Patent ID: 8840818
Filing Date: 2014-09-23
Classification: B29C

Abstract:
1. A system for injection moulding of plastic material pieces exhibiting a form of a solid of revolution with external and/or internal cylindrical surfaces, comprising: an injection device for injection of a plastic material, in a molten state, into a mould; a circular diaphragm for distributing circularly and evenly into a cavity of the mould, through an opening of a circular injection gate having a circular or annular form, the plastic material that is injected by the injection device; and control unit, including a heating inductor, adapted to be driven in frequency, and a temperature sensor, both arranged in the zone of said circular injection gate, wherein said control unit is adapted to constantly control, during a moulding cycle of a piece and as a function of a temperature detected by said temperature sensor, the temperature of the zone of said circular injection gate, by suitably driving said heating inductor, and to control in real time the phases of said moulding cycle, including the phases of injection of the plastic material into the mould and of the opening and closing of the mould, and wherein said control unit is further adapted to control in real time, through said heating inductor, the temperature of the zone of said circular injection gate, during the injection phase of the plastic material into the mould, also by taking into account the physical and rheological characteristics of the plastic material that is used to mould the piece.