Ring Extruder

Ring Extruder. A device for laminating (q.v.) shortening (q.v.) and dough (q.v.). It coextrudes (q.v.) both dough and fat from separate but interconnected hoppers through a wide ring orifice that produces a hollow dough cylinder with an internal lining of fat. Upon being flattened by a set of sheeting rollers (q.v.), this results in an initial dough-fat-dough laminate, and is followed by further lamination (q.v.) by a series of sequential foldings and sheetings. It is also the device that extrudes ring-shaped doughnut batters directly into the frying fat (q.v.) or, in the case of yeast-raised doughnuts (q.v.), for subsequent proofing (q.v.).