Influence of plastic packaging design on the sensor-based sortability in lightweight packaging waste sorting plants

Abstract

Lightweight packaging (LWP) waste is the largest post-consumer plastic waste flow in Germany. A crucial step in plastic recycling is sensor-based sorting (SBS) of LWP in sorting plants. While a more sorting- and recycling-friendly product design is believed to enhance SBS and plastic recycling in general, data to estimate this potential is limited. Here, we aim to quantify the real-world sortability of LWP articles by assessing a SBS cascade for plastic-type separation in a state-of-the-art LWP sorting plant. Our results reveal a polymer-specific distribution of packaging types and quantitatively confirm negative influences of sleeves/labels, composites, dark colors, and rolling shapes on the sortability at sorting plant scale. By extrapolating our results to all LWP sorting plants in Germany, we estimate that up to 48,300 Mg/a (95 % CI: 25,900 Mg/a – 78,500 Mg/a) rigid plastics could be additionally recovered at sensor-based plastic-type separation level alone through improved sortability.