Firework

Related Topics:
Fireworks :: Fireworks_Displays

A firework is classified as low explosive pyrotechnic device used primarily for aesthetic and entertainment purposes. The most common use of a firework is as part of a fireworks display.

Fireworks (devices) take many forms to produce the four primary effects: noise, light, smoke, and floating materials (confetti for example). They may be designed to burn with colored flames and sparks. Displays are common throughout the world and are the focal point of many different cultural and religious celebrations.

Fireworks were originally invented by the Chinese, for entertainment purposes, as a natural extension of the Chinese invention of gunpowder. In China, they were first made by firework masters who were well-respected for their knowledge on the many complex techniques used to create truly dazzling firework displays. Such important events and festivities as New Year's and the Mid-Autumn Moon Festival were and still are times when fireworks are guaranteed sights.

Fireworks are generally classified as to where they perform, either as a ground or aerial firework. In the latter case they may provide their own propulsion (skyrocket) or be shot into the air by a mortar (aerial shell).

The most common feature of fireworks is a paper or pasteboard tube or casing filled with the combustible material, often pyrotechnic stars. A number of these tubes or cases are often combined so as to make, when kindled, a great variety of sparkling shapes, often variously coloured. The skyrocket is a common form of firework, although the first skyrockets were used in war. The aerial shell, however, is the backbone of today's commercial aerial display, and a smaller version for consumer use is known as the festival ball in the United States. Such rocket technology has also been used for the delivery of mail by rocket and is used as propoulsion for most model rockets.

Improper use of fireworks may be dangerous, both to the person operating them (risks of burns and wounds) and to bystanders; in addition, they may start a fire if landing on flammable material. For this reason, the use of fireworks is generally legally restricted. In the United States, fireworks are classified as either consumer or display fireworks based upon the amount of pyrotechnic composition an item contains. Display fireworks are restricted by law for use by professionals. Consumer items are available to the public and are smaller versions containing limited amounts of material to reduce potential dangers.

Fireworks classifications in the United States

The United States government has classified fireworks and similar devices according to their potential hazards.

Old explosives classes

Fireworks and other explosives were originally divided into three classes.

Class A products were usually high explosives such as dynamite.
Class B included display or "special" fireworks, usually used at large events. They are generally more powerful than consumer fireworks, and usually require a license to use.
Class C fireworks are "common fireworks", or consumer fireworks. This includes sparklers, fountains, and other fireworks available at stands. These are permitted for private use by federal law.

New explosives classes

The U.S. government now uses the United Nations explosives shipping classification system. This new system is based on hazard in shipping only, vs. the old USA system of both shipping and use hazards. The BATF and most states performed a direct substitution of Shipping Class 1.3 for Class B, and Shipping Class 1.4 for Class C. This allows some hazardous items that would have previously been classified as Class B and regulated to be classified as Shipping Class 1.4 due to some packaging method that confines any explosion to the package. Being Shipping Class 1.4, they can now be sold to the general public and are unregulated by the BATF.

A code number and suffix (such as 1.3G) is not enough to fully describe a material and how it is regulated, especially in Shipping Class 1.4G. It also must have a UN Number that exactly describes the material. For example, common consumer fireworks are UN336, or Shipping Class 1.4G UN336.

Here are some common fireworks classes:

Class 1.1G (Mass Explosion Possible:Pyrotechnics) UN0094 Flashpowder
Class 1.1G (Mass Explosion Possible:Pyrotechnics) UN0333 Fireworks (Salutes in bulk or in manufacture)
Class 1.2G (Projecton but not mass explosion:Pyrotechnics) UN0334 Fireworks (Rarely used)
Class 1.3G (Fire, Minor Blast:Pyrotechnics) UN0335 Fireworks (Most Display Fireworks)
Class 1.4G (Minor Explosion Hazard Confined To Package:Pyrotechincs) UN0336 Fireworks (Consumer or Common Fireworks)
Class 1.4S (Minor Explosion Hazard Confined To Package:Packed As To Not Hinder Nearby Firefighters) UN0336 Fireworks (Consumer or Common Fireworks)
Class 1.4G (Minor Explosion Hazard Confined To Package:Pyrotechincs) UN0431 ARTICLES, PYROTECHNIC for technical purposes (Proximate Pyrotechnics)
Class 1.4S (Minor Explosion Hazard Confined To Package:Packed As To Not Hinder Nearby Firefighters) UN0432 ARTICLES, PYROTECHNIC for technical purposes (Proximate Pyrotechnics)

Pyrotechnic compounds

Colors in fireworks are usually generated by pyrotechnic stars–usually just called stars–which produce intense light when ignited. Stars contain four basic types of ingredients.

A fuel which allows the star to burn
An oxidizer—a compound which produces (usually) oxygen to support the combustion of the fuel
Color-producing chemicals
A binder which holds the pellet together.

Some of the more common color-producing compounds are tabulated here. The color of a compound in a firework will be the same as its color in a flame test (shown at right). Not all compounds that produce a colored flame are appropriate for coloring fireworks, however. Ideal colorants will produce a pure, intense color when present in moderate concentration.

