The Transfer of Flame-Retardant Effects

Abstract

Burning-rate measurements on double layers of the same fabric having one layer treated with flame retardant reveal that effects of the retardant can be transferred to the untreated layer. A system consisting of a layer of cotton sheeting treated with a phosphate flame retardant placed underneath a layer of untreated material burns at about the same rate as two identically treated layers with the same net average add-on. When this average is low, the combination bums more rapidly than two untreated layers, in accordance with evidence that inorganic phosphate retardants can increase the flame-propagation rate of cotton at low add-on levels. For the double layers of synthetic fabrics studied thus far, it was found that treating only one of the layers results in almost as good and sometimes better reduction of burning rate as treating both layers to the same net add-on. Such transfer effects need to be recognized and understood by those using flame retardants in practical heterogeneous textile systems.