ES2929446T3 - Device for applying powdered enamel to decorate ceramic tiles or slabs - Google Patents

Abstract

The applicator device (1) is suitable for transferring a certain design or decoration (D) to a ceramic slab or tile (PL), moved by a conveyor line (T) by means of powdered enamel (S). The applicator device (1) comprises: dispensing means (2), from which the previous powdered enamel (S) falls by gravity; a dosing unit (3), arranged below the dosing means (2), in which a movable support surface (31), consisting of a plurality of conveyor elements (30) placed side by side, receives the fallen enamel powder (S) and arranges it to form a continuous layer (H); a power element (32) for each conveyor element (30), which can be selectively activated to impart a predetermined incremental advance to it, such that a measured amount of the respective glaze powder (S) falls, by gravity, onto the underlying tile or ceramic tile (PL) in transit; an electronic processing unit (4), in which a matrix of cells (C) with the instructions for reproducing said predetermined design or decoration (D) is stored; a control and command unit (5), slave to the electronic processing unit (4), designed to drive each conveyor element (30) in phase relation with the advancement of said tile or ceramic plate (PL), so that in each cell (C) the amount of powdered enamel (S) provided for in said matrix is deposited. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Device for applying powdered enamel to decorate ceramic tiles or slabs

The present invention is part of the technical sector of machinery used in the ceramic industry for decorating ceramic tiles or slabs.

In particular, machines that apply decorations with powdered enamel are considered; said powdered glaze is subsequently fired to indissolubly bond with the relative ceramic tile or slab.

STATE OF THE ART OF THE INVENTION

According to a known technique, the powdered enamel is introduced into a hopper arranged above the conveying line with which the ceramic tiles or slabs advance.

The hopper extends transversally to the feeding direction, for example, with a width equal to that of said ceramic tiles or slabs, and is affected below by a properly calibrated rod slot, from which the so-called "dust curtain" emerges. " that is deposited on the underlying ceramic tile or slab in transit.

With this technique, a homogeneous layer of constant thickness is deposited that will give rise to a substantially uniform and monochromatic decoration.

For the realization of more complex decorations, hoppers are known that provide, in correspondence with the rod slot, a battery of shutters intended to be selectively controlled by an electronic control unit, based on a memorized cartography, to dispense dosed quantities. enamel unit width equal to that of the shutter, or to prevent its exit.

The main drawback of this technical solution, as is easy to understand, lies in the frequent maintenance required by the shutters, which must be small enough to offer a sufficient definition of the decoration and are therefore subject to clogging and a considerable wear, since the enamel powder used in the ceramic industry is glassy in nature and is therefore highly abrasive.

A variant of the described solutions provides for the hopper to deposit the powdered enamel on a moving belt located between the hopper itself and the underlying ceramic tile or slab; the same carpet is then deposited on the latter, in a later position.

With this measure it is possible to intervene on the speed of the moving belt, together with the speed of the transport line of the tiles or ceramic slabs, to modify the decoration parameters, including the thickness of the glaze powder, along the longitudinal development of the same tiles or ceramic slabs.

However, there remains a very binding limitation to the realization of decorations or designs in which many differentiations of the thickness of the enamel are foreseen in the different areas of the tile.

or ceramic slab, necessary to create not only different color tones, but also particular embossed effects on the surface of the ceramic tiles or slabs themselves.

These technical limits are very penalizing from a commercial point of view, since they prevent the creative imagination of designers from being adequately exploited, especially in the high-end range of ceramic products, which today have the highest profit margins.

SACMI's European Patent No. EP 2760594 B1 discloses a device for dispensing a loose solid material, comprising a series of vibrating elements arranged flanking each other to support the material at rest, each of which is associated with a piezoelectric means that vibrates to cause material to fall from the vibrating elements. The dispensing device also discloses heating means for heating the vibrating elements.

An object of the present invention is, therefore, to propose a powder enamel applicator device for decorating ceramic tiles or slabs that makes it possible to overcome the technical limits of known solutions and, consequently, increases the possibility of making designs or decorations. highly complex, with qualitatively optimal results.

