Patent ID: 7648352

Claim:
An extruder die assembly for improving the dimensional quality of a complexly shaped, direct expanded food product while imparting a distinct pattern therein, comprising: (a) a forming section comprising: (i) an entrance face having an inlet; (ii) a central passageway extending from the inlet to an outlet; (iii) a forming die element traversing the central passageway; (iv) an exit face having a first peripheral groove which circumscribes the outlet; (b) an injection section comprising: (i) an entrance face having a second peripheral groove circumscribing a co-injection die insert; said co-injection die insert having at least one capillary channel in fluid communication with the second peripheral groove, wherein said capillary channel includes an upstream discharge and a downstream discharge, said capillary channel imparting the distinct pattern; (ii) a supply port fluidly connecting the second peripheral groove to a fluid additive source; (c) means for coupling and sealing the exit face of the forming section to the entrance face of the injection section thereby positioning and aligning: (i) the first and second peripheral grooves so as to form and isolate a peripheral reservoir manifold therebetween; (ii) the forming die element and the co-injection die insert so as to seal the upstream discharge of the capillary channel; (d) a nozzle section comprising: (i) an entrance face having a complexly-shaped inlet, said inlet having a periphery which circumscribes said central passageway; (ii) a converging nozzle bore having at least one axially aligned ridgeline, wherein said ridgeline gradually projects into the nozzle bore as said nozzle bore converges; and (iii) an outlet having a complexly-shaped cross-sectional area.