The Influence Of Insolation On Performance Of Firefighter-clothing Fabrics

Firefighter clothing is one of vital protective gears, which protects firefighters from all kinds of harm of the fire.During being worn, its performance would be influenced by insolation, with performance increasing degradation. Therefore, it’s of great significance to research the influence of insolation on performance of firefighter-clothing fabrics.Based on designed xenon insolation simulation instrument, the m-aramid fabric and NomexIIIA are selected to study the influence of different radiant flux densities(7.48kw/m2,5.42kw/m2) and different time (0/3/6/9/12/15min) on their performances of physics, surface, calorifics and mechanics.The results indicates that after insolation density of fabrics increases, fabrics shrink, thickness of them grows, and grammage declines; The color of fabrics changes.At the time of15minutes,with the38%rise of radiant flux density, the value of chromatism of m-aramid fabric grows by152.9%, while that of NomexIIIA increases by49.5%. With the increment of radiant flux density and time, the resistance to surface wetting declines by one level. At the time of15minutes, with the38%rise of radiant flux density, the amount of moisture pickup of m-aramid fabric grows by445.6%, while that of NomexⅢA increases by279.25%; Infrared gun is applied to measure the temperature of surface. The temperature of surface is quick to be steady under the vitrification point(275℃). The value of TPP increase,which means the thermal protective performance enhances; Totally, the tearing strength displays the trend of decline. Apart from the tearing strength of across warp(TSAW) of m-aramid fabric being less than100N at7.48kw/m2, the others all meet the requirement of GA10-2002.During15minutes, at the irradiance of5.42kw/m2, the TSAW of m-aramid fabric declines by6.41%on average, while that of NomexIIIA increases, which shows that the TSAW of NomexIIIA has the trend of further improvement. At the irradiance of7.48kw/m2, the TSAW of m-aramid fabric declines by15.41%, while that of NomexIIIA reduces by14.26%. During15minutes, at the irradiance of5.42kw/m2, the tearing strength of warp direction (TSWD)of m-aramid fabric declines by8.42%on average, while that of NomexIIIA reduces by1.92%. At the irradiance of7.48kw/m2, the TSAW of m-aramid fabric declines by9.65%, while that of NomexIIIA reduces by14.45%.The degradation process is further analyzed. At the irradiance of5.42kw/m2, during15 minutes, pigments are resolved, which cause chromatism. The pigments of turquoise and bluish green of m-aramid fabric are resolved, while The pigments of turquoise of NomexIIIA is resolved. At the irradiance of7.48kw/m2, during the first6minutes, the main reason for chromatism is pigments being resolved, but after that it mainly because the fabrics are carbonized, which coincide with what is observe. The fact that density of fabrics increases after insolation, and fabrics shrink leads to the decline of space between yarns, the increase of friction and the reduction of force triangle, therefore, the TS declines; From SEM, the fiber surface becomes crude, even there appears crackle, that is to say the fiber becomes friable, which explains the reason for degradation of TS; most of the absorption peaks of infrared spectrometry become weaker. That of m-aramid fabric changes more sharply than that of NomexIIIA, and some acids and carboxylic acids are produced(from the pigments of m-aramid). The color of m-aramid fabric changes gravely than that of NomexIIIA, so does the change of TS.Finally, Forecasting models are constructed to predict values of the chromatism and TS after insolation from irradiation conditions based on the software of matlab. The results show that average error of the models is within12%, and the correlation between predicted and experimental value is above0.930, which shows high goodness of fittest, so that a firm foundation is layed for discarding the firefighter clothing.