STUDY ON COMBUSTIBLE CARTRIDGE CASES AND POLYMERIC RESIN BINDERS IN ITS COMPOSITION

Abstract

An understanding of the compatibility of different binder resins is essential for the upgradation of the properties of cartridge cases used in the propulsion systems of various ammunitions. This is essential in designing a new composition with a binder resin having higher glass transition temperature, in order to increase the serviceability of these cartridge cases in the areas with high atmospheric temperatures. The present studies have been done to investigate the suitability of thermoplastic resins having higher glass transition temperature in order to replace the existing polyvinyl acetate resin in the composition of cartridge cases. Experiments were performed with the comparative study of three different resins viz. Polyvinylacetate, Polyvinyl butyral and Polyvinyl chloride by making their blend with Nitrocellulose and cellulose in a proportion of 70:15:15 by weight. The processibility of resins in the composition of CCC is ensured by study of viscosity variation with respect to stress gradient and constant stress system. The prediction of their performances in the composition is carried out by the virtue of mechanical testing, modelling and simulation of thermal properties and ballistic performance followed by mechanical strength evaluation for each composition.