Digital watermarks trial starts in Copenhagen

Developers move one step closer to precision identification and sorting of plastic packaging waste through digital watermarks, with the potential to revolutionize the sorting and recycling process.

Over the next four months, a prototype sorting detection unit will be installed at the Amager Resource Centre (ARC) in Copenhagen, where the trials and demonstrations with around 125.000 pieces of packaging representing up to 260 different stock-keeping units (SKUs) will be held. Engineers will test for several parameters, including the speed and accuracy of the system, to ensure its ability to withstand the pressures of full-scale industrial operations. 

If successful, digitally watermarked products could be introduced to store shelves in Denmark, France, and Germany by the first half of 2022 for in-market demonstrations and industrial-scale trials.

Digital watermarks are imperceptible codes, each the size of a postage stamp. They cover the surface of a consumer goods packaging and carry a wide range of attributes such as packaging type, material and usage. 

Used packaging is collected and scanned on the sorting line with a high-resolution camera which detects and decodes the digital watermark. The packaging is then sorted into corresponding streams based on specified attributes, including food, non-food, or polymer types. This leads to more accurate sorting streams and higher quality recyclates to be channeled back into the plastic packaging value chain. 

This milestone marks the second year of the HolyGrail 2.0 project. Since its launch in September 2020, it has grown to include over 130 participating companies and organizations across the complete packaging value chain. The pioneering HolyGrail 1.0 was facilitated by the Ellen MacArthur Foundation between 2016 and 2019. 

‘We are delighted to enter the next phase of semi-industrial testing within the digital Watermarks Initiative together with our new partner, the Alliance to End Plastic Waste,’ said Michelle Gibbons, director of AIM. ‘An initiative like this can only thrive with the wide support of different key stakeholders in terms of expertise, but of course also financial support. Collaboration is the way forward to achieve the EU's circular economy goals, and we are confident that this technology has the potential to drive a truly circular economy for packaging.’

‘Recycling is a key pillar that must be invested in to advance a circular economy in plastic waste. The Alliance is excited to support the scaling of this project in its next phase of progress, in line with our mission to end plastic waste in the environment,’ added Jacob Duer, president and CEO of Alliance to End Plastic Waste. ‘As testing continues, we know there will be many things to solve along the way, but with strong collaboration of our public and private sector partners, we believe intelligent sorting can be a new frontier that could help dramatically improve plastic waste management.’

‘The City of Copenhagen has a political ambition to become the world’s first carbon-neutral capital by 2025. High-quality plastic recycling that substitutes new production and reduces incineration is a key instrument to reach this goal. HolyGrail 2.0 has the potential to achieve this, and we look forward to doing our part in the testing of the technology,’ said Merete Kristoffersen, head of the Waste and Resources division at the City of Copenhagen.

With the commencement of semi-industrial trials, HolyGrail 2.0 is on track to get to the exciting phase of in-market demonstrations planned for 2022.

The two machine vendors, Pellenc and Tomra, and the selected digital watermarks technology provider Digimarc are developing add-on modules for their detection sorting units to be combined with existing NIR (near infra-red) sorters. 

Both modules will be tested during the semi-industrial phase via trials at two different test locations. The first controlled tests using industrial-sized equipment and the Pellenc ST/Digimarc module are scheduled for October 2021 at ARC sorting center. 

Pending successful completion of the semi-industrial trials, brand owners and retailers will bring their enhanced products to Denmark, France, and Germany. During this commercial test phase, consumers will buy on-shelf products with digitally watermarked packaging. Used packaging will enter the waste stream after consumption. The sorting units will be placed in five different locations in France and Germany, including MRFs (Materials Recovery Facility), PRFs (Plastic Recovery Facility) and recycling plants. 

This last phase is scheduled to run until Q3 2022, and a public report outlining the techno-economic analysis of the digital watermark technology for sorting packaging waste will be issued.