Recycling of a multilayer barrier food packaging through the use of a nanofiller: Effect of post-consumer plastic bag conditions

Barrier food packaging films result very difficult to recycle since they are multilayer films composed by at least two different materials. In this context, aim of this study was to assess the use of a nanofiller for the mechanical recycling of multilayer barrier plastic bags used for food vacuum packaging. In particular, graphene nanoplatelets (GnPs) were used as nanofiller studying the effect of their concentration on the properties of the nanocomposites obtained by using polyamide (PA)/polyethylene (PE) bags as polymeric matrix. Moreover, the effect of plastic bags life conditions on the nanocomposite properties were evaluated by exposing the multilayer films to accelerated weathering or to contact with a fatty food simulant (olive oil). The results indicated that the incorporation of GnPs led to an enhancement of the morphology of the polymer blends, consequently resulting in nanocomposites with increased stiffness without a drastic reduction in ductility. The nanocomposites produced using post-consumer bags exhibited lower properties compared to materials produced using pre-consumer bags. However, even in this case, the addition of GnPs contributed to an improvement in the properties demonstrating that the use of this nanofiller can be a viable method to recycle multilayer packaging.