|Quickmatch is the most common fuse used in professional fireworks because it can burn at several hundred feet per second, even though it's just black match encased in a paper tube. How does this work? When bare black match burns, it produces a lot of gas, which escapes in every direction (left). The burning part only ignites the portion of the fuse directly in front of it, which then ignites the fuse ahead of it, etc. But when black match is covered by a paper "pipe" and ignited, the hot gases don't have anywhere to go except straight ahead. The amount of pressure and small size of the pipe cause the burning hot gases to shoot down it at incredible speeds, igniting the fuse way ahead of the actual flame point.||
SHELL BURST PATTERNS
|One spectacular effect (and my personal favorite) is aerial shell burst patterns. Shapes such as atoms (as shown), smiley faces, peace signs, and flowers can be created by carefully laying out the colored stars in the shape of the desired pattern within the shell (the stars inside the shell aren't actually colored, I just colored them for reference purposes). When the shell bursts from the center, each of the stars is propelled away from it in a different direction, "enlarging" the pattern of stars hundreds of times into the sky.|
|Whistling fireworks are usually made from thick, narrow bore
tubes that are about 3 cm long. The composition in the tube must be
well-consolidated to eliminate any air pockets which may act as a
mini-combustion chamber and cause the
device to explode. These type of fireworks require two things to
whistle: a special composition that will make a sound under certain
burning conditions, and an empty space in the tube to act as a
resonator. Whistles are filled only about halfway with pyrotechnic composition
so that when it burns, the empty tube above can vibrate to amplify and
enhance the musical tune that the composition creates.
The whistling device pictured here is a consumer Piccolo Pete. Because of its unusually large size, the pitch of the whistle changes as the composition burns away to create more hollow tube space above. Smaller whistles can be placed in fountains, shells, and rockets.
|Humming fireworks consist of a thick walled tube filled with powder and capped off at either ends with clay. A small hole is drilled in the side at such an angle that when the composition is ignited, the thrust spins the device around rapidly on its axis. During each revolution, there is a brief period of time when the thrust hole (the source of sound) is pointed towards the observer. The rapid increase/decrease of sound pitch created by the spinning tube results in a continuous noise that we perceive as humming. Hummers can be placed in shells, or used by themselves (such as Ground Bloom Flowers).|
|Strobe composition is a solid mixture that consists of two main parts: a composition that reacts easily, and one that doesn't. When the mixture is ignited, the more reactive compound burns to create a great deal of heat. This heats up the the more difficult to ignite portion of the mixture, which goes off with a sudden flash once it reaches ignition temperature. Strobe composition can be made into stars and put into shells/aerial effects, or just used by itself in the form of the consumer fireworks pictured to the left.|
more to come soon...
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