PRODUCTION OF PYROTECHNIC DELAY COMPOSITION
A process for producing a pyrotechnic delay composition includes admixing an oxidizer, a fuel, a surfactant and a liquid, to form a paste or slurry. The paste or slurry is dried to remove the liquid and to obtain a solid product which, if necessary, is rendered into particulate form. Optionally, the solid particulate product is classified to obtain a pyrotechnic delay composition in particulate form.
1 . A process for producing a pyrotechnic delay composition, the process including
admixing an oxidizer, a fuel, a liquid and a rheology modifier having the ability to alter or modify the burning rate of a delay element made from the delay composition, to form a paste or slurry;
drying the paste or slurry to remove the liquid and to obtain a solid product;
if necessary, rendering the solid product into particulate form; and
optionally, classifying the solid particulate product, to obtain a pyrotechnic delay composition in particulate form.
2 . The process according to claim 1 , wherein the rheology modifier is in particulate form.
3 . The process according to claim 2 , wherein the rheology modifier comprises a polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone and/or a powdered smectite clay.
4 . The process according to claim 2 , wherein the rheology modifier, when admixed with the other solid constituents, is in the form of an aqueous dispersion.
5 . The process according to claim 1 , wherein the rheology modifier comprises 0.25% to 4%, by mass, of the paste or slurry.
6 . The process according to claim 5 , wherein the rheology modifier comprises 0.1% to 2%, by mass, of the liquid-containing paste or slurry.
7 . The process according to claim 1 , wherein the liquid is an organic solvent.
8 . The process according to claim 1 , wherein the liquid is water.
9 . The process according to claim 1 , wherein the oxidizer comprises red lead, barium sulphate and/or potassium perchlorate.
10 . The process according to claim 1 , wherein the fuel comprises silicon, zinc, and/or magnesium.
11 . The process according to claim 1 , wherein the composition comprises, on a mass basis,
oxidizer 40-90%
fuel 5-60%
rheology modifier 0.1-2%
12 . A pyrotechnic delay composition, which is in solid particulate form, with the particles comprising an oxidizer, a fuel and a rheology modifier having the ability to alter or modify the burning rate of a delay element made from the delay composition.
13 . A pyrotechnic delay composition according to claim 12 , which includes, in addition to the rheology modifier, another surfactant.
14 . A pyrotechnic delay composition according to claim 12 , wherein the rheology modifier comprises a polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone and/or a powdered smectite clay.
15 . A pyrotechnic delay composition according to claim 12 , wherein the oxidizer comprises red lead, barium sulphate and/or potassium perchlorate.
16 . A pyrotechnic delay composition according to claim 12 , wherein the fuel comprises silicon, zinc, and/or magnesium.
17 . A pyrotechnic delay composition according to claim 12 , wherein the composition comprises, on a mass basis,
oxidizer 40-90%
fuel 5-60% rheology modifier 0.1-2%
18 . A pyrotechnic delay composition according to claim 12 , which contains no red lead.
19 . The process according to claim 1 , which includes admixing with the oxidizer and the fuel, another surfactant in addition to the rheology modifier.
20 . The process according to claim 1 , wherein the pyrotechnic delay composition contains no red lead.