Ceramic tiles, depending on the type of production and purpose, are made from a mixture of different types of clay, with the addition of other natural ingredients, as follows: Ingredients are pre-pressed with a pressure of about 500 kg / cm2, and then fired in ovens at temperatures from 1040 to 1300 ° C depending on the type of ceramic tiles.
Just like other ceramic products, ceramic tiles are durable, easy to clean, hygienic, fireproof.
The field of application of ceramic tiles is extremely wide: Ceramic tiles are used for cladding walls, floors, fireplaces, swimming pools, for protecting facades and plinths, installing raised floors, covering sidewalks, etc..
Types of ceramic tiles:
Currently, there are several main methods for the production of ceramic tiles:
Bicottura Is an enamelled ceramic tile designed for indoor wall cladding. Enamel gives shine to ceramic tiles and allows you to display patterns of any design, and also protects the ceramic body of the tile from moisture penetration.
The entire production cycle of this type of ceramic tiles takes place in two firing processes: the first – to create the base, and the second – to fix the enamel.
The body of ceramic tiles (“cookies”) is obtained in this way: First, a moist mass of red clay is pressed in special forms, then it is fired at temperatures up to 1040 ° C.
Such ceramic tiles are considered porous, with a water absorption rate of up to 10%. The cookie thickness is usually 5-7 mm. This type of ceramic tile is inferior in strength to all others, so it can be used exclusively in interiors..
Creation of cookies is a separate production cycle, at the end of which ceramic tiles undergo control of planimetric parameters and linear dimensions and, if the ceramic tiles do not meet the specified parameters, the rejected samples are automatically removed from the conveyor and go for processing. Rejected ceramic tiles are not allowed to the second firing phase – the enameling phase.
The enamel covering double-fired ceramic tiles can be glossy or matt and do not have high surface strength, as in monocotture, since these tiles, used mainly on walls, are not expected to be subjected to mechanical and abrasive stress, for example, they will walk on it. At the same time, the enamel is sufficiently resistant to the effects of household detergents used for cleaning ceramics, as well as to cosmetics and hygiene products that can come into contact with the surface of ceramic tiles in bathrooms..
Since the process of applying the enamel does not in any way affect the geometry of ceramic tiles, these parameters are no longer monitored after the end of production, and ceramic tiles are checked only for surface defects..
Externally, this type of ceramic tile is distinguished by:
Bicottura is usually made in collections consisting of several colors: a lighter one – most often the basic one in a series, and additional darker ones, and with a large number of decorated elements made in two different ways:
Monocottura Is a ceramic enamelled tile suitable for both wall cladding and flooring. Some of its types are frost-resistant and, accordingly, allow this type to be used outdoors..
The entire manufacturing process takes place in one firing cycle. A specially prepared mixture, consisting of different types of clay with the addition of other natural ingredients, is mixed in special drums and simultaneously moistened. Then it is dried and ground in huge vertical silos almost to the state of suspension, and fed through the dispenser in the necessary portions to the transport belt with subsequent placement in the mold, where a strictly dosed amount of this mixture is evenly distributed throughout the die shape. It should be noted that the size of the pressed ceramic tiles at this stage exceeds the nominal size by about 7-10% (roughly corresponds to the moisture content in the batch after the press), that is, ceramic tiles with a catalog size of 30×30 still have a size of about 33×33. All this happens because in the process of drying and final firing, the ceramic tile shrinks, decreasing in size, and this just explains the presence of the calibers assigned to the ceramic tile..
After leaving the press, the ceramic tiles are sent to a special final drying chamber, and then to the area where enamel is applied to the still unfired ceramic tiles, which after firing protects the tile body and gives the originally conceived design.
After applying the enamel, the ceramic tiles are fed into an oven up to 100 m long.Gradually heating up there to a temperature of up to 1200 ° C, and then gradually cooling down, the ceramic tiles undergo the same single firing, as a result of which the base acquires exceptional hardness and the enamel is fixed on it. forming a solid whole. The entire firing process is strictly controlled by computers at each phase of the oven. After leaving the oven, ceramic tiles arrive at the site for flaw detection and visual control of tonality and calibration, after which they are sorted by batches, packed, marked and sent to the finished product warehouse..
Tests at the flaw detection section consist in the fact that each ceramic tile hits the so-called rails located at the edges of the ceramic tile and a roller is rolled in the center, acting on the tile with a certain load. If the ceramic tile has a defect, then it does not withstand the load and breaks, automatically not being subjected to further tests.
