Abstract: The pyrotechnic ignition device of this invention comprises a hollow tubular coiled charge of pyrotechnic sheet material defining an ignition initiation position, the internal diameter of the charge decreasing and the wall thickness increasing over at least a portion of the charge extending from the initiation position in the direction of burning. This configuration enhances the reliability of ignition and the rate of flame development.Preferably the adjacent plies of the coiled charge are spaced apart. The preferred coiled charge also has a portion downstream from the initiation position in the direction of burning which decreases in external diameter and wall thickness in a direction extending away from the initiation position, the configuration of this portion being effective to enhance the speed and violence of burning of a main gas-generating propellant charge ignited by the coiled charge.

Abstract: The invention provides an improved process for the production of a pyrotechnic or explosive device containing encased hazardous solid material wherein the material is dispersed in an inert liquid, the dispersion is formed into droplets and the droplets are solidified in a cooling medium. The solidified droplets are loaded into a casing and freeze-dried in situ in the casing to produce dry particles of the hazardous material, which may optionally be pressed within the casing, advantageously under vacuum,Only the operations (if any) subsequent to the freeze-drying need special precautions to be taken to prevent damage to personnel or equipment.The invention is advantageous for the preparation of detonators, igniters and other devices containing hazardous materials for example lead azide, lead styphnate, pentaerythritol tetranitrate and boron/potassium nitrate mixtures.