Shrink film is heated so it contracts tightly around a product or a pallet load. It differs from stretch film in that it conforms to shape and seals against weather, which makes it the better choice for outdoor storage, mixed loads and multipacks - at the cost of needing heat to apply.
Shrink and stretch are not alternatives
They are often discussed as though you choose one, but they do different things. Stretch film is applied under tension and holds a load by containment force. Shrink film is applied loose and then heated, so it contracts and conforms to the shape of whatever is inside it.
The practical difference is sealing. A shrink hood over a pallet encloses it, which keeps weather out and makes tampering obvious. Stretch film leaves a spiral with gaps, which is fine indoors and much less so on a load that will stand in a yard.
| Shrink film | Stretch film | |
|---|---|---|
| Applied by | Heat - tunnel, oven or heat gun | Tension, by hand or machine |
| Holds the load by | Conforming and contracting | Containment force |
| Weather sealing | Good - encloses the load | Poor - spiral leaves gaps |
| Equipment needed | Heat source | Dispenser or wrapper |
| Suits | Outdoor storage, multipacks, mixed loads | Indoor pallet despatch |
| Energy use | Requires heat | None |
| Speed per pallet | Slower | Faster |
Shrink film against stretch film.
Where shrink earns its place
- Pallets stored or transported outdoors, where a sealed hood keeps the load dry - common in construction and agriculture, see Packaging for Construction Product Manufacturers.
- Mixed or unstable loads, where conforming to an irregular shape does more than tension around it.
- Multipacks, where several units need to travel and sell as one - common in food and drink, see Packaging for Food and Drink Producers.
- Tamper evidence, because a shrink wrap cannot be opened and reclosed invisibly.
- Printed presentation, where a shrink sleeve carries branding around an irregular product.
The cost side is equipment and energy. A heat tunnel is a capital item and a running cost, and a heat gun is slow and variable. That is why shrink tends to appear where its specific advantages matter rather than as a general wrapping method.
Specifying it properly
- Material. Polyolefin is clear, tough and shrinks evenly; PVC shrinks at lower temperature but is less tolerant; polyethylene is heavier duty and typical for pallet hoods.
- Gauge, against the weight and sharpness of what is inside.
- Shrink ratio, which has to match how far the film must contract to conform.
- Perforation, where the pack needs to breathe or where condensation would otherwise form.
- Heat source and dwell, because under-shrinking leaves a loose pack and over-shrinking distorts or burns through.
Condensation is the quiet failure. A sealed hood over a product that is still warm, or over anything with moisture in it, traps that moisture against the goods - which is worse than leaving it unwrapped. Perforated film exists for exactly this.
Common problems and what causes them
| Symptom | Usual cause |
|---|---|
| Loose, baggy finish | Under-shrinking - insufficient heat or dwell |
| Film burnt through | Heat concentrated in one place, usually a heat gun |
| Load still wet inside | Condensation sealed in; needs perforated film |
| Film splitting at corners | No corner protection, or gauge too light |
| Pack collapses in storage | Shrink used where structural support was needed |
| Uneven shrink | Wrong shrink ratio or inconsistent heat |
Shrink wrapping faults and their usual cause.
The last of those is worth emphasising: shrink film holds a load together, it does not hold it up. A stack that needs compression strength needs board, corner protection or strapping - the film contributes almost nothing structurally.
Choosing between a hood, a sleeve and a full wrap
Shrink is applied in three quite different ways and they are not interchangeable. Which one you need follows from what the film is protecting against rather than from what it is going around.
| Format | How it is applied | Best for |
|---|---|---|
| Pallet hood | Dropped over the load, then heated | Outdoor storage, weather sealing, whole-pallet protection |
| Shrink sleeve | Placed around a product or multipack, then heated | Multipacks, branding on irregular shapes, tamper evidence |
| Full shrink wrap | Sealed around the item, then heated | Individual products, flat goods, retail presentation |
Three shrink formats and what each is for.
The hood is the one most relevant to industrial despatch, and the one where the detail that matters most is the gusset: a hood that is too narrow will not drop over the load, and one that is too wide will not contract tightly enough to seal. Both produce a pallet that looks wrapped and behaves as though it is not.
Sleeves and full wraps belong more to product presentation than to transit, and they frequently sit alongside printed outer packaging rather than replacing it - see custom printed packaging.
The short version
- Shrink conforms and seals; stretch contains under tension. They solve different problems.
- Shrink is the better answer for outdoor storage, mixed loads and multipacks.
- It needs a heat source, which is its main practical cost.
- Perforated film prevents condensation being sealed against the goods.
- Shrink holds a load together but contributes no structural support.
Frequently asked questions
What is the difference between shrink wrap and stretch wrap?
Shrink film is applied loose and heated so it contracts around the load; stretch film is applied under tension. Shrink seals and conforms, stretch contains - which is why shrink suits outdoor storage and stretch suits routine indoor pallet despatch.
Do we need a heat tunnel?
For volume, yes - a heat gun is slow and produces variable results, including burn-through. For occasional pallet hoods a gun is workable provided the operator is consistent.
Will shrink wrap keep a pallet dry?
A properly applied hood keeps weather off, which stretch film does not. The thing to watch is condensation: sealing a warm or damp load traps the moisture inside, so perforated film is often the right specification.
Can shrink film be printed?
Yes - shrink sleeves are widely used for branding irregular products, and printed hoods are possible on pallets. See custom printed packaging.
Is shrink film recyclable?
Polyethylene hoods are widely recyclable through commercial streams; mixed materials and some sleeve films are harder. If that matters, specify it explicitly - see sustainable packaging.