Mechanically recycled PS offers drop-in solution for food applications

While the entire styrenics value chain has joined together to deliver on the intrinsic circularity of styrene, it might be said that it is the converters who are on the front line.

At Styrenics Circular Solutions, we know our converter members have a direct relationship with the brand owners and retailers and that they share their desire for the development of sustainable packaging for end consumers that retains all the excellent properties that polystyrene has to offer.

Recently, several converters had the opportunity to test food contact mechanically recycled polystyrene in their existing facilities - with overwhelmingly positive results.

Having been able to show that rPS truly offers a drop-in solution is hugely important for converters and brand owners: it means there is no need to purchase new equipment or make any adjustment to their existing extrusion or Form Fill Seal.

Moreover, the fact that the final application - in this case, yoghurt multipacks made from rPS - display the same performance as pots made from virgin material is crucial to brand owners and retailers alike.

The key test results shared by COEXPAN and Intraplás when they compared the behaviour of mechanically recycled polystyrene with virgin polystyrene in their existing facilities, showed that recycled polystyrene behaves exactly as virgin material. No adjustments were required in their equipment and the machines demonstrated the same productivity. Multipack yoghurt pots were produced using the existing form and fill and seal (FFS) machines, with both companies reporting that recycled polystyrene produced impeccable pots, with equipment running as normal, the same heating requirements, the same cutting tools and no change in productivity. (Intraplás:https://youtu.be/Tt2ihbWaJng )

“We found that rPS yoghurt pots have the same look and feel as those made of virgin PS,” said Anabela Ferreira of Intraplás. “They also retained the same resistance to vertical compression, an important factor for our brand-owner clients when they are transporting the yogurt, meaning no change is needed to their logistical process. Another winning factor is the fact that rPS multipack yoghurt pots also featured the all-important snap-ability.”

This latter feature was especially appreciated.

“The fact that a pot can be separated from a multipack with that same audible “snap”, a clean, safe break, is valued by brand-owners, retailers and consumers alike”, Ferreira added.

In addition to the tests conducted by COEXPAN and Intraplás, another SCS member, Greiner Packaging has been using recycled polystyrene in its plants and working with Swiss retailers Migros, running tests on the filling process at ELSA, part of Migros. They report achieving similar  positive results, confirming that recycled polystyrene can indeed be used as a drop-in solution. As Tobias Strasser, Managing Director, Greiner Packaging, attested: “When we converters present recycled polystyrene to our customers, we are able to deliver the same high quality as we did with virgin. There is no mechanical loss and so polystyrene is infinitely recyclable.”

(COEXPAN: https://youtu.be/XElHaw0b8S0 )

Converters are embracing recycled polystyrene as a new benchmark polymer for the industry. rPS retains the excellent qualities that converters appreciate when using virgin polystyrene. These include the rigidity of the material, meaning that less plastic needs to be used per yoghurt cup compared to other polymers - an important factor for brand owners and retailers. In addition, converters found that rPS retained the same levels of high productivity and low energy consumption (30 – 50% less than any available alternatives), with as result a smaller CO2 footprint.

Iain Sturges of COEXPAN explained this as follows: “Not only is rPS as good as virgin, but could even be described as better than virgin. The ‘r’ in rPS is all important as it demonstrates sustainability. From the market standpoint, there is a strong pull and interest in recycled polystyrene, with customers seeking the sustainable, fully circular element within their production and packaging. Recycled polystyrene delivers that in a truly outstanding, unparalleled way.”

Djivan Djierdjian, Executive Director of SIAMP-CEDAP, summed up this new era: “Polystyrene is now truly circular, meaning that the full population of all applications of any polystyrene product can now be sorted and are made fully circular by mechanical recycling even for food contact, or indeed by depolymerisation or dissolution, the two complementary recycling technologies that SCS is also focusing on.”

These developments and the sustainability implications are momentous for the entire value chain. Now that we have filed our first application for EU authorisation for food contact, and the performance of rPS meets the high expectations of converters and their brand-owner and retailer customers, our mission to fulfil the intrinsic circular potential of styrenics is coming to fruition. The whole value chain is now focussed on the scale up of recycling capacities in line with the EU Plastics Strategy.