JSC “Beryozastroymaterialy” is one of the first companies in the CIS that began to produce ceramic tiles by the modern technology of single firing “monoporosa”. The use of new technology has reduced gas consumption by 40%. The raw material mixture consists of clay, granite fines, sand and other natural ingredients that are crushed in a special tube mill, continuous method of wet grinding. The obtained ceramic slurry is dried in a spray dryer (atomizer) to obtain press-powder.
The press-powder enters the plant for semi-finished product by pressing on hydraulic presses. After leaving the press, the tiles are sent to the drying section, and then to the site of engobe application (it hides all the irregularities of the tiles and masks the body color of the tile) and glazing (special coating defined by design of tiles). After applying glaze tile is decorated and loaded in the kiln. During firing there are complex physical and chemical processes in the tiles that allow to get the finished product with high quality indicatorsin the end. As a result of firing tiles acquire hardness, strength; engobe and glaze tile form a strong unified whole. The glaze turns into a hard coating (matte or glossy), providing the desired decorative and physical and mechanical properties. After the exit from the kiln the finished products are supplied to the sorting area to control the tone quality of the front surface, deformation and calibration. Sorted production batches are packaged, labelled and sent to the warehouse of finished products. The sorting process is automated. The human factor is present only during the evaluation of the front surface of the tile and tone. This quality control process is used by all the leading manufacturers.
DETAILED PRODUCTION PROCESS
1. Transporting and storage of incoming raw materials
Shipping of raw materials to the plant is carried out in railway cars and trucks. Incoming raw materials stored in indoor warehouse, to protect them from rain. The supply of raw materials from the warehouse to the receiving bunkers of body-preparation department by an overhead grabbing crane.
2. Preparation of the slip mass
To prepare the body clay from Druzhkovsky field and clay from Novolukoml are used. The dissolution of clay is made with water and electrolyte in the mills of periodic action. The electrolyte is an additive for reducing the viscosity of clay suspensions without the addition of excess water. The clay suspension is drained into the pool with stirrers for storage. The grinding of such materials as sand, dolomite, granite screenings, tile recycle and suspensions of the clays is carried out in a two chamber tube continuous mill. As grinding bodies alumina balls with high hardness and density are used. Slip for floor tiles is prepared in ball mills of periodic action. All raw components are automatically dosed according to the recipe and fed into the mill at the same time with water and electrolytes for grinding to the desired sieve residue. The prepared slurry passes through magnetic and sieve enrichment and is stored in the drain basins with mixers before making him press powder.
3. Preparation of press powder
Press powder is produced by dehydration of the slurry in a tower spray dryer (atomizer). The slurry is fed into the dryer under pressure and sprayed through nozzles in the form of droplets that dry and form granules of the molding powder. Dryer is supplied with heat from a heat generator with a blast of the gas burner. Received press powder passes through the sieve and is fed into the silo for storage, where it is stored and averaged at the humidity for at least a day.
4. Pressing and drying of the tiles
Pressing of tiles is carried out on hydraulic presses by reverse extrusion, i.e. the front side down. The pressed tile is flipped and enters the dryer. The process of drying of floor tiles and wall tiles on double fire line is in horizontal roller dryers, while on single firing line in the vertical dryers. After drying the front surface of the tile is cleaned with rotating brushes from dust, and then the tile goes to the area of the glazing.
5. Engobing and glazing
Before applying the engobe and glaze the surface of the tiles is moistured by spraying water in a special chamber. Engobe is a special ceramic coating applied to the tile, after firing it is white. It is necessary to mask the color of the body and to align the tile surface before applying glazes. Glaze is a special coating that is applied on the engobe layer and after firing acquires all its essential characteristics: hardness, decorativeness, chemical resistance, water resistance, etc. Depending on the type of products engobing and glazing of tiles are made on the installations of various types: disc (for floor tile); slotted (for single firing) and “bell” type (for double firing). Preparation of engobe and glaze is carried out in ball mills of periodic action by wet milling of frit (a vitreous material in the form of pellets), additives and other components. JSC “Beryozastroymaterialy” has its own department for the production of frits, which produces most of the frits for engobes and glazes. The glaze can be matte, glossy, painted and unpainted. The preparation of colored glazes is by adding pigments according to the recipe. All colored glazes before leaving the production are checked for compliance with the color standard by using spectrophotometer. After the glazing the tile edges are cleaned from glaze.
6. The decoration of tiles
The decoration of tiles (patterning) is performed with a special mastic in two ways: rotative machines (using silicone rollers) and silk-screen machines (using mesh-stencils). To create more decorative effects are used special reactive, luster and protective mastic, toppings are used.
7. The application of engobe
The application of engobe on the rear side of the tile occurs in a special machine, the rotating roller. This is necessary to protect the rollers in the kilm from contamination with particles of tile body.
After decorating the tile is fired in a high-speed roller kilns of the firm “Sacmi” from Italy (one channel for floor tiles and two channel for tiles for double and single firing). Tiles are fired at a temperatures from 1085°С to 1175°С, depending on the product (floor tile or wall tile) and within 40-55 minutes. After firing, the tile is formed into boxes and sent to the sorting line.
9. Sorting and packing tiles
Unloading of boxes with tiles on to the sorting and packing line of the complex is carried out by unloading machine. Visual sorting of the face of the tiles on the line belt, is made by control managers in accordance with the requirements of State Standard. A special mark is appied in a definite place of the tile with a light sensitive marker, after that the machine sorts out tiles automatically to the sorting line or to the waste container. Linear dimensions, caliber and curvature of the tile are determined automatically during the passage of the tiles through the device “planar – caliber”. Removal and stacking of cardboard boxes with the tiles on the wooden pallets is carried out by a robotic stacker. The robot puts the boxes on several pallets at the same time. The bar code is glued with information about the design: name, date of manufacture, shift number, grade, caliber. Full pallet tied off with polypropylene tape, the driver of the forklift transports the pallet with the tiles and then places it on the platform for packing in stretch film. Forklift driver transports pallets adopted by the TCI controller to the warehouse of ready products.