New Procedures for Ceramic Process Control. The Importance of the Characteristics of the Ceramic Powders to be Pressed.

Analysis of the most common defects in ceramic products shows that they are directly attributable to the powder types and properties, to the dried porosity of the ceramic products and to possible changes of these characteristics within the products themselves. Among the methods of preparing ceramic products, pressing is the one most widely used. To optimize the entire powder compaction process, a complete knowledge of the powder types and characteristics and the parameters of the die filling is very important. Within the framework of a systematic investigation with the aim of characterizing new experimental methods for ceramic process control, the authors have studied the powder fluidity as a function of powder type, grain size and humidity by means of a new apparatus developed by the authors which enables a rapid check on the powder die filling.