Journal of Pyrotechnics

Titles and Abstracts for Issue No. 17, Summer 2003

Color Purity Measurements of Traditional Pyrotechnic Star Formulas

Brian V. Ingram [Sandia National Laboratories, PO Box 5800–MS 1452, Albuquerque, NM 87185, USA]

Abstract: Pyrotechnic formulas designed to produce colored flames are well known, but the trends in color quality due to individual formula components are less well understood. This paper presents spectrometer work done to record spectra and processes them into chromaticity coordinates. Major formulas of the basic additive colors of red, green, and blue were tested and compared. Impact sensitivities were gathered for those major formulas. Then single suitable formulas were chosen for the basic colors, which were then systematically altered and measured for color quality performance. The formulas were altered to investigate the role of oxidizer to fuel ratio, chlorine donor content, colorant content, and colorant source.

Keywords: color purity, chromaticity diagram, chromaticity coordinate, star formula, flame emission

Reprint Information: Number of pages = 18.

A Study of the Combustion Behaviour of Pyrotechnic Whistle Devices (Acoustic and Chemical Factors)

M. Podlesak* and M. A. Wilson** [*Weapons Systems Division, System Sciences Laboratory, DSTO, PO Box 1500, Edinburgh 5111, Australia; ** Pains Wessex (Australia) Pty Ltd, PO Box 90, Lara 3212, Australia, Formerly of Weapons Systems Division, Aeronautical and Maritime Research Laboratory, DSTO, Melbourne, Australia]

ABSTRACT: Pyrotechnic whistles have long been used in both civilian and military applications. It is known that, under certain conditions, these compositions burn in an oscillatory manner and have exhibited a tendency occasionally to explode with great power during combustion. Based on the results of experimental work and a study of the thermochemical properties of whistle fuels, a hypothesis is proposed that attempts to account for the observed high levels of explosive and acoustic power of pyrotechnic whistles. The formation of < 10 mm diameter hollow carbon spheres was observed in laboratory experiments involving the thermal decomposition of potassium benzoate (a whistle fuel) in a reducing atmosphere. At the moment of formation, the spheres may possibly be filled with combustible hydrocarbon gases and would be extremely reactive. If formed during the quiet cycles of an operating whistle device, their existence may explain the higher than expected acoustic power of pyrotechnic whistles. Such a hypothesis may also lead to an understanding of other hitherto unexplained explosions, where under conditions such as ‘cook-off’, the thermal decomposition of organic fuels used in some other pyrotechnics would result in the formation of new substances which are more reactive than the parent chemicals.

Keywords: whistle, combustion, acoustics, oscillating burning, pyrotechnics

Reprint Information: Number of pages = 15.

Reasons for Fuse Failure and Drift Distance of Spherical Fireworks Shells

Marc Speer [Speer Pyrotechnik, Hans-Böckler-Allee 51, 52074 Aachen, Germany / www.speerpyro.de]

Abstract: This work investigates the reasons for the ignition-failure of spherical (round) shells. It further statistically assesses the probability that the resulting blind (dud) shells will fall within a certain range from the launch point.

Keywords: fuse failure, shell drift, Magnus effect, interior ballistics, exterior ballistics, shell ballistics, blind shell, dud shell

Reprint Information: Number of pages = 18.

Some Properties of Explosion Generated Toroids

Fred Ryan and Joe Daugherty [PO Box 406, New Alexandria, PA  15670  USA]

Abstract: The mechanism of sound production from explosion-created toroids is discussed, as well as progress in rendering them more visible. The toroids, or “smoke rings”, are easily formed by exploding a small charge at the bottom of a cylindrical barrel that is open at the top. The stability, self propulsion, velocities, visibility, and sound frequencies are discussed. The dependency of these properties on the toroid production parameters is experimentally compared with theoretical predictions.

Keywords: toroid, vortex, smoke ring, explosion generated, sound emission, velocity, stability, frequency, visibility

Reprint Information: Number of pages = 12.

Feasibility Study on the Use of Nanoscale Thermites for Lead-Free Electric Matches

Darren L. Naud,* Michael A. Hiskey, Steven F. Son, James R. Busse, and Ken Kosanke† [* Los Alamos National Laboratory, High Explosives Science and Technology, DX-2, MS C920 Los Alamos, NM 87545, USA, †PyroLabs, 1775 Blair Road, Whitewater, CO 81527, USA]

ABSTRACT: Electric matches are used in the pyrotechnic industry to electrically initiate devices remotely and with precise timing. Unfortunately, most current commercial electric matches contain lead compounds, which when burned produce lead reaction products that may cause environmental pollution and contamination of firing areas. These lead compounds, namely lead thiocyanate, lead nitroresorcinate and lead tetroxide, are used in electric match pyrotechnic formulations because a small diameter resistive bridgewire can reliably initiate them. A possible alternative to lead-containing compounds is nanoscale thermite materials, otherwise known as Metastable Intermolecular Composite (MIC) materials. These super-thermite materials can be formulated to be sensitive to thermal stimuli, such as resistive heating. In the effort to produce a lead-free electric match, a feasibility study was performed using nanoscale aluminum and molybdenum trioxide mixtures in electric match formulations.

Keywords: nanoscale, thermite, lead-free, electric match, metastable intermolecular composite, performance test, sensitiveness test

Reprint Information: Number of pages = 11.

Communications:

• A Curious Observation during the Burning of Bulk Whistle Composition by L. Weinman

Please send comments and suggested corrections to:
B. Kosanke, Publisher, Journal of Pyrotechnics, Inc.
1775 Blair Road Whitewater, CO 81527 USA
Phone/FAX +970-245-0692

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Last updated 22-Dec-2006