An investigation of the effect of pigments and composition on coloured porcelain slip and body properties

In this study, the effect of the pigment addition on the slip and physical properties for colourless, yellow and black porcelain bodies and effect of the composition on yellow coloured body properties have been investigated. Different porcelain compositions were prepared by adding yellow and black pigment into standard colourless porcelain body composition. Addition of the pigment in to porcelain body changes the properties of casting slips and fired porcelain properties. The viscosity of the slip increases to from 48s to 53 s in the case of the addition of the yellow pigment into porcelain body formulation and it acts as thicker. In contrast, upon the addition of the black pigment, viscosity of the slip as flow time decreases from 48 s to 40 s compared to colourless slip viscosity and pigment acts as a thinner. Water absorption, apparent porosity, bulk density and deformation properties of samples were evaluated. The properties of porcelain body were changed by adding of pigments into the porcelain formulation. In black samples, because of the highest iron oxide content in the black sample among other samples, the apparent porosity and water absorption values were slightly reduced 0 and bulk density reached a value of 2.50 g/cm3 . When the different amount of quarts and K and Na-feldspar added to yellow coloured body, fired body properties changes. All of the results were interpreted, porcelain properties can be improved with more K-feldspar addition instead of kaolin in both of colourless, yellow and black bodies.