Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Dietmar Muller

Hiltmar Schubert

Mathias Helfrich

Helmut Bauer

Harald Franken

Rudolf Krohnert

Jurgen Kremp

Harry Seiter

Michael Mandt

In a process for the production of desensitized, high energy explosive, particularly hexogen (RDX), as a component of plastic-bound explosives or propellant powders, the particulate explosive with a grain size up to 20 .mu.m is suspended with a desensitizing polymer in aqueous dispersion, the slurries are applied to a rotary, heated roller, the applied material is dried at a temperature of &gt;100.degree. C. and is scraped from the roller after drying.

Process for the production of desensitized explosives

For producing propellant charge granular material several small diameter pellant charge strands are continuously extruded, individually placed on a support behind the extruder and conveyed over a setting zone. The strands are subsequently supplied on a sloping zone to a cutting plate with a number of guide holes corresponding to the number of strands. On passing out of the guide holes the strands are cut to the desired length by cutting blades rotating being the cutting plate.

Process and apparatus for producing propellant charge granular material

A stabilized high energy explosive, e.g. hexogen (RDX), octogen (HMX) or the like, as a component of NC or plastic-bound propellant charge powders (Lova-TLP) or plastic-bound explosives (PBX) has a particle size up to 5 .mu.m and a stabilizer incorporated into the explosive particles. In order to produce such an explosive, it is proposed that the explosive in the dissolved form and with the stabilizer in the liquid phase is mixed with a proportion of up to approximately 6% and the mixture is brought by flash drying into the solid phase with a particle size of up to 5 .mu.m.

Stabilized explosive and its production process

An apparatus for extruding plastic materials, particularly plastic explosives or propellants, has a casing, at least one pressing member moving therein, e.g. a rotating extruder screw and a shaping retainer plate terminating the casing at the outlet side, which is fixed to the casing and can be raised therefrom if an excessive overpressure occurs. So as to ensure rapid raising and a rapid release of the overpressure when a safety hazard occurs, the retainer plate is fixed to the casing by a mechanical or a gas pressure spring, whose spring tension is adjustable. It is also possible to provide a hydraulic pressure directed in opposition to the spring and by which the retainer plate can be raised in random manner from the casing.

Apparatus for extruding plastic materials

Triplebasic propellant powders consist of nitrocellulose, nitroglycerin or an equivalently acting explosive oil and crystalline nitroguanidino, which are processed by mixing with one another and plasticizing the NC by means of a solvent, e.g. acetone, as well as by kneading the mixture and subsequent shaping to solid propellant powder bodies. In order to improve the thermal stability, particularly the cold embrittlement behaviour, at least one organic titanate from the group of monoalkoxy, chelate, quaternary, neoalkoxy, cycloheteroatom or coordinated titanates and/or at least one organic zirconate from the group of neoalkoxy zirconates is added to the propellant powder in a proportion of .ltoreq.2%, preferably .ltoreq.0.5%. This addition improves the chemical stability of the propellant powder.

Triplebasic propellant powder and process for the production thereof

For the continuous or discontinuous production of propellant charge powder n strand form with axially parallel channels having a clearly defined identical diameter and reproducible geometry of the channel arrangement, a press is provided, which has at least one cavity, and which is provided in its strand-forming area with a plurality of needles for shaping the channels, said needles being constructed as open hollow needles and are subject to the action of a fluid with a limited overpressure.

Apparatus for producing propellant charge powder in the form of strands

A method for manufacturing plastically bonded propulsive powders and explves by means of an extruder which comprises a housing with at least one entry opening, under certain conditions a solvent supplementing opening, two co- or counterrotating screw shafts and a forming head. The method makes possible continuous production with minimal binder components of 4-6 percent. Firstly, the plastic binder in a fixed, soluble or suspended form is added by means of an entry opening for a period of time until the screws float in the plastic binder without opposing friction and without friction with the walls. The components of the propulsive powder, or correspondingly the explosive material in crystalline form, are added in steadily increasing proportions with a simultaneous reduction of the portion of the plastic binder and finally, the mixture ratio is held constant.

Method for producing plastically bonded propulsion powders and explosives

Single- or multi-base propellants are produced in a solvent process from ir starting components, of which at least one is moistened with alcohol, using a twin-shaft screw extruder, that has an inlet zone run at a raised temperature, then nextly a mixing and kneading zone and lastly an outlet zone. The temperature in the kneading and mixing zone and in the outlet zones is kept at a value that is higher than in the inlet zone. Furthermore there is a temperature drop towards the outlet zone.

Process and apparatus for producing single- or multi-base propellants

In the case of an apparatus for dewatering and plastifying water-wet mixts of materials for manufacturing explosives, as for example mixtures for producing propellent charges, using a screw extruder with one or more screws having kneading and conveying elements and a housing, possibly made up of axial sections, with a filling port for the said mixture as wetted with water, certain steps are taken for stopping the formation of slurries at the back end or part of the screw extruder, that is to say at the filling port there is an outwardly widening drain port with a drain duct joined thereto in which there is a conveyor for clearing the expressed water and the solids therein and moving them to the back end of the screw extruder.

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Karlsruhe, Germany

Dietmar Muller