Light-producing pyrotechnics

The intensity of light emitted by pyrotechnic compositions is determined by the temperature of the burning components which, in turn, is dependent on the composition. Pyrotechnic mixtures which burn between 2180 and 2250 °C contain chlorates and perchlorates as oxidizers, and an organic fuel such as shellac or rosin. In order to increase the flame temperatures to 2500-3000°C metals powders are added such as magnesium. Light-emitting pyrotechnic compositions also contain metal compounds which produce spectral emissions at characteristic frequencies. 

Ref A. Stettbacher, Explosivst 1956,27 Aluminum Flares are military devices contg pyrotechnic compns which are mixts of finely powdered substances compressed into candles. The most important ingredients in a pyrotechnic compn are the fuel and the oxidizing agent. To these are usually added other materials to intensify the color of the light produced, decrease the burning rate, act as a binder and waterproof the compn... 

Pyrotechnic flames always contain some solid or liquid particles, either ejected from the burning surface or as combustion products (smoke). At the temperatures of colored flame, these particles incandesce with near white light, reducing the purity of any colored light produced. 

Strobe effects are characterized by repeated flashes of light produced by a single pyrotechnic unit (for example, a star). 

The series Science in World War // contains occasional references to pyrotechnics, especially in the volume Chemistry by R. Connor et al., which has some information on smokes, light producers, and explosives. 

Ellem (Ref 138, p 181) also describes pyrotechnic means of producing explosive and whistling sound. Recent advances in the art of generating oscillating light signals are described in Section 8 of this article... 

Pyrotechnics which burn to produce heat, smoke, light and/or noise. 

Pyrotechnics are often used in the production of fireworks and primers. A pyrotechnic contains both a fuel and an oxidizer formulated to produce a lot of energy. The energy is then used to produce a flame or glow (matchstick) or combined with other volatile substances to produce smoke and light (fireworks) or large quantities of gas (firework rockets). 

PYROTECHNIC COMPOSITION Can be a substance or a mixture of substances used to produce effects (e.g. light, sound or smoke) as a result of non-detonative, self-sustaining exothermic chemical reactions. 

Barium nitrate is used to produce green color in flares, pyrotechnic devices in green signal lights and in tracer bullets. 

To produce this type of atomic emission in a pyrotechnic system, one must produce sufficient heat to generate atomic vapor in the flame, and then excite the atoms from the ground to various possible excited electronic states. Emission intensity will increase as the flame temperature increases, as more and more atoms are vaporized and excited. Return of the atoms to their ground state produces the light emission. A pattern of wavelengths, known as an atomic spectrum, is produced by each element. This pattern - a series of lines - corresponds to the various electronic... 

In addition to an oxidizer, pyrotechnic mixtures will also contain a good fuel - or electron donor - that reacts with the liberated oxygen to produce an oxidized product plus heat. This heat will enable the high-energy chemist to produce any of a variety of possible effects - color, motion, light, smoke, or noise. 

Place a small pile of the mixed composition on the fireproof board, insert a section of safety fuse into the base of the pile, and carefully light the end of the fuse with a match. Step back and observe the effect. Because of the generation of smoke by most pyrotechnic compositions, these tests are best conducted outdoors or in a well-ventilated area such as a laboratory fume hood. 3e certain no flammable materials are near the test area, for sparks may be produced. 

Pyrotechnic Devices. Items used for both military and nonmilitary purposes, such as producing bright lights for illumination, colored lights, or smoke for signalling purposes. These items are consumed in the process (Ref 40a, p 118 Ref 43, p A384-R)... 

Fuze, Flare. A fuze, such as MT (mechanical time), to initiate ignition of the charge in a flare, which is a pyrotechnic item designed to produce a single source of intense light for purposes such as target and/or airfield illumination... 

Pyrotechnic mixtures An oxidizer/fuel mixture that produces bright or colored lights, heat, fogs, or acoustic effects. 

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