How do they make fireworks explode in specific shapes?

463 views

I was at an event with a giant, choreographed firework show. Like they literally brought in Japanese masters of pyrotechnics for it. It was beautiful and all kinds of shapes like flowers and hearts and stuff.

And afaik they do different colours by burning different elements but how do they do specific shapes and like timings? Like one piece of firework having several different layers and colours and stuff. How does it not all explode at the same time in all kinds of directions?

In: 1125

13 Answers

Anonymous 0 Comments

[removed]

Anonymous 0 Comments

For shapes, the black powder charge can be shaped so that the ‘stars’ (glowing colored bits) are propelled outwards in specific shapes and distances based on their position around it… and for multiple concentric layers of colors, it’s one color of stars surrounding the others. Color changes and other effects can be created by how the stars have those different chemicals layered in them.

https://www.entertainmenteffects.co.uk/how-firework-shells-create-different-shapes/

Anonymous 0 Comments

The layers various shapes are structured by they way they are packed. The different layers are separated from each other and different fuses lead to each layer. Fuse length and material set the timing.

Anonymous 0 Comments

[removed]

Anonymous 0 Comments

Where do they test fireworks? I want to be their neighbour.

Anonymous 0 Comments

A firework with more “fuel” is going to travel farther than one with less “fuel”. A shape can be made when fireworks with different amounts of “fuel” are packed together in certain configurations. For instance, if you pack fireworks with all the same amount of “fuel”, you get a circle. If you pack the same amount of fireworks in the same configuration, but give some fireworks a little more fuel, you can get a square by making the corners travel further. The corners would have a little more “fuel” than the middle ones.

You also may not notice how many fireworks they might use to get one shape or scene. Essentially, we’ve fired so many fireworks that we know a lot about how it will act if we give it a little more “fuel” or add a certain chemical to make it burn a different color.

E: No duh this isn’t how it actually works. A 5 year old just needs to know the basic concept of *how* fireworks can get shapes and colors…

Anonymous 0 Comments

Generally speaking, the shape of the flower is directly correlated to how the shell is assembled. These shells are spherical. When they explode, momentum is imparted to each star. Stars near the edge of the sphere are given more momentum and fly further. Conventional “Oriental” style shells utilize rolled stars. Stars are rolled like gumballs in spinning drums and are built up with successive applications of solvent and composition. Careful rolling can yield layered stars which change color.

Consider the case of a ring shell. Stars are arranged around the equator of the spherical shell, with all void space filled with burst charge. When the shell explodes, the stars are propelled on a straight line outward from the equator forming a circle, or “ring” in the sky.

The shell’s explosive power comes from the burst charge. Conventionally this is black powder coated into an inert carrier such as rice hulls, but adjunct compositions are used to modify the performance. Stars are ignited by the burst charge, but stars burn only on the surface, which is why they burn for seconds rather than “instantaneously”.

Source: 15 years in the industry

Anonymous 0 Comments

[removed]

Anonymous 0 Comments

you can also eject pellets that do not burn. and control the time at which they start and stop burning.

Anonymous 0 Comments

There’s a crucial detail missing from these otherwise very good answers: the burst charge is evenly (as much as possible) distributed inside the entire shell, surrounding all but the outermost stars. This means the the stars near the periphery of the shell receive the oomph from the entire charge, while those close to the center get less of it, which again means that they stay in place relative to one another as they expand away from the burst.

If the charge was located only in the center of the shell, the stars closest to it would gain more speed and the pattern would be ruined.