The manufacturing process of ceramic tiles is really amazing for everyone. I, myself, wanted to know more about this process, so I searched for what I should know. Now here is a summary of the result. Raw MaterialsClay minerals collected from the earth's crust, naturally occurring minerals like feldspar used to lower the fire temperature, and chemical additives. needed for the shaping process make up the raw materials used to create the tile. Before being transported to the ceramic plant, minerals are frequently refined or beneficiated close to the mine. The raw materials must be ground up and sorted by particle size. Large chunks of material are reduced using primary crushers. It uses either a jaw crusher or a gyratory crusher, which works by rotating between steel cones or horizontally compressing steel plates, respectively. Smaller lumps are crushed again to form particles. Muller or hammer mills are frequently employed. In a muller mill, the material is crushed using steel wheels in a shallow, rotating pan; in a hammer mill, the material is crushed using quickly swinging steel hammers. Crushers of the roller or cone variety may also be employed. It could be essential to add a third particle size reduction phase. Grinding medium is used in conjunction with tumbling mill types. The ball mill, which comprises sizable rotating cylinders partially filled with spherical grinding media, is one of the most popular varieties of such mills. To separate particles in a certain size range, screens are utilized. To increase material flow, they work in a sloping position and are mechanically or electromechanically vibrated. The number of openings per lineal inch of the screen surface, or mesh number, is used to categorize screens. The size of the opening decreases as the mesh number increases. A glaze is a substance made of glass that is intended to melt onto the tile's surface during burning and stick to the tile's surface after cooling. Glazes are used for decoration and moisture resistance because they can be tinted or create unique surfaces.
Amazing Manufacturing Process of Ceramic Tiles
The completed product is obtained through a variety of procedures once the basic materials have been processed. Batching, mixing and grinding, spray-drying, shaping, drying, glazing, and firing are some of these steps. Nowadays, a lot of these tasks are carried out by automated machinery. BatchingThe quantity and kind of raw materials affect the body composition of various ceramic products, including tile. The raw materials also affect the color of the tile body, which can be either red or white depending on the number of raw materials utilized, including iron. It is crucial to combine the ingredients in precise proportions to get the desired qualities. Thus, batch calculations are necessary, which must incorporate both the raw materials' physical characteristics and chemical make-up. The raw components need to be combined after the proper weight of each has been established. Grinding And Combining2 The ingredients are combined in a shell mixer, ribbon mixer, or intense mixer after being weighed. A shell mixer is made up of two cylinders that are linked to form a V and rotate while the material is tumbled and mixed. Helical vanes are used in ribbon mixers, whereas quickly rotating plows are used in intense mixers. A finer particle size produced by this phase's additional grinding of the materials enhances the process of forming. Water must occasionally be added to a batch of numerous ingredients in order to improve mixing and produce fine grinding. Wet milling is the name for this procedure, which is frequently carried out in a ball mill. The resultant liquid mixture is referred to as a slurry or slip. Following dry milling, filter pressing—which removes 40–50% of the moisture from the slurry—is used to extract the water.
Spray dryingIf wet milling is used first, the extra water is often wiped away using spray drying. Pumping the slurry to an atomizer with a quickly spinning disk or nozzle is required for this. Small, free-flowing granules of the slip are formed as a result of the drying process that occurs when a rising hot air column heats slip droplets. This powder is appropriate for forming. Additionally, tile bodies can be made by dry grinding and granulating. Granulation is the process of turning previously dry-ground material into granules that may then be combined with water to create a powder that is ready for formation. Forming Tile is often created by dry pressing. The free-flowing powder, which contains an organic binder or has a low moisture content, is fed into the forming die using this technique via a hopper. Steel plungers compress the material, which is then released by the bottom plunger after being squeezed into a steel cavity. With working pressures as high as 2,500 tons, automated presses are used. There are a number of other techniques that can be used when the tile body is wetter and more moldable. Thinner tiles and tiles with irregular shapes can be produced more quickly and cost-effectively using extrusion and punching. In order to do this, a plastic mass must be compressed inside of a cylinder at high pressure before being made to flow out of the cylinder in short slugs. In one or more tiles, these slugs are then punched using hydraulic or pneumatic punching presses. Ram pressing is frequently utilized for strongly contoured tiles. Using this technique, two sides of a hard or porous mold installed in a hydraulic press are used to press extruded slugs of the tile body.
