In all ceramic manufacturing factories the usual problem related to drying occurs due to differential drying and hence differential shrinkage. This happens because the drying speed at the surface becomes high and hence the water flowing through the capillaries can not keep up with loss from the surface by evaporation. This surface dries out completely and shrinkage starts there because of this contraction.
The surface layers exert strong compressive pores on the interior and are in turn subjected to tensile forces which lead to surface cracking. The final stages of shrinkage are very critical because at the stage the tendency for cracking is very high.
To be contd….
