Keramin Ceramic tiles and porcelain gres production technologies
Ceramic tiles production process consists of several stages, involving raw materials processing and some manufacturing operations. We use only high quality clay, kaolin, feldspar, frit, sand, colorants and other materials. 
The number of operations depend on the type of tiles produced – glazed or unglazed.
Mixture and moulding powder preparation
Natural and synthetic materials are used for tile body production. All materials are thoroughly measured, crushed, ground and mixed until they form a homogeneous mixture. Clayey materials are dissolved in water into a creamy consistency with a follow up combined milling with nonplastic materials. The resulting water-filled mixture with approximately 40% humidity level is called a slurry.
Moulding powder preparation involves several operations, which lead to creation of homogeneous material of the right granulometry and humidity necessary for the upcoming process of moulding.  Along with the slurry pigment coloring technology, in 2009 “Keramin” adopted the technology of dry coloring.
We produce ceramic tiles using semi dry pressing technology. During the process of pressing the powder mixture with 4-6 % humidity is being compressed in two directions usually under the pressure of approximately 200-400 kg/sq. sm. That is when displacement and partial deformation of particles happens allowing the raw tile body to form a certain shape and obtain durability necessary for the following operations. 
For porcelain gres production “Keramin” JSC uses the latest innovative technologies and equipment from globally recognized Italian companies such as SACMI, LB, SYSTEM. Our new production line is equipped with automated press with operating pressure of 6200 tons.  Keramin was the first company among the manufacturers of ceramics in CIS and Eastern Europe countries to install this kind of equipment.  
After pressing, the tile body is dried with hot air in continuous operation drying machines. While moving along the conveyor tiles go through three stages– heatup, evaporation and cooling. 
The process of decoration of glazed tiles includes subsequently engobe coating, image printing and glazing of the tiles’ face surface. 
Engobing creates smooth and color stable surface.
“Keramin” uses several printing technologies depending on the type of product and the desired final result:
  • Screen printing. The image is printed by forcing color pastes through mesh stencils.
  • Rotocolor. This technology allows to produce tiles with non-recurrent patterns imitating natural stone, wood or textile. A paint coated silicone roller with laser cut design rolls over tiles giving them a vivid, natural looking pattern. 
  • Digital printing. The technology allows to enrich the creative process and expand the range of design solutions search, reproduce natural textures like stone, wood, marble with photographic quality on ceramics. Digital printing significantly improves the production logistics making it possible to produce pilot batches and commercialize new products very promptly.
  • Dry decorating with CROMA and COLOR VERTICAL DRY machines allows us to produce porcelain gres with advanced aesthetic and performance characteristics, extra durability and abrasion resistance. 
Glaze is applied to the dried tile body for single-fired tiles and to the previously fired body for multiple-fired products. 
Glaze is a mixture of various materials and minerals – frits, sand, kaolin, coloring agents and oxides – that are applied to the surface of the tile body and are melted. After cooling, the fusion hardens forming glass coating and giving the top layer of the tile exceptional characteristics.   
Chemical reactions and physical alterations take place in the tile body and glaze during the process of firing. The result of this influences the properties of the product. At this point a tile acquires the mechanical characteristics determining its performance as facing material. 
This is the final stage of the technological process. The firing takes place in gas-fired slot type roller-hearth kilns for 35-60 minutes. The process consists of three stages: maximum temperature heatup, exposure to high temperatures, cooling. 
For single-fired tiles raw moulded body is coated with glaze before firing. We use this method for glazed porcelain gres and floor ceramic tiles production. 
To create tiles for interior facing works we use double-firing method. First the tile body is fired. After that the surface is being coated with engobe and glaze, decorated and fired again. Tile body is fired at 1100˚С, the glaze is fired at 1020-1050˚С. Firing lasts for at least 40 minutes. 
Multiple firing allows to enrich our products’ design solution variety. This very technology makes it possible to decorate tiles with gold, platinum, metallized glaze, luster and vitrosas.
Decorative elements such as borders, panels and listels are made of ready tiles. Images are transferred using screen printing technology; surface is decorated with vitrosas and other materials. After that, tiles are fired and cut into piece-goods when it comes to listels and borders production. 
Sorting and packaging
All products are sorted according to the existing standards before they proceed to the packaging section and then to the storage. Sorting takes place at straight line conveyors. Packaging and palletizing is performed by robot-palletizers. Palletized products are stored according to color and design classification.