EVALUATION AND ENHANCEMENT OF RECYCLABILITY FOR COATED PACKAGING PAPERS

Abstract

In order to meet the European target for recyclability of packaging materials in general, and paper packaging in particular, harmonized guidelines have recently been published to test and assess the recyclability of coated papers, based on repulping and screening of recycled fibers in combination with visual evaluation of the quality of papersheets. Based on a design-for-recycling strategy, a first estimate can be made for the recyclability of current paper coatings, but the constant new developments in the sector and the commercialization of new coating materials require a standardized framework for experimental evaluation of recyclability. In this study, the testing protocol was validated in relation to variations in the repulping conditions such as repulping temperature, and number of revolutions for a selection of industrial packaging papers, including acrylic dispersion coatings or LDPE laminated paper. The testing procedure seems robust as influences of repulping temperature are inferior in the range of 30 to 50°C, while the influence of the number of revolutions is more critical and levels off within a given operation window. The statistical differences between repulpability of non-recyclable and recyclable packaging papers are detected in a benchmarking study against newspaper or tissue paper. For difficult-to-recycling papers, opportunities for improvement of coating removal or valorization of mixed fiber/coating brokes collected in the reject fraction should be further explored. As such, the functionality and circularity of coated papers can simultaneously be enhanced.