The present invention is directed to preparing pyrophoric foam granules having a specific infrared signature comprising the steps of (a) mixing a composition comprising a metal salt, carbohydrate, and wetting agent into a homogenous paste, (b) extruding the composition into strands, (c) cutting or spheronizing the strands into a predetermined size or length based on a specific thermal or infrared response to produce pyrophoric foam granules and (d) activating the granules by heating the composition at elevated temperatures under an inert or reducing atmosphere until the matrix is carbonized and the metal salt is reduced.

An igniter tube consisting of a combustible tube, on the inner face of which an ignition charge is deposited along the length of said combustible tube. The invention also relates to a method for producing the igniter tube.

An additively manufactured solid fuel grain for a hybrid rocket engine having a cylindrical shape, defining a center combustion port and comprising a stack of fused layers of polymeric material suitable for hybrid rocket fuel. Each layer is formed as a plurality of fused abutting concentric beads of solidified material arrayed around the center port. An oxidizer is introduced into the solid fuel grain through the center port, with combustion occurring along the exposed surface area of the solid fuel grain center port wall. Each concentric bead possesses a surface pattern that increases the combustion surface area and when stacked forms a rifling pattern of undulations that induces oxidizer-fuel gas axial flow to improve combustion efficiency. The port wall surface pattern persists during the rocket engine's operation as the fuel phase changes from solid to gas and is ablated.

An apparatus, system, and method utilizes at least two separate components during the process of producing the final product. At least one component during the process is produced using additive manufacturing, and additional components are components that are combined with the additively manufactured part. The apparatus, system, and method includes at least one energetic component and at least one second inert component. An additive manufacturing system produces a scaffold of said first energetic component(s). A system adds the second component(s) to the scaffold to produce the energetic material product.

A method of producing a propellant material element, such as an electrically-operated propellant material, includes extruding a propellant material through a heated nozzle. The nozzle may be heated to a temperature that is above the boiling point of a solvent that is part of the propellant material, yet is below a decomposition temperature of the propellant material. This allows some of the solvent to be driven off during the extruding process, while still preventing initiation of an energy-creating reaction within the material. The heating of the material in the extruding process, and especially the heating of the nozzle that the material is extruded through, may be controlled to remove an amount of solvent that results in the extruded material having desirable properties.

A device may include an electrically-operated propellant or energetic gas-generating material, additively manufactured together with electrodes for producing a reaction in the material. The device may also include a casing that is additively manufactured with the other components. The additive manufacturing may be accomplished by extruding or otherwise depositing raw materials for the different components where desired. The electrodes may be made of a conductive polymer material, for example using an electrically-conductive fill in a polymer.

The invention is directed to a method for the preparation of an energetic material product such as a propellant or explosive charge or grain, wherein said method comprises additive manufacturing comprising co-extrusion of at least two materials to form a multi-layered filament and layer-by-layer deposition of said multi-layered filament, wherein said multi-layered filament comprises a first material layer and a second material layer of which at least one comprises an energetic material. In another aspect, the invention is directed to an apparatus for use in this method, said apparatus comprising a co-extrusion nozzle

A system and method for producing fuel grain for a rocket engine horizontally with an additive manufacturing machine is disclosed. To begin, a fuel grain model is received. The fuel grain model is oriented in a direction of a central core axis and divided into two-dimensional layers with defined footprint areas. In accordance with the fuel grain model, a first layer is printed by applying successive fuel beads in a direction primarily parallel to the central core axis.

An apparatus, system, and method utilizes at least two separate components during the process of producing the final product. At least one component during the process is produced using additive manufacturing, and additional components are components that are combined with the additively manufactured part. The apparatus, system, and method includes at least one energetic component and at least one second inert component. An additive manufacturing system produces a scaffold of said first energetic component(s). A system adds the second component(s) to the scaffold to produce the energetic material product.

A method of manufacturing a multi-layered propellant grain is provided. The method of the present disclosure simplifies the setup necessary to produce multi-layered propellants by using industrial equipment that is more energy and space efficient than the machinery that is conventionally employed for such processes. The method comprises providing a first propellant formulation; providing a die configured to provide a structure having an outer shell and a hollow interior when material is extruded therethrough; extruding the first propellant formulation through said die, to produce a first propellant layer having an outer shell defining a hollow interior in the form channel having open ends; providing a second propellant formulation, said second propellant formulation being of low viscosity; injecting said second propellant formulation into said channel defined by said first propellant layer to form a second propellant layer disposed in said channel; and hardening said second propellant layer. The first and second propellant layers have different rates of burning.