中文Recycled plastic has an image problem, and it starts with the ink. Pull a printed flexible pouch out of the waste stream and try to recycle it, and you run into a stubborn reality: the ink wants to stay put. It discolours the recovered material, leaves odours, and contaminates the very polymer you are trying to save. Siegwerk, one of the world’s big ink players, just secured a European patent that attacks this problem at the molecular level — and it is smarter than it sounds.
The patent, EP4107326, covers a deinking primer technology. The trick is placement. Siegwerk puts a functional primer layer between the plastic substrate and the printed ink. During alkaline washing — the standard step before plastic gets reprocessed — that primer lets the ink separate cleanly from the material. No scraping, no harsh extra steps, just a layer doing its job at exactly the right moment.
The patent covers both solvent-based and water-based primer systems, and it reaches into the messy world of complex flexible packaging, including structures where the print sits between other material layers. Siegwerk’s wider deinking portfolio even covers UV printing applications. That breadth matters because flexible packaging is where recycling gets genuinely hard: bigger printed areas, laminated structures, adhesives, barrier films. Rigid packaging is easier to assess for recyclability; flexibles are the wildcard.
The timing is not accidental. The European Union’s Packaging and Packaging Waste Regulation (PPWR) starts introducing minimum post-consumer recycled-content requirements in 2030. The industry group CEFLEX estimates around 2.5 million tonnes of post-consumer recyclate from flexible packaging will be needed by then to hit those targets. To get there, the recovered material has to be consistently clean. Ink contamination is one of the things that quietly sabotages that goal.
Lara Kleines, Siegwerk’s recycling and polymer expert, noted that improving recyclate quality becomes more important as the value chain races to meet higher recycled-content rules — and that no single deinking approach will suit every construction or recycling stream. That honesty is refreshing. There is no magic bullet; there is good chemistry applied in the right place.
Siegwerk has already tested the technology across substrates, ink systems, and packaging constructions, both in its own labs and through collaborative industry projects. One standout example: a recyclable mono-material flexible pouch developed with partners that showed effective ink removal during recycling and picked up a German Packaging Award in Gold. That is the kind of proof point brand owners and converters actually trust — not a white paper, but a trophy.
The patent also complements Siegwerk’s U.S. patent (US12291051B2, granted in May 2025), strengthening its intellectual-property position around packaging deinking on both sides of the Atlantic. For a company, that protection is how you justify continued investment in circular solutions.
For printers and converters, the lesson is that ink and coating chemistry is no longer just about how the package looks on the shelf. It is part of the package’s whole-life story. Designing ink removal into the structure — rather than hoping the recycler figures it out later — is how printed flexible packaging becomes compatible with mechanical recycling and yields cleaner, higher-value plastic. As regulations tighten and brand owners chase real circularity, the converters who understand this now will be the ones winning the work later.
A little primer, in the right place, might be the reason tomorrow’s recycled plastic doesn’t carry the ghost of yesterday’s artwork.
Information source: INKISH.NEWS (inkish.news)
