Abstract

A roll calendered sheet propellant features thin sheets of solid propellant which have been consolidated by the calendering operation. After calendering, the sheet propellant is roll-printed or "coined" with a pattern, which forms propellant flakes after ignition in a gun/cannon system. The printed pattern consists of a designed flake geometry, for example, of contiguous diamond or square shapes providing flame communicating paths therebetween. The formation of propellant flakes depends upon a characteristic of propellants, specifically that they burn faster in zones of high residual stress. By varying the design of the roll printer, the printed pattern, in a two-sided printed sheet configuration, may include a cut in the pattern of the order of 15 to 40% of the propellant sheet uncut web depth. After roll printing, the propellant may be cut to length and rolled for insertion into a shell or cartridge case.