The push for eco-friendly packaging solutions has reached a critical juncture with the recent approval of the European Packaging and Packaging Waste Regulation (PPWR). This regulation emphasizes the importance of reducing waste and promoting sustainable practices through the 3R rule: Reduce, Reuse, and Recycle. While much attention has been given to structural materials, the role of chemicals such as inks, varnishes, and adhesives in ensuring recyclability has come into sharper focus.
“The use of inks and other chemicals significantly impacts the recyclability of printed packaging. However, specific criteria for recyclability under PPWR have yet to be defined. These will be published as 'Delegated Acts' by 2028, two years before recycling requirements take effect in 2030,” says Dr Lars Hancke, Manager Business Development Flexible Packaging at hubergroup Print Solutions.
But recycling targets under the regulation are ambitious: By 2030, all packaging must be recyclable. By 2035, flexible packaging must achieve a 55% recycling rate through “recycling at scale.” The challenge, according to Dr Hancke, lies in developing the necessary recycling infrastructure to meet these targets.
Extensive studies have been conducted to assess how printed inks influence the recycling process. Some notable challenges include:
• Lack of transparency in recycled films
• Stability issues at high temperatures (240–250°C) during the regranulation process
• Formation of volatile breakdown products
• Negative effects on the organoleptic (odour) and mechanical properties of recycled materials
“Scientific investigations, including those by RecyClass and Ceflex, indicate that nitrocellulose (NC) can pose challenges for mechanical recycling when used at higher concentrations. We anticipate restrictions on NC-based inks, likely in the form of maximum concentration thresholds,” Dr Hancke noted.
In the face of these developments, printers have several pathways to adapt:
• Threshold Compliance: If NC thresholds are introduced, printers can calculate and ensure compliance, continuing to use NC inks within limitations (e.g., 0.8% by weight). Combinations like NC/PU-coloured inks and pure PU white inks can work well within these limits.
• Switching to NC-Free Solutions: Printers who wish to avoid compliance calculations can opt for NC-free alternatives. In lamination, PU or polyvinyl butyral (PVB) systems may become preferred. For surface printing, ink suppliers are actively developing NCfree options equivalent to current NC/PU systems.
• Deinking Technologies: Integrating a deinking step into the mechanical recycling process can mitigate the impact of inks. Deinking typically involves hot washing at 40–80°C with 1–2% sodium hydroxide and surfactants. While surface printing responds well to this method, challenges remain for lamination.
Recommendations for Flexible Packaging Printers
Dr Hancke advises printers to stay informed and collaborate closely with their organizations and ink suppliers. “The landscape is evolving rapidly, and staying ahead requires proactive adaptation.” As the packaging industry faces increasing pressure to align with sustainability goals, the role of inks and chemicals in achieving these objectives cannot be overstated. Printers, converters, and brand owners must navigate this complex terrain with a keen eye on regulatory developments and innovative solutions. Dr Hancke’s insights underscore the importance of collaboration and readiness in shaping a more sustainable future for flexible packaging.