Pyrotechnic star

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Pyrotechnic stars are pellets or simply pieces of pyrotechnic composition which may contain metal powders, salts or other compounds that, when ignited, burn a certain colour or exude a spark effect. They are a part of all projectile type fireworks. The most common is the aerial shell. When you watch this firework, it will launch into the sky, burning a lifting charge. Once the shell has attained proper altitude, due to other mechanisms within the firework, it will ignite the stars.

[edit] Procedure

Stars are either rolled, pumped or cut.

Rolled stars are small cores of a hard material which are rotating in a cement mixer. First some water are sprayed on the cores. Then an amount of a pyrotechnic composition is dropped in the mixer. These two steps are repeated, and the stars will go bigger and bigger in a spherical shape.

Pumped stars are stars that has been pumped using a star pump. A dampened composition is put in the star pump and is pressed against a flat surface and ejected again creating cylinder shaped stars.

Cut stars is a dampened composition spread out to an even layer on a flat surface. The stars are then cut into cubes.

The stars are allowed to dry for some days before being put into the fireworks piece.

Priming the stars is often necessary because they may be hard to ignite. Priming consists of coating the surface of the star with a more easily ignited substance, such as black powder.

Certain examples of compounds commonly used in fireworks, and the colours they burn are listed in the pyrotechnic colorant article.