cz - Part 2
Glazes Pd – series are semiopaque or opaque glossy coloured glazes based on frits and ceramic stains or metal oxides. They contain no lead, antimony, arsenic oxides or any other toxic substances. They are suitable for glazing of dinnerware (food safe) or tiles. Recommended firing limits are 1000 – 1100 °C (stability of the colour shades is to be assured), if needed the upper limit can rise to 1150 °C (the intensity may be lost especially at pink, brown and yellow shades). All types of clay bodies with CTE alfa > 60 x 10-7 (K-1) and various colours can be used; on clay bodies with lower expansion crazing will occur.
In order to reach any special colour shades the mixing of basic glazes are possible, by mixing with white glazes Pw – series you get lighter shades. The fired glazes can be further decorated with onglaze colours, decals, gold, platinum and lustres. Glazing techniques: dipping, spraying.
Products GMU
Glazes of DW – series are white glossy glazes based on frits with the lead oxide content of 10-50%. The tin oxide is used as an opacifier, which gives to the glazes covering properties of middle up to high grades depending on its contend. DW 106 91 is an exection because of using zirkonium silicate as an opacifier.
Due to high lead contend , the glazes are not to be recommended for the production of dinnerware. They are to be fired up to 940-1000°C, on the artistic object they can be fired hotter at temperatures of 1100-1200°C (for example Dw 153 91); in such case you may obtain an interesting effect by the reaction with colored body. A thinner coat of the glazé is required in order to avoid the glaze running down.
The glazes are suitable for white as well as colored clay bodies with higher CTE a20-500 °C > 70·10-7K-1. Using a body with a lower CTE they can craze. After firing at more then 1100°C they do not craze even on bodies with lower CTE.
Glazes of P – series are transparent leadless colourless glossy glazes, based on frits, free of lead oxide (except P 011 91 – 1% PbO). They are fired in temperature range of 980 – 1150 °C; on the stoneware body some of them can be fired up to 1200 °C. They show a high chemical resistance and therefore they are food safe and suitable for the dinnerware, tiles and as an additional flux in raw feldspar transparent glazes for the temperatures of 1180 – 1250 °C. Some of them may be used for regulation of CTE, for example P001 91 or P 016 91. They are suitable for white as well as coloured bodies with CTE alfa (20-500 °C) = 52 – 70 x 10-7 (K-1).
In case of lower firing temperatures or for heavy coat of the glaze or during very slow cooling during firing, the fired glaze may lose its transparency and cloud, more or less.
The glazes can be coloured with ceramic stains by addition of 5 – 10% of stain. They can be used for the covering of underglaze designs under condition of min. firing temperature 1060 °C. Recommended glazing techniques: dipping, spraying.