ES2271186T3 - PROCEDURE AND INSTALLATION FOR THE FORMATION OF TILES OR CERAMIC Slabs. - Google Patents

Abstract

Procedure for the formation of ceramic tiles or slabs in a forming press (3) provided with mobile powder distributing means (100) suitable for depositing a layer of powders to be pressed into a molding cavity of the forming press (3) comprising the following operating steps: - in a hopper (6) provided with a discharge mouth of dimensions at least equal to the dimensions of the molding cavity, both in the direction of translation of the distributing means (100) and in the direction perpendicular to it, - deposit by default and / or randomly a mixture of powders of different characteristics in such a way that the hopper (6) is created a mass of powders that has a veining arranged in a varied manner within the mass , characterized in that it comprises the following additional operating steps; - from said mass of powders, remove portions that have, in the direction of translation of the distributing means (100), a dimension equal to a fraction of the length of the hopper mouth, and in the direction perpendicular to it dimension equal to the dimension of the hopper mouth, such that an entire layer of said dough is removed, - depositing said layer inside said molding cavity, and - pressing the powders.

Description

Procedure and installation for the formation of ceramic tiles or slabs.

The present invention relates to a procedure for depositing powders in mold cavities trainers for pressing by presses, and installation for the implementation of the procedure.

The investigations carried out in the sector of ceramics are currently aimed at obtaining products that mimic natural stone, such as marble and granite. These products are characterized by the presence of a grain Continuous random drawing that extends throughout the entire thickness of the slab.

These tiles or ceramic slabs are produced compacting, by hydraulic presses, crushed powders or mixed atomized and semi-dry regranulates varied in a predisposed or random way. Specifically, mixtures of powders deposited by appropriate means in the rigid steel mold forming cavities of which are you provide the presses, and then press to get the product.

A system widely adopted to supply the powders in the molding cavities involve the use of a carriage provided with a bottomless loading tray that moves from sliding shape along a support surface aligned with The mold stamp. The car moves between a position of load in which the tray is below a loading hopper, and a discharge position in which the tray is above the mold forming cavity, which in this way receives the powders that fall from the tray.

In practice, the loading procedure with the Use of the described equipment includes the preparation of a mixture of powders inside the loading hopper, the transfer of this mixing to the loading tray and moving said tray from the loading position to the unloading position to deposit the powder mixture contained in the tray inside the cavities of the press molds.

The document GB-A-1 326 638 unveils a encaustic tile molding installation comprising a powder filling unit for a tile mold.

The powder filling unit comprises a hopper with four compartments for different powders colors.

Located below the exit hole of each hopper compartment is a device for pouring the powder in the mold in which a tile is formed by compression.

The pouring device consists of a plate fixed dispenser that has a mouth whose shape corresponds with the monochromatic part of the drawing, a car that presents a slit that moves reciprocating on the plate and below the mouth of the hopper.

A gate and an underlying spout peak They control the transfer of powders to the molding cavity.

EP-A 0 693 352 gives know a device to supply powder material to a molding cavity loader cart in the manufacture of ceramic tiles, said loader car presenting at least a cargo compartment with dimensions in plan substantially equal to those of a molding cavity, and being operated with reciprocating movement between a retracted position in the which cargo compartment receives the material and a position advanced in which the cargo compartment releases the material in the underlying molding cavity.

The device comprises a surface horizontal that is substantially equal to the projection in plan from the cargo compartment of the car and is above it when the car is in its retracted position, and a plurality of openings for the passage of materials. Some means are provided to open and close respectively the openings of the perforated surface

The openings are distributed in the form of at least two separate pluralities and means are provided to transport the material that originates in a respective Supply container for each plurality of openings.

A charging system like the one described above performs the job of feeding the press perfectly continuously without limiting your productivity, but it shows certain inconveniences in those cases in which the main objective it is to deposit in the molding cavities a mass of powders mixed so as to maintain the same disposition as They were adopted when deposited in the loading hopper.

