While the recyclability of foamed polystyrene (PS) trays had previously been proven in practice, this has now also been confirmed by Styrenics Circular Solutions (SCS), the value chain initiative that is working to establish a circular economy for styrenic polymers.
The high purity mechanical recycling process for PS that has already been shown to be able to achieve purity levels that exceed 99.9%, has now been successfully adapted for the recycling of extruded polystyrene (XPS) food trays, making closed-loop processing of these food trays a real possibility.
In this case, the feasibility of the process was demonstrated in a collaborative effort undertaken by a number of actors across the value chain. The Corepla consortium, which already routinely collects post-consumer foamed PS trays in Italy, created a sorted fraction of foamed PS at its sorting centres. SCS member Tomra and waste management company Zimmerman then carried out the high-purity mechanical deep sorting, hot washing and flake sorting steps.
According to Tomra, foamed polystyrene packaging can be effectively and efficiently separated and sorted with existing technology, as styrenic compounds have a unique signal that enables easy and very precise sorting, an advantage which some of the other polymers do not have.
Recycling company Forever Plast S.p.A. was responsible for the dewatering and subsequent processing into PS recyclate. SCS member Versalis (Eni) verified the high purity of the PS recyclate in a quality assessment and converter Magic Pack, a member of ProFood (Unionplast), incorporated the recyclate into new foamed PS food trays.
The foamed PS trays produced according to this process are made up of 50% rPS, as well as being 100% recyclable themselves. They can also be recycled multiple times over again. For use in food contact applications, an ABA structure is opted for, in which recycled PS is used for the middle layer. Virgin PS is used for the two outer layers.
ProFood has already started commercialising the use of rXPS in combination with a PS functional barrier.
“This success story has positive implications far beyond Italy. The proof that XPS food trays can be effectively and efficiently sorted, recycled and returned even to its original food contact applications, should inspire accelerated scale-up,” said Jens Kathmann, Secretary-General of SCS.
“The results confirm that XPS trays are fully circular: they are already today widely collected in Corepla’s collection system in Italy,”added Claudio Bilotti, Polystyrene marketing manager at Versalis (Eni).
“The trays are easily sortable in Corepla’s existing sorting facilities and now have proven in practice to be recyclable in a closed loop thanks to the innovative high-purity mechanical recycling process adapted from rigid PS to foamed PS. The entire value chain is driving the rapid establishment of a high-purity recycling channel for all major PS applications and the uptake of rPS including from foamed PS trays into new products, including food packaging."
In France, “PS25”, a consortium composed of food manufacturers and producer responsibility organisation (PRO) Citeo, has agreed to finance a recycling scheme for polystyrene, including XPS, that will recycle yoghurt pots and meat or fish trays.
In Sweden, Swedish Plastic Recycling, is building a facility called Site Zero, which will be able to handle 200,000 tonnes of plastic packaging per year, double the current capacity. Eventually, the site will be able to recycle all packaging from the Swedish households, says Mattias Philipsson, CEO of Swedish Plastic Recycling. The facility will be completely climate neutral, with zero emissions.
Ireland has announced it will continue the separate collection of plastic household waste, including XPS packaging.
Belgian household packaging producer responsibility organisation Fost Plus has extended its separate collection in the ’blue bag’ to XPS food trays, among other items.