Stretch wrapping is one of the most efficient ways of securing bundled or palletised loads while also protecting them against dust and high humidity.
High-elasticity plastic film with a self-cling coating is dispensed from a roll either manually or by an automated wrapper, and is stretched along its length as it is applied. The film has good memory and will constantly try to return to its original length, so it gently compresses the contents together. As the film is rotated around the bundle or load it overlaps and the self-cling surface creates a seal.
Stretch film is manufactured using one of two processes.
- Blown film is tougher, more puncture-resistant and has a better memory, so is the preferred choice for load retention and stability.
- Cast film has other advantages; it unwinds from the roll more easily and quietly and is clearer, so visual identification of the stretch wrapped contents and scanning of barcodes covered by film are easier.
An additional pre-stretching process is sometimes added to film production, where the film is wound onto the roll under tension. Pre-stretched film needs no additional tension when it is applied as it has already reached the limits of its stretch. The results are increased load stability and a drop of up to 50% in film use.
Most small- to medium- users of stretch wrapping will use some form of hand dispenser tool as they are cheap and versatile. Smallest in the dispenser range is the compact Handy Wrap Dispenser that holds a stubby little roll of Handy Wrap film and is perfect for bundling and film strapping.
Larger hand dispensers generally require two-hand usage and one hand may also control a manual brake at one end of the film roll. This brake applies variable pressure to the cardboard core so the operator can increase or decrease the film tension as needed.
Some stretch film is wound onto an extended core that is several centimetres longer than the width of the film. This allows the operator to grip the exposed core ends and use them as handle and brake while applying the film. No dispenser is needed for this, although the method isn’t recommended for extensive use.