Glass-ceramic frits for porcelain stoneware bodies: effects on sintering, phase composition and technological properties

In the present work, the effects of glass-ceramic frits (10wt%) added to a porcelain stoneware body in replacement of non-plastic raw materials, were evaluated simulating the tile-making process. Each glass-ceramic frit plays its own peculiar effect on the compositional properties and only some precursors behave as real glass ceramic materials. The positive influence of glass-ceramic precursors in promoting the sintering stands out when temperature onset densification and sintering rate are considered: both of them are improved with respect to the reference body. The presence of glass-ceramic frits allows the preserve good technological properties, complying with the latest requirements of the industrials practice.