Printing of energetic materials

Patent metadata

Field	Value
Publication number	US-12428357-B2
Application number	US-202017436762-A
Country	US
Kind code	B2
Filing date	Mar 6, 2020
Priority date	Mar 8, 2019
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

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

First claim

The invention claimed is:

1. A method for the preparation of an energetic material product wherein said method comprises additive manufacturing comprising co-extrusion of at least two material feeds 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 comprising a first energetic material and a second material layer comprising a second energetic material,
wherein said first energetic material has a different burn rate or detonation velocity than the second energetic material, and
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 by independently controlling the extrusion rates of each material feed, such that a continuous gradient is obtained in a longitudinal direction of the multi-layered filament, wherein the continuous gradient may be from 100 wt. % of first material to 100 wt. % of second material.

2. The method according to claim 1 , 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.

3. The method according to claim 1 , 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.

4. The method according to claim 1 , wherein the second material has a higher viscosity than the first material.

5. The method according to claim 3 , wherein said shell layer comprises a UV-curable binder.

6. The method according to claim 1 , wherein said multi-layered filament has an inscribed circle of the cross section having a diameter in the range of 250 μm or more.

7. The method of claim 6 , wherein the multi-layered filament has an inscribed circle of the cross section having a diameter in the range of up to 1500 μm.

8. The method of claim 1 , wherein the energetic material product is selected from the group consisting of pyrotechnics, propellants, explosive charges, and grains.

9. The method of claim 1 , wherein the volume ratio of the first material layer to the second material layer is controlled by maintaining the sum of all extrusion rates essentially constant.

Assignees

• TNO

Inventors

• Straathof Michiel Hannes
• Van Bommel Kjeld Jacobus Cornelis
• Van Driel Christoffel Adrianus

Classifications

• C06B45/12

  having contiguous layers or zones · CPC title

• B29L2031/20

  Fuel-blocks, e.g. nuclear fuel elements · CPC title

• B33Y70/10

  Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials · CPC title

• B29C64/336

  of two or more materials · CPC title

• B29C64/209

  Heads; Nozzles · CPC title