Methods of preparing nitrocelluse based propellants and propellants made therefrom
AssigneeOrbital ATK, Inc.
InventorsWilliam J. Worrell, Benjamin R. Vaughan, Jeffrey D. Archambault, Milca Fils-Aime
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Abstract
Methods of preparing propellant compositions for power loads and firearms that include providing pre-shaped particle sized starting material, shaped consistent with a desired final propellant product shape, and thereafter nitrating and stabilizing the pre-shaped starting material using boiling stabilization processes. The resulting nitrated propellants of the methods reliably exhibit complete stabilization, high nitrogen substitution, high shelf life and acceptable ballistic performance.
Claims20
A method of making a cartridge for use in small firearms, the cartridge comprising a cartridge case containing a propellant and a primer, wherein the propellant comprises nitrocellulose particles having a final shape and size, the method comprising nitrating preshaped cellulose particles having a size of at least 50 microns to form nitrocellulose particles thereafter stabilizing the nitrocellulose particles by a series of boiling regimens, whereby the nitrocellulose particles are completely stabilized and wherein the final shape is the same as the preshaped cellulose particles.
A cartridge for small firearms, the cartridge comprising propellant contained within a cartridge case and a primer, wherein the propellant comprises separate nitrocellulose particles having a final shape and size, being completely stabilized and having a chemical stabilizer concentration of 2.0 wt % or less, the nitrocellulose particles being prepared by the method comprising:
- providing an amount of the preshaped cellulose particles, the preshaped cellulose particles having a size of at least 50 microns and having a shape of the final shape;
- thereafter
- nitrating the cellulose particles sufficiently to produce the nitrocellulose particles having at least 12% nitrogen at a location;
- thereafter, at the location,
- stabilizing the nitrocellulose particles by a series of boiling regimens, wherein the stabilizing comprises the steps of:
- subjecting the nitrocellulose particles to an acid boil regimen comprising boiling the nitrocellulose particles in an acid boil solution at an elevated temperature of at least 115° C. for a period of no more than 30 hours, the acid boil solution comprising substantially water;
- thereafter
- subjecting the nitrocellulose particles to a first neutral boiling of the nitrocellulose particles in a first neutral solution for a period of time, the first neutral solution comprising substantially water;
- and thereafter
- subjecting the nitrocellulose particles to a first alkaline boiling of the nitrocellulose particles in a first alkaline solution for a period of time, the first alkaline solution comprising substantially water, wherein the combined periods of time of the first neutral boiling and the first alkaline boiling is less than 30 hours,
- whereby the nitrocellulose particles are completely stabilized and exhibit complete nitration and wherein the shape is maintained and the preshaped cellulose particles are not subjected to any added plasticization;
- and thereafter
- drying the nitrocellulose particles,
- wherein the nitrocellulose particles are incorporated into the cartridge case.
A cartridge for use in small firearms, the cartridge comprising a propellant, wherein the propellant comprises separate nitrocellulose particles having a final shape, the propellant being prepared by nitrating at a location preshaped cellulose particles having sizes that include a cross-section length of at least 50 microns and having a shape consistent with the final shape to form nitrocellulose particles;
- and then, at the location, stabilizing the nitrocellulose particles, whereby the nitrocellulose particles are completely stabilized and exhibit complete nitration and wherein the shape is maintained, wherein the stabilized nitrocellulose particles in the propellant comprise at least 12.5% nitrogen;
- have a chemical stabilizer concentration of 2.0 wt % or less;
- and in cross-section, have a felted and/or non-plasticized appearance.
Dependencies are inferred from the claim text.