The impact of the German Packaging Act, which came into force 1 January 2019 and is backed up with hefty fines for non-compliance, has been significant. Based on the principle of extended producer responsibility, the essence is that any party responsible for placing packaged products on the market must pay a fee for the recycling of their packaging waste. The fee is calculated per kilo and varies according to the type of material. As a result, not only are companies keen to use recyclable packaging, the law also stimulates the use of less material for packaging.
The materials are classified according to a ‘minimum standard’ for recyclability, developed to provide a uniform framework for determining a material’s recyclability. The minimum standards are updated each year. However, to date, PA6, for example, has been listed as an “incompatible” component, for example, in the waste stream of the packaging group of film and PE-LD.
Chemical giant BASF decided it was time to take another look at just how incompatible PA6 actually was.
The company commissioned Institute cyclos-HTP GmbH to perform a series of tests designed to reassess the recyclability of polyamide 6 in coextruded PE / PA6-multilayer film structures in post-consumer packaging waste. BASF then planned to use the results as a basis for a reassessment of PA6’s classification.
Based on the results of the tests, Institute cyclos-HTP was able to certify that multilayer films made from PE/PA6 are certified to be recycling compatible for the PE film stream. This was analysed for PA6 concentrations of up to 30 percent in original packaging films.
“We are pleased that cyclos-HTP has been able to develop a scientifically sound basis for reassessment,” says Rolf-Egbert Grützner, Senior Manager Technical Support for Ultramid® extrusion polyamides, who coordinated with cyclos-HTP. “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.”
Next to confirming that PA6 was compatible for recycling in the waste stream of flexible polyethylene packaging, cyclos-HTP moreover classified PE/PA6 multilayer films incorporating so-called compatibilisers as well as up to 30 percent PA as fully recyclable materials. The compatibilisers ensure a homogeneous mixing of the two polymers which are normally incompatible in these concentrations, although this is not absolutely necessary due to the dilution of PA6 in the real waste stream. This makes a film-to-film” approach for PE/PA waste blends is a real recycling option, including manufacturing of “new” monolayer films, according to BASF.
The certified compatibility applies to both new injection moulding and blown film applications.
“For us, it was surprising what positive contribution the PA6 content in the analyzed concentrations has shown to the property level of the industrial polyethylene recyclate used as a reference,” said Dr. Roland Bothor, responsible for ecodesign and development projects at Institute cyclos-HTP GmbH.