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Note that every composition contains strontium
nitrate (Sr(NO3)2). That is because the strontium is responsible
for either a red or red-orange color. However, strontium nitrate
is not a great oxidizer - a mixture of Sr(NO3)2 and a fuel will hardly
burn. So a better oxidizer such
as potassium perchlorate or potassium nitrate
or an energetic fuel such as aluminum or magnesium
is added to give the extra energy needed for a fast combustion.
The rest of the components are either fuels, or a compound that serves as acombination fuel and binder, or parlon which is a binder but not really a fuel. Some older flare formulations also had things such as pitch, asphalt, wax, tallow, potassium chlorate and black powder. Those are not likely to be part of modern flare formulations. The flares are pressed dry. Friction MatchesSourceThe first "friction match" was invented by English chemist John Walker in 1826. According to Isaac Asimov in his Book of Facts, Walker rejected the idea of patenting his creation, citing the overwhelming benefit that useful matches could have to mankind. Because easily accessible fire could greatly impact the world in many various implementations, Walker claimed that matches were better left to public and free use by all humanity, rather than capitalized on by those who owned the manufacturing technology. Early work had been done by Robert Boyle and his assistant, Godfrey Haukweicz in the 1680s with phosphorus and sulfur, but their efforts had not produced useful results. Walker discovered a mixture of antimony(III) sulfide or stibnite (tin trisulfide - antimonite - Sb2S3), potassium chlorate, gum, and starch could be ignited by striking against any rough surface. Walker called the matches congreves, but the process was patented by Samuel Jones and the matches were sold as lucifer matches. The early matches had a number of problems: the flame was unsteady and the initial reaction was disconcertingly violent; additionally, the odor produced by the burning match was unpleasant. It is described as a firework odor — the pungent smell of sulfur dioxide. Lucifers reportedly could ignite explosively, sometimes throwing sparks a considerable distance. The term persisted as slang in the 20th century (for example in the First World War song Pack Up Your Troubles) and in the Netherlands and Belgium today matches are still called lucifers. In 1830, Frenchman Charles Sauria added white phosphorus to remove the odor. These new matches had to be kept in an airtight box but were popular. Unfortunately, those involved in the manufacture of the new matches were afflicted with phossy jaw and other bone disorders, and there was enough white phosphorus in one pack to kill a person. There was a vociferous campaign to ban these matches once the dangers became known. Safety Matchs"Household" safety matchesTheir safety is due to the separation of the reactive ingredients between a match head on the end of a paraffin-impregnated splint and a special striking surface, and the replacement of white phosphorus with red phosphorus. The striking surface is composed of typically 25% powdered glass, 50% red phosphorus, 5% neutralizer, 4% carbon black and 16% binder; and the match head is typically composed of 45-55% potassium chlorate, with a little sulfur and starch, a neutralizer (ZnO or CaCO3), 20-40% of siliceous filler, diatomite and glue. Some heads contain antimony(III) sulfide so they burn more vigorously. Safety matches ignite due to the extreme reactivity of phosphorus with the potassium chlorate in the match head. When the match is struck the phosphorus and chlorate mix in a small amount forming something similar to the explosive Armstrong's mixture which ignites due to the friction. Strike Anywhere MatchTwo French chemists, Savene and Cahen, developed a safety match using phosphorus sesquisulfide. They proved that the substance was not poisonous, that it could be used in a "strike-anywhere" match, and that the match heads were not explosive. They patented a safety match composition in 1898 based on phosphorus sesquisulfide and potassium chlorate. Albright and Wilson developed a safe means of making commercial quantities of phosphorus sesquisulfide in the United Kingdom in 1899 and started selling it to match makers.More on Safety MatchsSourcePotassium chlorate is sprinkled on a small mound of red phosphorus. A gentle tap with a hammer causes the mixture to explode. The gritty material on the side of a match-box is coated with red phosphorus. The match-head contains potassium chlorate and some red coloring. When the match-head rubs against the box, friction ignites the mixture of phosphorus and potassium chlorate. By separating the strong oxidizer (potassium chlorate) from the reducer (phosphorus) the matches are prevented from igniting spontaneously. Unlike the safety matches shown here, strike-anywhere matches are made with oxidizer and reducer together in the match head so that only friction or elevated temperature is required to ignite them. Safety matches are 'safe' because they don't spontaneously combust. You have to strike them against a special surface in order to get them to ignite. The match heads contain sulfur (sometimes antimony III sulfide) and oxidizing agents (usually potassium chlorate), with powdered glass, colorants, fillers, and a binder made of glue and starch. The striking surface consists of powdered glass or silica (sand), red phosphorus, binder, and filler. When you strike a safety match, the glass-on-glass friction generates heat, converting a small amount of red phosphorus to white phosphorus vapor. White phosphorus spontaneously ignites, decomposing potassium chlorate and liberating oxygen. At this point, the sulfur starts to burn, which ignites the wood of the match |
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