Flammability testing of wool/cellulosic and wool/synthetic fiber blends: Vertical flame spread and heat release results

Wool is a natural fiber with lower heat release/flammability than some synthetic fabrics, but it has not been well studied for its heat release when other fibers such as cotton, linen, and nylon are present in the woven fabric. In this article, the heat release and vertical flame spread of six commercially available natural color fabrics is reported. This includes 100% wool, 80% wool/20% nylon, 70% wool/30% linen, 45% wool/55% cotton, and 40% wool/38% cotton/12% nylon/10% metallic thread fabric. Heat release was measured through cone calorimetry (ASTM E1354) as a function of the sample mounting method, through microscale combustion calorimetry (ASTM D7309), and flame spread was measured by ASTM D6413. The type of insulated backing used greatly affected the cone calorimeter results, and fabric types did show some effects in vertical flame spread and microscale combustion calorimeter testing.