(1952).
7.
J. E. Tanner, "Effect of Binder Oxygen Content on Adia-batic Flame Temperature of Pyrotechnic Flares," RDTR No.
181, Naval Ammunition Depot, Crane, Indiana, August, 1972.
8.
T. Shimizu, Fireworks - The Art, Science and Technique,
pub. by T. Shimizu, distrib. by Maruzen Co., Ltd., Tokyo, 1981.
9.
J. E. Rose, "Flame Propagation Parameters of Pyrotechnic Delay and Ignition Compositions," Report IHMR 71-168, Naval Ordnance Station, Indian Head, Maryland, 1971.
10.
F. L. McIntyre, "A Compilation of Hazard and Test Data for Pyrotechnic Compositions," Report ARLCD-CR-80047, U.S. Army Armament Research and Development Command, Dover, NJ, 1980.
A "set piece" outlines the seal of the United States. The pyrotechnician creates pictures and messages by attaching hundreds of cigar-sized tubes, loaded with color-producing composition, to a wooden lattice secured in the ground.
The pattern of the tubes and the
choice of colors determine the picture that is produced. Fast-burn-ning fuse-"quickmatch"-connects the tubes and permits rapid ignition of the entire pattern. Thread impregnated with fine black powder is covered by a loose-fitting paper wrapper to make quickmatch.
The hot gas and flame is confined inside the paper sheath, and burning is very rapid. (Zambelli Internationale)
6
HEAT AND DELAY COMPOSITIONS
HEAT PRODUCTION
All pyrotechnic compositions evolve heat upon ignition, and this release of energy can be used to produce color, motion, smoke, and noise.' There are applications as well for the chemically-produced heat itself, and these will be addressed in this chapter.The use of incendiary mixtures in warfare can be traced back to ancient times, when it provided an effective means of assault-ing well-fortified castles. Naval warfare was revolutionized by the use of flaming missiles to attack wooden ships, and much effort was put into improving the heat output, portability, and ac-curacy of these thermal weapons.
As both weaponry and the use of explosives for blasting developed, the need for a safe, reliable way to ignite these devices became obvious, and the concept of a pyrotechnic "delay"
emerged. A variety of terms are used for materials that either ignite or provide a delay period between ignition of a device and the production of the main explosive or pyrotechnic effect. These include
1.
Fuse:
A train of slow-burning powder (usually black powder), often covered with twine or twisted paper. Fuses are lit by a safety match or other hot object, and provide a time delay to permit the person igniting the device to retreat to a safe distance.
125
126
Chemistry of Pyrotechnics
Heat and Delay Compositions
127
TABLE 6.1 Electric Match (Squib) Compositionsa TABLE 6.2 Typical Primer Mixtures a
Component
Formula
% by weight
by
weight
1.
Potassium chlorate
KC10
Note
3
8.5
Component
Formula
Lead mononitroresorcinate
PbC 6H3NO,,
76.5
KC1O 3
45
Nitrocellulose
15
1.
Potassium chlorate
Stab primer
Lead thiocyanate
Pb(SCN) 2
33
2.
Potassium chlorate
KC1O 3
55
Antimony sulfide
Sb 2 S 3
22
Lead thiocyanate
Pb(SCN) 2
45
2.
Potassium chlorate
KCI0 3
33
Stab primer
3.
Potassium perchlorate
KC1O,,
66.6
Antimony sulfide
Sb 2 S 3
33
Titanium
Ti
33.3
Lead azide
Pb(N 3) 2
29
Carborundum
5
a Reference 1.
3.
Potassium chlorate
KC10 3
50
Percussion primer
Lead peroxide
Pb0 2
25
Antimony sulfide
Sb 2 S 3
20
Trinitrotoluene
C 7 H S N 3 0 6
5
4.
Potassium perchlorate
KC10 4