Propellant charge or grain with printed energetic material layers

Patent metadata

Field	Value
Publication number	US-10759719-B2
Application number	US-201716087490-A
Country	US
Kind code	B2
Filing date	Mar 22, 2017
Priority date	Mar 22, 2016
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

Propellant charges or grains having printed layers of two or more energetic materials are described along with methods for preparing and using them.

First claim

The invention claimed is:

1. A propellant charge or grain, comprising two or more energetic materials with different linear burn rate, wherein the two or more energetic materials are layered as distinct, additive layer manufacturing print layers within the charge or grain such that two perpendicular cross-sections of said propellant charge or grain each have at least two linear burn rate gradients in non-parallel directions,
wherein said layers have a layer thickness in the range of 1-10 000 μm, wherein, when the propellant charge or grain has a longitudinal axis that is longer than axes transverse thereto, at least one of said perpendicular cross-sections is along said longitudinal axis, and
wherein said propellant charge or grain further comprises one or more perforations.

2. The propellant charge or grain of claim 1 , wherein said propellant charge or grain further comprises two or more perforations.

3. The propellant charge or grain of claim 1 , wherein the layers have a thickness in the range of 10-5000 μm.

4. The propellant charge or grain of claim 1 , wherein the layers have a thickness in the range of 50-2000 μm.

5. The propellant charge or grain of claim 1 , wherein the layers have a thickness in the range of 100-1000 μm.

6. The propellant charge or grain of claim 1 , wherein the layers have a thickness in the range of 200-800 μm.

7. The propellant charge or grain of claim 1 , wherein at least two linear burn rate gradients in each perpendicular cross-section are perpendicular to each other.

8. The propellant charge or grain of claim 1 , wherein the charge or grain comprises three or more energetic materials with different linear burn rate.

9. The propellant charge of claim 1 , wherein at least one of said linear burn rate gradients is such that the linear burn rate increases from the surface of the burn propellant charge or grain inwards.

10. The propellant charge of claim 1 , wherein at least one of said linear burn rate gradients is such that the linear burn rate first decreases and then increases from the surface of the propellant charge or grain inwards.

11. The propellant charge or grain of claim 1 , wherein said propellant charge or grain comprises 2-10 layers with different linear burn rate.

12. The propellant charge or grain of claim 1 , wherein said propellant charge or grain comprises 2-8 layers with different linear burn rate.

13. The propellant charge or grain of claim 1 , wherein said propellant charge or grain comprises 3-8 layers with different linear burn rate.

14. The propellant charge or grain of claim 1 , wherein said propellant charge or grain comprises a binder, which binder may or may not be an energetic binder.

15. The propellant charge or grain of claim 14 , wherein at least one of said energetic materials dispersed as a solid material in said binder.

16. The propellant charge or grain of claim 1 in the form of a triangular prism or rounded triangular prism, a rectangular prism or rounded rectangular prism, a pentagonal prism or rounded pentagonal prism, a hexagonal prism or rounded hexagonal prism, an octagonal prism or rounded octagonal prism, a sphere, a spheroid, an ellipsoid, a cylinder, a rosette, a cube, a cuboid, a cone, a square-based pyramid, a rectangular-based pyramid, a pentagonal-based pyramid, a hexagonal-based pyramid, or an octagonal-based pyramid.

17. The propellant charge or grain of claim 1 , in the form of a rosette prism, a hexagonal prism, a sphere or a cylinder.

18. A method of preparing ballistics, pyrotechnics, fireworks or solid or hybrid propellant rockets, said method comprising incorporating the propellant charge or grain of claim 1 into said ballistics, pyrotechnics, fireworks or solid or hybrid propellant rockets.

Assignees

• Nederlandse Organisatie Voor Toegepast—Natuurwetenschappelijk Onderzoek Tno
• TNO

Inventors

• Straathof Michiel Hannes
• Van Driel Christoffel Adrianus

Classifications

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• F02K9/12

  made of two or more portions burning at different rates {or having different characteristics} · CPC title

• F42B5/16

  characterised by composition or physical dimensions or form of propellant charge, {with or without projectile,} or powder (chemical composition C06B; {F42B5/24 takes precedence}) · CPC title

• C06B45/00

  Compositions or products which are defined by structure or arrangement of component of product (explosive charges of particular form or shape F42B1/00, F42B3/00) · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title