Parallel and Propagative Burning

K.L. and B.J Kosanke

Introduction: In effect, there are two basic mechanisms for pyrotechnic burning. One, which is primarily burning inward, perpendicular to the burning surface, and one in which accelerated burning along surfaces is most important. These can be termed “parallel” and “propagative” burning, and the same pyrotechnic material can manifest radically different burn rates depending on which type of burning predominates. A theoretical discussion of burn rates and the many factors effecting burn rate is beyond the scope of this article; however, a working knowledge of these two types of burning is useful in understanding the way in which a number of fireworks items function and, on occasion, malfunction. Also, should the need arise to dispose of pyrotechnic materials by burning, a knowledge of these two types of burning, and the potentially dangerous transition that might occur between the two, could be of critical importance.

It must be acknowledged that in the literature there is conflicting usage of the terms describing burn types and that the propellant powder industry uses similar terms in a somewhat different manner. In an attempt to avoid confusion, an appendix has been included to explain the powder industry’s use of the terms degressive, neutral, and progressive burning. Also, erosive burning is briefly discussed.


Ref: Selected Pyrotechnic Publication of K.L. and B.J Kosanke, Part 2, (1990-1992), pp 42-48
(K2_42)

© Journal of Pyrotechnics and CarnDu Ltd



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