Improved printing of energetic materials

Method according to the previous claim, wherein during said co-extrusion for forming the multi-layered filament, the volume ratio of the first material layer to the second material layer is varied.

Method according to any of the previous claims, wherein the volume ratio of the first material layer to the second material layer is varied such that a gradient of at least one material property is obtained throughout at least part of the energetic material product, preferably wherein said gradient is a continuous or essentially continuous gradient.

Method according to any of the previous claims, wherein the volume ratio of the first material layer to the second material layer is controlled by independently controlling the extrusion rates of each material feed and preferably by maintaining the sum of all extrusion rates essentially constant.

Method according to any of the previous claims, wherein said first material layer comprises a first energetic material and said second material layer comprising a second energetic material, preferably wherein said first energetic material has a different burn rate or detonation velocity than the second energetic material.

Method according to any of the previous claims, wherein said first material layer is at least one core layer comprising said first material and said second material layer is at least one shell layer comprising said second material surrounding said core layer, preferably wherein said core layer and shell layer are arranged concentrically.

Method according to the previous claim, wherein the second material has a higher viscosity than the first material.

Method according to any of the previous claims, wherein said multi-layered filament has an inscribed circle of the cross section having a diameter in the range of 250 μm or more, preferably up to 1500 μm, more preferably in the range of 500 to 1000 μm.

Energetic material product obtainable by any of the previous claims, said product comprising a deposited multi-layered filament comprising a first material and a second material of which at least one material comprises an energetic material.

Energetic material product according to the previous claim, wherein said first and second material are arranged in a pattern throughout at least part of the product.

Apparatus for use in a method of additive manufacturing of an energetic material product according to any of the previous claims, said apparatus comprising a co-extrusion nozzle and wherein said apparatus is adapted to suitably and safely process energetic materials.

Apparatus in accordance with the previous claim, wherein said co-extrusion nozzle comprises a co-extrusion die having an outer opening of which an inscribed circle has a diameter in the range of 250 to 1500 μm, preferably in the range of 500 to 1000 μm.