The patented technology - created by University of the West of Scotland (UWS) and Advanced Clothing Solutions (ACS) via the KTP programme – is set to be scaled up for commercial use with financial support from Scottish Enterprise.
The project will take ideas proven at lab-scale to develop a sanitisation chamber for installation at ACS’s automated fashion fulfilment facility on the outskirts of Glasgow.
Ozone, which is formed naturally through the interaction of solar ultraviolet (UV) and molecular oxygen (O2), can eradicate 99.7 per cent of 650 different kinds of pathogenic organisms.
Dr Mohammed Yaseen, of UWS’s School of Computing, Engineering and Physical Sciences, explained that the new solution creates ozone via UV or corona discharge, with the latter being more efficient, particularly for large scale ozone generation.
“We have a small unit with controlled ozone levels and a large unit for industrial automated garment sterilisation,” he said. “The air trapped within an air-tight chamber is usually sufficient to generate high quantities of ozone – up to 50ppm within a 100m3 volume.”
He explained that the power of the ozone generators and the size of the chamber are key determinants, adding that the use of oxygen as the feed gas increases the ozone yield by approximately three times.
Trials demonstrated that the system kills germs and viruses including E. coli, S. aureus and coronavirus, which can remain on clothing and fashion accessories. It is now being trialled on PPE.
“In our process, an exposure duration of five minutes at our desired concentration is sufficient to yield up to five log reduction in bacteria and fungi,” said Dr Yaseen, adding that up to 250 garments can be treated in five minutes with gaseous ozone.
“We have optimised the ozone concentration and exposure duration via extensive laboratory experiments,” he said. “The ozone dose which we apply is sufficient to remove a wide range of microorganisms typically found on used clothing and PPE.”
ACS prolong the life of used or damaged garments for some of the country’s biggest brands, through their sustainable textile repair, refurbishment, and cleaning service. The company clean around 45,000 garments each week.
Forty per cent of clothing purchased online is returned, with less than half of it being resold and the remainder ending up at landfill sites or being incinerated. Through extending the lifetime of a garment by three months, its carbon footprint is reduced by ten per cent and a pre-owned purchase, or a rented garment, saves 1kg in waste, 3,040 litres of water, and 22kg CO2.