In designing process lines for cookies and crackers, a steady material feed is absolutely critical to achieve consistent thickness and density in the dough sheet and thus consistent weight in the product. Controlling the gap in a set of calendering rolls may not be sufficient as the final thickness also depends on the roll speeds, in-feed sheet thickness, gap and dough rheology.

Using Fluent software, an engineer can determine the process window for dough sheeters and similar equipment. The flow model results can also reveal details such as recirculations zones which are highly undesirable. Material trapped in the recirculation will have a longer residence time in the machine and will experience more shearing. Both of these effects decrease the product quality. (courtesy of Eisenberg Research).

Pressure contours in a 3-roll sheeter

Material pathlines in a 3-roll sheeter