Today’s Leading Stretch Film LLDP Manufacturers
When we purchase our packaging materials, we often do not consider the vast amounts of effort and machinery that go into producing these products, which are so intrinsic to our packaging success. So, what machinery is involved in making one of our most commonly used commodities in the packaging industry: stretch wrap? Plastic extrusion is a high-volume manufacturing process in which raw plastic, such as linear low-density polyethene, is melted and formed into a continuous profile. An extruder is the equipment used to change solid polymers into molten polymers. Today, the marketplace for LLDPE stretch wrap is extremely fierce, with many processors’ profits being within a fraction of one another per lb. The processors that are experiencing growth are the ones who choose to invest in the new highly layered films created using multiple extruders.
Blown Stretch Film
Two extrusion methods are currently used to produce the traditional mono-extrusion stretch wrap of the past. “Blown stretch film” accounts for 30-35% of stretch wrap produced and is typically used for commodity hand wrapping. Blown extrusion uses melted plastic resin extracted into a closed circular bubble with air blown through it to cool the resin. This process involves a circular die, where the molten resin is inflated with air to form a bubble of molten plastic before being chilled and collapsed into a thin film. Airflow is blown on the outside of the bubble, which chills the film as it pulls upward. This creates a tube of thin film which can be wound into rolls for use. Blown stretch film is known for its higher durability and is suitable for wrapping sharp-edged products and heavier loads.
Cast Stretch Wrap
The most popular type of LLDPE stretch wrap is “cast stretch film”,; which accounts for 60-75% of all stretch wrap produced and is used mainly for machine wrapping. Cast extrusion production, though more costly in the initial machinery set-up, is cheaper in the long run when compared to blown extrusion. Cast stretch film is known for its high transparency, which increases product visibility and aids in inspecting the integrity of packaging. Cast extrusion differs from “blown” by using rollers to cool the plastic resin. One of the unique characteristics of cast stretch film is its superior adhesion and cost-effectiveness for smaller weights. Once the resin is extracted from the extruder, it is cooled and solidified on cooling rolls. When the film reaches the end of the cooling rolls, it is trimmed and can be rolled directly onto a material roll for resale.
Coextrusion Technology
In order for processors to enjoy success in today’s market, multi-layered stretch wrap needs to be produced using a coextrusion machine. Coextrusion is the process of pressing two or more materials through the same die to produce a single piece. These systems are designed to produce multi-layer film and have two or more extruders feeding a common die assembly. Coextrusion technology improves the wrapping process by enhancing efficiency, reducing costs, and minimizing environmental impact.
The number of extruders depends on the different materials comprising the coextruded film. For instance, a three-layer coextrusion consisting of a recycled or barrier material core and two outer layers of the same resin requires only two extruders. In contrast, a five-layer coextrusion comprised of a top layer of LLDPE, a tie-layer resin, a barrier resin, another tie-layer and an EVA resin layer would require four or five extruders. A typical three- to five-layer cast film extruder costs up to €700,000.
Since 1982, the market has been moving away from traditional mono-film, and today, manufacturers typically produce 7-layered films that can stretch 250%+. However, some European companies are creating a future-forward 34-layered film that can stretch up to 300%+ and is reigning in the stretch wrap production industry. The multi-layered films produced by coextrusion also offer superior tear resistance, ensuring reliable performance and stability under load.
Major Extrusion Companies in Europe Today
The growing trend of multi-layer LLDPE has led to the growth of dozens of nanolayers, which give the material a “plywood” structure, enhancing the stretch wrap’s tear and puncture resistance. This highly elastic thin plapolyetheneade from polyethene (PE) resins is used for pallet wrapping, bundling, securing, and packaging goods by stretching and compacting, tightly wrapping them together. So, what constitutes a nanolayer? A nanometer is 1/1000 of a micron. There are 25,400 nanometers in one mil. In a cast film, layers can be as thin as 100 nanometers. The elastic recovery properties of these films ensure that items remain tightly bound and enable improved cling performance for the safe transportation of goods. Then, when this film is stretched above 300%, you arrive at layer thicknesses of less than 25 nanometers (0.0009 mil).
Dutch Flexible Packaging
The country making the most giant waves in the extrusion industry is Holland, which has been utilising nanolayer extrusion technology since 2009. This technology helps keep items tightly bound during transportation due to its highly elastic recovery nature. In one of their leading manufacture’s most recent film structures, 22 of the 27 layers are nano in a “2 x 11” structure, allowing more expensive, higher-performance sub-skin layers to sandwich a thicker core. Of course, the company’s director is extremely tight-lipped regarding the formulation and layer configuration, though happily states that the company is now well on the way to producing its third nanolayer extrusion line with more than 50 layers.
