What is pre-stretched film?

How it is made

Pre-stretched film starts as conventional stretch film on a jumbo roll. On a pre-stretch rewinder the film runs between rollers turning at different speeds: the faster roller pulls the film longer and thinner before it is wound onto the finished roll. Stretching also aligns the polymer chains, which gives the thinner film its strength.

Öncümak's SP-1400 stretches film by up to 500% while rewinding. Three servo motors control the tension, and in tests it has produced film as thin as 4 µm. It makes pre-stretched film in both hand and machine rolls, and it can also rewind conventional PE stretch film, again as hand and machine rolls.

Pre-stretched film vs pre-stretch on a wrapping machine

The two are easy to confuse:

• Pre-stretched film is stretched in the factory, on a rewinder. The user receives a thin roll that is already stretched and applies it by hand, or on a simple wrapper.
• Powered pre-stretch is done on the customer's pallet wrapper: two rollers in the film carriage stretch conventional machine film as it is applied, typically by 150–300%, and in tests up to 320% with high-performance film.

Conventional hand film, stretched only by the operator's pull, typically reaches far less.

Advantages and limits

Pre-stretched film in transport

Picture a pallet of boxes sent by truck from one city to another. If it is wrapped with conventional film stretched only a little, the film still has plenty of stretch left. Braking, cornering and road vibration keep working on the load, the film gives a little more each time, and by the time the truck arrives the boxes on the pallet can have worked loose.

Pre-stretched film has already been stretched close to its limit in the factory, so it has little stretch left to give. It does not keep giving under braking and vibration the way loosely stretched conventional film does.

How much force it puts on the load, however, depends on how it is applied:

• By hand: the operator lays the film around the load with little tension. The European Commission's guidelines on cargo securing for road transport (2014) note that pre-stretched film applied by hand puts almost no force between the film and the load. It can stop columns of products from collapsing, but it does not stop layers from sliding, so on its own it should not be used to rigidify a load by hand. For heavy or unstable loads that travel by road, wrap by machine or add straps.
• By machine: a wrapping machine lays the film on under controlled tension, layer after layer, and builds real holding force.

Research on machine-applied film points the same way:

• In laboratory tests (Tkaczyk et al., Sensors, 2021), a load wrapped with multilayer film stretched 300% during wrapping passed a 0.5 g stability test that a load wrapped with standard film stretched 100% failed, while using about half as much film.
• Stretch film loses part of its holding force after wrapping: a 2025 study by the same group, with film applied by an automatic wrapper, measured a drop of about 10–20% soon after wrapping, and notes that the force declines further under dynamic loading and temperature changes, which is why loads can work loose on the road.

The European Commission's guidelines on cargo securing for road transport (2014) say cargo should be prevented from sliding, tipping, rolling, wandering or deforming substantially during transport, and list stretch film among the ways to bind a load to its pallet.

Is thinner weaker?

Not necessarily. Thickness alone does not decide how well a film holds a load: how far it was stretched and how strongly it pulls back (its "memory") matter just as much. A thin pre-stretched film applied correctly can contain a load that a thicker, loosely applied conventional film does not. See what stretch film is.

Standard or special jumbo roll?

Both can be used; what changes is the stretch ratio. A standard jumbo roll can be pre-stretched, but to a lower ratio. For high ratios such as 500%, you need a jumbo roll made for pre-stretching, from a formulation that can take that much stretch without breaking. On the SP-1400 the tension is controlled by three servo motors and adjusted from the touchscreen, so the machine can be set to the jumbo roll in use.

Folded edges

The edges are the most sensitive part of a stretch film roll, especially of pre-stretched film: a small nick at the edge is often enough to start a tear that runs across the film. Edge folding folds the edges of the film over before it is wound onto the roll, so the roll has reinforced, double-layer edges instead of a thin cut edge.

• Fewer tears: the edge resists nicks and tearing, even on sharp corners
• Easier handling: a stronger, smoother edge makes the film easier to work with by hand
• Less waste: fewer wraps broken at the edge and fewer rolls damaged at the edges

Edge folding is standard on the SP-1400 and optional on the SM-1300 2S models (SM-1300 2S, SM-1300 2S PRO). Edge folding is used on full-width rolls, so on these models it is available when they rewind without slitting.