# The mixing of the raw materials is achieved by two specially made bl
ades (often sigma type) set on in a "W" shaped trough, the rotation
of one blade being opposite to that of the other. The bottom of the
trough is curved upwards to from a ridge between the blades.
# The design of the blades helps in homogeneous mixing of the
ingredients. The action is repeated until the designed uniformity and
consistency of dough-mix is obtained.