Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B5/00—Producing shaped articles from the material in moulds or on moulding surfaces, carried or formed by, in or on conveyors irrespective of the manner of shaping
  • B28B5/02—Producing shaped articles from the material in moulds or on moulding surfaces, carried or formed by, in or on conveyors irrespective of the manner of shaping on conveyors of the endless-belt or chain type
  • B28B5/026—Producing shaped articles from the material in moulds or on moulding surfaces, carried or formed by, in or on conveyors irrespective of the manner of shaping on conveyors of the endless-belt or chain type the shaped articles being of indefinite length
  • B28B5/027—Producing shaped articles from the material in moulds or on moulding surfaces, carried or formed by, in or on conveyors irrespective of the manner of shaping on conveyors of the endless-belt or chain type the shaped articles being of indefinite length the moulding surfaces being of the indefinite length type, e.g. belts, and being continuously fed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B13/00—Feeding the unshaped material to moulds or apparatus for producing shaped articles; Discharging shaped articles from such moulds or apparatus
  • B28B13/02—Feeding the unshaped material to moulds or apparatus for producing shaped articles
  • B28B13/0215—Feeding the moulding material in measured quantities from a container or silo
  • B28B13/022—Feeding several successive layers, optionally of different materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B3/00—Producing shaped articles from the material by using presses; Presses specially adapted therefor
  • B28B3/12—Producing shaped articles from the material by using presses; Presses specially adapted therefor wherein one or more rollers exert pressure on the material
  • B28B3/123—Producing shaped articles from the material by using presses; Presses specially adapted therefor wherein one or more rollers exert pressure on the material on material in moulds or on moulding surfaces moving continuously underneath or between the rollers, e.g. on an endless belt

