PORCELAIN: A Stoneware Tiles

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.

Characteristics


Three major differences between porcelain and white/red single-fired tiles:

 PorcelainWhite/Red
Water absorptionless than 0.5%vary from <0.5% to >10%
Firing temperatureminimum 1240˚Caround 1100˚C
Breaking strength± 27N/mm2±22N/mm2

Composition

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:

MATERIALPERCENTAGE in weightAnalogyRole
Quartz±10-20%SkeletonConsidered as the structure of the tile
Feldspar±25%-35%BloodCapable of closing the pores during vitrification
Plastic clays±10-20%MusclesGives plasticity and workability because of their water molecules
Kaolin±30%-40%MusclesAlso provides plasticity
Carbonates  Calcium & magnesium