Recyclability of flexible laminates currently used in/for foodpackaging
Within CRISP (Center for Research in Sustainable Packaging) Wageningen Food & Biobased Research studied the recyclability and circularity of flexible laminates that are used in packaging applications.
Multi-material flexible packaging laminate films (MFPF) are used to pack a variety of processed food products (coffee powder, grated cheese, cured meats, prebaked breads, etc.). These MFPF protect the food products efficiently; with the least amount of packaging materials. A downside of MFPF packaging is that they are either more difficult or even impossible to recycle. Therefore developing better recyclable MFPF packaging is an important research topic, that needs methods to determine and define the recyclability of these packaging films.
In this project we developed methods to study recyclability considering all steps in the recycling value chain; collection, sorting, mechanical recycling and processing. This includes recognition by consumers during collection, the fate and behaviour during sorting (NIR recognition), mechanical recycling (float sink separation), the effect during processing (extrusion and film blowing) and on the recyclate quality (mechanical and optical properties). The flexible laminates studied were metallised PP film, PE/PA films , PE/PET films and PE/EVOH pouches. The study consisted of two main parts. The first part focusses on studying the recyclability of post-consumer MFPF and their effect in post-consumer PE film. The second part studies the lab scale recyclability of clean (pre-consumer) MFPF and their effect when processed with virgin film-grade PE pellets.
The study showed that most MFPF packaging will be difficult to remove from other packaging films even when combinations of NIR sorting and float-sink separation are used. This implies that they will be sorted into a recycling product that is predominantly composed of PE flexibles. TMFPF packaging negatively influences the processing behaviour (film blowing) of PE and the optical properties of the produced films. The study also showed that other contaminants (other types of plastic films, inks, glues, packaging components like paper labels) also hinder circular use of post-consumer PE film products. This implies that assigning measured effects to MFPF or other contaminants is extremely difficult and that film to film recycling of post-consumer packaging is challenging.