(Also called Stretch
Stretch wrap or stretch film is a highly stretchable plastic
film that is wrapped around items. The elastic recovery keeps the items tightly
bound. In contrast, shrink wrap is applied
loosely around an item and shrinks tightly with heat.
It is frequently used to unitize pallet loads but also may be used for
bundling smaller items.
Types of stretch film include bundling stretch film, hand stretch film,
extended core stretch film, machine stretch film and static dissipative
The most common stretch wrap material is linear
low-density polyethylene or LLDPE, which is produced by copolymerization of ethylene with
alpha-olefins, the most common of which are butene, hexene and octene. The use of higher
alpha-olefins (hexene or octene) gives rise to enhanced stretch film
characteristics, particularly in respect of elongation at break and puncture resistance.
Other types of polyethylene and PVC can also be used.
Many films have about 500% stretch at break but are only stretched to about 100
– 300% in use. Once stretched, the elastic recovery is used to keep the load
Other properties such as break strength, cling, clarity, tear resistance, static discharge, etc.
are also important.
Forklift truck loading
stretch wrapped pallet load.
unitizing, stretch wrap can have several functions:
- improved stability of products or packages, forming a unit load
- more efficient handling and storage of unit loads
- some degree of dust and moisture protection
- some degree of tamper resistance
and resistance to package
Making sure cartons stay on the pallet is an important consideration in
warehouse distribution, especially as the demands for increased throughput
continues to rise. Stretch wrapping is the most cost-effective way to keep loads
secured, on a pallet.
Typical fully automatic
Stretch wrap can be applied manually, semi-automatically or
Categories and sub-categories of stretch wrappers:
Manual (or Hand) Wrappers:
Core: An extension of the film's core serves as a handle for wrapping;
this type of wrapper offers little stretch control and is hard on hands.
Brake: A simple structure supports a film roll and a mechanical brake
system provides resistance creating stretch of the film.
- Pole Wrappers: Similar to the Mechanical Brake system, but
the roll and brake are at the end of an extended pole, creating an ergonomic
design which eliminates the need to bend to wrap the bottoms of loads and
strain to reach the tops of loads.
Wrappers: The load to be wrapped sits on a turntable which spins the
load relative to the film roll, which is housed in a carriage which can move
up and down a fixed "mast". Stretch is achieved by rotating the load at a
faster rate than the film is fed.
Wrappers: The film is housed in a carriage on a vertical ring, the
load is fed horizontally through the eye of the rotating ring, applying film
to the load.
- Rotary Arm
Wrappers: In this system, the load remains still while a rotating arm
turns around it wrapping the load. This system is used for light loads or for
speeds which would otherwise cause the load to topple due to high rotation
Automatic wrappers are generally a variant of a semi-automatic system, which
has had a conveyor system and automatic film cut and seal system applied to
- ASTM International
D4649 Guide for Selection and Use of Stretch Wrap Films
- Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons,
2009, ISBN 978-0-470-08704-6
- M.Hildreth, "Maximizing your Stretch Film Operation", 2006, ISTA, Pre