Researchers with ‘highly-trained nose’ dedicated to odour-free plastics recycling

Germany – Almost 60% of food, beverages, and other articles in Germany come in some type of plastic packaging, and yet half of it is simply incinerated. Young researcher Miriam Strangl of the Friedrich-Alexander University (FAU) argues that the bad smell of post-consumer plastics is part of the problem. She hopes her study may help develop strategies for reducing odours in recycled plastics.

Strangl is relying on her ‘highly-trained nose’ to decipher a range of compounds by their smell alone and confirms these findings through chemical analysis, aided by polymer recycling experts from the prestigious Fraunhofer Institute.

‘We were able to identify some of these strong-smelling contaminants in plastics for the first time ever,’ reports Strangl with great enthusiasm. ‘The different substances found in plastic packaging waste have a number of different smells, including mouldy, cheesy or acidic smelling molecules,’ she explains.

Her work is based on 100 litre samples donated by Germany’s Green Dot collection scheme. Findings so far indicate that, apart from odorous substances from previous contents such as food or cleaning agents, other processes might also lead to the unpleasant odours. ‘In addition to microbiological decay, this also includes aging plastics or the decomposition of residues from manufacturing such as solvents,’ so says Strangl.

She concludes that pooling such niche knowledge of industry experts will ultimately aid future targeted development of improved purification methods and manufacturing processes.