Eastern Europe
The European factories have collaborated with extrusion innovators Windmoller & Holscher KG and Cloeren since 2014. This new technology helps in securing pallet loads by providing a tighter and more stable wrap. They together are producing a 33-layered stretch wrap with a thickness measuring as little as 8 microns. This material is also suitable for heavier loads, ensuring durability and strength. Cloeren delivered its specialist feedback and die technology, while Windmöller & Hölscher provided industry-leading processing and manufacturing expertise for the cast stretch machine. This material uses 50% less film to wrap products when compared to typical stretch wrap. This advanced material offers excellent value for money and improves the carbon footprint of those who adopt it.
United Kingdom
In the UK, companies are not yet stocking the brand-new nanolayered technology, though they are well on their way. The new multi-layered films offer unparalleled tear resistance, ensuring reliable performance and stability under load. Companies are investing in multi-layered extruders by technology giants such as Macchi, one of the leading extruder brands that have been trailblazing since 1961. They offer cast and blown stretch wrap with over 250% stretch. The Italian extruder brand Macchi can now supply stretch film up to 11 layers.
Macchi Timeline:
- 1961 – Granted the patent for the first two-layer coextrusion die
- 1980 – The expansion of Coextruder 3-layer
- 2000 – Introduction of the Coex 5 layer & development of Coextruder 7 layer
- 2009 – The world’s first Coextruder 9 layer with nanolayers
Brückner Service
Since 1970, stretch wrap producers in Britain have been manufacturing and distributing 100% recyclable LLDPE. The new multi-layered films have unique characteristics that enhance their performance and versatility in various packaging applications. In recent years, the major players have been upgrading their existing traditional 3-layered extruders to 5-layers with the help of extruder machine technology provided by Brückner Service. Two additional co-extruders with melt pipes, filter and adapter block, and a new die with die lip adjustment were installed, all utilising Brückner’s state-of-the-art technology. Along with the new co-extruders, a new thickness gauge was installed to make the machines highly efficient.
Since 2010, the distribution of higher layer capacity has been much larger throughout Europe. The under-utilised capacity is due to the installed capacity not being utilised because of patent rows.
North America’s Extrusion Landscape
In North America, there has been limited progression in the multi-layer stretch wrap industry due to huge patent rows, which have been ongoing since 2012. Stretch wrap technology giants have filed lawsuits against nine stretch film processers claiming violations against patents covering films with seven or more layers. In November 2015, an opposing leading extruder manufacturer had the Federal Court rule in their favour, though their competitor is currently appealing. With 0.5% of retail sales lost to damage in North America, progress must be made to manufacture multi-layered stretch wrap. Linear low-density polyethene is commonly used in North American stretch film production for pallet wrapping, bundling, and securing.
Though limited, there are signs of innovation in North America. A stretch wrap factory based in New Jersey, currently America’s biggest stretch film producer, has installed a nine-layer cast stretch machine imported from Austria. This expansion has caused their competitors to increase their growth plans, and there are now talks of major developments throughout the US stretch wrap industry. Market experts estimate these developments will contribute to the stretch film industry growing 4.5% by 2017.
Extrusion in the East
With Europe’s technology paving the way, the Far East has been doing all it can to keep up with the competition. However, though the stretch wrap may be produced in Asia, the technology is strictly German. Reifenhauser has supplied over 15 extruder lines across Asia since 2014, ranging from 5 layers upwards. These extruder lines are used to produce highly elastic thin plastic film made from polyethene (PE) resins, which is essential for pallet wrapping, bundling, securing, and packaging goods.
A prominent Malaysian stretch wrap distributor has taken inspiration from Europe’s innovation. It is currently the number one stretch wrap manufacturer in the Asia-Pacific region, producing an eye-watering capacity of 200,000 metric tonnes per year across its 16 production lines. The high transparency of the films produced enhances product visibility, aids in inspecting the integrity of packaging, and improves warehouse operations by identifying products.
They have collaborated with German technology authorities Reifenhauser to produce innovative stretch wraps in the East. Their latest nanolayer extruder manufactures a 22-layered cast film with a thickness reduced to 6 microns and is the first of its kind to be installed in the Asia Pacific region. These major players export 90% of their films globally, including to Scotland.
Indonesia is also taking steps in the Asia-Pacific stretch-wrap industry, though it only exports LLDP stretch film up to five layers. This is because they only utilise American extrusion technology, which, as we know, has been stalled since 2012 due to bitter legal battles. Their products range from 15 to 12 microns, but this is no comparison to the 6 microns their competitors can supply.
The Future of Extrusion
With stretch wrap continuing to be one of the fastest-evolving film markets, there is a lot of optimism for those working within the field as demand shows no signs of slowing down. The future films are expected to have enhanced elastic recovery properties, making them highly stretchable and tightly binding when wrapped around items, especially during transportation. In 2014, stretch film production was divided into two categories: 1,467.4 million lb (75.8%) consisted of multi-layer coextruded film, and 468.4 million lb. (24.2%) was monolayer film. These future films will keep items tightly bound, ensuring improved cling performance for the safe transportation of goods. With technology ever growing and the demand the way it is, the future sees the production of multi-layered stretch wrap and the extruders needed to create it continue increasing their market share.
