Impact of Radiative Exposures on the Mechanical Properties of Fire-Resistant Fabrics
Date
2023-05-19
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0009-0006-4655-0325
Type
Thesis
Degree Level
Masters
Abstract
Firefighters’ protective garments are designed to protect them from elevated temperature and
heat flux environments. Typically, these garments are made of three layers: an outer shell, a
moisture barrier, and a thermal liner. At present, new firefighters’ garments must meet
performance criteria specified in test standards, but these do not apply to in-use garments. As the
performance of this clothing may degrade with use, quantitative methods for determining the
useful life of these garments without destroying them is a need for the fire service. One area of
such research has been the development of correlations between near infrared (NIR) spectral
results and changes in fabric properties. Research at the University of Saskatchewan (U of S) has
shown that NIR measurements can be correlated to deterioration in mechanical strength after
thermal ageing.
This study examined the performance of two Kevlar®/PBI fabrics after exposures to heat fluxes
ranging from 10 to 70 kW/m2 for durations ranging from 15 to 1200 s. These exposures were
conducted using a cone calorimeter and have been selected as representative of the wide range of
conditions expected on the fireground. After examination using an NIR spectrometer, tensile
testing was conducted on the specimens. The tensile strength values for thermally aged fabrics
were then compared against criteria in standards for new clothing.
Three correlations between exposure and duration were developed based on multi-variable linear
regressions, multi-variable nonlinear regressions, and single-variable nonlinear regressions.
These correlations were constructed from this research and past research datasets. These
correlations aim to predict the degradation these types of fabrics experience, and could be used in
future degradation. It was found that the multi-variable nonlinear regression correlation was the
most successful across different exposures, while the single-variable nonlinear regression was
able to predict degradation more accurately to an average standard error of 4%.
Description
Keywords
High-Performance Fabrics, Fire Protection, Non-Destructive Testing, NDT, Firefighter, Protective Clothing, Durability, Near-Infrared Spectroscopy, NIR, Mechanical Strength, Correlations, Modelling, Regressions
Citation
Degree
Master of Science (M.Sc.)
Department
Mechanical Engineering
Program
Mechanical Engineering