Extruder and method for extruding cord reinforced tire components

A method for extruding cord reinforced tire components with the use of an extruder comprising an extruder head, wherein the extruder head comprises a die for receiving an extrusion material, flow channels that debouch into the die and a cord guide for guiding cords into the die, wherein the die is provided with an elongate cross sectional profile that defines a first cross section of the extrusion material in the die, wherein the cross sectional profile has a profile width and a profile height, wherein the extruder head is provided with one or more first heating elements which are positioned at the die downstream of the flow channels, wherein the extruder further comprises a control unit that is operationally connected to the one or more first heating elements, wherein the method comprises the steps of receiving the extrusion material in the die, guiding cords from the cord guide into the die at a cord entry height with respect to the profile height so that the cords are embedded in the extrusion material, controlling the one or more first heating elements with the control unit to transfer heat into the extrusion material from a first side of the profile height at the die for generating an adjustable height temperature gradient in the extrusion material across the profile height, and controlling swelling of the extrusion material relative to the cord entry height from the first cross section to a second cross section after the extrusion material leaves the die by adjusting the adjustable height temperature gradient.