During this holiday season, you will certainly not fail to contemplate fireworks illuminating and coloring the sky. No doubt you will be tempted to make it yourself. And why not? It’s so pretty and festive that it would be a shame to miss it to start the year off right.
Fireworks are above all an explosion.
Fireworks are the result of explosions that occur during combustion. We are talking about pyrotechnics.
To create an explosion, you need gas under pressure. When there isn’t enough room to hold the gas, the object that contains it explodes. This is the case with the balloon. When you blow, there comes a point when the plastic in the balloon can no longer stretch without breaking. The balloon explodes with din.
The same principle is used for bombs or explosives. You heat a product that releases hot gas into an object. At one point, there is so much gas released that the pressure inside the bomb increases. And that’s the explosion.
Combustion
The fact that a body is burning.
Pyrotechnics
It is the set of techniques for manufacturing and using fireworks.
A firework is a chemical reaction
The combustion that sets off the explosion occurs between a fuel, which burns, and an oxidizer, which maintains the combustion.
For example, when you make a fire, the fuel is wood, and the oxygen in the air is the oxidizer. Without oxygen, no fire!
But in the case of the explosion, the quantity of oxygen present in the air is not sufficient to cause a violent explosion during its combustion. Another product is therefore needed!
For fireworks, a mixture of strong explosives is used, which consists of both oxidizers and combustibles, enclosed in a container.
The explosive mixture packed inside can be lit with a wick and boom!
How to make a rocket that rises in the sky?
The explosives powder should be placed in a cylindrical container open on one side. As the mixture burns, it releases gas at high speed backward. The rocket finds itself propelled upwards. To succeed, you need the right cylinder size, and the right amount of powder, otherwise the rocket will fall or explode directly on the ground.
And yes, pyrotechnics is a profession.
What explosives are used in fireworks?
Explosives like those used in gunpowder are used. For example potassium nitrate, strontium nitrate or potassium perchlorate.
These explosives are used to propel rockets and detonate them in the sky.
The firework bomb must reach the correct altitude. For this, specialists use a mortar to propel the bomb high in the sky. During its ascent, a wick burns and explodes the bomb of fireworks well above your head.
Combustible
It is the material used to produce energy when it is burned. Like coal or wood.
Combustive
Compound that causes or maintains combustion. For example, oxygen.
Where do the different colors come from?
The colors we see come from small granules that emit light. We are talking about luminescence chemistry.
The different colors come from the different metals that are placed in these granules.
For example, glowing strontium gives a red light, while copper will give a blue color. By combining copper and strontium, we will get purple.
To have a shower of sparks, we add aluminum granules.
How do you get original shapes in the sky?
These granules are put around the powder, but not just how. According to the design that we want to obtain in the sky, these granules will be positioned in specific ways. When the bomb explodes, the granules are propelled into the sky, retaining the initial shape chosen in the bomb.
Each bomb can also contain other small bombs to generate secondary explosions.
Obviously, it is forbidden to do this at home. Pyrotechnics is a profession.
Luminescence
It is the properties that certain bodies produce of light, under the action of a reaction for example.
Incandescence
It is the properties of a body to emit light when heated to very high temperatures.
