Company Naeen tile Industry Naeen tile Industry
NAEEN TILE Ind., is a company with more than one decade of experience in manufacturing ceramic tiles in Naeen, Esfahan, Iran. At NAEEN TILE we manufacture floor and wall tiles with the aim of offering a genuine and unique product to our customers with the total capacity of about 6 million square meters per year.
We are proud to produce:
These products are made in accordance with the International ISO 13006 standard in different sizes and are applicable for indoor and outdoor uses. These products can be used in all residential, commercial, and industrial applications. Because of the high quality of our products, they are already exported to many European, Asian, African and Latin American countries.
Our goal is to transmit our passion for ceramics to our customers, through unique products, with excellent designs that remain enduring over time both for its style and its quality. In order to always offer the highest quality products and design to the market, we have understood innovation and investment in technology and we are always at the forefront of the latest research and techniques. Therefore we work every day investigating and applying new techniques that allow us to offer a different product of the highest quality to our customers.
The founding of NAEEN TILE began on a property with 422,000 square meters located in Naeen, on the Isfahan-Naeen road, in 2001. The premises has a production land with approximately 90,000 square meters as well as on additional building with a total of 5,000 square meters office space. The production facilities consist of two ball mills, five presses (one of them is the most powerful press in Iran-PH 8200 SACMI), 3 kilns units, digital jet printers and other equipment and machineries from notable Italian companies. Our company initiated its Super Polish production line in 2016, assembled with state of the art machineries acquired from a notable Italian company (BMR). The new technology has enabled NAEEN TILE to product portfolio, further enhance the quality of its ceramics and to create Super Polished porcelain tiles with high glossy finishes up to 110 with gloss meter 60o.
Tile Production Process
The production process for tiles and ceramics can be divided into four main stages based on the type of the product. These stages include raw material preparation, firing, polishing and packaging of the products. The figure below shows a schematic of the tile production process.
This stage includes crushing or milling of stone, slurry and granule preparation. Raw materials used in this stage include Kaolin, Feldspar, Bentonite, Calcite, and other materials which are added based on chemical and physical properties of them. The mineral lumps of these materials are transported to the factory from mines and during the crushing step are reduced to average particle size of less than 20 mm using jaw or impact crusher machines. Figure 1 shows a schematic of a jaw crusher machine.
Each crushed raw material is kept in separate silos before being transferred to the slurry preparation step based on the main formulation determining the percentage of each raw material and using a box feeder and relevant conveyor belts. The slurry preparation includes several ball mills. Ball mills are large cylinders made from steel. The dimensions of these cylinders are designed so that their height is almost equal to their diameter and their walls are covered using rubber or alumina-based materials. These cylinders rotate around their main axis which is horizontal to the ground. As is evident from the name, these mills also contain several balls which mill the raw materials during the ballmill’s rotation resulting in uniform ceramic slurry.These balls are often made from alumina or sometimes from natural silica compounds (such as flint). The number, shape, size and hardness of these balls are important factors affecting the quality of the milled materials. Raw materials are added to the mills along with water and lubricants such as sodium silicate, sodium tripolyphosphate and sodium carbonate and produce a uniform slurry after milling at predetermined rpm and speed. Often, the inner walls of the ball mills are coated using rubber so that water does not contact the metal body of the mill. Raw materials are milled using alumina balls or silica pebbles with average diameters of 5 to 10 cm. The mixture of water, raw materials and lubricants are milled in the ball mill for approximately 6 to 8 hours. Raw material parties are crushed between balls, finally resulting in a homogenizedslurry with micronized particles. After completion of milling process, the average diameters of the particles in the slurry should be approximately 63 microns. After milling of raw materials and preparation of slurry, ball mills are stopped and the slurry is transferred into storage pools which include mixers. Figure 2 shows a schematic of one of the ball mills.
The quality of raw materials, mixing percentage, as well as properties of crusher products and slurry including density, viscosity and refuses are carefully controlled after milling.
Batch ball mills are stopped after adding the materials and completion of milling process in order to remove the slurry.
Another type of ball mill combines the process of slurry removal with the rotation of the ball mill and milling process. These ball mills are known as continuous ball mills and are made from two inter-connected chambers with the addition of raw materials and water occurring during rotation. Figure 3 shows the schematic of a continuous ball mill.
