Comparative study of two commercial stoneware pastes for plastic shaping by pottery wheel

Two commercial stoneware pastes traditionally used to produce ceramic objects were evaluated. The objective was the comparative characterization of the pastes and to find the most suitable to obtain fine ceramic objects using the pottery wheel. Both ceramic pastes were characterized by X-ray powder diffraction (XRPD), particle size analyses (laser diffraction) and thermal analyses (thermogravimetry-TG, its derivative-DTG, and differential thermal analysis-DTA). The technological properties like linear drying and firing shrinkage, moisture content and plasticity were also determined. The results showed that both pastes have appropriate properties making them suitable for plastic shaping by pottery wheel. In addition, the stoneware paper clay paste is "greener" due to its content of cellulose fibers which can come even from recycled paper.