| 摘要 |
In the present invention, there is disclosed an extruder comprising a feed diaphragm (6) opening into a divergent wall distribution chamber (1), communicating, on one hand, with a generally conical convergent central extrusion duct (3) by means of a circular central pre-expansion and/or retarding diaphragm (2) and communicating, on the other hand, with a generally conical convergent coaxial tubular extrusion duct (5) by means of an annular pre-expansion and/or retarding diaphragm member (4) wherein said central extrusion duct (3) and said coaxial tubular extrusion duct (5) have respective concentric central and annular outlet orifices (7 and 9) and wherein the opening of said pre-expansion and/or retarding diaphragm members and/or said outlet orifices and/or the distance between the planes of the outlet orifices can be adjusted in such a manner, that simultaneous separation of a central strand leaving the central outlet orifice and a coaxial tubular strand leaving the annular outlet orifice creates a core surrounded by a ring integrated with the core. The extrusion device comprises an elongated sleeve comprising one or two processing screws and at least one extruder according to the present invention. |
