Fraunhofer IVV works on reducing odor in recycled films

As Fraunhofer explains, if post-consumer plastics are going to be used for new products, they have to meet the requisite sensory, as well as physical and mechanical, standards. It analyzed LDPE films, principally shopping bags, from different collection systems, using chemo-analytical methods to identify no fewer than 60 odour-producing substances.
The results of the collaborative study with the Friedrich-Alexander University in Erlangen-Nürnberg, Germany, and the University of Alicante, Spain, have now been published (see link below).
Overcoming the challenges of collecting not just more recyclable plastics but also plastics of a suitable quality has been made all the more urgent by the EU’s new requirements in this area, Fraunhofer points out.
The odorants in the high-density polyethylene (HDPE) stream, personal care and detergent packaging fractions, for example, have already been analyzed. But, given that LDPE is another of the most commonly-used polymers, it is important to come up with similar analyses and solutions here, according to Fraunhofer’s Sensory Analytics department.
The majority of odorants identified were metabolites of microorganisms. These degradation products are more likely to form in commingled household waste; unsurprisingly, perhaps, given the higher organic fraction. Where plastics in general, or film specifically, is collected in a segregated stream, the overall odour levels were lower.