Polyester is the most widely-used clothing fibre in the world but is currently not a sustainable textile option and will likely end up discarded in landfill or polluting the environment. It is made from polyethylene terephthalate (PET), one of the most common consumer plastics, University of Portsmouth reported.
Researchers at the University’s Centre for Enzyme Innovation have already developed enzyme technology to reduce single use plastics, including PET, to their chemical building blocks, leading to safe and energy efficient recycling. Now they have set their sights on creating a similar process for polyester textiles.
The process of recycling synthetic fabrics using enzymes will not be an easy one. It is estimated that these textiles account for 60 per cent of clothes that are worn (EEA (2021) Plastic in textiles: towards a circular economy for synthetic textiles in Europe), and are often chosen for durability.
The addition of dyes and other chemical treatments make it even harder for these tough oil-based materials to be ‘digested’ in a natural process. Developing enzymes that can efficiently ‘eat’ polyester clothing, without energy intensive pre-treatment, is the biggest challenge.
Professor Andy Pickford, Director of the Centre for Enzyme Innovation at the University of Portsmouth said: “We will develop enzymes that can deconstruct the PET in waste textiles, tolerating the challenges that this feedstock poses, namely its toughness and the presence of dyes and additives.
“We will test the compatibility of our engineered enzymes with additives, dyes and solvents to select those enzymes that are best suited to polyester textile deconstruction. Then we will apply these enzymes to appropriately pretreated waste polyester textiles in laboratory-scale bioreactors to evaluate the potential and limitations of scaling up the technology.”
Clothing has some of the lowest rates of recycling, with much of it being incinerated or ending up in landfill. Whilst it is possible to turn good quality oil-based textiles into carpets and other products, current recycling methods are highly energy intensive. Scientists hope that enzymes developed at the University of Portsmouth will help them create a environmentally-friendly circular economy for plastic based clothing.