Producion Cycle For Double-Fired Glazed Tile

PREPARATION OF THE MIX

· carried out with the dry process

SHAPING

· obtained by dry pressing with hydraulic presses and mechanical presses

DRYING

· carried out in tunnel driers and in vertical fast hot-air driers

FIRING

· This cycle involves two phases of firing: the 1st is that of firing the
bisque ware, the 2nd the gloss firing ( firing of the glaze )
· Bisque firing: firing of the bisque ware is carried out in both tunnel kilns and in roller kilns at various temperatures depending on type of product:

1. Majolica T= 950 to 1000 °C
2. Cottoforte T= 950 to 1020 °C
3. Earthenware (white body ) T= 1030 to 1080 °C

· Gloss firing: firing of the glaze is carried out at a temperature of 800 to 950 °C, which is lower than the temperature used to fire the bisque ware in fast single-layer kilns

GLAZING

· This operation is carried out between the 1st and 2nd firing and consists of two sub-phases:

1. preparation of the glaze is achieved by wet grinding the glaze mix (formed by various components, frit, kaolin, additives, etc.)

2. application of the glaze by various techniques and machinery and equipment are used, depending on the desired aesthetic effects.