Definitions

• the present invention relates to a method and plant for forming ceramic tiles and slabs.
• Such ceramic tiles or slabs are produced by compacting, by hydraulic presses, semi-dry atomized, ground or re-granulated powders variously mixed together in prearranged or random manner. Specifically, the powder mixtures are deposited by suitable means into the forming cavities of rigid steel moulds with which the presses are provided, and are then pressed to obtain the product.
• the described method is implemented by a plant comprising a fixed hopper for containing a mixture of powders presenting bulk veining in imitation of a natural stone.
• a plant comprising a fixed hopper for containing a mixture of powders presenting bulk veining in imitation of a natural stone.
• movable means arranged to deposit in the cavity a succession of powder portions withdrawn from said hopper, until the cavity is completely filled.
• the described plant is little versatile in terms of format change, this now being an essential characteristic in a modern plant.
• the technology is increasingly aimed at obtaining ceramic slabs or tile having variable dimensions in accordance with market requirements. There is therefore the need for a more versatile plant which enables the tile or slab format to be changed rapidly without the need for lengthy interruptions in production.
• the object of the invention is to satisfy said requirement within the framework of a simple and rational solution.
• the invention provides a method for forming ceramic tiles or slabs in a continuous press arranged to form a slab of indefinite length comprising the following operative steps:
• said portions are withdrawn by moving the hopper with reciprocating movement in the belt advancement direction above suitable distribution means.
• a tile forming plant comprising a conveyor belt, above which there is positioned a hopper movable with to-and-fro movement in the direction of the belt axis and containing a mixture of powders presenting bulk veining in imitation of a natural stone.
• a hopper With said hopper there are associated powder distribution means arranged to enable a succession of powder portions to fall by gravity onto said belt, to create a continuous powder strip which said belt feeds to a continuous pressing station.
• the hopper is driven by usual known means.
• the powder distribution means comprise a fixed plate provided centrally with a slot perpendicular to the direction of translation of said belt, said plate having a dimension in the belt advancement direction equal to at least double the corresponding dimension of the lower mouth of said hopper, and a dimension in the direction perpendicular to said belt advancement direction equal to the corresponding dimension of the lower mouth of the hopper.
• the slot with which the plate is provided presents, in the belt advancement direction, a dimension which is a function of the graphic resolution to be obtained on the finished tile.
• the slot dimension in the belt advancement direction varies between 10 and 50 mm, and preferably between 20 and
• said continuous pressing station is arranged to compact the powder strip created on the belt to a pressure sufficient to obtain a continuous coherent product intended to undergo a second final pressing after being divided into blanks of predefined dimensions by a usual cutting station, before feeding the blanks to firing.
• the pressure exerted on said powder strip reaches a value not exceeding 100 bar.
• said continuous pressing station compacts the powder strip to a maximum pressure close to 250-300 bar.
• the thus compacted product does not require a subsequent second pressing, and can hence be divided into blanks by a usual cutting station, to be fed directly to firing.
• the plant can be provided with scraping devices to remove a thin layer of powders in order to display the veining present in said strip, and also with further devices for the controlled deposition of further decorative powders on said strip.
• FIG. 1 is a schematic s ide view of the plant according to the invention.
• Figure 2 is an enlarged v iew of the section ll-ll shown in Figure 1.
• Figures 3 and 4 schemat ically show the operation of the invention. Said figures show the plant 1 , which comprises a conveyor belt 2, above which there are positioned means 3 for creating a continuous powder strip 100 on the belt 2, a suction scraping system 4, a continuous pressing station 5 and a cutting station 6.
• the said means for creating the continuous powder strip 100 comprise a hopper 7 driven with reciprocating motion, in which the powders are deposited by an overlying movable feeder 70 also driven along two mutually perpendicular directions in a plane parallel to the plane of the belt 2, and caused by known means, not shown, to slide above the upper mouth of the hopper 7.
• the purpose of the feeder 70 is to deposit by gravity at least two powders of different characteristics into the hopper 7 such that they together form a mass presenting variously disposed veining reproducing that present in a natural stone. In other words this mass can be said to reproduce a block of natural stone, which is then cut into layers which are deposited on the belt 2 by the distribution means 8 associated with the hopper and described hereinafter.
• baffles 71 Figure 2 positioned at the hopper exit mouth.
• a second series of baffles 72 is associated with the upper mouth of the hopper, to mix the powders fed into the hopper 7 in order to create the veining and the aesthetic effects as randomly as possible in imitation of the veining appearing in a block of natural stone.
• baffles 71 or only the baffles 72 could be provided, or alternatively none at all.
• the hopper 7 is associated with a drive system, not shown, which causes it to translate with reciprocating motion above the powder distribution means 8.
• said distribution means 8 are associated with the lower mouth of the hopper 7 and comprise a fixed plate 9 provided with a slot 10, disposed perpendicular to the translation direction of the plate 9.
• the plate 9 has a dimension in the direction perpendicular to the belt advancement direction which is greater than the corresponding overlying dimension of the hopper 7, and a dimension in the belt advancement direction equal to at least double the corresponding dimension of the hopper 7.
• the slot 10 has a dimension in the direction perpendicular to the belt advancement direction which is equal to the corresponding dimension of the lower mouth of the hopper 7, and a dimension in the belt advancement direction which depends on the graphic resolution to be obtained on the finished tile.
• the slot 10 is provided lowerly with a perimetral surround 101 which delimits the thickness of the powder strip deposited on the belt 2, to prevent the strip sliding against the lower surface of the plate 9.
• the height of the surround 101 varies between 1 and 300 mm, depending on the actual embodiment of the invention.
• a usual device 40 for scraping the upper surface of the powder strip 100 Downstream of the hopper 7b there is positioned a usual device 40 for scraping the upper surface of the powder strip 100.
• Said device 40 is connected to a suction system, not shown being of known type, which enables a thin surface layer of powders to be removed from the strip 100 in order to exalt the graphics and the contrast between the different coloured powders of the strip 100.
• the belt 2 feeds the powder strip to a continuous pressing station 5, also of known type, comprising an upper compacting band 50 provided to compact the powder strip on the lower belt 2 to obtain a continuous compacted product.
• Means for laterally retaining the powder strip on the belt 2 are associated with said compacting band 50. These latter lateral retention means are not shown as they are known to the expert of the art.
• the compaction effected by the compacting band 50 is sufficient to obtain a compacted product which does not require further compacting.
• the maximum compacting pressure reaches values close to 300 bar.
• the product is divided into blanks of predefined dimensions by a usual cutting device 6.
• said device essentially comprises a rotary blade 60 for making the cut in the direction perpendicular to the belt advancement direction, and at least two further rotary blades 61 , only one of which is visible in the figures, for cutting the compacted product in the advancement direction of the belt 2.
• the described plant is controlled by a processor, not shown, which controls its operation in the following manner.
• the hopper 7 While the belt 2 advances ( Figure 4), the hopper 7 translates reciprocatingly on the plate 9 in such a manner as to deposit adjacent powder portions on the belt 2, to create thereon a continuous powder strip which is firstly scraped by the system 4, and then compacted in the compacting station 5. Downstream of the compacting station the rotary blades 60 and 61 cut the strip into blanks of predefined dimensions. It should be noted that when the hopper movement is reversed ( Figure 5) the manner of depositing the powders on the belt 2 varies, to the advantage of their random distribution, resulting in a greater naturalness of the different coloured veining present in the powder strip. The manner of distributing the powders can be further varied by changing the hopper translation speed, in addition to the movement of the overlying feeder 70.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Ceramic Engineering (AREA)
• Mechanical Engineering (AREA)
• Devices For Post-Treatments, Processing, Supply, Discharge, And Other Processes (AREA)
• Press-Shaping Or Shaping Using Conveyers (AREA)
• Finishing Walls (AREA)
• Glass Compositions (AREA)
• Panels For Use In Building Construction (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=29267132

Family Applications (1)

Country Status (9)

Cited By (3)

Families Citing this family (12)

Family Cites Families (7)

• 2003
  • 2003-02-17 IT IT000015A patent/ITRE20030015A1/it unknown
• 2004
  • 2004-02-06 PT PT04708750T patent/PT1594666E/pt unknown
  • 2004-02-06 AT AT04708750T patent/ATE330762T1/de not_active IP Right Cessation
  • 2004-02-06 CN CNB2004800034322A patent/CN100493875C/zh not_active Expired - Fee Related
  • 2004-02-06 WO PCT/EP2004/001185 patent/WO2004071733A1/en not_active Ceased
  • 2004-02-06 RU RU2005124702/03A patent/RU2354550C2/ru active
  • 2004-02-06 DE DE602004001338T patent/DE602004001338D1/de not_active Expired - Lifetime
  • 2004-02-06 EP EP04708750A patent/EP1594666B1/de not_active Expired - Lifetime
  • 2004-02-06 ES ES04708750T patent/ES2267045T3/es not_active Expired - Lifetime

Non-Patent Citations (1)

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