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

An extruder comprising at least two annular conical feed gaps situated between a rotatable rotor and a stator, and means for supplying the material to be extruded between the rotor and the stator, wherein, 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 comprises openings passing therethrough, so as to enable at least some of the material to be extruded to flow through the openings from one annular feed gap to another annular feed gap.

A multilayer plastic pipe comprising an inner and outer pipe and an intermediate layer, wherein the intermediate layer is formed of softer material and is situated between the inner and outer pipe, and at least one layer consists of reinforced solid or foamed reprocessed plastic wherein the solid outer surfaces and/or the intermediate layer formed of fiber-containing reprocessed plastic, comprise a diagonal orientation field.

A multilayer plastic pipe comprising an inner and outer pipe and an intermediate layer, wherein the intermediate layer is formed of softer material and is situated between the inner and outer pipe, and at least one layer consists of reinforced solid or foamed reprocessed plastic wherein the outer and/or inner pipe comprise stable fibers or wollastonite, the orientation of which differs from the axial direction.