EXTRUSION TECHNIQUE FOR EXTRUDED COMPOSITE PROPELLANT GRAIN

摘要

Extrusion techniques for double-base propellant are well established and are operational worldwide. Indian ordnance factories have facilities to extrude propellants of diameters ranging from 10 to 160 mm, but the extruded composite propellant (ECP) is an entirely new thrust area in the field of composite propellant. The research and development work on ECP is being carried out at the High Energy Materials Research Laboratory (HEMRL). These are based on high-density thermoplastic elastomers (TPEs) used as propellant binder with ammonium perchlorate (AP) as the oxidizer and aluminum (Al) as metallic fuel. This class of propellant not only provides higher energy, but also yields higher density impulses. It can also take up higher solid loadings (up to 90%) and has good dimensional stability. The extrusion of ECP with large diameters (0120 mm) has not been reported in literature so far. This paper presents the establishment of an extrusion technique for ECP grains with large diameters, which is the first of its kind. At the HEMRL, Viton-based ECP has been developed, characterized, and evaluated. Due to its higher dimensional stability and higher density of the order of 1.97 g/cc, the developed extruded composite propellant obtained by our extrusion technique can have various applications, such as for gas generators, thrusters, and auxiliary motors of advanced missiles.