Development of Explosive Feedstock for Commercial-off-the-Shelf (COTS) 3D Printers

Traditional manufacturing methods for producing warheads, propellants, and pyrotechnic systems are timely and costly. Additive manufacturing (AM) approaches offer one path of alternative manufacturing technologies. Among various technologies, powder bed fusion (PBF) is one promising approach. Hewlett Packards Multi-Jet Fusion printers utilize a unique PBF process that presents a desirable solution to the objective of producing energetics parts by COTS technologies. Successful solids processing in a COTS powder bed fusion system requires very specific material properties, both in terms of powder handling properties as well as the associated inking/binder system. This proposal will focus specifically on nylon based PBX systems, for which HP existing multi-jet inking systems are currently optimized. New processing techniques will be explored to improve material characteristics of AM feedstocks, namely microencapsulation of colloidal HMX by spray drying and emulsion polymerization routes. Select optimal formulations will be chosen for final printing of a small scale printed explosive on an HP Jet Fusion machine, or related development test bed. Associated performance, safety characteristics, and cost analysis of final printed parts of these developed formulations will be assessed, against existing production technologies.