Circular extrusion method and apparatus involving rotation around the die axis

Abstract From the Canadian patent

A method of making an extruded product is disclosed which comprises extruding fluid material through an annular die to an extrusion exit leading to the central space of the annular die while rotating the die around the axis of the annulus and collecting the extruded material on a collector while moving the collactor substantially along the axis of the annulus, wherein the collector, at least in the area where it collects the extruded material, is substantially cylindrical and is substantially coaxial with the annulus and comprises or is supported by an internal support and, in which method the speed of rotation of the die and of movement of the collector are such that the extruded material …