What are ceramic tiles and what are they made from?

Ceramic tiles are plates made of baked clay. Most often they are square and rectangular shapes, but can be made in the form of a complex geometric mosaic. It can be used to decorate walls and floors both indoors and outdoors.

1. Wear resistance is one of the most important qualities floor tiles, which characterizes the tile’s resistance to abrasion and its ability to maintain its appearance without changes. There is a PEI classification that includes five groups: PEI I - for walls in bathrooms, PEI II - for walls/floors in bedrooms, offices, bathrooms, PEI III is installed in any residential premises and in small offices that do not have a direct entrance from streets, PEI IV suitable for any living rooms, as well as for covering stairs, halls, corridors, PEI V is used both in private and public interiors with above average traffic (offices, shops, cafes, restaurants). For places with heavy traffic (traffic), it is recommended to use unglazed porcelain tiles (airports, train stations, shopping centers).
2. Water absorption is the ratio of the mass of water absorbed by a sample during its full immersion into water, to the mass of dry matter. The ratio is expressed as a percentage. The water absorption of glazed ceramic floor tiles should not exceed 3%, while tiles with a water absorption of more than 10% can only be used on indoor walls. The water absorption rate of tiles plays an important role when tiling pools. To do this, you need to use only special tiles, such as porcelain stoneware or clinker.
   
   
3. Frost resistance - the ability of tiles to resist temperature changes. Durability ceramic tiles is determined by two parameters: the presence and number of pores. Double-fired tiles are quite porous and therefore not frost-resistant. And single-fired tiles with a water absorption of less than 3% are considered frost-resistant. Porcelain tiles, unlike ceramic tiles, have a minimum level of water absorption - less than 0.05%.
4. Cracking is the appearance of fine cracks in the enamel coating. This happens with low-quality or incorrectly selected tiles under the influence of sudden temperature changes. This defect is sometimes present on the tiles before installation. When tiles crack some time after installation, the cause may be improper installation of the tiles: the use of poor mortar or glue, too thick or thin layer these materials.
5. Slip resistance is a characteristic that determines the ability of a surface to prevent an object placed on it from sliding. This property is a basic requirement for the safety of residential and industrial premises, as well as for outdoor floor coverings. In bathhouses, saunas and swimming pools, ribbed tiles with grooves are usually laid.
6. Chemical resistance is a characteristic of tile enamel, reflecting its ability to withstand contact with acids, salts, household chemicals at room temperature. It must resist the aggressive or mechanical effects of these substances without undergoing external changes. Tiles can be protected by filling them with epoxy materials that are highly resistant to chemical attack.
7. Tone and caliber. Tone - color saturation tiles, which may slightly differ from the declared color. It is indicated on the packaging by a number or letter. Caliber is the actual size of the tile, which sometimes differs by a couple of millimeters from the nominal one. The caliber is indicated on the packaging next to the nominal size. During production, tiles are sorted into batches of the same size and tone with the tolerance for differences established by the standards.
   
   
8. Bending resistance. The higher it is, the lower the water absorption of the tile. Porcelain tiles have very high bending resistance, while porous tiles have lower ones.
9. Tensile strength - the level of possible load that the tile must withstand. It directly depends on its thickness. The ability to withstand loads is especially important for floor tiles. The tile covering should be able to withstand loads such as the weight of a person or furniture easily and not break.
10. Surface hardness is a characteristic that expresses the ability of a surface to be resistant to scratches and damage. Scratches are clearly visible on a shiny tile surface, but on a matte surface they are less noticeable.

• What is clinker?
  The clinker material is an environmentally friendly, high-strength material, the production of which involves only natural factors: one hundred percent clay, water, fire (temperature).

  Firing clay has deep

  national traditions in Western European countries - Italy, Holland, Germany.
  Currently in Germany there are seed enterprises with a century and a half history. industrial history- Korzilius, Interbau, Stroher, Feldhaus Klinker.

  

  A wide range of products are produced from clinker ceramic products- facade tiles, floor tiles, steps, plinths, corners, decors, paving stones - intended for internal and external cladding of facades, columns, various architectural forms, paths, etc.
  The main characteristics and advantages of the clinker material are:
  - rough, textured, non-slip surface (anti-slip);
  - frost resistance;
  - high strength;
  - high resistance to chemical compounds, machine oil etc.;
  - high functionality, allowing you to veneer and pave almost any surface;
  - aesthetic, stylish appearance.

