A trial is underway in Belgium to test whether digital watermarks can improve the sorting of flexible food packaging and help increase the availability of recycled material for food-grade applications.

The trial will examine how invisible digital watermarks can be used to identify characteristics of packaging, including its material type and whether it has previously been used for food.

As part of the project, sorted bales of flexible film collected through Belgium’s household recycling system will be analysed using specialist sorting equipment.

The material will be sent to Hündgen Entsorgungs’ sorting centre in Germany, where high-resolution cameras supplied by machine manufacturer Pellenc ST will scan the packaging and detect Digimarc digital watermarks.

The watermarks are imperceptible codes applied across the surface of packaging during the printing process. Their use is being investigated as a way of creating more targeted sorting streams, particularly for flexible food packaging, which can be difficult to recycle into high-quality applications.

The trial is being led by Fost Plus, the organisation responsible for packaging waste recycling and reuse in Belgium, and forms part of the HolyGrail 2030 – Circular Packaging Consortium.

The consortium is facilitated by AIM – European Brands Association and brings together around 79 companies and organisations, including brands, technology providers, packaging converters, sorting companies, recyclers and research institutes.

Mondelez International, PepsiCo and pladis are among the companies participating in the trial.

Richard Akkermans, European R&D Packaging Productivity and Sustainability Manager at Mondelēz International, said: “HolyGrail 2030 is a pivotal, cross-industry initiative for better sorting and recycling of flexible packaging in the EU.

“Achieving circularity for food-contact flexible plastics isn’t just an ambition, it’s a necessity.

“In order to be ready for the ambitious recycled content targets in the upcoming EU Packaging and Packaging Waste Regulation, this market demonstration aims to provide the real-life technical learning that the value chain needs in order to increase the availability, compatibility and affordability of recycled plastic coming from new technologies.”

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Food-grade Recycling

The ability to produce high-quality recycled material from flexible food packaging remains challenging, with accurate identification and sorting among the issues facing the sector.

Digital watermarking could potentially help separate packaging according to characteristics that are difficult to identify through conventional sorting methods.

However, sorting is only one part of the process required to produce food-grade recycled material, which also requires suitable recycling and decontamination processes.

Liz Morrish, CEFLEX Leadership Team – Operations Director, said: “Food-contact recycled content is where the industry has some of the biggest challenges and the least time.

“This trial moves testing from evidence-gathering into commercial reality, which is exactly what bridging the gap between ambition and the 2030 targets requires.”

The trial comes as the European Packaging and Packaging Waste Regulation (PPWR) introduces new recycled content requirements for certain plastic food packaging from 2030.

The requirements include a minimum of 10% recycled content for some contact-sensitive packaging applications, increasing the focus on technologies that could improve the supply of suitable recycled plastics.