Safe Package of Sporting Paper Caps

The sporting paper caps which are used for starting signal pistols in Japan each contain about 0.05 g of a composition consisting of 74% potassium chlorate, 18% red phosphorus, 8% sulphur and small amount of starch. Recently, the hazard classification on the packaging of these paper caps for transportation on ships was discussed. 

sheet corrugated board was shown to perform well in absorbing shock in tests in which three sheets of corrugated board were put into a small case and the cases used as shock absorbers for preventing the propagation of explosion from a detonator. Second, the safety of the new package was shown by applying the United Nations classification tests for explosives. 

The commercial products of RADIE Co. Ltd. (trade name EVERNEW) were used as the sampls of sporting paper caps. Fig.5.1 and Fig.5.2 show the structures, cases and packages of the sporting paper caps. 

The explosive power of 100 sporting paper caps (about 5 g of explosive)was measured by use of MKIII ballistic mortar initiated by a No.6 detonator as shown in Fig.5.3. 

The length of the ballistic pendulum swing from the explosion of 100 sporting paper caps and one No. 6 detonator is 165 mm. That from only one No.6 detonator is 30 mm, so the net result from 100 sporting paper caps is 135 mm. In comparison with a 151 mm swing from 5 g of TNT, the explosion power of the sporting paper caps is 89% of that of TNT. 

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