• Delivery of material to the site
  We have delivery. To clarify the cost of delivery, you must contact the transport department. The transport department will require detailed address and phone number of the recipient.
  ATTENTION! Delivery is carried out to the entrance - you must unload the goods yourself.
• Is there delivery to the regions?
  We can help organize the delivery of clinker to the regions in the following form. If the client is already working with a transport company, we can undertake to contact this company and explain where to find us. If you need to deliver clinker from our warehouse to a warehouse transport company, we can carry out such delivery by invoicing the customer for transport services.

Firing - final technological operation clinker production. During the firing process from a raw material mixture of a certain chemical composition clinker is obtained, consisting of four main clinker minerals.
The composition of clinker minerals includes each of the initial components of the raw material mixture. For example, tricalcium silicate, the main clinker mineral, is formed from three molecules of CaO, the oxide of the limestone mineral, and one molecule of SiO2, the oxide of the clay mineral. The other three clinker minerals are produced similarly - dicalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite. Thus, to form clinker, the minerals of one raw material component - limestone and the minerals of the second component - clay must chemically react with each other.
Under normal conditions, the components of the raw mixture - limestone, clay, etc. are inert, i.e. they do not react with one another. When heated, they become active and begin to exhibit mutual reactivity. This is explained by the fact that with increasing temperature, the energy of moving molecules solids becomes so significant that mutual exchange of molecules and atoms is possible between them with the formation of a new compound. The formation of a new substance as a result of the reaction of two or more solids is called a solid-phase reaction.
However, the speed chemical reaction increases even more if some of the materials melt, forming a liquid phase. This partial melting is called sintering, and the material is called sintered. Portland cement clinker is fired until sintered. Sintering, i.e., the formation of a liquid phase, is necessary for more complete chemical assimilation of calcium oxide CaO by silica SiO2 and thereby obtaining tricalcium silicate.
Partial melting of clinker raw materials begins at a temperature of 1300° C. To accelerate the reaction of formation of tricalcium silicate, the clinker firing temperature is increased to 1450° C.
Thermal units of different design and operating principles can be used as installations for producing clinker. However, rotary kilns are mainly used for this purpose; approximately 95% of clinker is produced in them from the total output, 3.5% of clinker is obtained in shaft kilns and the remaining 1.5% in thermal units of other systems - sintering grates, reactors for burning clinker in suspension or in a fluidized bed. Rotary kilns are the main heating unit for both wet and dry clinker production methods.
The firing apparatus of a rotary kiln is a drum lined inside with refractory materials. The drum is installed at an angle on roller supports.
From the raised end, liquid sludge or granules enter the drum. As a result of the rotation of the drum, the slurry moves towards the lowered end. Fuel is fed into the drum and burned from the lowered end. The hot flue gases generated in this process move towards the material being fired and heat it. The burned material emerges from the drum in the form of clinker. Coal dust, fuel oil or natural gas. Solid and liquid fuel fed into the oven in a sprayed state. The air required for fuel combustion is introduced into the furnace along with the fuel, and is also additionally supplied from the furnace refrigerator. In the refrigerator it is heated by the heat of the hot clinker, cooling the latter at the same time. The air that is introduced into the furnace along with the fuel is called primary, and the air received from the furnace refrigerator is called secondary.
The hot gases formed during the combustion of fuel move towards the material being burned, heat it, and cool themselves. As a result, the temperature of the materials in the drum increases all the time as they move, and the temperature of the gases decreases.
The broken nature of the material temperature curve shows that when the raw material mixture is heated, various physical processes occur in it. chemical processes, in some cases inhibiting heating (sloping areas), and in others promoting sharp heating (steep areas). The essence of these processes is as follows.
Raw material sludge, which has an ambient temperature, enters the furnace and is suddenly exposed to the high temperature of the waste flue gases and heats up. The temperature of the exhaust gases decreases from approximately 800-1000 to 160-250 ° C.
When heated, the sludge first liquefies and then thickens and, with the loss of a significant amount of water, turns into large lumps, which, with further heating, turn into grains - granules.
