Polythene’s potential doesn’t stop with single layer films. Multilayered polythene and laminates offer an advanced solution for industries requiring enhanced functionality, durability, and performance. We believe that understanding the value of multilayered laminated films and their applications is an important part of the packaging industry.
What is multilayered polythene?
Making multilayered polythene involves stacking multiple layers of materials together, to form a composite. Different types and thicknesses of polythene can be used, or polythene might only be a small part of the composite. A “polythene sandwich” might be created around an insulating yet water-sensitive material, or polythene might simply be applied to a paper or fabric backing, for absorbency and additional strength. No matter the material choice, each layer is engineered to provide a specific benefit, like barrier protection, tear or heat resistance, reflectivity, or sterility.
Applications of multilayered polythene
Food packaging is one of the biggest uses of multilayered polythene. Laminated films act as a barrier against moisture, oxygen, and contaminants. You’ll commonly find foil and paper laminated bags protecting fresh ground or whole bean coffee in supermarkets, as an example.
Another common example is tetra packs, which are almost always a laminate of paper, aluminium foil and LDPE. These can store anything from milk and juice, to paint and pharmaceutical chemicals.
Multilayered polythene laminates provide a longer shelf life for many perishable goods, and are increasingly used to incorporate paper as one of the layers, as it offers a level of moisture control.
Healthcare and pharmaceutical packaging is another major area for laminates. Again, paper is commonly used as a substrate material, and antimicrobial layers are added in some cases. There are more advanced laminates that have properties essential for some medical packaging, like radiation protection or extreme cold and heat resistance.
How is lamination achieved?
The process of creating laminated polythene involves layering different materials together using heat, adhesives, or co-extrusion. This ensures the layers bond seamlessly, resulting in a unified film that combines the strengths of each layer.
In heat lamination, films are melted together under controlled heat and pressure. This requires compatible materials – but they can have different melting points. Typically, LDPE has a lower melting point than other materials before deforming, but applying pressure can help maintain integrity.
Adhesive lamination is more common, used in tetra packs and other consumer laminates. It uses a thin layer of adhesive to bond the layers together, which is ideal for combining materials with vastly differing properties.
With co-extrusion, you can create a single film with different properties on each side. To do this, layers of differently engineered polymers are extruded simultaneously, then rolled and stretched together – for molecular-level bonding into a single film. This might be useful for LDPE with a soft-touch, low slip exterior and a high slip interior, for example.
Benefits
Multilayered polythene films and laminates offer several benefits over single-layer alternatives, like enhanced barrier properties, tailoring for strength, flexibility, or environmental resistance – and for transport efficiency.
Key industries that benefit are packaging manufacturers like Tetra Pak and medical device manufacturers – but really, any industry that needs a packaging solution with complex features will benefit.
Too good to be true?
While multilayered films and laminates are incredibly functional, they are not without challenges. Many are difficult to recycle – the bonds can be incredibly strong, making separation infeasible in most cases. Advances in technology are enabling the development of more sustainable solutions, like recyclable single-polymer laminates, and some large manufacturers are initiating take-back schemes.
Plus, there’s an additional layer of complexity – which makes the manufacturing cost higher. These costs are passed down to customers, who may actively be looking for cheaper alternatives.
But multilayered films and laminates aren’t going anywhere. These specialist packaging materials have proven themselves as indispensable in our modern world – and with the right base polymer and films behind them, they’ll help us continue our way of life long into the future.
Polythene manufacturing specialists
Talk to the polythene experts at NPF Packaging, and design your own custom-blended polythene film for use in lamination processes. Enquire online to get a quote now, or call us on 01773 820415 to find out more about our manufacturing and design process.
