For many people stretch wrapping and shrink wrapping are interchangeable terms and simply mean holding goods with polythene. However, for those of us who spend our lives obsessed with the fine details of packaging we look at the two terms totally separately.
“Stretch wrapping” requires stretchfilm. The film is stretched as it unwinds from the roll and the elastic stretch effect holds the goods together in the same way an elastic band works. This is what the Samson Nano does. Using our unique 33 layer stretch film, it wraps pallets tightly. Because the machine is developed to work specifically with our unique film, it stretches it as far as it can go, meaning that the pallets it wraps are stable and can’t move anywhere. Watch our video below for more explanation:
“Shrink wrapping” requires shrinkfilm. The film is placed over the goods and then heated until it melts. When melted the “memory” in the film makes it try to shrink into the smallest shape possible. This makes the film mould exactly to the shape of the goods. It holds the goods together in the same way as a tightly fitted cardboard box.
Stretch wrapping was historically limited to heavy goods because the act of stretching the film would drag the load over. However with modern Power-Pre-Stretch technology the film is stretched between two driven rollers and then gently applied to the load. This means the stretch-wrapping is now the normal method for wrapping all types of pallets.
Shrink wrapping is limited by the need to heat the film to melting point (over 120 degrees centigrade) which often utilises gas flame shrink guns. This now makes the technology very limited for wrapping pallets , not to mention very expensive.
Shrink wrapping is however the normal method for wrapping trays of goods. Collation shrink film is used for example to securely wrap trays of canned soft drinks. These smaller packages tend to be wrapped in shrink tunnels which use electric heated elements to melt the film to shrinking point. A good example of the differences is a pallet of fizzy drinks. The cans are shrink wrapped in 24’s which are then stacked on a pallet for the whole pallet to be stretch wrapped.
For advice on the best method to wrap your goods please contact Samuel Grant Group.