The process of evaporation of mechanically mixed water from sludge (drying of sludge) lasts up to approximately a temperature of 200 ° C, since the moisture contained in the thin pores and capillaries of the material evaporates slowly.
Due to the nature of the processes occurring in sludge at temperatures up to 200 ° C, this zone of the furnace is called the evaporation zone.
As the material moves further, it enters the region of higher temperatures and chemical processes begin to occur in the raw material mixture: at temperatures above 200-300 ° C they burn out organic impurities and the water contained in the clay minerals is lost. The loss of chemically bound water by clay minerals (dehydration) leads to the complete loss of the clay's binding properties and pieces of sludge crumble into powder. This process lasts up to temperatures of approximately 600-700° C.
Essentially, processes occurring in the temperature range from 200 to 700 ° C, this zone of the furnace is called the heating zone.
As a result of the presence of the raw material mixture at this temperature, calcium oxide is formed, therefore this zone of the furnace (up to a temperature of 1200°) is called the calcination zone.
The temperature of the material in this zone increases relatively slowly. This is explained by the fact that the heat of flue gases is spent mainly on the decomposition of CaCO3: to decompose 1 kg of CaCO3 into CaO and CO2, 425 kcal of heat is required.
The appearance of calcium oxide in the raw material mixture and the presence of high temperature determines the beginning of the chemical interaction of the oxides of silicon, aluminum and iron found in the clay with calcium oxide. This interaction occurs between oxides in the solid state (in solid phases).
Reactions in solid phases develop in the temperature range of 1200-1300 ° C. These reactions are exothermic, that is, they occur with the release of heat, which is why this zone of the furnace is called the exothermic reaction zone.
The formation of tricalcium silicate occurs already in the next section of the furnace in the region of highest temperatures, called the sintering zone.
In the sintering zone, the most fusible minerals melt. In the resulting liquid phase, 2CaO-Si02 is partially dissolved and it is saturated with lime to 3CaO-Si02.
Tricalcium silicate has a significantly lower ability to dissolve in the melt than dicalcium silicate. Therefore, as soon as its formation has occurred, the melt becomes supersaturated with respect to this mineral and tricalcium silicate falls out of the melt in the form of tiny solid crystals, which are then, under given conditions, capable of increasing in size.
The dissolution of 2CaO-Si02 and the absorption of lime by it does not occur immediately in the entire mass of the mixture, but in its individual portions. Consequently, for more complete assimilation of lime by dicalcium silicate, it is necessary to keep the materials for a certain period at the sintering temperature (1300-1450°C). The longer this exposure is, the more completely the binding of lime will occur, and at the same time the larger the 3CaO-Si02 crystals will become.
However, it is not recommended to keep clinker at the sintering temperature for a long time or to cool it slowly; Portland cement, in which ZCaO - Si02 has a fine-crystalline structure, has higher strength.
The duration of clinker exposure depends on the temperature: the higher it is in the sintering zone, the faster clinker is formed. However, with an excessively high, and most importantly a sharp increase in temperature, a lot of melt quickly forms and the fired mixture can begin to clump. The large grains formed in this case are more difficult to heat up and the process of transition of C2S to C3S is disrupted. As a result, the clinker will be poorly burned (it will contain little tricalcium silicate).
To speed up the process of clinker formation, as well as in cases where it is necessary to obtain clinker with a high content of 3CaO-Si02, certain substances are used (calcium fluoride CaF2, iron oxide, etc.) that have the ability to reduce the melting point of the raw mixture. More early education liquid phase shifts the process of clinker formation to the region of lower temperatures.
During the sintering period, sometimes all the lime in the mixture does not have time to be completely absorbed by silica; the process of this assimilation proceeds more and more slowly due to the depletion of the mixture in lime and 2CaO Si02. As a result, in clinkers with a high saturation coefficient, which require maximum assimilation of lime in the eide ZCaO Si02, free lime will always be present.
1-2% of free lime does not affect the quality of Portland cement, but its higher content causes uneven changes in the volume of Portland cement during hardening and is therefore unacceptable.
The clinker from the sintering zone enters the cooling zone (VI), where flows of cold air move towards the clinker.
The clinker leaves the cooling zone at a temperature of 1000-1100 ° C and for final cooling it is sent to the furnace refrigerator.

