Fabric and die design for divided conduit

A method of forming a conduit having at least one strip-shaped fabric substrate dividing the conduit into channels, the method comprising:

• obtaining an extrusion die having an exit and defining a flow direction for polymeric material forming the conduit, wherein the die comprises an area configured to form the wall of the conduit and a slot having a thickness, a width, a first edge, and a second edge, wherein the slot is configured for receipt of a strip-shaped fabric substrate, wherein the slot extends in the flow direction along the extrusion die, wherein the thickness of the slot varies along the width of the slot, wherein the thickness of the slot is greatest at the first edge and second edge of the slot;
• introducing a strip-shaped fabric substrate into the slot, wherein the strip-shaped fabric substrate comprises a first longitudinal edge and a second longitudinal edge, wherein the strip-shaped fabric substrate is selected from the group consisting of a woven, non-woven, and knit, wherein the strip-shaped fabric substrate is air permeable, and wherein the strip-shaped fabric substrate comprises enlarged regions at the first longitudinal edge and the second longitudinal edge;
• introducing molten polymer at a first point in the extrusion die, wherein the molten polymer forms a first polymeric layer of the conduit, and wherein at the first point the slot and the area configured to form the wall of the conduit are not in communication;
• exposing the slot to the molten polymer at a point between the first point and the extrusion die exit forming the first polymeric layer of the conduit such that the first longitudinal and second longitudinal edges of the strip-shaped fabric substrate embed into the molten polymer;
• and
• extruding the conduit having at least one strip-shaped fabric substrate dividing the conduit into channels out of the exit of the die.