BARRIER PROPERTIES: AN OUTLOOK From sustainability and recyclability to compostability and ‘forever chemicals’ – barriers and coatings often play a central role in many of the key issues faced by the packaging industry. John Williams, CTO at Aquapack, gives us an overview on the big questions. PE: Out of all the issues faced by the packaging industry, sustainability is probably at the top of the agenda right now. In terms of barrier properties, what are the key sustainability concerns as things stand?
JW: If we think back to when packaging started – it was a primary functional item to protect contents and obviously deliver material to the consumer in a suitable fashion. And I think, obviously, materials were developed, including barrier materials, to maximize things like shelf-life and protection and all the functional aspects of the material without, at the time, any particular consideration regarding, for example, end-of-life and the drive towards what we now call the circular economy and sustainability. Particularly over the last ten years or so, we’ve accelerated the move towards these considerations. So that presents a problem, in that you’ve given something a barrier property and then perhaps you’re asking it to compost or recycle, after you’ve already created a much more complex, more difficult material to handle in those processes. | 26 | Packaging Europe
So that’s the challenge. It’s that crash point of saying, we need to think of this perhaps slightly differently, we need to look at our construction of our materials differently and our choice of materials differently, to gain – without losing the functionality aspect – that sustainability aspect.
PE: In terms of drilling down, then, let’s talk about recyclability first. What are some of the tensions in the relationship between barrier properties and recyclability?
JW: Well, I think packaging has generally moved to complex, more layered solutions because we have demanded more of it. We want better barrier layers, we want extra protection, we want UV protection, moisture protection, non-migration of materials. All those things have developed excellent materials in terms of their performance but, of course, as we’ve moved in that direction, obviously the catalyst of this in many ways was the drive towards lighter weight packaging, so flex
