Title of Invention : Producing composite glaze ceramic tiles|

[0001 ] [This Application is filed and provided based on a local Application, at IRAN'S Islamic Republic of Iran Intellectual Property Center No. 139750140003001733, dated May 20, 2019.

Technical Field

[0002] This invention is a method for the production of glazed ceramic tiles with brilliance and high resistance to mechanical and chemical attacks. This process in the field of:

[0003] C04B41/52: Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation.

[0004] C03C8/14: Glass frit mixtures having non-frit additions, e.g. opacifiers, colorants, mill- additions.

Background Art

[0005] Tile is a piece of synthetic ceramic with a few millimeters thickness and various lengths and widths. On one side it has a glossy surface and is completely smooth and polished. Tiles are pottery and ceramic products having special applications and importance in constructions, such as bathrooms, toilets, kitchens and public toilets, etc. Tiles are used for interior and exterior decoration as well as sanitation and moisture insulation purposes. Furthermore, materials, usually solid, mostly made up of non-metallic and inorganic contents are called ceramics. Moreover, according to some definitions, materials chemically composed of a mixture of clay, sand and feldspar made into semi-glass pieces at high temperatures are called ceramics which are almost inflammable, insoluble and very hard. Tile preparation steps:

[0006] The first step is selection and preparation of raw materials. Raw materials are clays

containing 60% to 70% of silica. First, extra materials, rock and other particles are removed.

[0007] Slurry preparation: slurry preparation means mixing the supplied materials with water to

create homogenous in the aquatic mixture. During water and clay mixing process, full contact and mixing of water with clay should be ensured.

[0008] Forming: The slurry is Pumped into spay dryer system for making ceramic granules with desired shapes and sizes in next step granules transfer to the mold in the pressing machine to form ceramic body with desired sizes and thickness.

[0009] Drying: If the piece is not dried appropriately or if it is dried too fast, it cracks, twists, shrinks or changes in volume. [001 0] Glazing on tile: after drying the biscuits for decoration and create a glassy layer on the surface of the tiles glazes are applied with very different formulations depend on type of production. Applying the glaze can be carry out with some equipment’s such as vela, bell tray, spray or disc.

[001 1 ] Firing the tiles: Tiles are fired in kilns. Temperatures and times for firing are depend on type of the production. A piece of tile consists of two parts:

[0012] The main part of a ceramic tile is its body.

[0013] The glaze on the tile which is a glassy material forming the outer part.

[0014] One of the most important factors in the tile industry is the selection of these two materials in such a way to achieve their equal expansion coefficient. The glazes include a wide range of Inorganic and mineral compositions. Ceramic glaze is usually a glass-like mixture composed of quartz, feldspar and other materials. These ingredients are then ground, powdered and made into a Slurry with water. The ceramic object is then formed with pressing and after glazing and decorating heated in the kiln to a certain temperature after drying. After glazing and firing the tiles, desired writings and designs can be applied with process named third firing and heated again. In this way, the writing and design on it becomes more durable.

Summary of Invention

[001 5] Producing composite glaze ceramic tiles is a technique process of producing for producing ceramic tiles with effects by making composite glazes which have high resistance to chemical and mechanical attacks. Current production processes have disadvantages such as impermanency of the effects on the tile surface, lack of resistance to mechanical and chemical destructive factors, inappropriateness for use in crowded places and outdoor environments, need for engobe and additional glaze or any complementary activities to achieve the desired effect in the production line, need for decoration through third firing, very high cost compared to common tiles, However, in the new method, the glaze is applied as a single layer on the tile biscuit without the need for engobe and separate glaze or any additional operations to carry out the desired effect in the glazing line. The firing is also carried out once without requiring decoration by the third firing, making it very economical in terms of engobe and glaze consumption and time for production.

[001 6] Engobe: A white or colored clay slip coating applied to a ceramic body to give it decorative color or improved texture and regulate flatness of the tiles.

Technical Problem

[001 7] In the current processes, effects such as bright particles and three-dimensional structure are added in the last step of production or applied with third firing methods. This causes some problems including:

[001 8] The effects do not last on the tile surface for long times. [001 9] They are not resistant to mechanical and chemical attack.

[0020] They cannot be used in crowded places and outdoor environments.

[0021 ] Need for engobe, additional glaze or any complementary activity to achieve the desired effect in the production line.

[0022] Need for decoration through third firing.

[0023] Very high cost compared to common tiles.

