IN Brief:
- Belgium's trial places invisible digital watermarks on flexible polypropylene food packaging entering normal household collection.
- Smart sorting will be followed by recycling trials, new-film production, and food-safety testing through early 2027.
- The project is testing whether a controlled food-contact PP stream can support future recycled-content requirements.
Fost Plus is leading a Belgian national-scale trial using invisible digital watermarks to separate flexible polypropylene food packaging from non-food material, with PepsiCo, Mondelēz International, Ferrero, and pladis among the participating brand owners.
The HolyGrail 2030 project is testing whether a distinct food-contact recycling stream can be created under normal retail, household collection, and sorting conditions. Flexible polypropylene packs such as crisp packets, snack wrappers, and films are marked before entering the Belgian market and then follow the country’s existing PMD collection route after use.
Specialist cameras detect the imperceptible digital watermark during the sorting stage, allowing marked food packaging to be separated from non-food flexible PP. Sorting trials are being conducted at Hündgen Entsorgung’s facility in Germany, where watermark-recognition equipment is used to create the additional material stream.
The technical problem is more specific than identifying polypropylene. Existing sorting systems can separate material families, but flexible PP from food and non-food applications can still arrive in the same output stream, limiting its suitability for returning to food-contact packaging.
Fost Plus states that there is currently no approved route to reprocess recycled flexible PP into new food packaging. HolyGrail 2030 is therefore testing whether application history can be carried with the pack through a machine-readable code and used as another sorting criterion.
The trial is deliberately operating with packaging that has been bought, used, folded, damaged, or contaminated by consumers rather than with pristine laboratory samples. That exposes the watermark system to the same handling conditions it would face if deployed commercially.
Sorting is only the second stage of a five-step programme. The separated food-contact PP stream is due to move into recycling tests during the fourth quarter of 2026, followed by film production between December 2026 and January 2027 and food-safety evaluation in the first quarter of 2027.
Those later stages are critical because a successful sort does not create food-grade recycled polymer by itself. The project still has to establish whether the separated material can pass through suitable recycling processes, be converted into film with usable performance, and meet the relevant European food-safety requirements.
The partner group reflects that full-chain requirement. Alongside the food and snack brands, Digimarc supplies digital-watermark technology, Pellenc ST contributes sorting equipment, Hündgen operates the sorting facility, and AIM facilitates the wider HolyGrail 2030 programme.
Belgium is acting as the national test market because the packaging can move through established household collection and sorting infrastructure before the additional watermark step is applied. The project is supported by Vlaanderen Circulair and forms part of a wider initiative involving around 75 companies and organisations.
The regulatory backdrop is the EU Packaging and Packaging Waste Regulation, which began applying generally in August 2026 and introduces future recycled-content requirements for plastic packaging. For certain contact-sensitive plastic packaging other than PET, the regulation sets a 10% recycled-content requirement from 2030, subject to the detailed statutory framework.
Those targets increase pressure on the supply of material that can be used in food-contact applications. Existing work on PPWR recycled-content calculation and verification will determine how qualifying material is counted, while the Belgian trial addresses the earlier physical problem of generating a sufficiently controlled feedstock in the first place.
Flexible packaging remains difficult because the formats are lightweight and efficient in use but challenging to collect and recycle into equivalent applications. A digital watermark does not change the polymer or solve contamination; it adds information that sorting equipment can use when deciding which packs belong in a more tightly controlled stream.
The approach will therefore stand or fall on detection accuracy, sorting yield, recycling performance, food-safety results, and economics rather than the watermark alone. Packaging that cannot be detected reliably after household use would reduce the purity of the stream, while a very pure stream still has limited value if recycling costs or film performance make closed-loop use uneconomic.
Fost Plus expects initial findings during the second half of 2026, with the full HolyGrail 2030 report and its own evaluation due in 2027. The project currently lists full implementation as a 2029 objective, leaving a relatively short period between validation and the 2030 recycled-content requirements.
That timetable gives the trial a practical focus. Brand owners need to know whether watermarking can be incorporated into packaging artwork and production, sorters need to know whether the signal survives real use, and recyclers need a feedstock that can be processed at useful scale and quality.
If those stages work together, digital watermarks could create a new sorting layer for flexible food packaging without requiring consumers to use a separate collection system. If they do not, the project should expose where the bottleneck sits — detection, sorting, recycling, safety, or economics — before companies commit to a wider rollout.
The final decision is therefore still some distance away. The current trial has moved the concept into real household material flows; the next tests will determine whether that extra information can be converted into recycled polypropylene that is technically and commercially suitable for new food packaging.
