Fewer than 20 years ago, the first 100% recycled PVC-U doors and windows were a proof of concept novelty that showed what could be achieved with mechanical recycling technology. Today, in more environmentally-aware times, recycled PVC-U is obviously a common and increasing ingredient in many new PVC-U window and door lines.
So, what does the future hold for what the industry refers to as ‘post-consumer’ PVC-U? And what technologies are around the corner to help it recover, recycle and reuse even more of this valuable resource?
Rethinking the recycling process
Mechanical recycling has been the standard technique for turning old PVC-U frames into new products for many years. It’s a relatively simple process: old frames are broken up, cleaned and pelletised to then be reincorporated into new window and door profiles or other products.
It works – and works well – because PVC-U is made up of millions of intertwined polymer chains that give it rigidity and strength (these also help prevent molten drops forming during fires, something PVC-U windows have been wrongly accused of in the past).
When the plastic is heated to melting point during recycling, these strands loosen but, crucially, they don’t break down as other polymers can in some other forms of plastic. That means when the melted plastic is reformed into new window frames, the chains re-entwine. So the recycled frames are just as strong as the original, virgin PVC-U ones, if not stronger. In fact, PVC-U can be recycled up to 10 times without losing any of its strength.
The only drawback of manufacturing PVC-U frames in this way is that it needs to be free from all other types of plastics. That’s fine when the raw material comes direct from replacement window projects or factory off-cuts, as it does in the Eurocell ‘closed loop’ recycling system.
But mixed waste loads, which contain many different types of plastic from all sorts of sources, are simply too costly to sort and separate and often end up in landfill instead. That’s an awful lot of plastic going to waste every year. So now, the focus for the future is on a newly-emerging technology: chemical, or feedstock recycling.
Here comes the science…
According to Jason Leadbitter, feedstock recycling is the “holy grail” of sustainable plastic production.
“The technology is still in its infancy,” he commented, “yet with the amount of research and investment behind it, it’s only a matter of time before it’s developed into a commercially-viable technique. When that happens, it will revolutionise the plastics industry and allow millions of tonnes of mixed waste plastic that today would be landfilled or incinerated to be reprocessed.”
During feedstock recycling, used plastic isn’t simply melted down and reformed, but heated to super-high temperatures in a special chamber. This breaks it down into its core ingredients, including gases that can be turned into chemicals like ethylene, which can then be used as raw materials for manufacturing plastic products.
The benefits to the environment are obvious. Less plastic waste in our countryside, rivers and oceans; less reliance on oil and other fossils fuels for raw materials; and lower emissions as a result.
The potential economic benefits for business and society are huge too. Now, most plastic packaging is used only once. In fact, it’s estimated that 95% of the value of plastic packaging material* – or £56bn to £85bn worth of plastic – is lost to the economy every year. Plastic that could be reclaimed, recycled and reused in future thanks to this cutting-edge new process.
Of course, the technology behind feedstock recycling can only make a difference if there’s a real will to change the way we all think about plastic waste and recycling. With the growing demands to act against marine plastic pollution, it seems the world is finally waking up to that need. So alongside new techniques to improve plastics recycling, expect to see more and more coordinated initiatives to promote sustainable plastic products from industry leaders like Eurocell, and from Europe-wide industry bodies like VinylPlus.
Predicting the future is always a risky business. But on plastics recycling at least, we can be cautiously optimistic that whatever lies ahead, it’s beginning to look a lot brighter.
*Plymouth University: www.pml.ac.uk/research/projects/new_plastics_economy