Applying co-extrusion, i.e. extruding two or more plastic substances simultaneously

Official title: {Applying co-extrusion, i.e. extruding two or more plastic substances simultaneously, e.g. for making filled dough products; Making products from two or more different substances supplied to the extruder}

A21C11/163 (Applying co-extrusion, i.e. extruding two or more plastic substances simultaneously) appears on 149 US grants and 85 published applications in this corpus.