Clinker tiles – facing material, which has long been actively used in the construction business. Also in early XIX centuries, the material was used to lay roads in Holland, immediately after which it began to be used in Russia and Western Europe.

According to historians, the technology for producing clinker tiles dates back to the 15th century, when people noticed that when clay bars were fired, they acquired completely different properties (the properties of porcelain stoneware).

The kilns in which the firing was carried out consisted of only one entrance and small room. Clay bars were placed inside it different forms, after which the entrance was sealed for several days. The brick inside, under the influence of high temperature, acquired the necessary physical properties.

Clinker tiles are produced mainly from natural material– clay. As a change color range natural dyes are used. Clay for firing should be different high level refractoriness, and have a minimum amount of various impurities.

Today, deposits of high-quality clinker suitable for the manufacture of clinker facing material are available in Poland, Germany, Spain, Holland and other countries.

Clinker tile production technology

At the present time, the production technology of clinker tiles has no fundamental differences from the production technology in medieval Europe. Although experts in this field distinguish 2 types of production:

• extrusion
• semi-dry pressing

Clinker tiles undergo a firing process at high temperatures. If, for example, when firing ordinary clay products, the material is exposed to temperatures of about 800-900 o C, then in clinker kilns working temperature is 1100-1400 o C.

Thanks to this temperature regime, the material changes its physical state, becoming more
durable. At the same time, the energy consumption is 4 times higher than the requirement than when processing clay products in the usual way.

Extrusion production method involves the use of special equipment - an extruder. The device is presented in the form of a screw grinder into which wet plastic clay is fed. After grinding it is molded using vacuum press. After drying, this workpiece is sent to the kiln for firing. The clinker material after extrusion is different high density, strength, resistance to abrasion, mechanical and chemical influences.

Semi-dry pressing method also involves a pressing process using special equipment. However, unlike extrusion, starting materials placed in a kiln for firing without pre-drying. As a result of this production method, the clinker product has a low density, which significantly weakens its strength.

The semi-dry pressing method is needed in order to obtain clinker products with low thermal conductivity. And in some cases, such products are valued much more than, for example, resistance to mechanical or chemical influences.

Equipment for the production of clinker tiles

Special equipment is used to produce high-quality clinker products. During the processing process, the clay passes through an extruder, special device for pressing and creating the required shape (machines are belt, vacuum, rotary, lever), pre-drying chambers and a firing oven.

Forming molds, into which wet plastic clay is placed, have a matrix layer that provides the highest possible level of sealing and thermal insulation to the output material.

Naturally, the main equipment for the production of clinker tiles is a kiln. Such a room is a kind of tunnel about 150 m long. It contains heating sources in the form of an open fire.

Clinker elements are fed in special trolleys that move through the kiln at a fairly low speed. Thus, gradual heating and firing of the clay occurs. Such kilns operate in continuous mode, which allows firing a large number of products.

Clinker production does not require significant energy consumption. High price finished material can be justified only by the costs of delivering material (clay) from deposits. But the price is more than compensated for by the performance qualities of the material. It is this indicator (price-quality) that makes the use of clinker very popular in various areas of the construction industry.

Technical and operational characteristics of clinker

With the help of high-temperature treatment, clinker tiles receive most of their positive characteristics. The material has practically no pores, therefore it does not allow moisture to pass through and provides high waterproofing to the room. Mold and bacteria do not accumulate in the walls, so the service life of such walls is much longer than usual.

Clinker tiles are insensitive to alkalis and acids, therefore they are often used for cladding residential buildings. This material is frost-resistant, which is why it is often used in the construction of building facades in regions with low temperatures. temperature conditions(clinker can withstand up to 50-80 frosty seasons). In comparison with conventional brickwork, on which already after 1-2 winter periods light traces appear, clinker tiles retain their original appearance for a long time.

Clinker has a number of advantages:

• low moisture absorption;
• environmental friendliness;
• a wide variety of colors;
• high strength and frost resistance;
• unlimited service life.

