Effect of Particle Size on the Mechanical Sensitivity and Thermal Stability aspects of Pyrotechnic Flash Compositions

S. P. Sivapirakasam, M. Surianarayanan,* F. Chandrasekaran and G. Swaminathan

Abstract: The mechanical and thermal sensitivity of pyrotechnic flash compositions consisting of mixtures of potassium nitrate (KNO3), sulphur (S) and aluminum (Al) with varying particle sizes of KNO3 and Al indicated that, irrespective of the composition of the cracker mixture, all the compositions were found to be thermally and mechanically sensitive. Although the impact sensitivity results reflected the change in the surface area of the particle sizes, the changes were within a narrow range of limiting impact energy (LIE) (7.5–9.1 J). Further it was difficult to pinpoint a particular sieve fraction as sensitive since the response to explosion depended normally on the flash composition and the particle size but also on the density and the compactness of the chemicals DSC studies on the effect of the Al particle size showed that a decrease in the Al particle size led to a second exothermic activity. This behavior should be viewed with caution when considering safety aspects.

Keywords: pyrotechnics, flash composition, fireworks, impact sensitiveness, friction sensitiveness, differential scanning calorimeter, potassium nitrate, sulphur, aluminum


Ref: JPyro, Issue 23, 2006, pp39-50
(J23_39)

© Journal of Pyrotechnics and CarnDu Ltd



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