The present invention involve a method for severance of materials made of
polycarbonate, polycarbonate laminate and aciylic/polycarbonate laminate,
a canopy fracturing system and a conopy having the canopy fracturing
system.The present invention utilizes a linear shaped explosive charge
placed at a predetermined distance or stand off from the polycarbonate
material to be severed. The coreload of the charge is determined such
that the minimum coreload necessary to effect severance of a given
thickness of polycarbonate material is utilized. A retainer is placed
around the charge and affixed to the material such that the charge is at
the proper stand off from the material. The retainer surrounds the back
side of the charges but leaves open space between the charge and the
material to be severed. Upon detonation, the charge creates an explosive
cutting force, or jet blast, that severs the polycarbonate material.
Also, provided are methods for intersecting explosive charges about a
pattern to be severed and methods for transferring detonation between
such intersecting explosive charges.