Societe Nationale Des Poudres Et Explosifs

Louis J Leneveu

Didier J Treneules

Jacques Boileau

Jean-Pierre L Cartier

Bernard W Wiedemann

Jean-Marc Peyrard

Monique Tromeur

The present invention relates to the field of propellent charges for small and medium calibre arms. The invention relates to a process for the manufacture of fragmentable propellent charges, which consists in a first stage in coating powder particles with a mixture of dinitropolystyrene and of a compound of the polyvinyl nitrate and/or polyvinyl acetate type and, in a second stage, in compressing at between 100.degree. C. and 140.degree. C. the powder particles thus obtained. The invention also relates to the fragmentable charges obtained by the process and to the coated particulate powders obtained at the end of the first stage of the process. The fragmentable charges according to the invention exhibit a temperature behaviour which is superior to that of traditional fragmentable charges and are suitable for cartridgeless ammunition intended for arms with a high rate of fire.

Temperature-resistant, fragmentable propellent charges

The present invention relates to nitrocellulose single-base propellent powders which exhibit good resistance to aging and to moisture. The powders according to the invention characteristically contain zinc carbonate whose particle size distribution is between 2 and 50 micrometers as an additive. The zinc carbonate is incorporated in the powder during the blending. The powders according to the invention find their preferred applications as propellent powders for ammunition intended for warships or for aircraft or as powders intended for gas generators for pyrotechnic devices.

Aging-resistant single-base powder, process for manufacture, and

The present invention falls in the field of propellant charges for ballistic ammunitions which have combustible or a non-combustible casing. According to the invention, the ammunition is constituted by a casing 2 placed around a shell 1 and closed by a portion 3 which carries the primer 4. The casing contains a mixed charge constituted on one hand by fragmentable balls 5 and on the other hand, by grains 6 of propellant powder. The balls 5 are constituted by agglomerated propellant powder. The charges according to the invention may be prepared on an industrial scale very easily and in a very reproducible manner and they permit an appreciable increase of the coefficient of filling of the casing.

Mixed charges for ammunitions with a casing constituted by agglomerated

The present invention relates to a new type of fragmentable charge for weapons of small and medium caliber. The process for the manufacture of fragmentable charges of propellant powder containing nitrocellulose, according to the invention, is characterized in that, in a conventional process for the manufacture of propellant powder containing nitrocellulose, with solvent, a glazing operation is carried out, in which a glazing solution containing at least polyvinyl nitrate and a stabilizer is sprayed onto the grains of powder, and in that, after evaporation of the solvent from the said solution, the grains of powder thus obtained are compressed at between about 80.degree. and 120.degree.. The invention also relates to the fragmentable charges obtained by means of this process.

Fragmentable charges of propelland powder coated with polyvinyl nitrate,

Unit charge of propellant powder, which can be fragmented and has the ballistic properties of a granular charge. A charge of this type consists of 85 to 97% of grains of propellant powder containing nitrocellulose and 15 to 3% of a thermoplastic energy-producing binder which is in the form of small solid grains, under normal conditions, and has the following composition:

Fragmentable propellant containing polyvinyl nitrate binder

The present invention relates to continuous triturators and malaxators having a horizontal drive shaft. The apparatus preferably comprises a semi-circular chute surmounted by parallelepipedal vertical walls, and a stirrer consisting of a shaft which is concentric with the chute and carries rigid blades perpendicular to this shaft, at least one in four of the said blades being extended by a tongue which rubs against the chute, and the materials constituting the various elements which can come into contact with the grains of propellant powder being conductors of electricity. Apparatus which makes it possible to carry out continuous surface treatments of granular propellant powders.

Apparatus and process for continuous surface treatments of propellant

A mouldable thermoplastic composition comprises (i) polyvinyl nitrate, (ii) nitrocellulose and/or polyvinyl acetate and (iii) 2-nitro-diphenylamine and may be used to form combustible articles such as cartridge cases. Preferably, the composition comprises from 30 to 90% by weight of polyvinyl nitrate based on the total weight of components (i) and (ii). The composition may comprise up to about 30% by weight, based on the weight of components (i) and (ii), of at least one additive selected from cellulose acetate, dinitrotoluene, phthalates, non-volatile esters, heterocyclic ketones, ureas and ABS copolymers. The combustible articles may be formed by compression moulding or injection moulding. Preferably the mouldable composition is formed into granules using the 'with solvent' technique for making single base propellants, and the granules are mixed with a porous powder comprising nitrocellulose prior to being moulded to form the combustible article.

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Chateaulin, France

Louis J Leneveu