BASF co-publishes insight into recycling PE/PA multilayer films

Working in collaboration with Institute cyclos-HTP, BASF has co-published a new insight into the mechanical recycling of co-extruded flexible packaging films containing polyamides (PE/PA multilayer films).

An independent testing and certification body, cyclos-HTP systematically investigated the recyclability of PE/PA multilayer films on behalf of BASF and confirmed its results in June 2021. The conclusions of these investigations are now available in a 25-page publication available on both the BASF and cyclos-HTP websites.

Co-extruded PE/PA multilayer films with PA6 and PA6/6.6 concentrations of up to 30 per cent were used with tie layer materials. Based on the established CHI standard, cyclos-HTP tested the recycling compatibility and recyclability of these films in the PE film stream from commercial sorting processes for household flexible plastic packaging waste.

Institute cyclos-HTP is using these updated results for the differentiated certification of the recyclability of individual flexible PE/PA packaging structures by performing case-by-case reviews.

Dr. Rolf-Egbert Grützner, Senior Manager Technical Support of Ultramid extrusion polyamides and co-author, said: “It is time to correct the categorisation of polyamide 6 and also the realted A6/6.6 co-polyamides as 'incompatible' contaminants and put it on a solidly updated basis.

“We are pleased that cyclos-HTP has been able to develop a scientifically sound basis for reassessment. It is time to correct the categorization of polyamide 6 and also the related PA6/6.6 co-polyamides as ‘incompatible’ contaminants and to put it on a solidly updated basis”

The publication was also authored by Dr Roland Bothor, responsible for ecodesign and future packaging projects at Institute cyclos-HTP GmbH, who added: “For us, it was surprising what positive contribution the PA6 content in the analysed concentrations has shown to the property level of the industrial polyethylene recyclate used as a reference.”

An excerpt from the publication notes that ‘As the classification of packaging materials with regard to their recyclability is very closely intertwined with political and economic interests, a holistic approach for evaluating the advantages and disadvantages of individual polymers and the associated packaging solutions while considering pragmatic constraints is not only impossible, but in individual cases also not wanted.’