– THIRD FIRING –
It consists in decorating ceramic products and in their subsequent re-firing at generally low temperatures. Therefore allowing the use of special decorative materials (lustrous, iridescent, precious metals, glass grits, etc.) which by nature may not withstand the rather high temperatures necessary to fire ceramic bodies.
The product characteristics are given regarding the production process we are going to use. Torrecid Group quality control system emphasises on the following parameters:
Dry application vitrosas, flat screen
Particle size distribution is very important due to the opacity consistency and points outside the vitrosa area. It depends on the percentage of very thin and very big particles.
Dry application vitrosas, dry application machine
Also the particle size distribution is very important in order to obtain the right fluidity and the correct application.
Wet application vitrosas
Particle size distribution, it´s very important the quantity of big size particles due to the flat screen working life and to avoid tonality changes.
Printing powders silkscreen
Depending on the effect we want to reach, to decorate or to give thickness. For the first one the residue should be really small 1%, 45 microns mesh, For thickness the residue should be between 15% and 10 %, 45 microns mesh.
Seripoles, coloured glaze granulates, dry application
Particle size distribution, in order to apply with 55 mesh flat screen. Fluidity, should be enough to apply in continuous way and not too high to avoid product accumulation. Colour integration in the powder, the colour must be integrated, not added. If we add the colour we will have tonality changes due to the colour separation from the powder. This happens because there are different particle size between neutral base powder and the colour.