Plastic packaging plays a vital role in our daily lives, providing convenience and protection in countless applications. Unfortunately, it also has a significant environmental impact—but this doesn’t have to be the case.
In a circular economy, the valuable materials used in plastic packaging are recovered from waste streams and then reused in new products. The EU’s updated Packaging and Packaging Waste Regulation (PPWR) aims to accelerate the transition to a circular economy by setting mandatory recycled content targets that packaging manufacturers have to meet by 2030 and 2040.
Improving waste streams is key to increasing recycled content
Currently, just 12.6% of the plastic used in packaging is made from post-consumer recycled content.¹ The PPWR targets vary depending on the type of plastic and its use, but the gap between where we are now and where we need to be is significant.
To meet these regulatory requirements, we need more high-quality recycled plastic—and for that, we need greater quantities of high-quality waste that is suitable for recycling channels. Today, only 26.9% of plastic waste in Europe is recycled, with far too much recyclable plastic ending up in landfill or incineration.²
The main challenge lies in efficiently sorting mixed waste streams. The HolyGrail 2.0 initiative is directly addressing this issue with an innovative solution: digital watermarking technology.
What is digital watermarking?
Digital watermarks are small, imperceptible codes that cover the surface of plastic packaging. The codes store information about the type of plastic and its application, among other details. These codes can be detected and read by high-resolution cameras on sorting lines, allowing the waste packaging to be efficiently and accurately sorted into appropriate waste streams.
HolyGrail 2.0, led by AIM – European Brands Association and powered by the Alliance to End Plastic Waste, is leading efforts to evaluate the potential of digital watermarking technology. Bringing together over 120 companies and organizations from across the packaging value chain, the initiative aims to demonstrate the technical and economic viability of using digital watermarks to accurately sort packaging waste on a large scale.
Recent trials have shown promising results. Focused on sorting flexible packaging to create specific types of output fractions—notably food-grade PP flexibles and hygiene-grade PE flexibles—from a mixed waste stream, the trials aimed to validate the technology’s detection and sorting capabilities on an industrial scale.
Carried out in an industrial setting (the Huendgen Entsorgung material recovery facility in Germany), the tests used real waste streams with additional quantities of digitally watermarked polypropylene (PP) and low-density polyethylene (LDPE) films mixed in. The results were impressive, with detection efficiency exceeding 95%, sorting efficiency over 85%, and purity levels above 70%. When using two-pass sorting, the purity levels of the output fractions could improve by another 20%.
Moving towards smarter sorting
Following the success of the trial on flexible packaging, the next phase involves a three-month trial at the same site to sort post-consumer digitally watermarked rigid packaging introduced to the Danish and German markets by various HolyGrail 2.0 member companies.
Following this, two industrial recycling tests will assess the sorted materials, with Borealis testing the PP films and PE flexibles, and another site handling the non-food PET bottle stream.
While the timeline for digitally watermarked packaging to reach the market is still uncertain, these trials clearly demonstrate the technology's potential. Implementing it would lead to better, more accurate sorting, resulting in higher quality recyclates that benefit the entire packaging value chain and move us significantly closer to a circular economy for plastics.
Want to learn more about Digital Watermarks?
To stay up to date on how we are accelerating action on circularity follow us on LinkedIn
¹ Figure from 2022. Source: Plastics Europe (2024), “The Circular Economy for Plastics: A European Analysis”, p19.
² Ibid, p20
Comments