How are fireworks shaped?

Fireworks, also known as fireworks, fireworks, China's four great inventions -
Color effect
The main use of flame color reaction only. Different metals and their compounds glow differently when they burn. The specific colors correspond to the following
Sodium Na Li Copper K Steel Rb Cs Ca Sr Copper Cu Ba
Yellow violet violet violet violet violet brick red magenta green yellow green
Metal luminisers and hair colouring agents are added to the fireworks process to create a riot of colours
, sound effect
The explosion of gunpowder agents in limited space will produce a large amount of gas, some gas shuttle through the nozzle can make pleasant whistle or flute sound; some gas directly blast the container can produce blasting or figurative sound to achieve the sound effect. The sound is mainly based on the difference in the space where the explosion is made, which is similar to wind music. Different instruments have different timbres under the air flow
Spark effect
Different fireworks effect is different, some like shooting stars, have chrysanthemum
When the hard charcoal powder or aluminum powder, iron powder into the agent, after the combustion of some particles in the photointercept body is not completely burned out is ejected, these particles are ejected to meet the oxygen in the air, will occur a second combustion reaction, resulting in different colors and a certain brightness.
Hard charcoal powder can produce golden stars; Iron powder can produce steel blue star; Aluminum powder "can produce white small bright star, using the effect of spray wave can produce a variety of fireworks image, such as can be made into gold, white, steel blue spray flowers; Or parts that produce scurffling bee poles (called curvature), somersaults (called hydrangeas), and so on
Some agents can burn strongly after being ignited to produce a certain brightness and light color, and produce a bright pulse phenomenon. The effect is flicker. In addition to the addition of metal powder, but also to the addition of a large number of solid and liquid products of the material. This can make the agent burning, due to the presence of metal powder will produce higher temperature and greater brightness, when the solid and liquid residue under the cover - layer waiting for the burning of the agent, that is, low temperature radiation will appear to give a person a sense of extinction, the next layer of agent is lit, and will produce high temperature and greater brightness. Then use the solid and liquid residue to look at the next layer of agents, so that the class, there will be a phenomenon of light off. The use of this pulsating phenomenon of light and light, can be made like snowflakes, red stars and other fireworks products and various jujube parts. Other effects are made in a similar way.