Other firework materials

According to JIS, the grade of cotton string is expressed by a hank number(1 hank=840 yard=768 m) per 1 pound(453.5 g) with an authorized moisture content the grade of hemp string by fibronumber(1 fibro=300 yards=274 m) with a similar moisture content. The authorized moisture 

The seeds must be well dried before use. It is said that seeds which have been stored for more than a year and which have lost their germinating power are the best to use. Commercial seed contains a small amount of cotton and dust which must be removed with a suitable sieve. This is important to avoid residual fire sparks among the seeds and to obtain good bursting charge grains. 

As the cultivation of cotton in Japan is declining there is a shortage of cotton seeds on the market, but of course a large amount of cotton is produced in the USA, India and China. At present, in place of the cotton seeds many of the fireworkers use rice chaff for small or medium shells and Japanese cypress seeds for large shells. 

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Fireworks, when not properly handled, can result in injury, loss of life and property damage. The problems of safety are in many ways different from those of most explosives and propellants. In general, the sensitivity of fireworks to shock and impact is considerably less than that of many explosives and propellants. On the other hand, most fireworks are more sensitive to sparks and flame than most other explosive materials. 

In the case of sparklers they should not be handled by small children who might chew at the live composition, poke the wires into their eyes, burn themselves with sparks or pick up the burnt-out wires while still hot. Sparklers should not be handed around while burning, they should not be used near animals, the eyes, flammable materials or other fireworks. 

Other typical pyrotechnic fuels include charcoal, sulfur, boron, siUcon, and synthetic polymers such as poly(vinyl alcohol) and poly(vinyl chloride). Extensive use has been made of natural products such as starches and gums, and the use of these materials continues to be substantial in the fireworks industry. MiUtary pyrotechnics have moved away from the use of natural products due to the inherent variabiUty in these materials depending on climatic conditions during the growth of the plants from which the compounds are derived. 

Several explosives are mixtures of compounds of potassium and other substances. It is an important raw material for making explosives, matches, and fireworks. 

Strontium nitrate [Sr(NOj)j], when burned, produces a bright red flame, and it is used in fireworks. During mihtary combat, it is used to make tracer bullets so that their paths can be tracked at night. Strontium is also used in making specialty metals when alloyed with other metals and in the manufacture of soaps, greases, and similar materials that are resistant to extreme high or low temperatures. 

In 1801 the French pyrotechnist Claude-Fortune Ruggieri described the use of metal salts in the production of coloured flames. By the early nineteenth century the firework maker had at his disposal a diverse arsenal of materials, many of which are still in use today. The following substances were documented by Audot and others at around that time ... 

The DuPont company rapidly saw that HNO3 was the key in making cheap explosives, all of which need nitrates and nitro compounds, and they rapidly became the largest producers of HNO3. World War I was a good period for DuPont, but the explosives business is inherently cyclical (fortunately), and dynamite and fireworks have limited markets. Therefore, DuPont began to explore other uses of cellulose, a raw material for smokeless... 

When that book was published, most of those who would misuse its information were in prisons or nuthouses. The rational, lawabiding person was trusted with no end of potentially dangerous materials. He was also trusted to teach his children the dangers of anything they were permitted to use, such as fireworks. His children were trusted, not only in playing with the fireworks safely, but they were also trusted not to cause damage to property or to other children. 

It would be ideal to reject this material from fireworks, but it is quite difficult even at present, because no other oxidizer can surpass potassium chlorate in burning speed, in ease of ignition or in noise making, using the smallest amount of composition. The match head composition cannot be made without it it is also absolutely necessary for some dye smoke, small crackers and various kinds of toy caps. However these articles tend to become a source of explosion, and we must treat potassium chlorate compositions with respect and caution. 

Pine root pitch was obtained as a bi-product of the distillation of turpentine oil during World War II in. Japan. After the war it was found to be useful for firework use, but the substance is not produced at present and is in short supply. When the reason why this material gives such a large burning rate to perchlorate compositions is better understood, it might surely be possible to produce such a substance by some other method. 

Ammonium nitrate and ammonium sulfate both have other uses also. For example, ammonium nitrate is used to make explosives, fireworks, insecticides and herbicides (chemicals that kill insects and weeds), and rocket fuel. Ammonium sulfate is also used in water treatment systems, as a food additive, in the tanning of leather, in fireproofing materials, and as a food additive. 

Strontium and its compounds have relatively few commercial uses. The pure metal is sometimes combined with other metals to form alloys. An alloy is made by melting and mixing two or more metals. The mixture has different properties than the individual metals. Compounds of strontium are sometimes used to color glass and ceramics. They give a beautiful red color to these materials. Strontium compounds also provide the brilliant red color of certain kinds of fireworks. 

The fire dust or sparks which are produced by iron or carbon create the colour which resembles that of the black body. The colour of the sparks of "Senko-Hanabi" which is caused not only by carbon but also other materials, also resembles the colour of the black body. We feel that the colour of the aluminium fire dust is a little different from the black body. The colour changes from red-orange to yellow, white yellow and silver as the temperature increases, and the locus may be written as the LH line (Fig.33). Anyhow we can produce various colours of the fire dust or sparks except blue and green by adjusting the temperature and selecting substances which make up the component material in firework compositions according to the principle of the colour temperature. 

The most important problems at present in the firework field to avoid the degeneration of mixture may be how to select the materials wnich do not react to each other. 

In other words, in case of hre, wood burns and iron bends, but the time that elapses between hre and collapse in the case of wooden structures may be substantially longer than that of an iron strnctnre. The discharge tnbes of the fireworks that we use at New Year are made not of steel but of cardboard, and the discharge nozzle is made not of special metallic materials but of paper or in... 

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