Quick answer: Stretch film is made from plastic pellets, mainly LLDPE (linear low-density polyethylene). The pellets are melted, pushed through a wide flat die as a thin sheet, cooled on a chilled roller, trimmed, and wound onto cores. Most hand pallet wrap is made this way, which is called the cast process. The things that decide how well a roll performs, such as the resin, the layer recipe and how steadily the line runs, can’t be seen from the outside. That’s why weighing a roll tells you more than looking at it.

Most people who buy stretch film never see it being made. That’s a big part of why quality can vary so much between rolls that look the same on the shelf. This guide walks through how a roll is made, where the differences creep in, and what it means for the film you’re buying.

The raw material

Pallet wrap starts as small plastic pellets. The main one is LLDPE, a type of polyethylene that can be stretched a long way without tearing and then pulls back against the load. We explain why in our guide to LLDPE vs LDPE.

Alongside new LLDPE, a roll can contain recycled plastic pellets. In our film, at least 30% of the plastic by weight is post-consumer recycled material. Small amounts of additives are also used, for example to help the outer surfaces cling to each other.

Step by step: the cast process

Melting. The pellets are fed into extruders, which are heated barrels with a turning screw inside. The screw pushes the plastic forward and melts it into a thick, even liquid.
Layering. Most stretch film isn’t one single layer. Several extruders feed different blends into the same die at once, so the film comes out as a thin sandwich of layers. The outer layers are usually set up for cling, and the inner layers for strength and stretch.
Casting. The molten plastic flows out of a long, flat die as a very thin curtain and lands on a large chilled roller. It cools and sets almost instantly. That fast cooling is what gives cast film its clarity, its smooth, quiet unwind and its natural cling.
Measuring. Thickness is checked across the width as the film runs. Good lines adjust the die continuously so the film stays even from edge to edge.
Trimming. The thick edges of the sheet are cut off. On most lines these trims are ground up and fed straight back into the process.
Winding. The wide sheet is slit into rolls of the right width, such as 400mm, and wound onto cores to the right length, such as 250m.
Packing. Rolls are checked, labelled and boxed, six to a box in our case.

What about blown film?

The other way to make stretch film is the blown process. The melted plastic is pushed out through a round die and inflated into a tall bubble, which cools more slowly in the air before it’s flattened and slit. Blown film tends to be tougher against punctures but is usually hazier and noisier to unwind. Our guide to cast vs blown stretch film compares the two in more detail.

Where quality actually gets decided

Two rolls can look identical and behave quite differently on a pallet. The reasons are all inside the process:

The resin. Different grades of LLDPE stretch and resist tearing differently.
The layer recipe. How the layers are balanced decides how far the film stretches, how well it clings and how it holds tension over time.
Cooling control. If the roller temperature drifts, the film’s properties drift with it.
Thickness control. Film that’s thin in places will tear there first.
Winding. Rolls wound too tight or too loose can unwind badly or have damaged edges.

A film that cuts corners on any of these can still have the right thickness printed on the box and perform noticeably worse in your warehouse.

Where recycled content fits in

Recycled plastic has to be blended in at the start, when the pellets are melted. It can’t be added afterwards. Post-consumer recycled plastic varies more than new resin, so getting it into thin film without losing strength takes careful control of the blend and the line. It’s one reason recycled content claims are worth checking. Our guide on PCR and PIR recycled content explains what to ask.

Why we make our own film

We make our film ourselves rather than buying in finished rolls and putting our name on the box. That means we’re responsible for the whole process, from the pellets to the packed carton. If a batch isn’t right, we know where to look.

What this means for the roll in your hands

You can’t see the resin grade or the layer recipe, but you can check the results. Weigh the roll and compare it with the published weight. Pull a length and see how far it stretches before it starts to neck in or tear. Listen to how it unwinds. Our guide on checking a roll’s real length and thickness shows you how, with nothing more than a tape measure and some scales.

It’s also why we publish the real weight of every roll alongside the length and thickness. Weight is the number that’s hardest to fake and easiest to check.

FAQs

What is pallet wrap made of?

Mainly LLDPE, a type of polyethylene. Our film also contains at least 30% post-consumer recycled plastic.

Is cast or blown film better?

Neither is better for every job. Cast film is clearer, quieter and clings well, which is why most hand pallet wrap is cast. Blown film is often tougher against punctures but hazier and noisier.

Why is some film so noisy to unwind?

Noise usually comes from how the film was cooled and how strongly the layers cling. Blown film tends to be louder. Cast film unwinds more quietly.

Why does film have several layers?

So each layer can do a different job. The outside layers are usually set up to cling, and the inner layers give strength and stretch.

Is hand film the same as machine film?

They’re made in a similar way, but machine film comes on bigger rolls, often 500mm wide and much longer, and is made to be stretched hard by the machine’s rollers. Hand film is sized so a person can handle it. Our standard core rolls can be used either way: by hand, on a dispenser, or on a wrapping machine that takes a 400mm roll on a 50mm core.

You can see the full range, with the recycled content and weight of each roll, on our stretch film page.

How Stretch Film Is Made, and Why It Changes What You’re Buying