Opportunities and Challenges of a New UV -based 3D Printing Technique for Composite Solid Propellants

The 3D printing of composite solid propellant grains represents a new additive layer manufacturing production technique, granting improved shape control. Faster prototyping or innovative grain shapes can be obtained, surpassing classical mandrel-based cast curing production. Propellant slurry deposition and binder curing are two fundamental enablers. The present chapter describes a UV-based production method jointly developed by Politecnico di Milano and Politecnico di Torino. The text will discuss the main features of the technology and highlight some of the key problems faced by the research team, which stem from the intrinsic properties of the heterogeneous propellant slurry. The discussion will focus on high viscosity, layer adhesion, and variation of ballistic properties, supported by experimental evidence.