secure. Thinner but better-built film is just as strong, and less material goes on each pallet.
“Before I propose Power, I ask about the load and the stretch wrapper. We select the test batch so that you see the result on your line before you order a series.”
Łukasz Zębala, production technologist, Dominopack
The takeaway for purchasing: when comparing offers, look not only at the microns and the price of stretch film per kilogram, but also at the stretch at which the film holds the load.
Does the colour of stretch film change the choice of thickness?
No. We match the thickness to the load and the colour to the application. Transparent stretch film is chosen most often, because labels and goods are visible through clear film, which makes warehouse work and shipment checks easier. Black film hides the load from view, and colours help mark pallets by customer or zone. We produce film in nine colours, and each colour in the same thicknesses.
How many metres of film does a roll of a given thickness hold?
The thinner the film, the more metres from the same weight. The length of film on a roll can be calculated from the net weight (without the core), width and thickness. The density of stretch film is 0.92 g/cm³:
roll length [m] = net weight [g] / (0.92 × width [cm] × thickness [cm]) / 100
For a 3 kg net roll with a width of 50 cm:
| Film thickness | Roll length |
|---|---|
| 23 µm | approx. 283 m |
| 17 µm | approx. 384 m |
From the same weight, 17 µm film gives over 100 m more.
Chart data in a table
| Thickness | Roll length |
|---|---|
| 10 µm | 3,522 m |
| 12 µm | 2,935 m |
| 15 µm | 2,348 m |
| 17 µm | 2,072 m |
| 20 µm | 1,761 m |
| 23 µm | 1,531 m |
| 30 µm | 1,174 m |
An 18 kg machine roll (16.2 kg of net film on a 1.8 kg core) 500 mm wide holds about 2935 m of 12 µm film, about 1531 m of 23 µm film and about 1174 m of 30 µm film.
This does not mean it is always worth buying the thinnest film. Film that is too thin on a difficult load increases the risk of damage, needs extra wraps and the gain in metres disappears. That is why we calculate the cost of wrapping one pallet, not the price per kilogram. If you use 50 g too much film on each pallet, at 100 pallets a day and 250 working days this adds up to 1.25 t of film a year.
How do you check whether your current film thickness is right?
Before you change the thickness, collect some data:
- Weight, height and type of your most common pallets (cartons, sacks, buckets, items with sharp edges).
- The type of stretch wrapper and the stretch it currently works at, or the information that you wrap by hand.
- The number of wraps at the bottom and top of the pallet.
- Problems from recent months: punctures at the corners, shifted cartons, transport complaints.
With this data our technologist will select the film thickness and type: hand, machine, pre-stretched or Power. We check every change of thickness in a test batch, on your pallets and your stretch wrapper, before you place an order for a full delivery.
Free packaging audit
If you want to check the thickness selection on your line, book a free packaging audit. Our technologist spends about 90 minutes in your hall and measures the actual film thickness, the working stretch of the stretch wrapper and the consumption per pallet. Within 5 days you receive a report with the cost of wrapping one pallet and the recommended film variant. The audit is free and does not oblige you to buy.
We deliver stretch film on a schedule with our own fleet, and we prepare the roll in the weight you need, because we produce the cores ourselves. Tell us what you wrap in a request for quotation, and we will match the stretch film thickness to your load.
Frequently asked questions about stretch film thickness
What stretch film thickness for pallets?
For hand wrapping, light and even pallets are usually wrapped with 10-15 µm film, and mixed pallets and pallets with sharp edges with 20-30 µm film. The most often chosen hand film thickness is 23 µm. We match machine film to the stretch wrapper and the load in the range of 10-30 µm.
Stretch film: 17 or 23 microns?
17 µm film gives more metres from the same weight: a 3 kg roll 50 cm wide has about 384 m, while in 23 µm it has about 283 m. 23 µm film has a larger strength reserve for heavier loads and sharp edges. The choice is best checked in a test batch.
How much does a machine film roll weigh?
A machine film roll weighs from 5 to 18.2 kg net. Hand film comes in rolls from 1 to 3 kg, and pre-stretched film in 300 or 600 m rolls without a core.
About the author
Łukasz Zębala
Production technologist, Dominopack
Every day he sets the parameters of our production and knows packaging machines from the settings side. He selects machine film, Power film and technical cores. During the free packaging audit he comes to your hall with scales, a micrometer and a stopwatch and watches packaging with the stretch wrapper running.