This facing material is often used together with thermal insulation, resulting in an ideal coating for building facades. Such panels are called thermal panels, and are currently very popular.

Clinker tiles and brick - the most durable, reliable, status, prestigious solution for facade finishing country house or administrative building. It is worth recognizing right away that clinker is far from the cheapest option, however it will not only increase market value your home, but will also give you a feeling that is difficult to measure in money. confidence, prosperity And superiority that will stay with you forever.

Pressed or extruded tiles?

By entering the query “clinker tiles” or “clinker facade” into Google or Yandex, you will receive more than 100,000 articles and proposals where you will be offered clinker facades from Polish, Russian, Belgian, German and even Belarusian production. and so as not to get lost in these proposals, we suggest you understand the issue once and for all:

What is hidden behind the phrases “clinker”, “clinker facade” and “clinker tiles”?

Essentially the word CLINKER- this is a derivative of the description of the characteristics of brick, which came to us from the Middle Ages. It came from the word KLINK, which describes the ringing sound emanating from a burnt brick after being struck. For builders, before the era of certificates and technical tests, this sound was one of the few criteria for assessing the quality of the material from which walls were laid. The louder a brick sings, the higher its strength, the fewer impurities it contains and the greater the load it can withstand. This is where the derivative KLINKER comes from – a sign of reliability, durability, and high quality.

Now, in the era of technological progress, measurement accuracy, precise regulation of production processes and the use of construction and finishing materials, word CLINKER turned more into a beautiful marketing story accompanying completely different Construction Materials. And in order to choose a reliable and durable material for cladding the facade, it is not enough to hit two tiles against each other. You need to dig a little into production technologies. manufacturers and sellers facade materials Clinker is any facing tiles, having the appearance of a brick.

That is why we need to figure out what production technology facade tiles guarantees us the durability and status of that same “Clinker”

The dilemma is whether to prefer only aesthetic aspects or to take into account technical ones as well. IN this moment There are two technologies for the production of ceramic facades: And cold pressing.

They differ both in production method and in functions, which have a direct impact on cost and efficiency of use. Some of them have, for example, smaller tolerances, others are more resistant to adverse weather conditions. By providing this information, we hope that the investor will be able to make informed decisions based on it, taking into account not only his own preferences and expectations, but also technical aspects in order to enjoy the end result in the form of beautiful and durable facades for many years.

Ceramic facade tiles can be produced using two technologies:

1. Technology extruded clinker.

This traditional technology used in the production of clinker, bricks and cobblestones.

Blanks made from plastic masses of refractory purified clay with a moisture content of 15 to 30% are passed through an extruder, which, without creating supernatural pressure and without disturbing the molecular structure of the raw material, gives future tiles or bricks geometric shape. Then raw billet cut into individual products, decorative elements are applied using soot mixtures and natural pigments. After which the blanks enter a tunnel kiln and are fired for 48 hours at a temperature of 1300 degrees C. Firing gives the final shape, creating porosity sufficient for vapor permeability and burning out all kinds of organic impurities from the structure of the raw material.

The output, after mandatory two-stage quality control, is extruded clinker tiles. clinker with a unique front surface created by the elements of fire, water and earth. Each extruded tile is unique. And there is nothing more to say about the strength of the material fired at extremely high temperatures.

2. Semi-dry pressed clinker.

The tiles are produced using the semi-dry pressing method. When pressing, a powdery mass with a moisture content of 4 - 6% is compressed in two directions, usually under a pressure of about 200-400 kg/cm2. Under pressure, the granules move and partially deform, due to which the unfired tile acquires the strength necessary for subsequent operations. During the pressing process, the molecular structure is compressed, reducing the pores that discharge steam and creating additional internal stress in each individual tile.

What is affected by the difference in technological processes?

if we ignore aesthetic features appearance between tiles produced by pattern pressing and natural firing methods

At this stage we can distinguish 2 fundamental differences between extruded clinker and semi-dry pressed facade tiles

1. Adhesion. Ability to set and hold time on adhesive solutions when performing outdoor work

Semi-dry pressed tiles pressed against a dry, almost glassy and smooth surface without any open micropores formed after aggressive pressing. The glue is not able to penetrate deep into the structure of the plate. This certainly limits the possibilities of communication with adhesive solution and to obtain sufficient connection strength, specialized adhesive mixtures. Especially when the tiles are used on outdoors: not only in frost in winter, but also in summer - the sun and large daily temperature fluctuations can lead to separation of the tiles from the substrate (load-bearing wall).

