Title of Invention | "A PROCESS FOR THE PREPARATION OF GLASS, CERAMIC OR STONE TILES" |
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Abstract | This invention relates to a process for the manufacture of glass and/or ceramic tiles having a matt surface and rounded edges comprising in subjecting the formed tiles having sharp edge and glazed/matt or speck surface to the step of an abrasive action for a period of 1-4 hours by putting said tiles into a drum having abrasive material contained therein under the normal temperature and pressure till the tiles get the matt surface and round edges wherein said abrasive material comprises silica, sand and/or grinding media. |
Full Text | FIELD OF INVENTION This invention relates to a process for the manufacture of glass and/or ceramic tiles. In particular this invention relates to a process for the manufacture of glass or ceramic tiles having a matt surface and rounded edges. PRIOR ART A process known in the art for the manufacture of glass tiles consists in passing molten glass between the nip of two rollers and such as to form a sheet of tiles and, wherein, adjacent tiles are separated by a V notch. One of said rollers has serrations to impart a roughened surface to the base of the tiles. The other roller has normally a plain surface and such as to impart a corresponding plain surface to the front face of the tile. The adjacent tiles are separated from each other at the V notch which are then cooled. The process of manufacturing glass from pulverised or crushed glass and employed for filtration applications is also known in the art. Such a process consists in adding a binder to pulverised glass and which is then pressed in a mould. The pulverised glass used for such applications has a substantial particle size so as to impart the required porous properties to the glass. Such a compacted mass is heated or fired to a temperature at which glass becomes slightly viscous. It would be apparent that such a glass must necessarily be permeable and possess porosity properties, as the glass is employed for filtration purposes. Another process is known in the art which envisages the use of pulverised glass for the manufacture of glass tiles. Such a process consists in grinding or pulverising glass of a single type or colour to a fine mesh size of approximately 100 to 200 mesh and to which is added a dispersing agent and a colouring agent and/or opacifying agent. Such a raw meal is pressed in a mould and then fired to a temperature above the softening point, but not high enough to deform the tile. The temperature normally employed is about 700°C or above, depending on the property of glass. Several distinct disadvantages are associated with such a known process for the manufacture of a glass tile. One such disadvantage is that the tile had sharp edges. Another disadvantaqe is the addition of a dispersing agent to the raw meal, and which contributes to the end cost of the tile. It is generally believed that such a dispersing agent was added to the raw meal for performing two functions. The first of such function was to allow a proper dispersion of the colouring and/or opacifying agent. The colour propertiem to the tiles were imparted by the addition of known colouring agent. Similarly, the opacifying properties to the tiles were imparted by the addition of known opacifying agents. The second function is correlated to the fine particle size of the crushed glass. It is generally believed that a dispersing agent was added to the crushed glass as the glass employed in the known process was crushed to a very fine particle size. Further, it would be apparent that as a colouring and/or opacifying agent was added to the raw meal, a chemical reaction takes place during the step of firing to impart the required aforesaid properties to the tiles and for which a gradual raising of temperature at the rate of 5°C/min was required with a further a soaking period of at least on hour. Thereafter, the tiles were subjected to a gradual cooling. Yet another process is known from our prior Indian patent no.157991 which consisted in crushing a single or different glass to form a mixture of glass of a particle size not less than 10 mesh. The mixture is crushed under pressure to form a shaped composite, which is then heated to a temperature of 800 to 900°C to allow a further compaction of at least 5%. Such a step of heating causes a deformation of the edges of the tile so as to cause a rounding of the edges and simultaneously to impart a polished or glazed surface to the tile. Silica is also added to the mix as an additive. OBJECTS OF THE INVENTION An object of this invention is to propose a novel process for the manufacture of glass and/or ceramic tiles having a matt surface. Another object of this invention is to propose a process for the manufacture of glass and ceramic tiles having a matt surface with smooth edges. Still another object of this invention is to propose a process for the manufacture of glass or ceramic tiles having a matt surface with smooth edges and with a speck surface. A further object of this invention is to propose a process for the manufacture of glass and/or ceramic tiles having a matt surface with smooth edge* which is economical. BRIEF DESCRIPTION OF INVENTION. According to this invention there is provided a process for the manufacture of glass and/or ceramic tiles having a matt surface and rounded edges comprising in subjecting the form tiles having sharp edge and glazed/matt or speck surface to the step of an abrasive action by putting said tiles into a drum having abrasive material contained therein under the normal temperature and pressure till the tiles get the matt surface and round edges. In accordance with this invention, the starting material comprises a formed tile having sharp or jagged edges or tiles of irregular or broken shape and glazed/matt or speck surface. The tile is subjected to the abrasive process of the present invention to form smooth edges and also to impart a matt surface. The abrasive action/abrasive process i» carried out in a dry form. Thus, and as by way of example, an abrasive material like silica, sand and/or grinding media is introduced into a rotatablc drum and the tiles are introduced into such a drum. Alternatively, such a step of abrasion comprises a wet process in which water is added to the dry abrasive media contained in the drum. Preferably, a matt surface is imparted to tile which is totally coloured and can also include a tile having a coloured coating on the top surface the tiles can also have specified surface. A process for the manufacture of a glass ceramic tiles having a matt surface and rounded edges according to a preferred embodiment is herein described in the details. The form tiles having sharp edges and glazed/matt or speck surface in accordance with the process of this invention are subjected to the step of abrasive action by putting the formed tiles into a drum having an abrasive material like silica, sand and or grinding media therein in the dried form and under the room temperature and pressure. The time required to provide the matt surface and rounded edges to the tiles depends on the hardness of the tiles and rotating/vibrating speed of the machine. Generally the time required for providing the matt surface and rounded edge is in the range of 1-4 hours. This constitutes a dry process. According to an option the process of abrasion comprises a wet process. For this purpose water is added to the abrasive media contained in the drum. I CLAIM: 1. A process for the manufacture of glass and/or ceramic tiles having a matt surface and rounded edges comprising in subjecting the form tiles having sharp edge and glazed/matt or speck surface to the step of an abrasive action by putting said tiles into a drum having abrasive material contained therein under the normal temperature and pressure till the tiles get the matt surface and round edges. 2. A process as claimed in claim 1 wherein said abrasive material comprises silica, sand and/or grinding media. 3. A process as claimed in claim 1 wherein said tiles are subjected to the abrasive action for a period of 1-4 hours. 4. A process as claimed in claims 1 to 3, wherein water is added to the abrasive media contained in said drum. 5. A process for the manufacture of glass ceramic or stone tiles having a matt surface and rounded edges substantially as herein described and illustrated. |
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3749-del-1998-correspondence-others.pdf
3749-del-1998-correspondence-po.pdf
3749-del-1998-description (complete).pdf
3749-del-1998-petition-others.pdf
Patent Number | 220208 | ||||||||
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Indian Patent Application Number | 3749/DEL/1998 | ||||||||
PG Journal Number | 28/2008 | ||||||||
Publication Date | 11-Jul-2008 | ||||||||
Grant Date | 16-May-2008 | ||||||||
Date of Filing | 14-Dec-1998 | ||||||||
Name of Patentee | UDAY GUPTA | ||||||||
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Inventors:
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PCT International Classification Number | C03C 23/00 | ||||||||
PCT International Application Number | N/A | ||||||||
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PCT Conventions:
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