1977 Charles .G. Wade US Atlas Powder Company proposed not adding the sensitizer, only 1 on the 6th detonators reliable emulsion explosives detonated. Its main feature is the use of sensitization of hollow glass microspheres.
Thin-walled hollow glass beads from sodium borosilicate material with a special process, closed the tiny sphere, the sphere inside the parcel certain amount of gas, its specific density, low thermal conductivity, low oil absorption, particle size and chemical composition controllable superior performance, which makes it very suitable as emulsion explosives sensitizers.
Hollow glass microspheres uniformly distributed stable formation of numerous tiny bubbles of space in explosives. In the role of external initiation impulse, each bead by adiabatic compression local temperature form burning point, and detonated outside the mechanical energy is focused on those burning point is at a temperature high enough to cause burning and oil phase oxidant the violent exothermic chemical reactions such as decomposition, to detonation.Internal phase emulsion explosive matrix supersaturated solution, the density is large, liquid beads were separated by the film; the Foreign Secretary for the film, the density is relatively small, in the long-term storage in the aqueous phase has a tendency to sink, the oil phase has a floating trend, final lead to breaking. Most of hollow glass microspheres diameter between 10μm to 150 μm, and a matrix of internal phase droplet diameter of 10-1μm to 1μm, Foreign Minister film thickness of 10-3μm to 10-2μm.After addition of cenospheres, nearly one-third of the space of the substrate surface granularity “huge” hollow microspheres occupied surface of each bead around the oil droplets are associated with many closely together. They play the role of care afloat stabilizer.
In summary, hollow glass beads is a multifunctional additive in emulsion explosives.