Surface of pressed tiles, magnified

In case they have a porous and rough structure, which provides a large contact surface of the adhesive mortar. The glue penetrates easily and deeply into micropores open system, which leads to special strength of the glued tiles.

Magnified surface of extruded tiles

2. Vapor permeability. The ability to quickly remove wet vapors from the façade during natural and extreme temperature changes

They have low water absorption, so they may seem more stable and durable. The reality is completely different. It is worth considering the internal structure of two materials that have a direct impact on the performance and ease of use of the stove. In the technology of producing a dry compressed body of tiles with a structure of compressed chaotic material particles, between which the micropores are closed with very thin capillary channels. This results in low water absorption and also very slow water flow. It is assumed that no water has entered such products. However, this assumption is purely theoretical. The water remaining in the tiles, due to the closed structure and compacted material, cannot be removed and this will lead to expansion when freezing in the cold. Consequently, this may cause damage to the tiles. Additional risks of moisture escaping from glued tiles. Dry pressed boards do not have the ability to remove water outside the substrate. Water partially enters the tile and, remaining under it, can weaken the bond with the substrate, the supporting frame.

Structure and behavior of water in pressed tiles

Facade clinker Structure and behavior of water in.

The internal structure of tiles obtained using extrusion technology is completely different. During production process extrusion, the microstructure is not damaged and retains its natural, homogeneous character. A network of interconnected capillary channels makes it possible to quickly remove moisture out; they have less absorbing capacity than, but water easily flows back into environment. The microporous structure makes the facade tiles resistant to freezing of water remaining in the tiles. In addition, due to its structure, tiles made using extrusion technology easily get rid of water between the tile and the adhesive layer, which prevents the possibility of its accumulation in the tile area. Thus, extruded tiles have higher adhesion to the base and, accordingly, the tiles are less likely to come off the base. There is less water absorption due to the internal structure, the tiles are more durable and more resistant to extreme weather conditions.

Structure and behavior of water in extruded tiles

Facade tiles. Aesthetics.

As already mentioned, the aesthetics of the tiles are pressed and completely different. Of course, there is no way to say which one is better, because both groups have their supporters and opponents. For some, the smooth, repeating surface of pressed tiles from element to element has a plastic, artificial appearance; for others, the surface is too “strict”. Pressed products are produced in molds so that the structure of the model is repeatable and their surface is highly reproducible. They are characterized by greater accuracy than extruded, fired products, and have smaller tolerances and color. The surface is very smooth, often covered with engobe, therefore, it is a stretch to say that they are artificial, plastic, and only the size resembles a brick. The pressed plates have a thickness of 6-7mm and, therefore, are filled with fugue (joint filler) small space between the tile and the base, which reduces the water resistance of the wall. The structure of such joints in pressed tiles is smooth and unlike the joints used in a brick facade.

When gluing pressed tiles, the tile cannot be pressed hard to create a successful simulation brickwork. Thin mortar is also less durable and, as a result of wind and air suction, can crack and crumble.

Clinker is made in exactly the same way as clinker bricks, from the same raw materials and using the same technology. So the surface looks similar to that of traditional clinker products. They are not as smooth as pressed tiles, they also have higher frost resistance. They are so perfect that after covering the facade, no one can say whether it was faced with tiles or bricks. The range of products produced using extrusion technology is rich in natural colors and surface structures, like clinker bricks. Often facade tile manufacturers offer the same or similar colors of tiles and bricks needed to complete associated elements such as facades, chimneys, fences and landscape design. Due to the fact that they are produced in thicknesses of 9-14mm, they can use the same grouts as for sealing joints for bricks, therefore, their particle size and structures are identical to the surface of masonry mortars. We hope that based on the above information, the investor, considering the technical and aesthetic aspects, will be able to make informed decisions and have tiled walls with trouble-free operation.