Apparatus for degassing molten plastic material and associated method for controlling its operation

An apparatus for degassing molten plastic material comprising:

• a treatment chamber provided with at least one entry port associable with supply means for a flow of molten plastic material containing a gaseous component, at least one exit port for said material and at least one suction opening for at least partial suction of the gaseous component which is in fluid communication with means for applying a controlled pressure, the molten plastic material being in transit through the treatment chamber from the at least one entry port toward the at least one exit port along a first transit direction and the at least one suction opening being interposed between said entry and exit ports along the first transit direction, and
• extraction means for the molten plastic material which are associated downstream of said at least one exit port for removing said material along a second transit direction, and which comprise a substantially cylindrical jacket extending along said second transit direction and provided with at least one entry opening which is associated in communication with said at least one exit port and at least one exit opening, a transfer screw for the molten plastic material, which is supported in rotation about a longitudinal axis thereof inside said jacket between said entry opening and said exit opening, and rotational actuation means for said screw, an annular channel being defined between an outer surface of the transfer screw and an inner wall of the jacket for a passage of the molten plastic material from the entry opening towards the exit opening along the second transit direction,
• further comprising detection means for a measured value referring to a pressure of the molten plastic material inside said annular channel, which are functionally associated in input with electronic management and control means configured to compare said measured value with a reference value.