Fraunhofer IVV works on reducing odor in recycled films At a time when many are temporarily losing any sense of smell – and taste – thanks to the effects of the coronavirus, Fraunhofer IVV has publicised its research into identifying off-odours in low-density polyethylene (LDPE) film collected for recycling, and strategies for minimising them. 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. ![]() 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. https://www.sciencedirect.com/science/article/pii/S0956053X20300210 Published: 03/30/20 |