Abstract: It is described an apparatus for the extrusion and mixing of plastic materials, for example rubber-based and silicone-based materials, comprising a dump extruder body whereon two conical screws (2) converging towards an extrusion die (3) suitable for being occluded by closing means (4) are mounted, the conical screws (2) being accommodated within a low-pressure compounding chamber (1) and within a pair of converging conical channels also defining a high-pressure chamber (2?), said low-pressure chamber (1) corresponding to an upstream area with respect to an extrusion direction, wherein said high-pressure chamber (2?) and/or said low-pressure chamber (1) accommodate a presser body (5, 5?, 6), defining a movable wall suitable for causing a controlled change in the volume of the respective chamber (1, 2?).

Abstract: A machine for the mixing and extrusion of rubber-based and silicone-based plastic materials and method thereof is disclosed, comprising a dump extruder with conical converging twin screws (10) arranged in a batching chamber (12) in which the outlet of the dump extruder is temporarily closed by a removable blind flange (11), the batching chamber also acting as a compounding chamber.

Abstract: An extruder, in particular for elastomer material, is described, the extruder being of the type comprising an extruder body provided with a cylindrical chamber inside which an extrusion screw is rotatably inserted, and a plurality of mixing pin members inserted in the casing of the cylindrical chamber and projecting inside the the chamber, wherein each pin member is arranged tangential to the core of the screw, opposite interruptions in the thread of the screw and passes through the whole of the chamber, engaging in both the opposite walls of the casing.