An Experimental and Theoretical Investigation of Bread Dough Sheeting

The forming of wheat flour dough sheets passing through a pair of cylindrical rolls is studied experimentally and theoretically with regards to the stresses and strains experienced by the dough. Experimental information is obtained using an instrumented sheeting apparatus, which is similar in scale to small bakery equipment. The ratio of the feed sheet thickness to the roller gap width has a strong influence on strains and stresses, whereas the speed of the rollers is found to be of comparatively minor importance. An approximate model for the sheeting of dough is developed and compared to the experimental data. The model is able to predict the detachment thickness correctly, but not the final thickness of the sheet--most likely due to viscoelastic recoil after detachment--nor the experimentally observed forces, torques and surface normal stresses.