Fire Safety Science Digital Archive

The flammability properties of pure Nylon 6 and clay additives of 2 and 5% in thicknesses ranging from 1.6 to 24 mm were examined. Data were obtained over a range of radiant heat fluxes (17 to 55 kW/m²). The heats of combustion did not change with loading, and were 28 +/- 1 kJ/g. The critical heat flux for ignition also did not significantly change as it decreased from 17.7 to 16.0 for pure nylon to 5% clay addition. However, the addition of the clay could increase the ignition time by 30 to 100% over the pure nylon. This is believed to be due to the increased char residue and decrease in mass loss rate accordingly. The residual char-like yield was nearly identical to the clay loadings. The overall average mass loss rate was reduced by up to 50% for 5% clay over pure nylon for a given heat flux and thickness. For the clay nano-composites, the average burning rate increased as the thickness decreased. A theoretical model qualitatively explains the effect of thickness.