What Is BOPE Shrink Film?
You may be unfamiliar with the term ‘BOPE’ that’s cropping up more and more in discussions about plastics, packaging and sustainability, but it is worth getting acquainted, as it’s set to gain more traction over the coming months and years. However, there’s no need to dig out your chemistry textbooks – our shrink film experts are here to explain what this material is and why it’s big news for plastic packaging.
How is BOPE film different?
BOPE is an acronym of the term Bi-axially Oriented Polyethylene, a chemical designation for a category of flexible plastic films created under specific conditions. This specification of Polyethylene (PE) film is manufactured using a ‘blown’ process, meaning that the plastic sheeting is pulled in two directions, otherwise known as ‘bi-axially’ stretched. This biorientation is typically achieved by inflating a ‘bubble’ shaped column of film inside an extruder using air pressure, which serves to pull the film both in transverse (TD) and machine direction (MD) at the same time, before the material is cooled and laid flat. Alternatively, biorientation can be achieved using a specialist tenter frame to apply the two-directional stretch force uniformly, but this method is mostly used for stabilised films such as BOPP (Biaxially-Oriented Polypropylene). Our technical film guru Josh Gibson explains that ‘all of this multi-directional stretching results in a transformative PE flexible material that is thinner as well as stronger than non-stressed polymer alternatives, with exceptional clarity and improved barrier properties. Most importantly, BOPE represents a significant step forward for the recyclability properties of plastic films.’
Why is BOPE more recyclable?
The reason BOPE plastic is more readily recyclable is that it is created from a single polymeric family – polyethylene. At a time when there is a global drive for simplified structures, this breakthrough mono-material is infinitely preferable to the use of mixed material products and laminates (polymers are commonly integrated with foils for example) which are notoriously hard to recycle. The recycling infrastructure currently in place in the Western world is simply not sophisticated enough to easily and cost-effectively separate or delaminate the finely layered, adhesive materials moulded together in traditional plastics in order to sort them into each relevant recycling stream. BOPE, as a single polymer LDPE material, can therefore be classified as 100% mechanically recyclable to SPI code 04, meaning that it can be recycled with bags at larger stores and supermarkets. Earning its place in the circular economy models that are championed by leading environmental groups like WRAP, recycling BOPE plastic packaging helps to reduce our dependence on finite petrochemical resources, cuts waste and prevents plastic pollution.
The barrier properties of BOPE film
A major challenge for mono-materials like BOPE comes in the form of barrier requirements, demanded by many applications, particularly those involving foods where the packaging needs to prevent leakages or the escape of gas-flushed modified atmospheres (used to preserve foods and extend their shelf lives to reduce waste). In many circumstances, this need for barrier properties has led to an additional layer or coating being added to plastic films, thereby rendering them less easily recycled. However, the process of biaxial orientation is proven to actually improve the barrier properties of Polyethylene, meaning that BOPE remains classified as a mono-material with great recycling credentials – a huge win for the plastic packaging industry.
At Yorkshire Packaging Systems, all of our polyolefin shrink films are classified as BOPE materials, making them ideal candidates for recycling post-use. Furthermore, as OPRL members, our polyolefin films are authorised to display clear and consistent recycling symbols on-pack, to encourage the uptake of recycling behaviours by end consumers. ‘I’m delighted to be able to offer this range of BOPE classified shrinkable films to our customers, putting them right where they need to be in the current discussions about plastic packaging and eco-friendly choices’ says Josh.
For a complimentary sample of any of our shrink films, contact us today.