Patent ID: 7754124

Claim:
A method for coating a substrate comprising: providing a plurality of metered, separate individual streams of coating material to an extrusion head; receiving the plurality of metered, separate individual streams of coating material at a plurality of corresponding respective receiving regions of a flow joiner within the extrusion head; expanding each of the plurality of metered, separate individual streams of coating material in a plurality of corresponding respective expansion regions of the flow joiner; joining the expanded plurality of metered, separate individual streams from the plurality of corresponding respective expansion regions of the flow joiner into a coating flow at an annular space of the flow joiner, each of the plurality of corresponding respective expansion regions having a first end adjacent each of the plurality of corresponding respective receiving regions, each of the plurality of corresponding respective expansion regions having a second end adjacent the annular space, the second end being wider than the first end, the plurality of corresponding respective expansion regions each having a substantially triangular shape; and extruding the coating flow on to a substrate.