Process for extrusion of pyrotechnical compositions
AssigneeSociete Nationale des Poudres et Explosifs
InventorsPierre Cougoul, Marc Saunier, Jean Lucien Tranchant
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Abstract
Screw extruder and process utilizing same for the production of extrusions formed of compositions based on plasticized nitrocellulose. Process comprises at least one sequence of the following main operations carried out in corresponding zones in the extruder: (i) mixing and shearing the constituents of the composition to effect gelatinization thereof; (ii) retarding the forward movement of the composition by throttling; and (iii) drying the gelatinized composition by evaporation under a reduced pressure prior to extrusion of the composition from the outlet die of the extruder.
Claims9
A process for the production of propellants based on nitrocellulose, said nitrocellulose being gelatinized by an explosive oil, which comprises introducing the constituents of the propellant into a screw extruder and subjecting the mixture of the constituents in the extruder to the following steps (1) mixing and shearing the constituents of the composition to effect gelatinization thereof;
- (2) compacting;
- (3) retarding the forward movement of the composition;
- (4) drying the gelatinized composition by evaporation under reduced pressure;
- (5) progressively pressurizing prior to extrusion of the composition from the outlet die of the extruder, carrying out said sequence of steps:
- (1), (2), (3), (4) and (5) at least once.
Dependencies are inferred from the claim text.