Circular Economy, Sustainability, Recycling

Digital Watermarks: tests successful

12/04/2022 | 2 min read

Amber Augustus

Second phase of the HolyGrail 2.0 Digital Watermarks initiative completed with semi-industrial tests
Cups from Greiner Packaging convinced with over 90 % identification and ejection rate
Third phase with commercial products to start soon in test markets Denmark, France and Germany

Digital watermarks are invisible to the human eye, yet they contain a trove of information. They will play a key role in the packaging market and Europe’s sorting facilities in the future, especially when it comes to recyclability.

160 partners from right across the value chain

The HolyGrail 2.0 Digital Watermarks Initiative is driven by the European Brands Association (AIM), powered by the Alliance to End Plastic Waste, and supported by more than 160 well-known companies and organizations from across the entire packaging value chain. Its members aim to use digital technology to improve how packaging waste is sorted, making it easier to obtain high-quality recyclates in the EU. The industry pools its expertise from one end of the packaging chain to the other, with the stakeholders involved in the project ranging from brands, retailers, and converters to EPR systems, waste disposal systems, and recycling companies. Greiner Packaging is also a partner: “Close collaboration with full commitment is the only way to achieve the European goals for a well-functioning circular economy,” says Amber Augustus, product group manager and project manager for the initiative at Greiner Packaging. “We need do a better job of sorting of our postconsumer waste in EU waste management systems – and that includes accurately identifying plastic packaging. This will result in more efficient, higher-quality recycling.”

Semi-industrial sorting test completed

The goal of the initiative is to prove that digital watermarking technologies can be used for accurate sorting on a large scale. The Digital Watermarks Initiative HolyGrail 2.0 is divided into three phases. In the first, a prototype watermark detection system was developed. In the second phase, which has just been completed, semi-industrial sampling and testing was carried out. At Greiner Packaging, we produced different types of packaging for that – direct-printed cups, sleeved cups, IML cups, and our K3^® cardboard-plastic combinations were sent to the test sorting facility in Copenhagen, Denmark.

Amber Augustus, Global Product Group Manager at Greiner Packaging

90%-plus identification and ejection rates for Greiner Packaging

The results achieved by these novel watermarked packaging solutions are promising – the majority of cups from Greiner Packaging performed impressively with 90%-plus identification and ejection rates. “Of course, we feel very positively about those results, but we also take some learnings from the tests,” Augustus states. The digital watermarks are incorporated into the decoration on the packaging, so the way a cup arrives onto the sorting line is critical. Due to their size and geometry, short cups particularly often end up on the conveyor belt with their undecorated bottom or opening facing up. When this is the case, the watermarks cannot be detected. Nor will there be watermarks present that can be detected by the system if the decoration is lost at an early stage – for example, if the consumer separates the cardboard sleeve from a cardboard-plastic combination and disposes of it separately.

Digital watermarks in 3D

We need a new approach to situations like these. We are therefore starting with an attempt to integrate 3D digital watermarks, embedded in plastic, directly into the plastic packaging itself.

Amber Augustus, Global Product Group Manager bei Greiner Packaging

Phase 3 with commercial products

In the third phase of the initiative, brand manufacturers are now going a step further, with activities across the entire value chain and an expanded project scope. The aim is for digital watermarks to prove their potential under real market conditions. Commercial products will be brought to three test markets (Denmark, Germany, and France), with large quantities required for the test results to be meaningful. “Naturally, we at Greiner Packaging also want to do our part here. That is why we are currently in talks with potential partners to supply with packaging solutions that feature digital watermarks,” Augustus explains.