In this sense in the system described, during gravity transfer from the supply hopper to the loading tray, undesirable mixing occurs that harms part or all of the powder disposal achieved within The supply hopper. An additional undesirable mixing occurs during carriage movement between the loading position and the discharge position of the powder mass contained in the tray. This is because during the movement of the car the tray slide over the sliding surface aligned with the upper surface of the mold stamp. This slip gives as a result a partial remixing of the powders within the tray, with which aesthetic effects are often generated undesirable

It has also been found that the use of a system as described in the final product determines a appearance that presents numerous inaccuracies in the drawing wanted.

An objective of the present invention is to overcome the drawbacks of the known technique within the framework of a simple and rational solution, which does not harm the productivity of the forming chains.

This and other objectives are achieved according to the invention by a system of loading the cavities in the presses Formers that minimize remixing of mixed powders during its transfer from the loading hopper to the tray and from the tray to the press forming molding cavity. The invention It comprises a method according to claim 1. Specifically, the training procedure according to the invention It comprises the following stages of operation:

-

in a hopper provided with a discharge mouth of at least dimensions equal to the dimensions of the at least one molding cavity of a forming press, both in the direction of translation of car as perpendicular to it,

-

deposit by default and / or random a mixture of powders of different characteristics of such a way as to create in the hopper a mass of powders that it presents a vein arranged variously within the mass,

-

from said mass of powders, remove portions that have, in the tray translation direction, a dimension equal to one fraction of the dimension of the hopper mouth, and in the direction perpendicular to it a dimension equal to the dimension of the mouth from the hopper, so as to remove an entire layer of powders from said mass,

-

deposit said layer in an orderly manner inside of said at least one cavity, and press the powder.

According to the process of the invention, said portions of powders are deposited inside a translation capable tray having dimensions in plan at least equal to the dimensions of said at least one cavity of the molding press. Said tray can be moved between a loading position in which it is below said hopper and a discharge position in which it is above said at least one
cavity.

It should be noted that the hopper according to the invention it has a capacity to contain a mass of powders Enough for several loads. If tiles are to be provided that mimic the natural stone, a mass of dusts is deposited in the hopper that presents a grain that extends inside the dough, to The way of a stone block. This offers the advantage of obtaining tiles or slabs that have a grain that varies in shape continue, as would be obtained by sectioning said stone block natural in successive layers.

The invention also includes the installation to implement in the procedure described above, in accordance with the Claim 6. This installation comprises a hopper for containing a mixture of powders that has a grain inside the dough in imitation of a natural stone, said hopper having some dimensions in plan at least equal to at least one cavity of a forming press, being associated with the mouth bottom of said hopper means mobile powder distributors capable of depositing in said at least one cavity a succession of portions of powder removed from said hopper, until filling completely said at least one cavity.

According to an embodiment preferred of the invention, said hopper is fixed to said means powder distributors, which are associated with the lower mouth of the hopper, are mobile and are arranged to remove said portions of powder and deposit them in succession inside the bottomless cargo tray of a car that moves between a loading position, in which the tray is below the powder loading hopper, and a dust discharge position, in which said at least one tray is above minus a molding cavity of a forming press.

Said distributing means comprise a translation-capable plate provided in its center with a slit perpendicular to the direction of translation of said carriage, being said plate having a length equal to at least twice the length of the lower mouth of said hopper, and a width greater than the width of the lower mouth of the hopper, presenting said slit a width at least equal to the width of the molding cavity, and a dimension in the direction of translation of the car that is a function of the graphic resolution to be Get on the finished tile. In this sense, the higher the dimension of said slit in the direction of carriage translation, Less will be the graphic resolution of the finished product.

Additionally, with this tray you can go associated with a mobile shutter panel, which can be moved between a removed position in which it is below the tray for its load, and an advanced position in which the edge front of the mobile panel rests on the press mold stamp and is coplanar with her.

The use of the mobile panel provides the advantage to reduce the remixing of dusts during car advance between the loading position and the unloading position.

