Japanese firework shells are of two principal types, the so-called poka and the warimono (chrysanthemum). The poka breaks just hard enough to disperse its contents into the air. The shell is made only as strong as it needs to be to withstand the shock of being fired. In contrast, the chrysanthemum shell must be strong …
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Category:Books – Shimizu Articles
Selected Pyrotechnic Publications of Dr Takeo Shimizu
Chapter 1 — Preface
The beauty of fireworks arises from their creation of organized patterns, mainly of fire, that consist of colors, lines and their movement and change in space and time. Chrysanthemum shells, also called ‘warimono’ (which means hard-breaking shell’), produce uniquely beautiful effects by creating patterns resembling chrysanthemums on the background of the sky. Until now, the …
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Burning Rate and Grain Size of Component Materials of Pyrotechnic Mixtures
Dr Takeo Shimizu ABSTRACT: It has been generally believed that the finer the grain size, the faster the burning when we select the component materials of a pyrotechnic mixture. It is not always true because a small explosion occurred in the past when we tested a smoke mixture, although it contained a dye of very …
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Stabilizing Firework Compositions – I. Minimum Solubility Law to Foresee the Degeneration, II. A New Chemical Method of Magnesium Coating
Dr Takeo Shimizu ABSTRACT: These studies concern two important problems at present: one is how to select the component materials of a mixture not to cause degeneration, and another is to find a more effective method of magnesium coating than those at present. A firework mixture generally consists of several solid materials which are closely …
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The Surface Explosion of Pyrotechnic Mixtures
Dr Takeo Shimizu ABSTRACT: In the past we sometimes observed a fairly large burning star caused an explosion with a loud noise at the very moment when it fell onto the ground. The star did not explode totally, but only with the thin surface layer. The burning surface layer of the star may be very …
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The Effect of Hot Spots on Burning Surface and Its Application to Strobe Light Formation with Mixtures Which Contain No Ammonium Perchlorate
Dr Takeo Shimizu ABSTRACT: The objective of this work was to make clear the effect of hot spots or hot spot materials on burning pyrotechnic compositions and to find practicable strobe light compositions without ammonium perchlorate which is not always popular in the firework field, using the effect of hot spot materials. As the hot …
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An Example of Negative Explosives: Magnesium Sulfate/Magnesium Mixture
Dr Takeo Shimizu ABSTRACT: At the Eleventh International Pyrotechnics Seminar, 1986, in Vail, Colorado, I reported on a study of pyrotechnic mixtures with a theme, “A Concept and the Use of Negative Explosives”. A further study has been continued on the same subject as before. In the former report it was known that magnesium sulfate/magnesium …
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Ballistics of Firework Shells
Dr Takeo Shimizu ABSTRACT: Heretofore we have had four important problems with calculations in this field, i.e., with the interior ballistics when using Black Powder as the propellant: (1) to obtain a suitable form function of the propellant which consists of irregular grains, (2) to obtain solutions when the burning rate ofthe propellant grains is …
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A Concept and the Use of Negative Explosives
Dr Takeo Shimizu ABSTRACT: In general, a pyrotechnic composition consists of an oxygen donor such as KNO3, KClO3, or KClO4, etc., an oxygen donee such as organic resin and some other inert substances. When substances, CaCO3, Al2O3, SiO or CaSO4, etc. are contained in it, they are regarded as an inert substance, because they are …
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Hypothesis on the Cause of Serious Accidents Related to Salutes Charges
Dr Takeo Shimizu Abstract: First, we hypothesize that a serious accident related to the use of salutes may be caused by the simultaneous explosion of several salutes or salute components, resulting in an unexpected, abnormally strong shock wave. To prove our theory, we conducted three experiments. In Experiment 1, we examined the transfer of the …
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