The next step includes the preparation of powder from the slurry. Powder preparation is carried out using spray dryers. The slurry obtained from the mills are first deposited into slurry tanks which result in a homogenous slurry and improves its plasticity before entering the spray dryer. Piston pumps spray the slurry with relatively high pressure into the hot spray dryer chamber, in which, the slurry is mixed with hot air resulting in evaporation of water and preparation of powder with predetermined particle size and water content.
The heat inside the spray dryer chamber is produced by a large torch. The chamber’s air and evaporated water exit from spray dryer after passing through cyclones and removal of dust particles and the powdered product is deposited onto a conveyer belt through the funnel placed under the dryer chamber before being transported to the powder silos. The quality of the powder depends on the following factors;
Figure 4 shows a schematic of the spray dryer.
Figure 5 shows the overall base material preparation process and different steps of tile production.
The summery of the process in this stage is placing the powdered raw materials with suitable particle size inside the die before compressing them. This results in the materials taking the shape of the die. The water content of the powder used in this stage should be approximately 5% and the particle size should be constant and determined. Today, tile manufacturing industries use modern and powerful presses which are even able to apply the patterns during a pressing stage. The pressing stage is one of the most important units in the tile manufacturing factories which is due to the fact that powdered raw materials are shaped into the base of the tile in this stage which can result in various challenges due to this structural change.
Pressing machines used in tile and ceramic industry are often hydraulic presses with approximate pressure of 4000 to 6000 tons. Based on the power of the hydraulic press, the surface area of the die is selected so that each square centimeter of the die is under approximately 280 to 300 Kilograms of pressure. This means that by increasing the power of the hydraulic press, it is possible to increase the surface area of the die and therefore the production capacity. The dies used in tile and ceramic manufacturing are the matrix punch dies made up of two sections of upper punch and lower punch and heated body. Each die can have various number of cavities depending on the press capacity and the tile of the tiles. Granulated raw materials are fed into the die though a feeder and the raw body is manufactured through the pressure applied from the upper punch. After pressing the granulated materials, the products are removed from the lower punch and are moved toward front of the press table through a system of rollers. Figure 6 shows the schematic of one of the pressing machines used in tile production.
The next step is drying the pressed products using dryers in order to remove the water from the tile body immediately after the pressing process. These dryers are often divided into vertical and horizontal variants. In these dryers, hot air is blown into the dryer chamber through pipes. Tiles are moved inside the dryer using roller system. Vertical dryers have a process cycle length between 35 to 70 minutes while horizontal dryers require retention time of 6 to 20 minutes. The following figure shows the schematic of a horizontal dryer with three levels.
In both types of dryers, the drying duration of the tile body depends on the size and thickness of the tile. In new dryer systems, problems such as cracks and fracture of tiles are less common and a more uniform temperature is maintained during the drying process at different zones of the dryer.
The equipment used in this stage is similar to those used in slurry preparation during raw material processing. In this stage, the raw materials of the glaze, mostly including frit and kaolin as well as other additives are added to ball mills along with water and glaze slurry is prepared after ball milling for a predetermined amount of time. It is worth noting that the walls of the ball mill in this stage have alumina coating and the milling is carried out using alumina balls. The milling is carried out during rotation of the ball mill chamber and due to the raw materials being crushed between balls. The glaze slurry cannot be used directly and it is necessary to use an underglaze layer between the main tile body and the glaze. Underglaze formulation is a combination of characteristics of the base and the glaze and, in practice, attaches the glaze to the main body. If the underglaze is not used and the glaze is applied directly over the body, factors such as cold, high temperature, humidity and impacts can remove the glaze from the tile. Underglaze is prepared using the same method as the glaze and using ball mills.
The glazing lines include the body of the lines and the equipment installed along the line. The body of the line includes bases, chassis, transportation belts and engine with variable speed gearbox which is used to adjust the speed of the glazing line at the engine gearbox output. The force is transferred from engine gearbox to transportation lines using pullies and belts. Other equipment is installed along the glazing lines depending on the type of product (floor or wall tiles) as well as type of the tile (simple or patterned). By placing the raw body or biscuit at the start of the glazing line and moving it along the line, the following processes are carried out in the order stated:
Figure 8 shows the schematic of underglaze and glazing equipment.
After applying the engobe and glaze, now is the time to print and decorate the tiles. Printing process during tile production has undergone significant changes from old days. The picture below shows one of the old tile printing machines.
