The thermal decomposition and heat release properties of the nylon/cotton, polyester/cotton and Nomex/cotton blend fabrics

Cotton blends are very important and widely used in our lives. In this research, the heat release properties and the flammability of the nylon/cotton, the polyester/cotton and the Nomex/cotton blends are investigated. By comparing with the heat release rate (HRR) and other thermal parameters calculated from their individual components, it is found that both the nylon and the polyester have interaction when they are blended with cotton during the decomposition process. For the nylon/cotton fabrics, the blend has lower total heat release (THR) and much higher percent char yield than the arithmetic sum of those of cotton and nylon as single fibers. The char yield of the nylon/cotton blends decreases when the blend contained less cellulose. But for the polyester/cotton fabrics, the blend has higher THR than the arithmetic sum of cotton and polyester as single fibers with a bit increase in the percent char yield, and its char yield increases as the cotton ratio in the blend decreases. It is illustrated that the interaction that occurs between nylon and cotton is different from that between polyester and cotton. In the case of Nomex/cotton blends, the actual HRR curve matches well with the simulated curve, and the THR and percent char yield are almost the same as the calculated data. There is nearly no interaction between Nomex and cotton components during the degradation of the blend. Overall, the results show that the decomposition process of blended fabrics is not simply the addition of the decomposition process of the component single fibers, but is in fact more complicated.