Another object of the invention is to provide an applicator device with high reliability and precision in operation, without requiring excessively frequent maintenance interventions.

Another object of the invention is to propose an applicator device in which there are no parts subjected to the abrasive action of enamel powder, in order to guarantee constant operating results over time and to avoid the costly replacement of parts.

Another object of the invention is that the applicator device is made with relatively simple technical solutions, which can be easily integrated into normal production lines, both in terms of assembly and operation.

SUMMARY OF THE INVENTION

These and other purposes are fully achieved by a powdered glaze applicator device for decorating ceramic tiles or slabs, said powdered glaze being supplied to reproduce a predetermined design or predetermined decoration, a variable amount of the same powdered glaze being provided to be deposited on selected portions of the surface of said ceramic tile or slab, the latter moving horizontally along a conveyor line below said applicator device, comprising: dispensing means, provided with a tray for containing said powdered glaze , being provided in said tray at least one lower rod opening, extending transversely to said tile or ceramic slab, for the release by gravity of said powdered glaze;

- a dosing unit, arranged below said dispensing means and in which there are: a plurality of transporting elements, arranged side by side and oriented according to the transport direction of said ceramic tile or slab, to define in its part uppermost a movable support surface of predetermined width, intended to receive the powdered enamel released by said dispensing means to continuously form a layer of said powdered enamel power elements, associated with each of said transporting elements, which can be activated selectively to impart a predetermined incremental advance to the relative conveying element, such that a metered amount of enamel powder is induced to fall, by gravity, onto the underlying ceramic tile or slab in transit with a duly timed movement; - an electronic processing unit, in which a matrix is stored in digital form in which the entire surface of said ceramic tile or slab is divided into cells with a predetermined unitary surface, in each of which are the instructions for the reproduction of said predetermined design or decoration;

- a control and command unit, associated with said electronic processing unit, designed to actuate each conveyor element, present in said dosage unit, in phase relation with the advancement of said tile or ceramic slab, so that at each one of the said cells, the unit quantity thereof is deposited with the required amount of enamel powder, with the necessary thickness, in accordance with the provisions for the corresponding cell, in the said matrix.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the invention will be evident from the following description of the preferred embodiments of the powder enamel applicator device for decorating ceramic tiles or slabs, according to the object, according to what is proposed in the claims and with the help of the attached drawings, in which:

- Fig. 1 is a schematic side view of a first embodiment of the powder enamel applicator device;

- Fig. 2 shows a plan view of Fig. 1, without the powder enamel to highlight some constructive features;

- Fig. 2A shows a view in partial section according to the plane ll-ll of Fig. 2;

- Fig. 3 illustrates, in a schematic side view similar to that of Fig. 1, a second embodiment of the applicator device;

- Fig.4 illustrates a plan view of Fig. 3 without the enamel powder hopper, to highlight the lower organ; - Figs. 5A and 5B show as many schematic side views of a third embodiment of the applicator device, in two different operating steps;

- Fig. 6 illustrates, in a side view on an enlarged scale, an optional spreading device applied to the applicator device;

- Fig. 7 schematically illustrates a ceramic tile or slab with a decoration applied by the device;

- Fig. 8 illustrates a detail on an enlarged scale of the ceramic tile or slab of Fig. 7 with highlighted areas in which the applied powder enamel has different thicknesses from area to area.

DETAILED DESCRIPTION OF THE INVENTION

In the above figures, the reference number 1 indicates, as a whole, a powder enamel applicator device S for decorating ceramic tiles or slabs PL.

The latter move horizontally along a conveying line T, extended below said applicator device 1 and provided with its own motor elements, the structure of which will not be further detailed because it is known.

The powder enamel S must be suitably distributed, according to variable amounts, in correspondence with selected portions of the surface of said ceramic tile or slab PL, to reproduce a predetermined design or predetermined decoration D.

The ceramic tile or slab PL with the design or decoration D still in the powdered state will be introduced, according to the known technique, into a firing kiln (not shown), in which the powdered enamel S will be melted and ^{permanently incorporated into} the ^{the material of the ceramic tile or slab} P ^l , ^{becoming a single body with it.}

According to the invention, the applicator device 1 comprises dispensing means 2, which comprise a tray 20 for containing the powdered enamel S.

