Abstract: 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.

Abstract: 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.