爆竹一問(用英文答）

What Is a Sparkler?
All fireworks are not created equal! For example, there is a difference between a firecracker and a sparkler. The goal of a firecracker is to create a controlled explosion. A sparkler, on the other hand, burns over a long period of time (up to a minute) and produces a brilliant shower of sparks. Sometimes sparklers are called 'snowballs' in reference to the ball of sparks that surrounds the burning part of the sparkler.

Sparkler Chemistry
A sparkler consists of several substances:
-An oxidizer
-A fuel
-Iron, steel, aluminum, or other metal powder
-A combustible binder

In addition to these components, colorants and compounds to moderate the chemical reaction also may be added. Often, firework fuel is charcoal and sulfur.

Sparklers simply may use the binder as the fuel. The binder is usually sugar, starch, or shellac. Potassium nitrate or potassium chlorate may be used as oxidizers. Metals are used to create the sparks. Sparkler formulae may be quite simple. For example, a sparkler may consist only of potassium perchlorate, titanium or aluminum, and dextrin.
Reaction Details
Now that you've seen the composition of a sparkler, let's consider how these chemicals react with each other:

Oxidizers
Oxidizers produce oxgen to burn the mixture. Oxidizers are usually nitrates, chlorates, or perchlorates. Nitrates are made up of a metal ion and a nitrate ion. Nitrates give up 1/3 of their oxygen to yield nitrites and oxygen. The resulting equation for potassium nitrate looks like this:

2 KNO3(solid) --> 2 KNO2(solid) +O2(gas)

Chlorates are made up of a metal ion and the chlorate ion. Chlorates give up all of their oxygen, causing a more spectacular reaction. However, this also means they are explosive. An example of potassium chlorate yielding its oxygen would look like this:

2 KClO3(solid) --> 2 KCl(solid) + 3 O2(gas)

Perchlorates have more oxygen in them, but are less likely to explode as a result of impact than are chlorates. Potassium perchlorate yields its oxygen in this reaction:

KClO4(solid) --> KCl(solid) + 2 O2(gas)

Reducing Agents
The reducing agents is the fuel used to burn the oxygen produced by the oxidizers. This combustion produces hot gas. Examples of reducing agents are sulfur and charcoal, which react with the oxygen to form sulfur dioxide (SO2) and carbon dioxide (CO2), respectively.

Regulators
Two reducing agents may be combined to accelerate or slow the reaction. Also, metals affect the speed of the reaction. Finer metal powders react more quickly than coarse powders or flakes. Other substances, such as cornmeal, also may be added to regulate the reaction.

Binders
Binders hold the mixture together. For a sparkler, common binders are dextrin (a sugar) dampened by water, or a shellac compound dampened by alcohol. The binder can serve as a reducing agent and as a reaction moderator.



Here are also some more information and related web sites since the words are limited:
http://chemistry.about.com/od/fireworkspyrotechnics/a/sparklers.htm

Hope these are useful for you~ =]

A firecracker (also known as a cracker, noise maker, or banger) is a small explosive device primarily designed to produce a large amount of noise, especially in the form of a loud bang; any visual effect is incidental to this goal. They have fuses, and are wrapped in heavy paper casing, as to contain any explosion. Firecrackers, along with fireworks are now thought to have originated in China.Firecracker brands, packs and labels Early (pre-1920s) Chinese firecrackers (AKA Mandarin firecrackers) were typically 1/2-inch to 2-inches long, and approximately 1/4-inch in diameter, and were charged with black powder. Mandarin crackers produced a less loud, duller thud when they exploded, compared to modern flash light crackers (which utilize a different explosive composition known as flash powder). Mandarin crackers produced a dimmer, less brilliant flash when they exploded also. Individual Mandarin crackers were most often braided into "strings" of varying lengths, which, when set afire, would explode in rapid sequence. Generally, the strings (sometimes containing as many as several thousand crackers) would be hung from an overhead line or high hook before being ignited. Most Mandarin crackers were coloured all red and did not generally have designs or logos decorating their exterior surface (AKA a "shell wraps"). Occasionally a few yellow and green Mandarin crackers were created and would be braided into the predominantly all red strings, to symbolized the emperor and the ruling class, while the numerous red crackers symbolized the common man.
Once flash powder, which produces a significantly sharper and brighter bang, replaced black powder as a firecracker's explosive charge (in approx. 1924) manufacturers began competing to gain the purchasing loyalty of the consuming public (i.e., mainly boys 8-16 years of age). Literally thousands of brands were created during the flash light cracker's heyday period from the 1920s through the early 1970s. Only a small percentage of brands lasted more than a year or two. Nowadays, collectors actively seek out examples of the various labels which contained the brand name and image associated with that brand.

圖片參考：http://en.wikipedia.org/skins-1.5/common/images/magnify-clip.png
A very successful early flash light cracker brand from the class-1 era (i.e., pre-1950); this particular class-1 label was most likely used on firecracker packs between 1945–1949. Until very recently (i.e., mid 1980s) firecracker production was a low-tech process. They were entirely handmade, beginning with the operation of rolling thin tubes. Once the firecracker tubes were rolled by hand (most commonly from newspaper) and labelled, and then filled with powder, their ends were crimped and fuses inserted... all by hand. These finished firecrackers were usually braided into "strings" and sold in packs which came in many sizes... from the very small (called "penny packs" containing as few as 4 to 6 firecrackers) to the most common size packs (containing 16 and 20 crackers per pack), to larger packs (containing 24, 30, 32, 40, 50, 60, 72, 90, 100 and 120 firecrackers), to huge "belts" and "rolls" (firecracker packages which contained strings of several hundred to several thousand crackers each). Firecracker packages were typically wrapped in colourful and translucent glassine paper, as well as clear cellophane. Glassine was the most popular, however.
The final packaging operation involved applying a branded pack label on each and every pack and then bundling quantities of finished packs into larger wholesale lots called "bricks" which contained an average of 80 packs each (varying according to the size of the packs being bundled. For example, packs of 32 crackers might only have 40 packs to the brick, compared to packs of 16 or 20 which would have 80 packs to the brick.