The tray 20 has, advantageously, the shape of a hopper and is provided with a lower rod opening 21, extending transversely to the ceramic tile or slab PL, for the release by gravity of the mentioned enamel powder S.

The tray 20, and the relative lower rod opening 21, have a width preferably equal to that of the ceramic tile or slab PL (Fig. 2).

Below the tray 20 there is a dosing unit 33, in which a plurality of conveyor elements 30 are arranged, arranged one next to the other and oriented according to the transport direction F of said ceramic tile or slab PL, and capable of defining in its upper part a mobile support surface 31 of predefined width, preferably equal to or greater than those of the tray 20 as well as of the ceramic tile or slab PL.

The movable support surface 31 is intended to receive the enamel powder S released by the rod opening 21 of the tray 20, so that a layer H of said enamel powder S is continuously formed.

Said layer H of enamel powder S has preferably, but not necessarily, a uniform thickness.

The rod opening 21 is advantageously arranged a few millimeters above the movable support surface 31, in order to limit the escape of the enamel powder S.

Each of said conveyor elements 30 is associated with the respective power elements 32 (Fig. 2A), consisting, for example, of the well-known electric stepper motors or the like, optionally provided with encoders, electronically controlled and capable of performing rotations. with predetermined amplitude angle precision, also very small.

The applicator device 1 also comprises an electronic processing unit 4, in which a pattern or decoration scheme D intended for the ceramic tile or slab PL is stored digitally.

According to an exemplary and non-limiting embodiment of the invention, this drawing or decoration scheme D comprises a two-dimensional matrix, the entire surface of the mentioned ceramic tile or slab PL is divided into cells C with a predetermined unit surface, and each cell C is associated an element of this array. In each of the aforementioned elements of the matrix, the instructions relating to the presence or absence of enamel in the corresponding cell C and, possibly, the amount of enamel that must be applied to it, are recorded with an appropriate coding. Therefore, the entire matrix contains sufficient information to reproduce the default pattern or default decoration D on the entire tile or slab PL.

The applicator device 1 further comprises an actuation unit 5, electrically connected to the electronic processing unit 4 and controlled by the latter according to actuation sequences defined by a program residing in it, according to the aforementioned drawing or decoration scheme D. The unit drive 5 is provided to drive, in a suitable phase relationship with the advancement of the conveyor line T, the power elements 32 of each conveyor element 30 present in said dosing unit 3, as further specified below.

The power elements 32 can be activated simultaneously, in order to move all the conveying elements 30 in a direction consistent with the advance of the same tile or ceramic slab PL, in a phase of formation of said layer H of glaze powder S, or selectively to impart to at least one conveyor element 30 a predetermined incremental advance, in such a way that a metered amount of enamel powder S is induced to fall, by gravity, onto the underlying ceramic tile or slab PL, in underlying traffic.

In practice, depending on the decoration to be made, one or several longitudinal strips of said continuous layer H, each of which has a width corresponding to that of the respective driven conveyor element 30, is advanced further, by a predetermined rate, with respect to the front of the continuous layer H, until exceeding the front limit of the mobile support surface 31, so that predetermined amounts of glaze fall on the ceramic tile or slab PL and, at the end of the phase, on each of the aforementioned cells C thereof, the amount of powdered enamel S is deposited, with the necessary thickness, in accordance with what is established in the aforementioned matrix of cells for the realization of the predetermined design or predetermined decoration D (Fig. 8).

According to a characteristic of the invention, each conveyor element 30 can work with adjustable speed, in order to deposit, in the unit of time, different quantities of enamel in powder form on the cell C of tile or slab PL.

In a first embodiment of the applicator device 1, illustrated in Figs. 1, 2 and 2A, said plurality of conveyor elements 30 is constituted by a series of belts 33, wound in a closed loop on a respective pair of pulleys 34, 35.

Each belt 33 has a section such that its external side 33E is flat and of a width that does not exceed that of one of the said cells C of the matrix (Fig. 2A).