Lithium (medium red) Li₂CO₃ (lithium carbonate)

Color	Metal	Example compounds
Red	Strontium (intense red)	SrCO₃ (strontium carbonate)
Orange	Calcium	CaCl₂ (calcium chloride)
Yellow	Sodium	NaNO₃ (sodium nitrate)
Green	Barium	BaCl⁺ (barium chloride ions)
Blue	Copper halides	CuCl (copper chloride), at low temperature
Purple	potassium	KNO₃ (potassium nitrate)
Gold	Charcoal, iron, or lampblack
White	Titanium, aluminum, or magnesium powders

The brightest stars, often called Mag Stars, are actually fueled by Aluminum. Magnesium is rarely used in the Fireworks Industry due to its inability to easily form a protective oxide layer. Often an alloy of both metals called Magnallium is used.

Types of effects

Peony

A spherical break of colored stars. The peony is the most commonly seen shell type.

Chrysanthemum

A spherical break of colored stars, similar to a peony, but with stars that leave a visible trail of sparks.

Dahlia

Essentially the same as a peony shell, but with fewer and larger stars. These stars travel a longer-than-usual distance from the shell break before burning out. For instance, if a 3" peony shell is made with a star size designed for a 6" shell, it is then considered a dahlia. Some dahlia shells are cylindrical rather than spherical to allow for more large stars.

Willow

Similar to a chrysanthemum, but with long-burning silver or gold stars that produce a soft, dome-shaped weeping willow-like effect.

Palm

A shell containing a relative few large comet stars arranged in such a way as to burst with large arms or tendrils, producing a palm tree-like effect. Proper palm shells feature a thick rising tail that displays as the shell ascends, thereby simulating the tree trunk to further enhance the "palm tree" effect. One might also see a burst of color inside the palm burst (given by a small insert shell) to simulate coconuts.

Diadem

A type of Peony or Chrysanthemum with a center cluster of non-moving stars, normally of a contrasting color or effect. The name comes from the Latin word for "jewel".

Kamuro

A dense burst of glittering silver or gold stars which leave a heavy glitter trail. The name refers to a common Japanese hairstyle.

Crossette

A shell containing several large stars that travel a short distance before breaking apart into smaller stars with a loud crackling sound, creating a crisscrossing grid-like effect. Once limited to silver or gold effects,colored crossettes such as red, green, or white are now very common.

Spider

A shell containing a fast burning tailed or charcoal star that is burst very hard so that the stars travel in a straight and flat trajectory before burning out. This appears in the sky as a series of radial lines much like the legs of a spider.

Horsetail

Named for the shape of its break, this shell features heavy long-burning tailed stars that only travel a short distance from the shell burst before free-falling to the ground. Also known as a waterfall shell. Sometimes there is a glittering through the 'waterfall.'

Time Rain

An effect created by large, slow-burning stars within a shell that leave a trail of large glittering sparks behind and make a very loud sizzling noise. The "time" refers to the fact that these stars burn away gradually, as opposed to the standard brocade "rain" effect where a large amount of glitter material is released at once.

Fish

Large inserts that propel themselves rapidly away from the shell burst, often looking like fish swimming away.

Shell of Shells

A large shell containing several smaller shells of various sizes and types. The initial burst scatters the shells across the sky before they explode. Also called a bouquet shell. When a shell contains smaller shells of the same size and type, the effect is usually referred to as "Thousands". Very large bouquet shells (up to 48 inches) are frequently used in Japan.

Salute

Main article: Salute (pyrotechnics)

A shell containing a large quantity of flash powder rather than stars, producing a quick flash followed by a very loud report. Titanium may be added to the flash powder mix to produce a cloud of bright sparks around the flash. Salutes are commonly used in large quantities during finales to create intense noise and brightness. They are often cylindrical in shape to allow for a larger payload of flash powder, but ball shapes are common and cheaper as well.

Lampare

A shell containing a burst charge of flash powder that sits above a container of liquid fuel, usually diesel fuel or kerosene, to produce a fireball in the sky.

Mine

A mine is a ground firework that expels stars and/or other garnitures into the sky. Shot from a mortar like a shell, a mine consists of a canister with the lift charge on the bottom with the effects placed on top. Mines can project small reports, serpents, small shells, as well as just stars. Although mines up to 12 inches in diameter appear on occasion, they are usually between 3 and 5 inches in diameter.

Roman Candle

Main article: Roman Candle

A Roman candle is a long tube containing several large stars which fire intermittently at a regular interval. These are commonly arranged in fan shapes or crisscrossing shapes, at a closer proximity to the audience. Some larger Roman candles contain small shells (bombettes) rather than stars.

Cake

Main article: Cake (firework)

A cake is a cluster of small tubes linked by fuse, that fire small aerial effects at a rapid pace. Tube diameters can range in size from 1/4 inch to 4 inches, and can sometimes have over 1,000 shots. These are often used in large quantities as part of a show's finale. The variety of effects within individual cakes is often such that they defy descriptive titles and are instead given cryptic names such as "Bermuda Triangle", "Pyro Glyphics", "Waco Wakeup", and "Poisonous Spider", to name a few. Others are simply quantities of 2.5"-4" shells fused together in single-shot tubes.

World Pyro Olympics

The World Pyro Olympics in Manila is an annual international competition amongst the most prestigious fireworks companies in the world. The event is the largest and most intense international fireworks competition worldwide.

External links

Pyrotechnics

Gourt Home::Gourt :: Firework