The Production Process of ITALON Porcelain Stoneware
Porcelain stoneware is the most advanced ceramic product to date. Its characteristics, which include zero water absorption, frost resistance, increased abrasion resistance, durability, and availability of large formats, will allow you to create coordinated solutions for floors and walls, both in interiors and exteriors. Porcelain stoneware acquires all its unique technical characteristics during the production process.
In this article we will share the secrets behind the production process of Italon porcelain stoneware, carried out using Italian technology at a factory in the Stupino city near Moscow.
Let’s take a virtual tour of the factory!
UNLOADING AND STORAGE OF RAW MATERIALS
The production process begins with unloading and storing raw materials.
The basic mineral composition of porcelain stoneware includes:
- Kaolin clays. They impart binding properties and plasticity to the raw material base and allow tiles to retain their shape after pressing.
- Quartz sand. It is the primary element of the tiles.
- It reduces the porosity of fired products, facilitating the sintering process and imparting strength, compactness and durability to the material.
The tiles obtain their color when various synthetic pigments (metal oxides) are added to the raw material base.
SELECTION OF RAW MATERIALS, DOSAGE, PREPARATION OF THE BASE RECIPE AND GRINDING OF THE RAW MIXTURE
In order to prepare the base raw mixture, all materials must be dosed in strict proportions according to the recipe then loaded into receiving bins and mixed. As a next step, raw materials go into special drum-type mills, inside of which there are several communicating chambers with grinding bodies made out of calibrated sea stones. The constant rotation of the mills with the addition of water causes the grinding bodies to hit each other and gradually grind the particles of the raw mixture.
As a result, we get a homogeneous aqueous suspension called barbotine, or slip, of a gray-beige color, reminiscent of kefir in consistency. Further, the mixture is colored by adding previously prepared dyes to the mix.
ATOMIZATION
The next stage is atomization, during which the slip is dehydrated at a temperature of ~ 550˚С and brought to a moisture content of ~ 6% which is required for pressing. The slip is sprayed under high pressure into the atomizer cylinder, where it is subjected to a stream of hot air. Water quickly evaporates, and spherical granules with a size of no more than 650 microns are formed.
After that, the dried crude atomized powder is stored in silos, where it is cooled to ambient temperature.
Subsequently, different shades of crude atomized powders are taken from the silos and mixed according to the formula or recipe.
PRESSING
Next step is pressing. At this stage, the tiles obtain their shape according to the designed format, the powder gets compacted and porosity reduces; the mounting plane is formed as well as the texture, if necessary.
At the pressing stage on the mounting side of the tile, the famous “arrow” makes its appearance to indicate the direction of exit of the tile from the press.
DRYING
At the end of pressing, the tiles are removed from the mold, but they are not yet ready for firing, as their residual moisture level is too high. Therefore, they are moved to the dryer, where moisture content is reduced to 0.5% by weight at a temperature of 130˚C.
GLAZING
After leaving the dryer the tiles go to the glazing line, where the desired pattern is digitally printed on them and coated with a special protective layer. At this stage a vast variability of graphics can be created with the help of digital printing.
Homogeneous porcelain stoneware passes through this line but is not coated with any decorative composition. After the glazing line, semi-finished tiles are placed in special boxes for storing raw products. It is important that damp and therefore fragile tiles are not subjected to any mechanical stress while waiting for firing.
FIRING
The next stage is firing in a single-channel roller gas kiln. Firing is carried out in several stages, the maximum temperature reaches 1230°C, and the firing time varies from 0.5 to 1.5 hours.The exposure to the high temperature creates a uniform glass-like structure. At this stage, the actual dimensions of the tiles are significantly reduced, the color developed, and the tone and pattern get fixed. Products acquire their unique technical characteristics such as strength, hardness, frost resistance, wear resistance; and the water absorption rate less than 0.5%
MACHINING: RECTIFICATION AND SURFACE TREATMENT
After exiting the kiln the tiles are stored on a table for fired products. Then they go to the line for rectification and, if necessary, for additional machining of the surface. Rectification allows to get tiles of identical actual size with precisely even edges, which can be laid with a minimum grout joints of 1.5-2 mm (starting from 2 mm for a maxi-format 120×278).
The additional mechanical treatment of the surface helps achieve lux, satin, honed satin and polished finishes.
SORTING
The last step is sorting. Two main tasks are carried out here:
- The first is to group products by caliber (by the actual size of the tiles) and by shade (by the color characteristics of the surface).
- The second is to detect and classify faulty tiles. In this case, the products of the first grade are separated from the products of other grades, marked by some defects.
Sorted tiles are stacked in boxes (while they are grouped by grade, shade and size).
ADDRESSED STORAGE
Packaged tiles are placed at the warehouse with addressed storage, from where they are delivered to customers.
Now you know everything about the production of Italon porcelain stoneware. Each of the stages plays an important role in the process of creating the material of impeccable quality, with unsurpassed technical characteristics. If you want to get advice, see products in person and buy tiles, please contact official Italon dealers. All information about authorized Italon showrooms are available in our “Dealer Locator“