According to a variant of the invention, said powder distributing means comprise two belts opposite coplanarians, each of which has one end wrapped around an elastically loaded roller, being rigid its other end with a fixed retaining element, being directed each of said straps around a crazy roller, said opposite rollers being spaced from each other in a predetermined magnitude based on the graphic resolution to get on the finished tile. The crazy rollers are supported by a mobile frame induced to move by a proper drive that has the effect of making the opening between said rollers move in reciprocating at least more beyond the front and rear edges of said hopper, so that the powder portions are removed and deposited in the tray of underlying load through said opening.

In another simplified embodiment of the invention said hopper and said dispensing means are mobile between a removed loading position in which they are separated from said at least one cavity, and an advanced discharge position in which at least one cavity is above said. The powders are loaded into said at least one cavity causing said distributing means are transferred with respect to the hopper when it is in the material discharge position.

Other characteristics of the procedure e Installation of the invention are defined in the claims.

The operation of the procedure of the invention and the constructive characteristics and merits of relevant means for its implementation will be better understood from the following description provided with reference to figures in the accompanying drawings illustrating a form of particular preferred embodiment of said means and some of its constructive variants by way of non-limiting example.

Figure 1 is a schematic side view of the installation according to the invention.

Figure 2 is an enlarged view of the plane II-II of Figure 1.

Figures 3 to 15 even show schematically the stages involved in two loading cycles of the  molding cavities according to the invention.

Figure 16 is a view partially in section of a variant of the invention.

Figure 17 is a top plan view of another variant of a detail of the invention.

Figures 18, 19 and 20 show the stages of operation involved in another variant of the invention.

These figures show installation 1, which is It is located upstream of a forming press 3.

Installation 1 comprises a loader car 4 provided with a bottomless tray 5 equipped with baffles internal 50, the tray preferably presenting the same dimensions in plan that the lower matrix 30 of the press trainer 3.

To the front and rear ends of the tray two flat horizontal plates or tabs are fixed, whose purpose will be explained later.

The car 4 moves reciprocating between a position to load the powders to be pressed, in which tray 5 is below an overlapping hopper 6, and a powder discharge position in which the tray is exactly above the lower die 30 of the press trainer 3.

With reference to Figure 2, carriage 4 is limited by 7 wheels to move along two guides rectilinear parallels 8 fixed to a support frame, not shown.

The carriage 4 is fixed, by means of two blocks 40, to two parallel belts 9, each of which passes around two pulleys 10 and 11, the pulley 11 being fixed to the output shaft of a gearmotor 12, whose operation causes the car to move.

Below panel 4 there is a panel 14 to close the bottom of tray 5. Panel 14 moves between a retired position, in which it is below the tray when it is in the dust loading stage, as seen in Figure 1, and an advanced position in which the leading edge of the panel rests on the stamp 31 of the mold of the press 3 and is coplanar with her (Figure 5).

As seen in Figure 2, panel 14 is powered by a rack system driven by a gearmotor 15.

Specifically, said panel is supported by a frame 16 capable of moving along two guides longitudinal 160 by wheels 17. To the lower surface of the frame 16 is attached a zipper 18 that cooperates with a pinion 19 whose rotation is caused by said gearmotor 15.

Between the carriage 4 and the upper hopper 6 is located a distributor means 100 for the contained powders in the hopper In the illustrated embodiment, said means they comprise a translation plate 20 and provided with slit 21 for distribute the powders contained in hopper 6, the slit being 21 perpendicular to the direction of travel of the car Four.

With reference to Figure 2, plate 20 is supported on two parallel guides 22 along which you can slide by wheels 23. On each of the two guides 22 is fixed a belt 24 and 25 that cooperate with pulleys 26 and 27 fixed to the shaft of a gearmotor 28, whose drive promotes the plate translation 20.

The gearmotor 28 drives the plate in reciprocating beyond the front and rear end of the two tabs 520 of tray 5.

