Nederlandse Organisatie Voor Toegepast-natuurwetenschappelijk Onderzoek Tno

Michiel Hannes Straathof

Christoffel Adrianus Van Driel

Dinesh Ravindre Ramlal

Laurens Daniël Van Vliet

Jeichienus Johannes Van Der Werff

Kjeld Jacobus Cornelis Van Bommel

Martijn Zebregs

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.

Printing of energetic materials

The invention is directed to a co-layered propellant grain having an exposed outer surface, wherein said propellant grain comprises an outer layer comprising a slow burning propellant composition located on essentially the entire outer surface of the grain, and an inner layer comprising a fast burning propellant composition having a higher linear burn rate than said slow burning propellant composition; wherein said propellant grain has a structure such that after ignition, the inner layer becomes increasingly exposed at the outer surface.

Co-layered propellant charge

The invention is in the field of propellants. In particular the invention is directed to a propellant for ammunition, such as medium and large caliber gun ammunition, having improved performance. In accordance with the present invention a propellant charge comprises one or more longitudinally extending, progressive-externally burning grains having a number of perforations passing through the grains in the length direction and having a cross-sectional shape (perpendicular to the grain's length direction) that is elongated.

Propellant charge

A propulsion element including a catalyzing reactor is disclosed. The catalyzing reactor comprises a reactor entrance and a reactor exit and an internal structure arranged for flowing a reacting medium through the reactor from the reactor entrance to the reactor exit. The reactor structure comprising at least one thin walled reactor channel arranged between the entrance and the exit of the reactor. The channel having a channel wall that includes a catalyst and that defines a flow path, in which channel in use, a catalyzed exothermic reaction takes place in the medium as it flows along the flow path. The at least one channel is looped to have a portion of its flow path that is downstream with respect to the reactor entrance in heat exchanging contact with a portion of a flow path that is that is more upstream with respect to the reactor entrance, so as to transfer heat between a downstream portion of the reacting medium to an upstream portion thereof.

Propulsion element including a catalyzing reactor

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

Growing community of inventors

Delft, Netherlands

Michiel Hannes Straathof