Extrusionsverfahren und Extrusionsvorrichtung zur Herstellung eines mit einem Boden verschlossenen Keramikrohres

The extrusion device has a mouthpiece (3), a mandrel (4) which is arranged coaxially with respect to the mouthpiece and in which a piston (6) can be moved coaxially in a cylinder bore (5), said piston comprising a cylinder head (6.1) which closes the cylinder bore (5), and a closure piece (7) which closes the mouthpiece (3) and can be temporarily withdrawn, the inner shape of the closure piece (7) and the outer shape of the mandrel (4) defining a gap (8) which corresponds to the shape of the base (1) which is to be produced. Inside the cylinder bore (5), a lift cylinder (6.2) is arranged in which the piston (6) can be movably guided independently from a gas pressure prevailing in the cylinder bore (5) Advantageously, the closure piece (7) can be heated and cooled.