Defects of the enamel surface are checked visually, simultaneously with determining the tone of the tile.
The main differences between monocottura and bikotura:
1.higher density of the material, as a result of using a more powerful press, and a higher firing temperature, and as a consequence, the presence of series with low water absorption (<3%) and, accordingly, frost-resistant;
2. a thicker and more durable ceramic tile base;
3.Stronger, more wear-resistant enamel.
The enamel of single-fired ceramic tiles, in addition to increased strength characteristics, is resistant to household detergents, and some types of these ceramic tiles are also highly resistant to aggressive chemical environments.
Two types of decors for monocotture are produced: floor and wall.
The production of floor decors is very similar to the production of the base material, with the only difference that a pattern of a given design is applied to the blanks of the required format, which is then also fired, and therefore the strength of the decor enamel is not inferior to the strength of the base field. Wall decors (if the series also has a designation recommended by the designers of the factory as “wall for interiors”) are made using the same technologies as for bicottura, respectively, without having the strength characteristics of the main field.
In many cases, monocottura ceramic tiles are offered as floor tiles of the appropriate color and size for some bicottura series, thus complementing them, or they can be offered as independent series with wall decors and be recommended for use both for wall and floor.
Monoporosa – this is a separate type of single-fired ceramic tiles – this is. This type of ceramic tile is produced using the technology of pressing and subsequent single simultaneous firing of the ceramic tile body and the applied glaze. In this it is completely similar to monocotture. But thanks to the use of slightly different components in the preparation of the batch, the physical properties, and, accordingly, the field of application of this ceramic tile, differ significantly, and are closer to the bicottura tiles. For the production of monoporose, clay with a high carbonate content is used. During firing, as a result of chemical processes, a highly porous white mass is formed, with high water absorption (up to 15%). The strength of such ceramic tiles is noticeably lower than the strength of traditional monocotture, therefore the base has a thickness of 12 mm. Naturally, such ceramic tiles can only be used indoors..
This technology allows baking large-format slabs of almost ideal dimensions, which, after additional machining of the edges (rectification), can be laid with minimal seams. In the production of bicottura, where the base itself is made from red clays, the light enamel must be thick enough not to lose color, while in monoporosis, the white base allows you to apply a thin layer of light enamel. These two characteristics dictate the stylistic performance of the monoporose tiles – the colors in the series usually imitate natural marble. Decors are made both in the traditional way – by drawing a pattern on ceramic tiles, and by cutting with water under high pressure on special equipment: in this way, you can get a very beautiful prefabricated decor using, among other things, pieces of natural stone.
A white porous base and a thin layer of enamel require special rules for working with ceramic tiles of monoporosis: for laying it is necessary to use a white adhesive composition, rubbing the seams very carefully, trying not to damage the enamel. The surface for laying large format ceramic tiles must be perfectly flat..
We add that the so-called rectified ceramic tiles, the use of which allows you to create, as it were, a single surface, without visible large seams. Thus, the impression is created that the surface is faced with natural stone.
Rectification is an additional mechanical processing of an already finished material, which consists in cutting off the side edges of both matte and polished ceramic tiles on special machines to give all ceramic tiles in a series a uniform size in each format. The equipment is configured in such a way that it also processes different formats in one series according to a given template so that, for example, in one ceramic tile 30×30, two ceramic tiles 15×15 are laid along the length, or in one ceramic tile 45×45 – one ceramic tile 30×30 and one ceramic 15×15 … This operation makes it possible to lay ceramic tiles of different formats, as well as to combine matt and polished ceramic tiles of the same series with minimal seams, which is an additional advantage and is almost impossible for unrectified ceramic tiles..
General recommendations for the selection of ceramic tiles can be formulated as follows:
Bicottura – it is used for wall cladding in interiors, sometimes also for flooring (if the selected series is recommended for such use), but only in those rooms that do not directly interface with the street and where, therefore, there is no risk of damaging the enamel with abrasive particles (sand , dust).
Monocotture – it is used for cladding all types of surfaces in interiors, and also, especially resistant types of this tile can be used as a floor covering in public places with a not very intensive flow of people (you still need to take into account that enameled ceramic tiles, one way or another, will wear out during operation faster than porcelain stoneware). Also frost-resistant series can be used for outdoor work..
Monoporosis – wall cladding inside the premises.