As can be seen in figure 11, rotary equipment includes a cylinder made from silicone with tiny holes etched on its surface transporting the paint and prints from the cylinder’s surface to that of the tile. This process is shown in the following figure.
Today, with recent development in the tile printing, this process is carried out using digital printing equipment using jet printing technology. In year 2000, KERAJET company in collaboration with FERRO ENAMET, introduced the first commercial digital printing equipment. Figure 13 shows the schematics of this digital printing equipment.
In order to apply prints using these machines, first the digital printed image is prepared using scanners or taken using digital cameras is processes using a graphic processing software and sent to the printer as a digital file. The printer then, transports paint or ink from various reservoirs inside the equipment (or color bars) to the printing head in order to apply the print to the tile. These printing heads have nanosized nozzles which are used to spray the ink onto the tile’s surface. Figure below shows the schematic of one of the printing heads used in digital printing equipment.
Digital printing machines are capable of printing images with resolution of 1000 dpi. However, for normal stone and wood patterns, a resolution of 300 to 500 dpi is often sufficient, resulting in a significantly higher resolution compared to old printing methods. As can be seen, in this printing method, unlike previous methods, there is no physical contact between the tile’s surface and the printing machine. Other advantages of digital printing compared to old printing methods are as follows:
Continuous rolling furnaces are the newest and most feasible furnaces for quick firing of ceramic products. Current studies and experiences indicate that the cost of ceramic production (including tiles, tablewares, and sanitaryware products) in these furnaces is lower compared to other types of furnaces. However, this does not mean that other types of continuous furnaces are not used and currently, non-rolling furnaces are more suitable for firing of products with high content of volatile compounds, those with complex shapes or large sizes and products requiring high firing temperatures. Since rolling furnaces have pre-defined dimensions as well as short firing duration, they are not capable of firing large parts (in regards to height) or products with varied formulation (in body and glaze). These furnaces are used in two types of single firing and double firing methods. The single firing method is often used for firing of floor tiles while double firing is used for wall tiles, China dishes and sanitary products. The figure below shows the schematic of a rolling tile firing furnace and its various sections.
As can be seen, rolling furnaces are designed as a long tunnel (chamber) which is preconstructed based on the customer’s requirements using light-weight refractory materials with dimensions of 750*750 to 1000*1000 (mm) and the height of up to 750 (mm) (for two story furnaces). In these furnaces, products enter the furnace from one side during refractory rollers and move through various furnace zones during their path. The highest temperature is felt at the middle of the furnace and firing process is carried out in this zone. Cool air is blown in the opposite direction of roller (product) movement which cools the products after firing under controlled conditions. Therefore, products have only a slight temperature difference with the ambient temperature when exiting the furnace which prevents thermal shocks in the products. These furnaces often work using various fuels including natural gas, methane and light liquid fuels (Kerosene). Electrical rolling furnaces are also among the types of rolling furnaces but are not able to support temperatures higher than 1200 (℃) due to high electricity cost and problems with acquiring suitable electrical heating elements and are often only used for firing of decorative products.
Due to the high importance of rolling furnaces and controlling firing stages, these furnaces are often equipped with automated systems for controlling temperature, speed, roller rotation, firing air flow and furnace pressure.
This process is used when it is necessary to improve the quality of the surface or to create a higher polished surface in the tiles. This process is carried out after the firing step. Often, before polishing process, adjustment of the edges and squaring of the tile is carried out in order to create more uniform angles and rounding the sharp edges of the tile before polishing. Due to various reasons including pressing conditions and firing process, the surface of the tile might not be uniform and smooth, resulting in pinhole defects or a twisted surface. Polishing process helps remove these problems. The polishing process is carried out using polishing tools with varying hardness levels. During this process, water is used for cooling and washing of the surface and removing polishing debris from the surface. This process is very similar to the polishing process used in decorative and building stones.
Tiles exiting the furnace may not have uniform quality. The problems during production line and especially during glazing line including chipped edges, lack of prints, misplaced printing, color changes, presence of external particles and impurities on the surface of glaze and other problems can lead to defects on the tiles surfaces which are sometimes invisible to the naked eye. Therefore, sorting machines and human elements are used to grade and sort tiles based on national and international standards before sending them to the packaging section. During the packaging, after packaging the tiles in cartons based on their grades, production date, size, grade and the printing color are printed on the packages and the product is transferred to the warehouse for storage and distribution. All these steps are carried out using automated and robotic equipment.