Descriptive study and evaluation of shrink hoods with recycled content for regulatory compliance

Abstract

In preparation for the European Commission's Packaging and Packaging Waste Regulation (PPWR), mandating 35% recycled content in tertiary plastic transport packaging by 2030, distributors are already producing films with similar content. As part of the TETRA-CORNET MultiRec project (HBC.2023.0176), funded by VLAIO VLAIO and in collaboration with industry partners, this case study evaluates shrink hoods with 30% and 35% post-consumer recycled (PCR) content, designed to protect palletised loads of 1.3 tons of bricks. This study provides a framework for systematic assessment of these films, enabling their improvement in a later phase, aligning with regulatory requirements and ensuring transport performance, and identifying correlations between mechanical, thermal, and chemical properties as well as transport performance. Key mechanical properties, such as coefficient of friction (dynamic COF: 0.19–0.25), tensile stress, and thermal shrinkage, were analysed, revealing notable variability between films. Differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) assessed thermal transitions (melting peaks: 118–124 °C) and molecular weights, while gas chromatography-mass spectrometry (GC-MS) identified additives. PCR granulates exhibited notable variability, including lower melt enthalpy (95-103 J/g) compared to the full films (>108 J/g), indicating reduced crystallinity. Granulate colour varied noticeably, with lighter ones having lower molecular weight (199.6 kg/mol) than darker ones (275.3 kg/mol). Transport simulations further highlighted performance differences between films, emphasizing the need for tighter control over variables such as PCR composition, compensatory measures in virgin fractions, and production parameters. In conclusion, this study highlights the variability in both PCR granulate and film properties, emphasizing the need for systematic and open research to address performance challenges and support the transition to circular materials while maintaining sufficient transport protection in demanding applications.