CurvCode digital watermark technology is key for high-quality recycling of Multilayer flexible packaging

The CIMPA project shows that digital watermarking is an effective technology for advanced sorting of Multilayer flexible packaging. The CurvCode digital watermark, together with NIR detection, enables sorting based on criteria like ‘material structure’ and ‘usage’ (food versus non-food). This last feature is highly important when using recycled waste to manufacture new food-packaging.

FiliGrade has designed sample Multilayer flexible packaging carrying CurvCodes specifically for CIMPA. Sample packaging with CurvCodes were produced by CIMPA partners Eversia (Spain) and Leygatech (France), plastic films manufactures.

Some of the packaging products designed for CIMPA are shown in Figure 1.

FiliGrade – in close cooperation with CIMPA partner Pellenc ST – developed a joint prototype sorting-line combining NIR and digital watermarking technologies. This prototype generates sorted fractions that meet specific quality criteria. These results cannot be achieved when these technologies are used on a stand-alone basis.

Sorting trials were carried out using the joint prototype located at the facilities of Pellenc ST. Even though the joint prototype is not yet fully optimised for sorting flexible packaging, the yield and purity results are compelling.

Using sample Multilayer flexible packaging carrying CurvCodes produced for CIMPA, very strong ‘first-pass’ sorting results were achieved under semi-industrials conditions. Sorting yield averaged around 94% with purity-levels exceeding 80%. NB. After using a ‘second/third’ sorting cascade, purity and yield levels exceeded 99%.

Encouraged by these promising results, FiliGrade and Pellenc ST will continue working on the joint prototype in 2024.

CIMPA white paper

The results obtained within the CIMPA project on sorting have been summarized on the white paper “Two automated sorting solutions for multilayer flexible packaging”, writted by Filigrade and Pellenc ST.