Manufacture of double-base propellant grains

Claim 1

THE PROCESS FOR PREPARING CAST DOUBLE-BASE PROPELLANT GRAINS WHICH COMPRISES AGITATING FIBROUS NITROCELLULOSE IN AN AQUEOUS BATH CONTAINING ORGANIC LIQUID SOLVENT WHICH HAS ACTIVE SOLVENT POWER FOR SAID NITROCELLULOSE AND WHICH HAS AN APPRECIABLE VAPOR PRESSURE AT 100*C., SAID SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF SOLVENTS SOLUBLE IN WATER IN ALL PROPORTIONS AND SOLVENTS HAVING LIMITED SOLUBILITY IN WATER, SAID SOLVENTS BEING PRESENT IN AMOUNT TO SOFTEN AND DESTROY THE FIBROUS STRUCTURE OF THE NITROCELLULOSE WITHOUT DISSOLUTION THEREOF, CONTINUING AGITATION WITH REMOVAL OF SUBAND IRREGULAR PARTICLES OF THE NITROCELLULOSE HAVING A BULK DENSITY ON A DRY BASIS OF AT LEAST ABOUT 25 POUNDS PER CUBIC FOOT ARE OBTAINED, REMOVING SUBSTANTIALLY ALL WATER FROM THE RESULTING DENSIFIED NITROCELLULOSE PARTICLES, CHARGING THE RESULTING DRY DENSIFIED NITROCELLULOSE INTO A PROPELLANT GRAIN CASTING MOLD, EVACUATING AIR THEREFROM, INTRODUCING A NITROGLYCERIN CASTING LIQUID INTO THE MOLD TO COMPLETELY FILL ALL VOIDS AND JUST COVER THE NITROCELLULOSE PARTICLES, AND CURING THE MIXTURE OF NITROCELLULOSE AND CASTING LIQUID IN THE MOLD UNTIL THE PARTICLES OF NITROCELLULOSE ABSORB ALL OF THE CASTING LIQUID AND BECOME SWOLLEN AND FULLY COLLOIDIZED AND THE WHOLE MASS IN THE MOLD, DUE TO THE SOLVENT ACTION OF THE CASTING LIQUID ON THE NITROCELLULOSE, CONSOLIDATES AND WELDS TOGETHER INTO A SOLID, UNITARY, HOMOGENEOIUSLY COLLOIDED DOUBLE-BASE PROPELLANT GRAIN CONFORMING TO THE SHAPE OF THE CASTING MOLD.