Apparatus and method for extruding a fluid material

An extrusion die, comprising:

• a first die body and a second die body that define an extrusion cavity therebetween, the extrusion cavity having:
• an inlet;
• a primary manifold that extends from the inlet along a flow direction, the primary manifold having a back end portion, and a front end portion that extends from the back end portion along the flow direction, the front end portion being defined by opposing front-end inner surfaces of the first and second die body, respectively, at least one of the opposing front-end inner surfaces tapering towards the other of the front-end inner surfaces as it extends along the flow direction, the at least one of the opposing front-end inner surfaces having a first curved portion that extends from the back end portion towards a front line of the primary manifold, and a second curved portion that extends from the front line towards the back end portion;
• an intermediate chamber that extends from the primary manifold along the flow direction, the intermediate chamber having a back line that is coextensive with the front line of the primary manifold, and a front line that is spaced from the back line of the intermediate chamber along the flow direction, the front line of the intermediate chamber being tapered away from the back line of the intermediate chamber as the front line of the intermediate chamber extends outwards towards first and second ends, and the intermediate chamber having a depth along a third direction, perpendicular to the flow direction and a second direction, that is less than a depth of the primary manifold;
• and
• an outlet in fluid communication with the primary manifold along the flow direction, the outlet defining a slot that is elongate along the second direction perpendicular to the flow direction.