The purlins 33 are mutually close to each other in a sufficient number to cover at least the width of said ceramic tile or slab PL, and their upper horizontal branches are adapted to define said mobile support surface 31.

In order for the upper horizontal branch of each belt 33 to be taut, the relative electric motors 32 are associated with the downstream pulleys 35, and are preferably contained within them, without protruding laterally (see again Fig. 2A).

In a construction variant of said first embodiment, a collection plate 36 is provided, located - immediately below said upper horizontal branches of the belts 33, intended to retain any powdered enamel S dragged between one belt 33 and the other, avoiding the drop onto the underlying PL ceramic tile or slab (Fig. 1).

In a second embodiment of the applicator device 1, illustrated in Figs. 3 and 4, said plurality of conveyor elements 30 is constituted by a drum 37 with a horizontal axis formed by discs 38 contiguous and close to each other, in sufficient number to cover at least the width of said ceramic tile or slab PL (Fig. 4). .

The thickness of each disc 38 is not greater than the width of one of the aforementioned cells C of the matrix, while the mobile support surface 31 is constituted by an upper portion of the circumference of said drum 37.

The electric motor 32 of each disk 38 (not shown in the figures) is preferably contained within it, without protruding laterally.

In a third embodiment of the applicator device 1, illustrated in Figs. 5A and 5B, there is an intermediate horizontal belt 6 between said dosing unit 3 and the underlying ceramic tile or slab PL.

The intermediate belt 6 extends longitudinally for a length greater than or equal to that of the ceramic tile or slab PL, it is provided with drive means -not shown because they have a known structure- independent of those that drive the conveyor elements 30 and the line of transport T, and is intended to be previously actuated in phase relation with the dosing unit 3, to receive all the design or decoration D made up of the enamel powder S supplied by the same dosing unit 3 in its upper branch 6S ( Fig. 5A), and then in phase relation with the transport line T of the ceramic tile or slab PL, to transfer said design or decoration D to the latter (Fig. 5B).

In the mentioned Figs. 5A, 5B, by way of non-limiting example, the dosing unit 3 has been shown with the belts 33 already illustrated in Fig. 1, but obviously it is possible to alternatively provide the dosing unit 3 with the drum 37 of the second described embodiment.

Fig. 6 schematically illustrates a separation unit 7, associated with the dosage unit 3, the latter being indistinctly of the type with belts 33 (as illustrated by way of example) or drum 37.

The separation device 7 is located in the area of the conveying elements 30 where the aforementioned drop by gravity of the enamel powder S occurs, and it comprises at least one nozzle 70 for the expulsion of compressed air for each of said conveying elements 30. , which can work in phase relation with the activation of the latter in order to reduce the amount of falling enamel dust S, directing a surplus part Se towards a recovery tile 71 suitably arranged nearby.

In the construction example shown in Fig. 6, the battery of nozzles 70 is arranged below the conveyor elements 30, in the space between them and the tile or ceramic slab PL in transit; the expulsion of the compressed air occurs towards the front with respect to its movement, and slightly upwards, so that said excess part of enamel powder S can be directed and collected by said recovery tile 71.

From the above description it can be seen that the proposed applicator device has the necessary prerogatives to obtain the predetermined functional results.

In particular, the technical limits of known solutions are exceeded in terms of the possibility of creating complex decorations, with differentiations in both the longitudinal and transverse directions of the local thickness of the enamel powder, which is carefully dosed as intended in a cellular matrix. stored, which divides the surface to be decorated as if it were the pixels of an electronic image.

Within a certain limit, even with the help of the described optional separation device, it is possible to obtain a high definition of the decoration, certainly superior to that allowed by the solutions of the state of the art.

A very advantageous aspect resides in the fact that the powdered enamel is not induced to pass through the dosing elements, such as plugs and the like, necessarily of small dimensions, if not very small, and therefore subject to the clogging and wear, so the reliability and precision of operation are high, without requiring frequent maintenance.

Less frequent maintenance and no costly parts replacement mean cheaper decorating plant management and fewer downtimes, therefore higher productivity with less potential for waste.

