Digital watermarks could be future of material sorting, says EMF

Research carried out by the Ellen MacArthur Foundation (EMF) and its New Plastics Economy programme has found digital watermarks to be the most encouraging technology in the future of waste sorting.

This has motivated AIM, the European Brands Association, to start a cross-value chain initiative to test whether watermarks can help plastic be recycled in a swifter, more efficient manner.

Happy Cow cheese with digital watermarksThe project will include over 85 companies and organisations and will be entitled “HolyGrail 2.0”.

Digital watermarks are postage stamp-sized imperceptible codes placed on the surface of a piece of packaging. They can hold a wide variety of information such as manufacturer, SKU (Stock Keeping Unit), type of plastics used and composition for multilayer objects.

After a piece of packaging has been put in a recycling bin, it will be taken to a waste sorting facility where the watermark will be scanned and packaging items will then be distributed into the correct stream depending on what kind of material it is.

The standard high resolution camera used will be able to detect specific materials in a way that people on a sorting line will struggle to decipher, leading to a much more accurate and faster process.

"The three key ingredients here are innovation, sustainability and digital, combined to achieve the objective of the [European] Green Deal towards a clean, circular and climate neutral economy", outlined Michelle Gibbons, Director General at AIM. "It is terrific to see such enthusiasm from across the industry and to be able to unite such expertise from the complete packaging value chain, from brand owners and retailers to converters, EPR [extended producer responsibility] schemes, waste management systems, recyclers and many more. Collaboration is the way forward to achieve the EU's circular economy goals."

Research has been undertaken in recent years to make the sorting process at materials recycling facilities (MRFs) as efficient as possible. With a substantial elevation in the amount of packaging being recycled, waste sorting facilities are under increasing pressure to perform to a high standard.

A “tag and trace” system, similar to the digital watermark idea, was trialled last year by Polytag. This system also featured the options for consumers to scan their products on their smartphones to view information on the recycling process.

The EMF is a key player in moving towards a circular economy, having produced “The New Plastics Economy: Rethinking the future of plastics” report with the World Economic Forum (WEF) in 2016.

It has also managed to gather nearly 300 companies to agree to eradicate plastic waste at its source and commit to eliminating problematic plastic, making 100 per cent of plastic packaging recyclable and to keep the plastic being used in circulation.

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