Press release for immediate release – Brussels, 24 November 2025
We are proud to announce the successful completion of semi-industrial sorting trials on HDPE milk containers enhanced with CurvCode digital watermarking technology.
These trials, conducted at Pellenc ST’s headquarters in Pertuis, France, mark a significant milestone in advancing a circular economy for packaging, with CurvCode technology now reaching Technology Readiness Level 7 (TRL 7).
With the support of HolyGrail 2.0, the project group brought together leading companies from across the packaging value chain. HDPE milk containers, produced by ALPLA for Dutch private-label supplier FarmDairy, were coded with CurvCode digital watermarks by FiliGrade Sustainable Watermarks. The containers, both with and without sleeves/labels, were deliberately contaminated with milk to simulate post-consumer waste, ensuring the trials reflected real-world waste management challenges. The background stream consisted of baled post-consumer PE waste from the Netherlands.
The trials utilised a joint prototype machine developed by technology provider FiliGrade and machine supplier Pellenc ST, combining digital watermarking and NIR (Near Infrared) technology. Overseen by the HG2.0 technical team, the testing was conducted from September to December 2024, on both clean and contaminated samples, with process and sample optimisation throughout.
The line operated at an industrial standard speed of 3 m/s. In spite of physical limitations of the test-equipment, strong sorting efficiency and purity results were achieved.
These results demonstrate the robust performance of CurvCode technology under semi-industrial conditions. Incremental improvements – such as increasing code coverage, optimising belt distribution, and software adjustments – are expected to further enhance results and prepare the technology for full industrial trials, targeting TRL 8.
Importantly, CurvCodes applied to HDPE milk containers have minimal visual impact, preserving the packaging’s appearance and supporting brand owner and consumer acceptance.
This achievement paves the way for the next phase: industrial-scale trials to accelerate progress towards a circular economy for packaging.
FiliGrade contact: m.delint@filigrade.com
HolyGrail contact: circularpackaging2030@aim.be