Effects of Milk and Cream Residual Contents in Beverage Carton Packaging Used for Recycling

Abstract

Milk and cream are often sold in beverage carton packaging. After use, the unconsumed liquid residues and adhering content remain in this packaging. These food residues end up in the recycling cycle, where they pose troubles in the aqueous processing. The aim of this empirical study was to quantify milk and cream residues in beverage carton packaging from recycling streams. 949 recovered cartons that had been filled with milk or cream and consumed in Germany, Austria, and the Czech Republic were analyzed by gravimetric measurement. For 1-liter cartons, the mean value of the residual quantity was 6.6 g residue for every liter filling quantity, with a range of 1.0 to 71.9 g/L. This corresponds to 0.66% residual quantity by mass, with an assumed density of 1.0 g/cm³. Considering a mean value for all the carton weights with residual quantity of 35.8 g for 1-liter cartons, here some cartons without closures, and 29.2 g without residual quantity, this results in a packaging material content of 81% by mass for recycling. The rest is food waste that ends up in the recycling stream. This can be a task for packaging designers to further improve easy-to-empty solutions.