Redesigning the appearance of recycled containers for packaging applications: The effect of paper waste physicochemical properties on the performance of paperboards with obvious recycled content.

Significant efforts have been made over the past decade to facilitate the recognition of environmentally friendly packaging and promote sustainability. Yet, consumers remain confused by the excess of labels and claims used to communicate sustainability. In our previous work, we modified the appearance of recycled fibre‐based packaging by incorporating visible particles of fibre‐based waste. This strategy enabled consumers to better identify packages with a high recyclability level, enhancing their environmental perception towards sustainable products. However, the incorporation of such large waste particles proved to be detrimental to the mechanical properties of the paperboards. In this study, we further investigate the influence of the physicochemical properties of the added fibre‐based waste on packaging performance. Using a similar strategy to enhance the environmental perception, we herein studied the effect of mixed office waste (MOW), old magazines (OMG), and polylactic acid (PLA) paper cups. The presence of hydrophobic and difficult‐to‐process and difficult‐to‐disperse waste, such as the PLA paper cups, significantly altered the mechanical performance of the paperboards, whereas more hydrophilic and easy‐to‐disintegrate waste (MOW and OMG) had a lesser effect regardless of the size of the particles. Strength agents such as cationic starch (CS) and cellulose microfibrils (CMFs) successfully restored the properties of the paperboards containing MOW and OMG but were less effective for PLA paper cups. A multi‐ply strategy overcame the limitations of CS and CMFs using the redesigned paperboard as an outer ply for aesthetic purposes and a 100% recycled inner ply for restoring strength. [ABSTRACT FROM AUTHOR]