Development of Wildland Firefighters’ Protective Clothing with Improved Thermal Protection
Creators: Kosareva, Elena
Publisher: name: University of Alberta Library
Year: 2024

<p>This research was focused on the development of wildland firefighters’ protective clothing with improved thermal protection properties. Specifically, a new shirt design was developed, and garments were constructed which incorporated a three-dimensional warp-knitted fabric in specific areas. These areas were the shoulders, upper front and upper back torso, neck, and wrists of the shirt where no air gap occurs between the clothing and the body of the wearer. Previous researchers had found that these areas are prone to second-degree burn injury when wildland firefighters’ protective clothing was evaluated on an instrumented manikin in a simulated flash-fire test scenario. To determine whether the three-dimensional warp-knitted fabric in the newly designed shirt improved the thermal protection provided by the shirt, the following four interrelated studies were conducted. In the first study, the heat and flame thermal performance of selected fabric systems representing the shirt that is currently worn by wildland firefighters in Alberta (control shirt) and the newly developed shirt prototype were assessed at the bench-scale level. Thermal performance was predicted by the values of thermal protective performance (TPP), radiant heat resistance (RHR), and cylinder heat transfer performance (CHTP). The second study was focused on the evaluation of the thermal comfort of selected fabric systems, also at the bench-scale level. Comfort properties were predicted using thermal resistance and evaporative resistance in a total heat loss (THL) calculation, together with air permeability. Study three was focused on the development of the design of the shirt prototype and its construction. The development of the new shirt design included reproduction of the control garment, pattern editing for the development of the new shirt design, and three-dimensional simulation of both the control shirt and the new shirt prototype using CLO 3D software. The software allowed for visual simulation of the control shirt and prototype shirt on an avatar with the same dimensions as the instrumented manikin used for full-scale flash fire testing at the University of Alberta’s Protective Clothing and Equipment Research Facility (PCERF). Three prototype shirts along with three control shirts were constructed to conduct study four. Study four was focused on the full-scale flash fire manikin testing of the shirts from study three worn as part of a wildland firefighters’ protective clothing ensemble. Three control shirts and three prototype shirts were tested for 4 seconds of flame exposure. Percentage of the manikin surface reaching a predicted second- or third-degree skin burn injury was recorded for the control and prototype shirts.Overall, the bench-scale test results showed that the incorporation of a three-dimensional warp-knitted fabric between the outer and base layers of a garment system substantially improved thermal protection over systems that included the outer and base layers alone. Test results showed: 1) an increase of TPP, RHR, and CHTP values with ~200% improvement in thermal protection; 2) a decrease of THL values by 41% to 56%; and 3) an increase in air permeability by 30% to 43%. A novel design for the shirt worn by wildland firefighters was successfully produced using CLO software and innovative construction techniques were implemented which allowed the inclusion of the inflexible three-dimensional warp-knit fabric into the garment. Control and prototype shirts were constructed for full-scale thermal protective performance assessment by the flash fire instrumented manikin test. The prototype shirt design decreased the total burn area of the manikin surface by approximately 6% compared to the control shirt. The three-dimensional warp-knitted fabric specifically impeded thermal energy transfer in the areas of the upper front and back torso, upper arms, and neck during the full-scale flame engulfment test.</p>