Multi-layer packaging, while excellent at preserving the freshness of food, falls down on being easy to recycle at the end of its life. But what if we could create a type of packaging that had all the functional benefits of multi-layer packaging and could easily be recycled after use?
Professor Eric Beckman and his team at the University of Pittsburgh, US, recently won $200,000 (£150,000) from the Ellen MacArthur Foundation to do just that.
Beckman tells MRW: “What we pitched to the foundation was that we could create something that had multiple layers but every single one would be from the same material: polyethylene (PE), where we mess around with the micro-structure to get each layer to do the job it needs to do. And if you collected this, shredded it and melted it, it would all just be PE again, so you wouldn’t require separation and you could just reuse the PE.”
Their idea is to use nano-engineering, mimicking the way nature uses just a few molecular building blocks to create a huge variety of materials. By manipulating PE molecules, the researchers believe they can design each PE layer to perform a specific function that would have otherwise required a different material, creating a fully recyclable PE product such as a juice box.
Beckman explains that the multi-layer packaging currently in circulation “works brilliantly” but was designed with function rather than recyclability in mind.
He says: “Each of the layers each has a different job to do: one layer will keep oxygen from getting in and spoiling the food and another layer keeps water out, other layers will block light from getting in and damaging the food, some layers are adhesives to keep everything together and some just provide strength.”
He believes that the recycling solutions developed so far for such materials have been about “hoping to bolt something on to the end which is ‘good enough’ – but the packaging itself was never designed to be recycled”. Beckman adds that many such types of packaging were developed up to 65 years ago, when the end of life of the packaging was not a consideration.
“What is interesting is that we came up with something that is just very different: let’s design the packaging to be functional yet able to be recycled. Most of the time people propose ways of dealing with existing packaging and then bolt something on at the end,” he says.
“As an academic, I am allowed and encouraged to think more broadly about the problem. I think about whatever will solve the problem in the best way – I have that advantage.”
Beckman and his team are currently at the very early stages of their work, but they hope to have a prototype together by the end of the year that demonstrates the concept: “We are in discussions with some major polymer producers to do this as a joint development project, just because of the scale involved.”
So far all the funding is from the Ellen MacArthur Foundation but, once the concept has been developed and proven, it is hoped that further funds can be raised.
“This is a very high-risk project, quite frankly – the Ellen MacArthur funding basically seeds the programme. It allows us to get going and then generate funding from people who are a bit more cautious than the foundation. The foundation wants to support things that are high risk but if they work are very high reward.”
Initial work will be done in the US at the university, although Beckman has already signed an agreement with a European company to help it do some testing.
Beckman says the first step is to see if they can do what they think they can do, “which is create the construct using nothing but PE”, and “first and foremost get the barrier properties that we need”.
He adds: “The key aspect of multi-layer packaging is to keep oxygen and moisture away from the food and, if you can’t do that, then the others things are just not relevant.”
If the concept can be proven, then Beckman says it would be “a question of working with engineers in the packaging field to see how you would do this continuously at a high rate” to mass produce it and drive down costs.
If the team is successful, it would eventually involve recyclers in its project: “What we are hoping is that we don’t need to ask recyclers to change anything that they are doing – that these multilayer packages will simply have a little number 1 on them and they can just process them the same way they do anything with a little number 1 on it.”