Legacy propellant production and load, assembly and pack would greatly benefit from additive manufacturing techniques that would reduce environmental impact, improve weapon performance, and decrease weapon susceptibility to insensitive munition (IM) threats while maintaining reasonable production and lifecycle costs. Solvent-based gun propellant manufacturing, which is used for all BALL POWDERS®, M14, M31A2, etc., utilizes volatile organic compounds (VOCs) (ethyl ether, ethyl acetate, ethyl alcohol) for processing. In addition to the significant environmental impact of processing with VOCs, which includes hazardous waste disposal, these processing methods have been shown to introduce performance variability. Acetone is often used as a processing solvent and is considered to be VOC exempt; however, when it is contaminated with energetic materials or other gun propellant constituents, it must still be treated as a hazardous waste.
Solventless gun propellant manufacturing (JA2) improves the environmental impact; however, man-in-the-loop hazardous operations and high production costs have significantly stifled transition to propellant production. Additionally, liquid propellant components are known to have migration issues resulting in variable performance and even weakening of combustible cartridge cases. Moreover, where propellants are processed with or without solvent, post-formulation extrusion operations limit the degrees of freedom for propellant geometries due to a fixed cross-sectional area design. The limitations on gross propellant geometries and more refined compositional gradients (deterrents and/or surface coatings) stifle in-flight propellant performance and tailorability.
The Weapons Systems and Platforms Program Area supports development of technologies and processes that are associated with the manufacture, operations, and maintenance of military equipment, weaponry, and munitions. These life cycle stages of a system may impact workers, the environment, and surrounding communities. Increasing the sustainability of these systems offers opportunities to identify and manage these impacts to lower associated life cycle costs and improve mission readiness. DoD’s Sustainability Analysis uses a life cycle approach to evaluate potential impacts associated with costs, ecosystem quality, human health, and resource availability.