Sonoco accurately sorts containers in HolyGrail 2.0 digital watermarking trials

21 Jun 2022 --- Sonoco has participated in European recycling trials showing that digital watermarks yield accurate packaging sortation, distinguishing between food and non-food applications. The HolyGrail 2.0 initiative aims to assess whether digital watermarks can enable better sorting and higher-quality recycling rates for packaging in the EU. 

After recent trials in Copenhagen, Denmark, Sonoco says it can demonstrate high compatibility of its rigid paper containers using this technology across all sizes and material specifications.

“This technology could help less-developed countries to quickly get up-to-speed with the sorting of (packaging) waste, bypassing the need for cascading NIR and conveyor belt systems, and infrastructure that has been used in countries like the UK and US for decades,” Peter Görlitz, sustainability manager Europe, Sonoco, tells PackagingInsights. 

“The new technology enables the separation of food and non-food material, which is particularly important for closing material loops and increasing recycled content in packaging.”

The first HolyGrail 2.0 sorting prototype was successfully validated in March this year following semi-industrial trials using NIR and digital watermark detection to sort packaging waste with 99% success, presenting the potential to develop new, more granular post-consumer recycling streams.

Trialing digital watermarks
Holy Grail 2.0 is driven by AIM – the European Brands Association, and powered by the Alliance to End Plastic Waste.

Görlitz explains digital watermarks can contain information about packaging such as: what material the packaging is made of, if or how the packaging should be recycled, product information and more.

The HolyGrail 2.0 initiative helps to prove the viability of digital watermarking for sorting packaging waste.Trials in Copenhagen found that using digital watermarks on packaging resulted in 98-100% being correctly detected, with a subsequent total ejection rate of 90-100%.

During the live trial in a mix of five different packaging types of various brands, 96% of Sonoco’s rigid paper containers were correctly detected and ejected. These results demonstrate an additional approach to sort Sonoco’s EnviroCan rigid paper containers into the paper recycling stream.

“Other potential uses for digital watermarks on packaging include: tracking components during the packaging manufacturing process, obtaining product information when scanning at checkouts and providing additional information for consumers, for example if it’s recyclable, or component separation instructions for recycling,” adds Görlitz.

Advantages over conventional sorting
Imperceptible postage stamp-sized, digital watermarks on packaging make it possible to effectively sort packaging material into specific waste streams. Conventional sorting technologies cannot reliably identify multi-material packaging, so they can end up in the wrong recycling streams or drop to the refuse stream altogether.

The company says with this new digital watermarking technology, it becomes possible to separate materials more accurately into distinct streams, even in cases of multi-material packaging.

“The Digital Watermarks Initiative HolyGrail 2.0 has the goal of assessing whether the digital watermarks technology can enable better sorting and higher-quality recycling rates for packaging in the EU. Today, more than 160 partners across the value chain are working together to refine and commercialize this concept,” says Görlitz.

“Sonoco, one of the largest global sustainable packaging companies, is a member of the HolyGrail 2.0 initiative to prove the viability of digital watermarking for sorting packaging waste and the business case at scale, likely with global implications.”

In other news, Sonoco has agreed to acquire Ball Metalpack, a leading metal packaging manufacturer for food and household products and reportedly the largest aerosol producer in North America, for US$1.35 billion.

Ball Metalpack is a joint venture owned by Platinum Equity (51%) and Ball Corporation (49%). The business was formed in 2018 and is headquartered in Broomfield, Colorado, US.

By Natalie Schwertheim

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