Researchers have finally found out why a high-performance fabric commonly used in firefighting and other protective garments weakens prematurely when it’s exposed to moisture.
The Research: The study investigated the accelerated hydrothermal aging of various fabrics typically used as outer shells in clothing for firefighters, oil and gas workers and electricians.
The fabrics were immersed in water at temperatures ranging from 60 to 95 C for up to 1,200 hours.
After exposure, some of them lost significant tensile strength—the stress a fabric can withstand without splitting or breaking—without showing any visible signs of degradation.
The cause was found to be the high sulphur content in some of the fibres, leading to an accelerated loss in fabric strength when exposed to moisture.
That degradation weakens the safety of protective garments when exposed to sweat, water, rain, snow or laundering.
Besides fibre damage, the water-repellent finish in some of the fabrics also showed degradation, which adds to safety concerns.
The Researchers: The project was led by Saiful Hoque, a researcher in the Faculty of Agricultural, Life & Environmental Sciences (AELS) at the University of Alberta in Canada.
- The others who worked on the project were Patricia Dolez, ALES professor, and .Professor Hyun-Joong Chung and Ankit Saha of the U of A’s Faculty of Engineering.
- Dolez had led earlier research that showed laundering contributes to a loss in performance in some fire-protective fabrics.
- The study was funded by the Natural Sciences and Engineering Research Council of Canada.
The way ahead: The next steps would be to share the latest findings with textile manufacturers.
What they said:
We’re hoping to work with the industry to come up with solutions. We now have the data we needed on the degradation of fire-protective fabrics (due to long-term exposure to water) to select the right material to use.
As the garment weakens over time, there’s no way to know whether the wearer is still protected or not. Now we know the root cause, and this gives information to the manufacturers to find a solution to this problem.
— Saiful Hoque
Researcher, Faculty of Agricultural, Life & Environmental Sciences
University of Alberta
