CIMPA’s members worked on a questionnaire to collect data from waste management and recycling organisations. These data aimed to address technical requirements for waste films packaging sorting and recycling (mechanical recycling and other technologies). Data has been collected during the last quarter of 2021.
For the sorting step, the efficiency of detection and orientation will mostly be impacted due to the complexity of the film – multimaterial , especially presence of metallization or other barriers, versus a monomaterial film. The ballistic behaviour and color of the film are also important characteristics to make a film sortable. Indeed, films need to stick to the conveyor to be well sorted and the carbon black used in dark films or metallization block the detection.
Today, based on the most used technologies (NIR & VIS), only few multi-layers are technically able to be detected, and not always : PA/PE, PE/PA/PE, PE/EVOH/PE and BOPPmet-BOPP. Whereas all multi-layers are asked to be sorted by recyclers because considered as contaminant excepted films with EVOH barrier. EVOH is here not considered as a contaminant because it is accepted at a dilution rate in the global PE films stream (below 5%, CITEO’s guidelines). Moreover, ability to sort multi-layers films will also depend on the ratio (thickness and quantity) of barrier in the film composition.
Manufacturers of sorting machine develop other technologies to enhance sorting in general : Digital Watermarks, Artificial Intelligence, profile detection, X-ray Fluorescence…
For the mechanical recycling step, the multilayer flexibles are considered as the principal pollution, especially with a metallized, PA or PET barrier. Those pollutions will impact the yield of the recycling process and the quality of the recycled plastic. A low quality of recycled films restricts applications to the production of garbage bags and agricultural pipes. All of the applications that use the plastics from the recycling of flexible plastics packaging, are “non-food contact application”. The main reason of this observation is that Europe have not yet EFSA agreement for food contact from recycled polyolefin.
Despite these observations, the majority of respondents does not focus currently nor in a near future on the issues of the multilayer on the recycling of the plastics flexible. Probably because they have many other difficulties to deal with before tackling the problems of multilayers.
CIMPA’s project is then a good opportunity to solving problematics related to multilayers films at the sorting and recycling step.
This task named “Specification requirements from waste management and recycling organizations” is part of the Work Package 1 of thhe project “Systematic transition to the circularity of multi-layer films”. The work has been coordinated by PAPREC, the leader company in France for plastic mechanical recycling, with an annual production of over 100Kt.