[0024]

Solution to Problem

[0025] The composite structure in the process of producing glazed composite ceramic tiles is

comprised of a ceramic body (glazed) with dispersed metal-ceramic particles, and all the desired properties of this glaze are provided through this composite structure. The permanence of the shining particles (effects) and their resistance against mechanical and chemical destructive factors are ensured through dispersing shining particles and creating composite structure on the surface and depth of the glaze. With the new formulation of this glaze, the flexibility created in it and application of some slight changes, it is easy to use this glaze for all types of tiles, including single-firing and double-firing wall tiles, floor tiles and porcelains for the facades and floors of various places, even crowded places such as business centers, cafes, shops, parking lots and outer facades of buildings even in the cold areas with heavy rainfalls without any worries about damages and destruction of the created effects. In current tiles, first, engobe and then glaze should be applied on the tile’s dried biscuit, and then glittering particles or effects are sprayed or created via dry application once, or a few supplementary times, on the surface of the glazed tile. While in the method claimed here, it is applied as a single-layer glaze on the tile’s biscuit without the need for engobe or separate glaze and any additional operations to create the desired effect on the glaze line and fired also in one session (without the need for decoration for third firing) and therefore, quite economical in terms of application and consumption of engobe and glaze. The particles in the glaze can affect all the parameters effective in production such as melting temperature, thermal expansion coefficient, surface tension, etc. and help adjust them due to their dispersion on the surface and depth of the glaze and existence of composite structure. Ceramic tiles can be produced in both unpolished and polished types. The use of polish can result in greater surface brightness and smoothness.

Advantageous Effects of Invention

[0026] Having a homogeneous and completely integrated durable composite structure with unique properties.

[0027] Durability of the resulting effect under different conditions of abrasion and chemicals due to the existence of brilliant particles both on the surface and depth of the glaze. [0028] High flexibility in formulation, process and usability in the production of all types of double firing and single-firing wall ceramic tiles, floor ceramic tiles and porcelains.

[0029] Possibility to using in all places, indoor and outdoor spaces, crowded places with high traffic, building facades and floors of the spaces outside buildings.

[0030] Integration of all glazing stages into one stage, simplification of the process and more

economical production.

[0031 ] Possibility for producing polished and unpolished ceramic tiles.

Brief Description of Drawings

[0032] This text contains an attachment and including 1 Drawings.

Fig.1

[0033] [fig.1 ] Flowchart for the process of producing tiles with special brilliant glaze.

Description of Embodiments

[0034] The desired glaze includes a base comprised of an engobe, a special matt glaze and mica and aluminum particles as effects. The special brilliant glaze formulation used in the base glaze is applied depending on the type of tile for the part specified in Table 1 . After carefully weighing the raw materials, additives will be charged into the ball mill depending on the metre of production and production conditions (Table 2). When the materials are completely charged, the ball mill is started and the output shall be the same as the conditions mentioned in Table 3. The last step of glaze preparation is adding metal and ceramic particles to the glaze in the mixer (Table 4). After adjusting the glaze conditions for application in the production line, first the appropriate weight of the applied glaze must be obtained for having proper tile coverage and flatness. As mentioned before, application of this glaze is possible through using all the equipment required in the glaze line including bell tray, vela, airless spray and double disc, but the best technique is the use of double disc. After the application of glaze, it is time to fire the glazed tile. Depending on the type of tile produced, the appropriate temperature and cycle should be provided for complete firing of the glaze and then the tile enter in the kiln. In the tests carried out, the temperature and cycle applied should comply with those mentioned in Table 5.

[0035] After the tiles are firing, the chamfering process is done to make the sides of the tiles square and more accurately sized, which can be carried out in wet or dry states, depending on the type of tile. If the manufactured tile is unpolished type, it is transferred to the sorting line and prepared for delivery after packaging. In case the tiles manufactured require polishing, they enter the polish line for complete polishing and application of Nano materials. They are then transferred to the sorting and packaging lines.

Examples [0036] Carried out as per the flowchart for the process of producing tiles with special brilliant glaze.

[0037] [Table 1 ]

[0038] [Table 2]

[0039] [Table 3]

[0040] [Table 4]

[0041 ] [Table 5]

Industrial Applicability

[0042] Possibility of production in all wall and floor tile and porcelain factories for usage in all private and public places, including houses, offices and companies; crowded shops and business complexes, parking lots, facades of buildings and floors of outdoor spaces. Due to its nature and structure, this glaze can be used in all types of ceramic tiles, including double-firing and single firing wall tiles, floor tiles and porcelains in all interior and exterior spaces.