Method for making a product to be extruded, and an extruder

A method for extruding material to form an extruded product comprising:

• (a) providing an extruder comprising at least one rotatable rotor disposed between a plurality of stators or at least one stator disposed between the at least one rotor and a second rotor, said rotor and stators or stator and rotors defining at least first and second conical feed gaps disposed one within the other in a radial direction,
• (b) feeding a first portion of the material into the first feed gap through a first supply conduit and a second portion of the material into the second feed gap through a second supply conduit;
• and
• (c) adjusting the temperature of the material in the first or second portions by separately regulating a rate at which the material flows through the respective first and second conduits and by regulating a speed at which the at least one rotor rotates.

A method for making a coextruded product with at least first and second material layers, said method comprising:

• (a) providing an extruder comprising at least one rotatable rotor disposed between a plurality of stators or at least one stator disposed between the at least one rotor and a second rotor, said rotor and stators or stator and rotors defining at least first and second conical feed gaps disposed one within the other in a radial direction;
• said extruder further comprising a tool for making a wall thickness of the coextruded product constant, said at least one rotor, first and second feed gaps and tool being disposed in the extruder such that a first material that has passed through the first feed gap comes together with a second material that has passed through the second feed gap before contacting the tool;
• and
• (b) feeding the first material to the first feed gap and the second material to the second feed gap to cause said first and second materials to be coextruded in the extruder to form said coextruded product.