Stretch film and shrink wrap are both plastic films used in packaging, and they are routinely confused. They solve different problems using different mechanisms, require different equipment, and are made from different materials. The confusion comes from the fact that both are transparent plastic films that end up wrapped tightly around something.
Stretch Film
Stretch film is wound around a load under tension. The film is stretched as it is applied — typically 100% to 300% of its original length — and it clings to itself and to the load through mechanical force and static friction. No heat is involved.
Mechanism: Elastic deformation. The film is stretched during application and its tendency to recover holds the load together. The cling comes from tackifiers in the film or from the inherent surface properties of the polymer.
Materials: Almost exclusively linear low-density polyethylene (LLDPE). Cast or blown extrusion. Typical thickness ranges from 12 to 35 microns.
Applications: Pallet wrapping, unitizing loads for transit, bundling items for shipping. The goal is stability — keeping boxes on a pallet, holding irregular items together, protecting against dust and moisture during transport.
Equipment: Hand-held dispensers for low-volume operations, turntable or rotary-arm wrappers for pallets, orbital wrappers for long or irregular loads. None require heat.
Shrink Wrap
Shrink wrap starts loose and contracts when heated. The film is placed around or over a product in a relaxed state, then passed through a heat source — a tunnel, a heat gun, or a steam chamber — that raises the film temperature past its activation point. The oriented polymer chains relax, the film shrinks, and it conforms tightly to the product.
Mechanism: Thermal relaxation of oriented polymer chains. During manufacturing, the film is stretched (oriented) and then cooled, locking in the orientation. Heat reverses this, causing the film to contract toward its original dimensions.
Materials: Polyolefin (the most common for retail shrink wrap), PVC, polyethylene. Film selection depends on the application, clarity requirements, and shrink ratio needed.
Applications: Product packaging (software boxes, food trays, multi-packs), tamper evidence, bundling, and labelling. This last application — labelling — is where shrink sleeves come in.
Equipment: L-bar sealers or side-seal wrappers to form the wrap around the product, followed by a shrink tunnel (hot air or steam). A heat gun is used for low-volume or irregular work.
Key Differences
| Stretch Film | Shrink Wrap | |
|---|---|---|
| Mechanism | Elastic tension; film is stretched during application | Thermal contraction; film shrinks when heated |
| Heat required | No | Yes |
| Typical materials | LLDPE | Polyolefin, PVC, PE |
| Primary applications | Pallet wrapping, transit stability | Product packaging, tamper evidence, labelling |
| Equipment | Stretch wrappers (hand or machine) | Sealers + shrink tunnels or heat guns |
| Film orientation | Not oriented (stretches in use) | Oriented during manufacture (shrinks in use) |
| Contact with product | Usually wraps around the outside of a pallet or bundle | Conforms directly to the product surface |
Why People Confuse Them
Both are clear plastic films. Both end up tightly wrapped around something. In casual conversation, “shrink wrap” is often used generically for any plastic wrapping, including stretch film on pallets. In the packaging industry, the distinction matters because the materials, equipment, and physics are completely different.
The confusion is also fed by the fact that both can be used for bundling. You can bundle six bottles together with stretch film (wound under tension) or with shrink wrap (a sleeve or sheet that contracts under heat). The end result looks similar. The process and equipment are not.
Where Shrink Sleeves Fit
Shrink sleeves are a specific application of shrink wrap technology. A shrink sleeve is a tube of printed, oriented film that is placed over a container and then shrunk in a heat tunnel to conform to the container shape. It is used as a label, not as transit packaging.
What distinguishes a shrink sleeve from general shrink wrap is the seam. A shrink sleeve starts as a flat printed web that must be formed into a tube by bonding one edge to the other. This bond is a solvent weld — the solvent dissolves the polymer on both overlap faces, the chains interdiffuse, and the joint becomes permanent as the solvent evaporates.
The seam is what makes the tube. Without it, you have a flat sheet that can wrap around a product (like general shrink wrap) but cannot form a close-fitting tube that slides over a bottle and then shrinks to fit.
For more on how shrink sleeves work, see What Is a Shrink Sleeve?. For the seaming process itself, see The Five Classes of Seaming Solvent.