DRYING / INSPECTION
Drying is usually the stage where most rejects are generated, especially because of drying cracks.
The root causes often stem from defects at the casting stage which were not seen during the finishing step, eg. cracks in hollow parts of products or joint parts.
Too fast drying, uneven atmosphere (temperature or moisture), careless storage are also potential causes of drying cracks.
From a raw materials point of view, the use of minerals confers good particle packing able to absorb or prevent the generation of cracks leading to a significant improvement in yield.
Handling between the de-molding and kiln phase applies stress on the pieces. Using higher plasticity clays is sometimes needed to increase the strength of the body. See section on lack of plasticity under Casting.
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