PORCELAIN: A Stoneware Tiles
What we commonly refer to as porcelain tiles are highly vitrified stoneware tiles.
(vitrify = to turn or transform into a glass or a glassy substance, particularly by heat fusion)
Porcelain tiles are an improvement over white clay single-fired tiles, which were an improvement over red clay single-fired tiles.
Three major differences between porcelain and white/red single-fired tiles:
|Water absorption||less than 0.5%||vary from <0.5% to >10%|
|Firing temperature||minimum 1240˚C||around 1100˚C|
|Breaking strength||± 27N/mm2||±22N/mm2|
The percentages of raw materials required to make porcelain tiles have shifted in recent years to accommodate faster production periods, contemporary technology, market competitiveness, and the product mix of producers. Here is the common composition:
|MATERIAL||PERCENTAGE in weight||Analogy||Role|
|Quartz||±10-20%||Skeleton||Considered as the structure of the tile|
|Feldspar||±25%-35%||Blood||Capable of closing the pores during vitrification|
|Plastic clays||±10-20%||Muscles||Gives plasticity and workability because of their water molecules|
|Kaolin||±30%-40%||Muscles||Also provides plasticity|
|Carbonates||Calcium & magnesium|