Patent ID: 6680012
Filing Date: 2004-01-20
Classification: B29C

Abstract:
Injection moulding method in which plastic material contained under pressure in an antechamber is injected into a mould cavity and fills said mould cavity under pressure, the antechamber having an entrance and an exit both with closure means, the volume of the antechamber being reduced after the closing of the entrance by axial movement of a piston into a final position to such a degree that the pressure in the reduced volume of the antechamber causes the filling of the mould cavity by expansion of the plastic material after the opening of the closure means of said exit, characterised in that after closing of the entrance to the antechamber the position of the piston and the pressure in the antechamber are monitored, and the final position of the piston is determined by a calculation which takes account of at least one value of the measured pressure and of the position of the piston at which said pressure was measured.