Proposed model of a mixing mechanism

In constructing a model, it is better to describe the outline first and fill in the details later. Such an outline should be left flexible enough to accommodate various details. If the initial model is too detailed, it tends to be too rigid to modify later. Then, the modification of the outline requires a fresh start each time it occurs. 

The outline of the model proposed here consists of (i) changes in the material during mixing, (ii) mechanical actions and (iii) material-machine interaction. 

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