Beyond polypropylene: a sustainable “drop-in” solution for industrial packaging applications

The European packaging sector, a significant and growing industry reliant on fossil-based plastics, faces increasing pressure to transition towards sustainability due to environmental concerns over waste generation and resource depletion. Regulatory mandates, alongside corporate commitments and consumer demand, are driving the need for circular economy solutions and alternatives to conventional polymers. Polypropylene (PP), a cornerstone material particularly in rigid packaging applications like extruded corrugated sheets, is central to this challenge A systematic investigation identified a blend of bio-based and compostable polyesters as a viable candidate. The formulation was optimised using mineral fillers and functional additives to achieve the necessary melt rheology and cost-competitiveness for industrial scale-up. Industrial-scale extrusion trials confirmed the material’s processability as a direct "drop-in" on existing PP machinery, requiring no hardware modifications and only minor adjustments to processing parameters. The resulting corrugated sheets exhibited favourable mechanical performance compared to the PP benchmark, including higher compressive and flexural strength and statistically identical indentation resistance and a full compatibility for standard downstream processes. To mitigate process-induced degradation and optimise performance, reactive extrusion was utilised to enhance melt strength and ductility. Furthermore, the material’s end-of-life potential was validated through mechanical recycling simulations. Results confirmed that the material maintains its mechanical and rheological integrity throughout multiple industrial regrind loops, while the use of functional processing additives further enhances the performance of recycled fractions. This research delivers a validated, circular-economy-compliant solution that aligns industrial production with evolving environmental standards without sacrificing manufacturing efficiency.