The German institute for recyclability and product responsibility Cyclos-HTP (Aachen; www.cyclos-htp.de) has completed a series of tests to reassess the recyclability of PA 6 in coextruded PE-PA 6-multilayer film structures in post-consumer packaging waste. The tests were commissioned by German chemicals and plastics giant BASF (Ludwigshafen; www.basf.com) to ensure that the benefits of packaging containing polyamides do not get sidelined due to recycling restrictions.

The institute said some multilayer films based on PE-PA 6 are certified as recycling compatible for the PE film stream. This was analysed for PA 6 concentrations of up to 30% in original packaging films. The result, says BASF, was intended to form the basis for a review of PA 6 classification in the “minimum standard” to determine the recyclability of packaging, in accordance with the German packaging act (VerpackG). Until now, PA 6 has been listed as an “incompatible” component, for example, in the waste stream of the packaging group of film and LDPE.

Additionally, Cyclos-HTP also classified PE-PA 6 multilayer films as fully recyclable materials under certain conditions – while using compatibilisers in PA 6-containing film structures in addition to PA 6 content of up to 30% in original packaging films. The compatibility of examined PE-PA 6 systems applies to both new injection moulding and blown-film applications.

Roland Bothor from Cyclos-HTP said, “For us, it was surprising what positive contribution the PA 6 content in the analysed concentrations has shown to the property level of the industrial polyethylene recyclate used as a reference.”