Method for producing homogeneous material with an extruder, an extruder, and a multilayer plastic pipe

摘要

PCT No. PCT/FI96/00658 Sec. 371 Date Jun. 4, 1998 Sec. 102(e) Date Jun. 4, 1998 PCT Filed Dec. 12, 1996 PCT Pub. No. WO97/21532 PCT Pub. Date Jun. 19, 1997A method for producing a homogeneous material with an extruder is provided. The extruder has at least two annular conical feed gaps situated between a rotatable rotor and a stator so that the material to be extruded is supplied between the rotor and the stator. Between the delivery point of the material to be extruded and the nozzle of the extruder in the direction of travel of the material the at least one rotor or stator of the extruder is provided with openings passing therethrough so that at least some of the material to be extruded is made to flow through the openings from one annular conical feed gap to another annular conical feed gap. The invention also relates to an extruder and to a multilayer plastic pipe.