SCREW ELEMENT OF A CO-ROTATING TWIN SCREW EXTRUDER, AND CORRESPONDING SCREW AND CO-ROTATING TWIN SCREW EXTRUDER

摘要

The screw element (10) according to the invention comprises a single-piece body (11) which is provided with an inner bore (12) designed to receive a drive shaft rotating about an axis (X-X), such that a plurality of screw elements (7, 8, 9, 10), including the screw element (10), is stacked on said drive shaft. In order to facilitate the production of screws for a co-rotating twin screw extruder, which screws have consecutive threads having a direct pitch and a reverse pitch, respectively, the invention provides for the single-piece body to comprise: two separate axial parts which are opposite one another along the axis, a first part (14) being provided with one or more outer threads (15) having a direct pitch only, and the second part (16) being provided with one or more outer threads (17) having a reverse pitch only; and a connecting zone (18) between the first and second parts, which zone is configured on the outside to connect, transversely to the axis, the, or at least one of the, threads of the first part with the, or at least one of the, threads of the second part.