The Evolution Of Pallet Wrap
New materials and manufacturing processes mean that stretch wrap has become more efficient than ever.
Looking at the pallet wrap market today, you’d be surprised at how far technology has brought us in the last 50 years.
The dawn of delivering goods on pallets began in the 1960s, when supermarkets gained popularity over the local shopkeeper as the grocery outlet of choice. Rather than deliver to small shops, producers began to deliver large loads to regional distribution warehouses. This called for the use of pallets, allowing goods to be moved in bulk quickly and with the aid of a forklift.
It was in the early 1970s that manufacturers realised that wrapping products securely on a pallet would increase load stability, preventing damage to the load. Other benefits were quickly realised too — the wrapping of goods would provide protection from dust, moisture and sunlight and act as a visual disguise for the cargo underneath, deterring tampering and theft.
The ease of applying stretch film meant that it was rapidly adopted within many different industry sectors. The earliest type of pallet wrap was made from PVC (polyvinyl chloride), a product patented by German inventor Friedrich Heinrich August Klatte in 1913, which, by the 1950s was in huge global demand. Used across many different applications including shoes, cables, clothing and even healthcare, PVC initially seemed an appealing option for pallet wrap in the 1970s as it was able to stretch up to 50%. But there was a problem; its durability. It was prone to tearing and as inventory became lost or broken, another material had to be found.
LDPE (low density polyethylene) had been around in a film format since 1945. Stronger than PVC, it had just one problem, its formula meant it wasn’t particularly pliable and its composition meant it was only extendable by 30%. The challenge was on to give the material greater elasticity. The answer came in the development of LLDPE (Linear low-density polyethylene). Structurally different from LDPE, it was first produced by DuPont in Canada in 1959. Used initially for film, injection, and rotational moulding, it was finally introduced to the U.S. market in 1976.
In the following years, several other companies including Dow Chemical and Union Carbide started to produce LLDPE’s. Blown film was the fastest growing market in the US, with refuse bags taking the lead, followed by pallet stretch wrap. By the late 1980s, 75% of the volume of LLDPE produced could be attributed to the production of film in the US and Europe.
By the 1980s, stretch film had become a packaging and logistics staple, but with larger pallets and containers becoming more commonplace, there was increasing pressure to develop a film that would stretch even further, whilst at the same time providing superior durability.
Up until this point, films had consisted of a single ‘mono layer’, but by 1982, manufacturers in the US had started to experiment with the production of triple layered film. Each layer performed a different function which improved its overall composition; an outer layer for cling, a centre layer for flexibility and an inner layer for stability. The combination of the 3 layers gave outstanding stretch of up to 100%. Over time, this discovery led to further layers being added, and by the start of the 21st century, a typical stretch wrap was made up of between 7 and 9 layers.
Modern day stretch wrap
Pallet stretch films have come a long way in the last decade and we now see the manufacture of films tens of layers thick. But what is the reason for adding these additional layers?
The answer is fairly simple. The range of Polymers available to manufacture film—including mPEs, propylene-based elastomers, olefin block copolymers, LLDPEs, ULDPEs, and VLDPEs— is much broader than it was a few years’ ago. There’s also the use of Nanotechnology, the science that gives us the ability to manipulate individual atoms and molecules. This has allowed us to take giant leaps forward in the development of new materials.
Nanolayer structures have the advantage of giving stretch film a “plywood” effect, in which layers are latticed rather than linear. This enhances mechanical properties such as puncture and tear resistance and it increases and improves film performance.
When the available selection of polymers are combined to produce the plywood effect, adding more layers would seem understandable. Laboratory testing, or controlled testing standards don’t reveal an immediate benefit of choosing 33 layers over 9, but benefits are apparent in the wrapping process itself. When nanolayer films are applied to the same wrapping process, wrapping speeds can be twice that of conventional films. In companies that ship large volumes this equates to big money—twice as many pallets can be wrapped in the same period.
Nanolayer film also carries the benefit of:
- Reducing packaging costs
- Generating efficiencies and throughput in the packing process
- Improving transit security
- Lowering damages in the transportation process
- Carrying environmental benefits compared to current “non-nano” films
What constitutes a Nano film?
Formerly known as a millimicrometre, a nanometer is 0.001 of a micron. Only a few years ago, film that was 25 to 30 microns was considered thin, but pressures in the industry have led to the production of increasingly lighter films. This is known as down gauging.
In cast film (rather than blown), layers can be as thin as 100 nanometers. When this film is stretched above 300%, the layer has a thickness of less than 25 nanometers. The industry has reached the consensus that a “nanolayer film” is comprised of a majority of layers of less than one micron each. Some 9 and 11 layer films, and certainly all 20-50 layer films fit the definition of nanolayer film.
Hazel 4D’s ExtremUS STRETCH FILMS
Hazel 4D’s Extremus Series 33 Stretch Film is one of the next generation stretch films. With 33 layers, it holds superior resistance to tearing and puncture. It is as thin and as flexible as standard film, giving it complete versatility and ease of use.
Extremus Series 33 Film means less film is needed to secure a load properly and packaging costs are significantly reduced — plus it can be stretched further than 400%, making it one of the most stretchable films in the industry today.
To learn more about Extremus Stretch Films click here