Plate 20 has a dimension in the direction perpendicular to the direction of advance of the car that exceeds the size of the press molding cavity in the carriage forward direction, and one dimension in the direction of carriage advance which is at least twice the dimension corresponding cavity. Slit 21 has a dimension in the direction perpendicular to the direction of advance of the car that  is equal to the corresponding dimension of tray 5, and a dimension in the direction of advance of the car that depends on the graphic resolution to be obtained in the finished tile. From the tests performed, it was found that to obtain a sufficient quality of graphic resolution of the pressed tile, the dimension of the slit in the carriage forward direction should not exceed four times the depth of the molding cavity. Preferably this dimension is between one and two times the molding cavity depth.

Hopper 6 has dimensions in plan at least equal to the dimensions of the molding cavity, and a height of at least three times the height of the tray charge, so that powders deposited by known means, not shown, in the hopper they globally form a mass that presents a veining within the mass that reproduces the one present In the natural stone. That is, it can be said that this mass reproduces a block of natural stone, which is subsequently sectioned in layers that are deposited in the tray through the slit 26. To limit dust collapse during loading and unloading of hopper, its interior volume is divided by rigid partitions 60

The installation described to implement the process of the invention is also provided, among its various parts susceptible to mutual movement, with known sliding sealing means, not shown for being of known type, to prevent undesirable spillage of the powders. Specifically, said sliding sealing means are located between the lower mouth of the tray 5 and the panel 14, below the upper mouth of the tray 5 and the plate 20, and between the lower mouth of the hopper 6 and the plate
twenty.

Figure 16 shows a variant of the invention that differs from the described embodiment with respect to of said powder distributing means 100, which are located between the loading hopper 6 and the tray 5 of the carriage 4.

In the description of the variant of the invention the elements already described in the illustrated embodiment will indicate with the same numerical references.

In this variant of the invention, said means 100 powder distributors comprise two straps or curtains opposite coplanarians 50, one of whose ends is fixed to a fixed retaining element 52, and the other end is rolled around a tree 53 elastically loaded by a spring, whose purpose is to keep the curtain tensioned. Between said tree 53 and said fixed element 52, curtain face passes around a roller loco 54 supported by a frame 55 capable of translation. Said mobile frame is driven by a drive unit appropriate.

In the illustrated embodiment said drive unit consists of a rack system driven by a gearmotor 58.

As can be seen in Figure 16, the two rollers around which the curtains 50 pass are coplanarians and are separated by an adjustable distance to provide an opening through which, during the translation of the frame, dust portions are removed from the hopper upper 6 and are deposited in the underlying loading tray 5.

Figure 17 shows another variant of the invention as regards the loading tray 5. In this variant, the loading tray 5 is provided with two partitions or longitudinal parallel plates 71 in the vicinity of their edges lateral. The dimensions of the molding cavity will then be equal to the tray section bounded by the edges front and rear of said partitions 71.

The purpose of partitions 71 is to eliminate imperfections due to the collapse of dusts against the walls of hopper 6 during tray loading. Figures 18, 19 and 20 show a simplified variant of the invention. In this variant of the invention, neither carriage 4 is present equipped with tray 5 or the underlying panel 14. The figures show a loading hopper 81 totally similar to hopper 6 and described with the only difference of being associated with a frame support, not shown, for translation between a position retracted in which appropriate means deposit a mass of dusts in hopper 81, and an advanced position (Figure 19) in the which hopper 81 is exactly above the molding cavity  of the press 3.

The powder distribution media 100 se They are present below hopper 81.

Said means comprise a plate 82 completely similar to plate 20, except that said plate is susceptible to translation, like the hopper, up above the cavity of molding (Figure 19).

Plate 82 has a slit 820 identical to the one already described slit 21. Once the hopper 81 and plate 82, plate 82 is made to move relative to the hopper so that the powders are deposited directly in the Press molding cavity 3 through the 820 slit.

The drive means and control of hopper 81 and plate 82 since they are known by the expert in The matter.

The described installation is regulated by a processor, not shown, that controls the implementation of the procedure as follows.

With reference to Figures 3 to 15 inclusive, at the beginning of the training cycle the distribution plate 20 is removed so that the tray 5 of the carriage 4 is filled with a succession of portions of dust that pass from hopper 6 to the tray through the slit 21.

