The root causes of cracks are multiple and often to be found in the shaping steps but also, too fast drying, uneven atmosphere (temperature or moisture), incautious storage are potential causes for the drying cracks.

From a raw materials point of view, the use of minerals allowing a good packing of particles and able to absorb or avoid crack generation lead to significant improvement of the yield.

Cracks can occur when the piece presents thickness differences or at the junction of solid and hollow cast parts. The design of the piece can be modified or the casting time adjusted. The body should be strong enough to absorb the stresses. This can be increased by the use of finer and stronger kaolin like Grolleg, Standard porcelain or Super Standard Porcelain.

Powdering during finishing and / or fragile pieces

The finishing  and handling operations apply stresses on the pieces. They can create breakage or defects of the pieces. To facilitate the finishing operation and avoid the creation of defects from de-moulding to firing it’s sometimes needed to increase the strength of the body with higher plasticity kaolins or clays.


Ball Clays

Contact us about Drying