What’s Inside of a Firework?
- Black Powder – the propellant. It is an old formula made from potassium nitrate, sulfur and charcoal. When it is ignited, the nitrate oxidizes the sulfur and charcoal which results in hot gasses.
- Mortar (container) – the outer cylinder chamber made of plastic or metal. It can be a short, steel pipe with a lifting charge of black powder in the bottom or surrounding stars.
- Stars – the pyrotechnic compounds that explode and create the colors and effects. They are spheres, cubes or cylinders about the size of a pea to a tennis ball.
- Shell – a hollow sphere made of pasted paper and string. The shell is cut in half and packed with stars.
- Bursting Charge – inside the middle of the shell to ignite the firework. The charge ignites the outsides of the stars, which burn with showers of sparks.
- Fuse – allows a time delay for the explosion.
How Do They Create Multi-Explosions, Effects and Colors in One Firework?
Multi-break shells create multiple stages for the firework. Stars of different colors and compounds are used to make different effects. The shells are filled with other shells or have multiple sections that are ignited with individual fuses. After the first section bursts, the next fuse is ignited and bursts the second, which then ignites the third fuse and so on.