Development of thermal layer using low twist yarns and roving of aramids and FR viscose blend

In this study, various fabrics of FR Viscose, m-aramid, and p-aramid have been manufactured using low-twist yarn as well as roving, and then studied for their thermal and mechanical properties. The ring-spinning system is used to manufacture different low-twist yarns and roving. Twenty-one (21) woven fabric samples with 1 up 1 down plain weave using three combinations out of these yarns and roving in warp and weft have been produced. The three combinations are Yarn/Yarn, Yarn/Roving, and Roving/Roving. The radiant heat transfer index (RHTI24) and convective heat transfer index (HTI24) of the fabrics of m-aramid, p-aramid, and FR viscose made out of Yarn/Yarn combination with different blend compositions are found in the range of 7.5–11.4 s and 7.2 – 9.6 s respectively. However, the fabrics made out of Yarn/Roving and Roving/Roving combinations with different blend compositions show radiant heat transfer index and convective heat transfer index in the range of 11.4 – 19.9 s and 10.5–17.7 s respectively. The HTI24 – HTI12 values of all the samples are found to be more than 4 s, which indicates a good escape time from feeling pain to suffering a second-degree burn in both convective and radiant heat. All 21 woven fabrics qualify for the passing criteria of flame spread as per EN 469 standard. Statistical analysis (ANOVA) is carried out using SPSS software in order to establish the correlation between the fabric samples made out of three types of fibres and their blends in the Roving/Roving combination with convective heat and radiant heat properties.