As is evident from Figures 3 and 9, in the start of each loading cycle tray 5 is below the hopper, but it has moved in the direction of carriage advance in a magnitude at least equal to the dimension of slit 21 in the same direction, so that a portion of the eyelashes 520 is below said hopper 6. This is necessary to transfer the portions of powder on the tray without changing its arrangement.

When filling the tray through that slit, Undesirable mixing of powders is minimized.

Once the tray is filled, the carriage 4 advances, together with the panel 14, until the panel rests on the press stamp with which it is coplanar (Figure 5), thereby preventing undesirable mixing of the powders, which It could occur if the car slides on a fixed operating table as in the known technique. Instead, the carriage continues to move until it is positioned exactly on the lower die of press 3 (Figure 6). Once in position, the processor causes the lower matrix of the press to descend, as shown in Figure 7, to form the molding cavity to receive the powders contained in the tray. Once the molding cavity is loaded, the panel is returned to its retracted position, below the mouth of the hopper 6 (Figure 8), after which the removal of the tray 5 is caused to below the mouth of the Hopper 6 when retracting carriage 4 (Figure 9). At this time the powders contained in the molding cavity are pressed. Pressed and dusts, the upper die matrix is raised so that, during the next loading cycle, the carriage advance promotes the removal of the tile formed by the press 3 by the usual pusher, not shown, fixed to the edge front of
car 4.

Figures 10 to 15 show the following cycle loading of the invention. This cycle differs from the previous one only in the sense that the powders are loaded in tray 5 by moving the distributor plate 20 in the opposite direction to its displacement during the previous load.

The variant of the invention shown in the Figure 16 works completely identical to the way embodiment described above.

The operation of the variant of the invention shown in Figures 18, 19, 20 is controlled by a processor as follows.

With reference to Figure 18, at the beginning of load cycle, hopper 81 and plate 82 are in position retracted, that is, away from the forming press 3. While they are in this position, some means, not shown, deposit in the hopper 81 a mixture of powders in a predisposed and / or random manner, to create in it a mass of powders that presents a veining that mimics natural stone Once loaded hopper 81, the processor makes that the hopper and the plate 82 move above the cavity of press molding 3. When hopper 81 is exactly by above the molding cavity, the processor promotes descent of matrix 30 and the translation of only plate 82 to deposit in the cavity, through the slit 820, a succession of portions of powder until completely filled.

Once the cavity is loaded, the hopper is removed 81 and plate 82 to start the pressing cycle. In this moment the cycle is repeated identically.

It should be noted that the invention can be subjected to numerous constructive variations, all of them included within the inventive concept described above.

Claims (18)

1. Tile formation procedure or ceramic slabs in a forming press (3) provided with means mobile powder distributors (100) suitable for depositing a layer of powders to be pressed into a molding cavity of the forming press (3) comprising the following stages of functioning:

-

in a hopper (6) provided with a discharge mouth of dimensions so less equal to the dimensions of the molding cavity, both in the transfer address of the distributing media (100) as in the direction perpendicular to it,

-

depositing in a predetermined and / or random manner a mixture of powders of different characteristics in such a way that the hopper (6) is created a mass of powders having a veining arranged in a varied manner within the mass, characterized in that it comprises the following stages of additional operation;

-

from said mass of powders, remove portions that have, in the translation direction of the distributing media (100), a dimension equal to a fraction of the length of the mouth of the hopper, and in the direction perpendicular to it a dimension equal to the size of the hopper mouth, such that it is removed an entire layer of said dough,

-

deposit said layer inside said molding cavity, and

-

Press the powders.

