The Research On Coating Process Of Small Particles And Combustion Properties

Based on the traditional drum coating process,the coating equipment was designed and improved after the analysis of the adhesion behavior of the small particles in the process of coating according to the spraying method of coating solution and the agglutination device of adhesive particles.The effects of coating process parameters and conditions on the coating quality of small particle propellant were studied.The optimum coating conditions for 6/7 and 7/19 small particle propellants were determined.The burning capacity of the different coating thicknesses and the different TiO2 contents in the coated propellant,the monolayer coated and the double coated propellant,the mixed charge of porous granular propellant and the double coated propellant were studied by means of a closed bomb.The results show t:hat the design and improvement of the drum coating equipment,optimization of the coating process conditions and parameters can solve the problem of particles adhesion in the coating process and obtain uniform coating,substantially not adhesive coated propellant.With the increase of the coating thickness or the increase of the TiO2 content in the coating layer,the insensitive flame retardancy of the coating increases obviously.By adjusting the thickness of the coating and the Ti02 content in the coating,the combustion performance of the coated propellant can be effectively adjusted.Using the double-coated propellant prepared in this paper,the burning progressivity of the coated propellant can be further improved,and the effect of lowering the high temperature coefficient of the propellant charge can be obtained.The mixed charge of the porous propellant and the coated propellant significantly reduced the initial ablation peak of the porous propellant and improved the combustion incipientity of the propellant charge.The ignition of the charge consistency of the coated propellant was improved.At the same time,compared with the single coated propellant charge,the mixed charge can significantly reduce the temperature coefficient of the low normal temperature charge in the circumstances of keeping reduce the temperature coefficient of high normal temperature charge.The research results of this paper have some instructive significance for the application of coating technology in small and medium caliber weapons.