The formed component is removed by applying a vacuum to the top half of the mold to separate the part from the bottom half and then forcing air through the top half to separate the top portion. The portion needs to be finished further, and extra material must be taken out. Recently, pressure glazing, a different method, was created. By pressing the spray-dried glaze directly into the die containing the tile body powder, this method combines glazing and shaping at the same time. Benefits include the elimination of glazing lines and the waste material (referred to as sludge) produced by the traditional method of glazing. DryingEspecially if a wet process is employed, ceramic tile typically needs to be dried (at high relative humidity) after being formed. Drying removes the water at a slow enough rate to prevent shrinkage cracks, but it can take several days. It is common practice to utilize continuous or tunnel dryers that are heated with gas, oil, infrared lamps, or microwave radiation. Thin tile responds better to infrared drying than thicker tile does to microwave drying. Impulse drying is a different technique that uses brief bursts of hot air moving transversely as opposed to continuing moving in the direction of the material flow. GlazingSimilar techniques are used to produce the glaze for the tile body. The raw components are weighed, combined, and dry- or wet-milled after a batch formulation has been calculated. Then, one of the numerous techniques is used to apply the milling glazes. Centrifugal glazing, also known as discing, involves feeding the glaze via a rotating disc that throws the glaze onto the tile.
A stream of glaze is applied to the tile as it travels on a conveyor in the bell/waterfall process. The glaze may occasionally be sprayed on. Screen printing is used for various glaze applications on, beneath, or between wet-glazed tiles. During this procedure, a rubber squeegee or equivalent tool is used to push the glaze through a screen. Additionally, dry glazing is employed. This entails coating a wet-glazed tile surface with powders, crushed frits (glass materials), and granulated glazes. Following burning, the glaze's component parts merge together to create a surface that resembles granite. FiringThe tile needs to be heated very hot after glazing in order to reinforce it and give it the desired porosity. For firing tile, there are two different kinds of ovens or kilns. It typically takes two steps to produce wall tile or tile that is wetly milled rather than ground dry. This procedure involves firing the tile at a low temperature (bisque fire) before glazing. The volatiles and most or all of the shrinkage are removed from the material in this stage. Then, in a procedure known as glost firing, the body and glaze are heated collectively. B oth firing methods take place in a tunnel or continuous kiln, which is made up of a chamber through which the goods are slowly conveyed on shelves made of heat-resistant materials called refractory batts or in containers known as saggers. Fire temperatures in a tunnel kiln can reach 2,372 degrees Fahrenheit and can burn for two to three days (1,300 degrees Celsius). Roller kilns are typically used for tile that only needs a single burning and is typically prepared by wet milling. These kilns do not need kiln equipment like batts or saggers because a roller belt transports the goods. Roller kilns can fire items for as little as 60 minutes at temperatures of up to 2,102 degrees Fahrenheit (1,150 degrees Celsius).8 The tile is prepared for packaging and shipping after being fired and tested.
Manufacturing Process of Ceramic Tiles
The various production processes produce a range of pollutants; these emissions must be under control to meet air quality regulations. Fluorine and lead compounds, which are created during burning and glazing, are among the contaminants created during tile manufacturing. Lead compounds have been greatly decreased with the recent development of low- or no-lead glazes. Scrubbers, which essentially spray the gases with water to remove dangerous pollutants, can be used to reduce fluorine emissions. They can also be managed using dry techniques, such as fabric filters that have lime coatings. The recovered lime can then be used as a starting point for new tiles. The tile sector is also creating methods to reuse the sludge and wastewater generated during milling, glazing, and spray-drying. Some facilities already recycle the overspray from glazing and the extra powder produced during dry pressing. Additionally, rejected tiles and used glaze are recycled throughout the body preparation stage. Quality AssuranceThe majority of tile manufacturers now use statistical process control (SPC) during every stage of production. To make sure that criteria are met before the material is used, many also maintain tight communication with their raw material suppliers. Particle size, milling time, drying temperature and time, compaction pressure, dimensions after pressing, density, firing temperature and duration, and other processing parameters are monitored using charts in statistical process control. Before the finalized product is produced, these charts help to enhance yields by spotting equipment issues, out-of-spec situations, and other issues.
The finished product must adhere to specified requirements for its chemical and physical characteristics. Standard tests developed by the American Society of Testing and Materials are used to determine these qualities (ASTM). Mechanical strength, abrasion resistance, chemical resistance, water absorption, dimensional stability, frost resistance, and linear coefficient of thermal expansion are just a few of the properties that may be measured. The slip resistance, which is assessed by measuring the coefficient of friction, has grown in importance more lately. No standard has yet been created due to the possibility that additional variables (such as good floor design and maintenance) could render the results useless. The upcoming Tile makers will focus on creating and marketing new tile goods, such as modular or cladding tile, larger-sized tile, slip- and abrasion-resistant tile, and tile with a polished, granite or marble finish, in order to continue market growth. This is being done through creating novel glazes, glaze applications, and body formulas, as well as by using cutting-edge processing tools and methods. In an effort to boost output, cut costs, and raise quality, automation will continue to be crucial. Additionally, production technology will continue to alter as a result of problems with the environment and energy resources.