Abstract: A continuous mixer or kneader, particularly for explosive, potentially explosive, and other critical materials, wherein longitudinally split barrel sections are maintained closed by a mechanism which is actuated to instantly split the barrel sections under emergency conditions to permit the material inside to be treated to prevent or inhibit ignition of the material. The machine includes an extruding die and a cutter, for cutting extruded strands to lengths, which is coupled to the mixer shaft in the barrel, and in addition includes mechanism for interrupting the cutting of strands when the barrel sections are split.