*Originally published August 9, 2021 in the University of Alberta Folio
By BEV BETKOWSKI
Firefighters risk their lives battling blazes, but the aging of their suits also poses a hazard that a University of Alberta researcher, partnering with industry, is working to eliminate.
An end-of-life sensor that detects gradual breakdown in garments from exposure to heat, moisture and ultraviolet (UV) light has been developed by clothing and textiles scientist Patricia Dolez, in partnership with Edmonton-based company Davey Textile Solutions.
The patch-like device, when applied to their garments, will help firefighters detect when the outer shell fabric has reached an unsafe performance level.
“These fibres age silently and lose their performance, so this sensor technology is a breakthrough in terms of safety for workers exposed to heat and flame,” said Dolez, the project’s lead researcher, and an assistant professor in the U of A Faculty of Agricultural, Life & Environmental Sciences (ALES).
The sensor patch will provide a way to assess the garment without destructive testing–having to cut out samples to test the condition of the fabric through conventional methods such as strength testing.
Damage to the garments may not be visible to the naked eye before considerable loss in performance has occurred, Dolez said. “Firefighters have no good way to know how safe their clothing really is–you can’t tell just by looking at it.”
The sensor patch uses graphene–a flaky substance composed of carbon atoms to form conductive tracks on the patch’s surface. When the exposure to heat, moisture or UV light exceeds a certain level, the graphene track is disrupted and loses its electrical conductivity.
Firefighters would use a simple voltmeter to check the safety levels of their clothing on the sensor patch–a result that comes within seconds.
The sensor, which has been provisionally patented and is still under development, also comes at an optimal time as the National Fire Protection Association (NFPA) prepares to upgrade its recommendations on garment maintenance because of an underlying threat of diseases like cancer that can be caused by fire-associated harmful substances leaching into the fabric, Dolez noted.
“The current recommendation is to wash firefighting garments twice a year, but the problem is, all the existing data that determines when the clothing needs to be replaced, is based on that once or twice a year washing,” she said.
New NFPA recommendations are expected to bump up the laundering frequency to after each exposure to a firefighting incident, which means monitoring technology also needs to be amped up. “The sensor is important to be able to gauge what the garment is going through with each washing.”
One of five industry partners working with Dolez, Davey Textile Solutions manufactured the fire-resistant fabrics that will be used as part of the sensor patch. The company is producing reflective trims for protective garments.
The sensor, once fully developed, could be used not just by firefighters but also by other clients in the oil and gas, electrical, construction and mining industries, said Lelia Lawson, research and development officer for Davey Textile Solutions.
“This is an example of how we try to be ahead of the curve to provide new proactive items to the marketplace,” said Lawson, noting that one of the biggest questions for clients in heavy industry is knowing when to retire personal protective equipment (PPE).
“The sensor takes the ambiguity out of that question.”
The research, which began in 2018, has also produced two scientific papers by graduate students studying clothing and textiles science in ALES and chemical and materials engineering in the Faculty of Engineering. The papers explored the application of graphene on high-performance fabrics, and how its conductivity is affected by different aging conditions simulating service use.
Through the Human Ecology Practicum Program, a student also worked with Davey Textiles Solutions to develop a business case for market applications for the sensor, and ”was able to provide a lot of good information which supported the need for this product in the industry,” Lawson said.
The sensor project “is making good progress” and the expertise offered by the company is invaluable, Dolez said.
“Their collaboration ensures that what we develop will be relevant for industry; as researchers we can develop something that is a great idea, but if no one is able to produce it, it’s not useful, so by having industries like Davey Textile Solutions at the table, we’re making sure what we develop will end up being used.”
The sensor technology is the latest in a series of projects the Department of Human Ecology has had with the company, including developing clothing to protect workers against steam burns, through the U of A’s Protective Clothing and Equipment Research Facility. That work resulted in the Canadian General Standards Board updating a standard used by employers when selecting appropriate PPE for their workers.
Currently, Dolez and Davey Textile Solutions are collaborating to recycle material from used industrial coveralls–otherwise be destined for the landfill–into fibres that can be used to make new textiles.
“We’re aiming to manufacture new fabrics for PPE and for other consumer goods,” Lawson said. “There are more clients who want to purchase sustainable products.”
Working with various U of A researchers from Human Ecology and the Department of Mechanical Engineering, Davey Textiles Solutions benefits greatly from their applied research, Lawson said.
“We can commercialize products from their work, and it’s rewarding to have research that evolves into something that can be realized in the marketplace.”
The practicum students the company has hosted over the years also bring fresh perspectives to developing clothing and textiles, she added, noting that the company has hired six graduates from the Human Ecology program, herself included.
“It speaks volumes to the calibre of students from the program. They are very well-rounded because they study humans in their near environment, how they interact, and along with the theoretical knowledge of textiles they also help with understanding how these textiles can impact lives. And that helps create better products.”
In addition to in-kind support provided by Davey Textile Solutions and the other industry partners, the research is funded by a Natural Sciences and Research Council of Canada (NSERC) Strategic Partnership Grant. The sensor research team also includes Jane Batcheller from Human Ecology and Hyun-Joong Chung, associate professor in the Department of Chemical and Materials Engineering.