2. Method according to claim 1, characterized in that the deposit of said powder layer is carried out directly in said molding cavity, said hopper (6) being arranged on said molding cavity, the hopper being able to move in the same direction as the distributing means of powders 3. Method according to claim 1, characterized in that the deposition of said powder layer in the cavity is carried out by depositing said layer in a mobile tray (5) provided with dimensions in plan at least equal to the dimensions of said molding cavity , and causing said tray (5) to move from a loading position in which it is located below said hopper mouth to a discharge position in which it is located above said molding cavity, the hopper being ( 6) in a fixed position with respect to the tray (5). Method according to claim 1, characterized in that the dimension of said powder portions in the direction of translation of the distributing means (100) is at most four times the depth of the cavity. 5. Method according to claim 1, characterized in that the dimension of said powder portions in the direction of translation of the distributing means (100) is between one and two times the depth of the cavity. 6. Installation for the formation of ceramic tiles or slabs in a forming press (3) provided with mobile powder distributing means (100) suitable for depositing a layer of powders to be pressed into a mold molding cavity ( 3), which comprises a hopper (6) for containing a mixture of powders of different characteristics so that a mass of powders is created in the hopper (6) that has a veining arranged in a varied manner within the dough, presenting the mouth of discharge of the hopper dimensions in plant at least equal to the dimensions of the molding cavity, characterized in that said powder distributing means (100) comprise a plate (20) provided with a free slit (21) having a dimension in the direction of translation of the distributing means (100), equal to a fraction of the length of the hopper mouth, and in the direction perpendicular to it equal to the dimension of the hopper mouth, and being obl Aided to move in a reciprocating manner below the mouth of the hopper to allow the fall of portions of powders by gravity through the slit (21) and form said layer of powders. 7. Installation according to claim 6, characterized in that said hopper (81) is mobile between a retracted loading position in which it is away from the cavity, and an advanced discharge position in which it is above said cavity, depositing the powder distributing means (82) said powder layer directly in said molding cavity. 8. Installation according to claim 6, characterized in that it comprises a mobile tray (5) having dimensions in plan at least equal to the dimensions of said cavity, said tray (5) being able to move from a loading position in which it is below said hopper mouth to be loaded with the layer through the slit (21) to a discharge position in which it is above said cavity to discharge said layer into the cavity, said distributing means being interposed of powders (100) between the hopper (6) and the tray (5). 9. Installation according to claim 6, characterized in that the dimension of said slit (21) in the direction of translation of the distributor means (100) is at most four times the depth of the cavity. 10. Installation according to claim 6, characterized in that the dimension of said slit (21) in the direction of translation of the distributor means (100) is between one and two times the depth of the cavity. 11. Installation according to claim 6, characterized in that the slit (21; 820) is formed in a translation plate (20; 82). 12. Installation according to claim 9, characterized in that said plate (20) has a dimension in the direction of translation of the distributing means (100) which is at least twice the dimension of the lower mouth of said hopper (6) in the same direction, and a dimension in the direction perpendicular to the previous one that is at least equal to the dimension of the lower mouth of the hopper (6) in the same direction. 13. Installation according to claim 8, characterized in that said plate (20) is driven below said hopper (6) by a geared motor that causes the plate (20) to be translated in such a way that it leads to said slit (21) of alternating form at least beyond the front and rear edges of the mouth of said hopper (6). 14. Installation according to claim 8, characterized in that a mobile shutter panel (14) is associated with said tray (5), said translation panel (14) being able together with the tray (5) between a retracted position in which it is below the tray (5) during loading, and an advanced position in which it reaches the leading edge of the mold stamp with which it is coplanar. 15. Installation according to claim 14, characterized in that said panel (14) is moved by a drive unit (15). 16. Installation according to claim 6, characterized in that said powder distributing means comprise two opposite coplanar belts (50), each of which has one end wound around an elastically loaded roller (53), its other end being rigid with a fixed retaining element (52), passing each of said belts (50) around a crazy roller (54) spacing the corresponding roller around which the other belt passes, in a predetermined magnitude based on the thickness of the tile that It is going to form. 17. Installation according to claim 16, characterized in that said crazy rollers (54) are supported by a mobile frame (55) driven in translation by a drive unit (58) which causes the opening between said rollers to be reciprocated at least beyond the front and rear edges of said hopper (6). 18. Installation according to claim 6, characterized in that said tray (5) has two parallel partitions (71) located in the vicinity of its longitudinal edges, the area between said partitions (71) and the front and rear edges of the tray ( 5) at least equal to the dimensions of said molding cavity.