|Monthly Tech-Tip |
Clay bodies used in industry are not somehow magically better than those used in hobby, pottery and education. They are simply more closely tuned to the forming machinery and process. Their formulations prioritize the minimization of rejects and the maximization of production.
Industrial clays have plasticities that are enough to form but not more than that (to increase drying speed, reduce drying shrinkage). They also often contain additives (e.g. binders) to improve drying hardness. And a percentage of scrap recycle.
Every industrial process and product has priorities to which the recipe of a clay can be optimized. Examples of property balancing are whiteness vs cost, whiteness vs drying properties, degree of vitrification vs warping in the kiln, grog percentage vs surface quality, plasticity vs drying time, plasticity vs drying performance, material cost vs firing temperature, binder content vs clay content, local clays of less than ideal properties vs imported clays, local clay percentage vs danger of bloating, etc.