Detonator initiating power

For both technical and economic reasons, current detonators contain a base charge of high explosive which provides the main initiating power of the device. The most satisfactory high explosives for use as base charges are PETN, tetryl and RDX, and of these the first is by far the commonest, because of its sensitiveness and relatively low cost. 

Impact Sensitivity — less sensitive than PA and TNT FI 120% PA. French test with 10kg weight (mouton) gave at the height of drop 2.50 meters, 50% detonations Initiation Sensitivity — 50g sample pressed to sp gr 1.23 in a paper cylinder 30mm diam required 2g MF for its detonation Power (Strength) — si more powerful than TNT, but less powerful than EDNA. Ballistic Mortar... 

No 8, contains 0.35 g ASA 0.55 g tetryl. PETN can be used as an alternative base charge for tetryl to obtain detonators of increased initiating power or to reduce the detonator charge required. The corresponding charge of ASA PETN are 0.20 0.22 g respectively for the No 6 cap and 0.20 ... 

Below this diameter LVD can be stable for lengths of up to 25 charge diameters. LVD is not affected by the initiating power of the detonator, provided the detonators are weak enough not to initiate normal detonation... 

It is noteworthy that max LVD (ie, LVD at transition diam) is independent of particle size, and indeed of the type of expl (it is essentially the same for TNT, PETN, RDX and Tetryl). For charge diameters between min diam for LVD and min diam for normal detonation, even powerful initiators will produce only steady LVD provided the charge is of sufficient length. For 1.3mm Tetryl particles at 0,91g/cc and charge diam d = 20mm, it was found that LVD -2.14km/sec and LVD pressure is about 14.5kb. Expts with oil-coated or crushed particles suggest that the main reaction in LVD is a surface combustion... 

Properties of Ag-salts of 1-(iV-nitramino)-, 2-(Wnitramino)-, 5-(W-nitramino)tetrazole, and l-methyl-5-(fV-nitramino)-tetrazole have been examined. The initiation power of these salts was estimated from minimal blasting charge in RDX. Silver salts of l-(W-nitramino)- and 2-(iV-nitramino)tetrazole have a DDT (deflagration-to-detonation transition) period shorter than the salts of 5-(W-nitramino)tetrazole and l-methyl-5-(W-nitramino)tetrazole. The salt of 2-(fV-nitramino)te-trazole is a more powerful initiative explosive than lead azide <2006MI39>. 

Properties Bright-yellow crystals or amorphous powder or granules. Sp. gr. 1.63. Explodes when heated to a temperature of 180°. Less sensitive to impact than either lead azide or mercury fulminate, much less sensitive to friction than the latter, and does not get dead-pressed. Cannot be detonated under water with a No. 8 electric detonator. The strength (sand-bomb test) is about, twice that of mercury fulminate or lead azide. The initiating power is greater than... 

Boosters Articles consisting of a charge of detonating explosive with or without means of initiation. They are used to increase the initiating power of detonators or detonating cord. UN App. B, ICAO A2, lATA App. A... 

Initiating efficiency, sometimes referred to as initiating power, strength, or priming force, is the ability of a primary explosive to initiate detonation in a secondary explosive adjacent to it. It is usually reported as a minimum amount of primary explosive necessary to cause detonation of the adjacent high explosive with 100%... 

Organic compounds with high azido content are very sensitive to friction and impact, causing strong explosions. For example, cyanuric azide is very sensitive against mechanical stimulus and thus decomposes very easily by detonation. Although the initiation power of this detonation exceeds that of classical primary explosives no technical application has been found so far for this compound due to its high vapour pressure. 

In general terms, PETN can be characterized as a sensitive , brisant, and powerful high expl. Explosive sensitivity is a rather nebulous quantity, but there can be no doubt that PETN is a much more sensitive material than TNT, but rather less sensitive than Lead Azide. In particular, PETN requires very little priming i charge (less than 1 mg LA) to initiate its detonation. This is the characteristic that makes PETN so widely used in blasting cap base charges, in detonating cord and in boosters... 

Brisance and power are quantities that can be defined more exactly than sensitivity, and PETN is one of the most powerful and brisant expls known. It is also among the most studied expls, from both exptl and theoretical points of view. In this section we will consider PETN s steady detonation parameters, thermochemistry, and initiation characteristics,... 

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