The embodiments of the powder enamel applicator device, although essentially illustrated and described, are relatively simple for those skilled in the art, easy to build and can be easily integrated into normal production lines, both in terms of their assembly as to its operation.

However, it is understood that what has been described above has an exemplary and non-limiting value, so that the variations in detail that may be necessary for technical and/or functional reasons, both in the method and in the device, are now considered to be included. in the same scope of protection defined by the following claims.

Claims (8)

1. Powdered enamel applicator device (S) for decorating ceramic tiles or slabs (PL), said powdered enamel (S) being intended to reproduce a predetermined design or predetermined decoration (D), with a variable amount thereof powder enamel (S) intended to be deposited on selected portions of the surface of said tile or ceramic slab (PL), moving horizontally along a conveyor line (T) below said applicator device (1), in which includes: - dispensing means (2), provided with a tray (20) to contain said powdered enamel (S), being provided in said tray (20) at least one lower rod (21) opening, extending transversely to said tile or slab (PL), for gravity release of said powdered enamel (S); - a dosing unit (3), arranged below said dispensing means (2) and in which a plurality of conveyor elements (30) are arranged, arranged side by side and oriented according to the transport direction of said tile or ceramic slab (PL), to define in its upper part a mobile support surface (31) of predetermined width, intended to receive the powdered enamel (S) released by said dispensing means (2) to continuously form a layer (H) of said enamel powder (S); power elements (32), associated with each of said conveyor elements (30), which are configured to be selectively activated to impart a predetermined incremental advance to the relative conveyor element (30), so that a metered amount of enamel powder (S) is induced to fall, by gravity, on the underlying tile or ceramic tile (PL) in transit with a suitably synchronized movement; - an electronic processing unit (4), in which a scheme corresponding to said pattern or decoration (D) for said tile or slab (PL) is digitally stored; - a drive unit (5), controlled by said electronic processing unit (4), configured to advance each conveyor element (30) present in said dosing unit (3), in phase relation with the advancement of said ceramic tile or slab (PL), to deposit on the surface of said ceramic tile or slab (PL) measured quantities of powdered enamel (S), with the necessary thickness, in accordance with the aforementioned drawing or decoration scheme (D) . 2. Applicator device according to claim 1, characterized in that in said electronic processing unit (4), said drawing or decoration scheme (D) is represented in the form of a matrix, in which the entire surface of said tile or slab ceramic (PL) is divided into cells (C) with a predetermined unitary surface, in each of which the instructions for reproducing the mentioned predetermined drawing or predetermined decoration (D) are recorded; the advance speed of each one of the mentioned conveyor elements (30) is defined in such a way that in each one of the mentioned cells (C) of unitary surface area the expected amount of enamel powder (S) is deposited. 3. Applicator device according to claim 1, characterized in that said plurality of conveyor elements (30) is constituted by a series of belts (33), wound in a closed loop on a respective pair of pulleys (34, 35), approximated to each other. in sufficient number to cover at least the width of said ceramic tile or slab (PL), and by the fact that said mobile support surface (31) is constituted by the upper horizontal branches of said belts (33). Applicator device according to claim 3, characterized in that said power elements (32) are associated with the pulley (35) downstream of each mentioned pair, so that the upper horizontal branch of the respective belt (33) is taut. . 5. Applicator device according to claim 1, characterized in that said plurality of conveyor elements (30) is constituted by a drum (37) with a horizontal axis formed by discs (38) contiguous and close to each other, in a sufficient number to cover at least the width of said ceramic tile or slab (PL), due to the fact that said mobile support surface (31) is constituted by an upper portion of the circumference of said drum (37) and due to the fact that said power elements (32) are associated with each of the same discs (38). 6 . Applicator device according to claim 1, characterized in that between said dosage unit (3) and the underlying ceramic tile or slab (PL) there is an intermediate carpet (6) arranged horizontally, provided with drive elements independent of those that drive said elements. conveyors (30) and said conveying line (T), said intermediate mat (6) extending longitudinally for a length greater than or equal to that of said ceramic tile or slab (PL), intended to be first previously actuated in phase relation with said group dispenser (3) to receive the entire design or decoration (D) made up of the enamel powder (S) supplied by the same dispensing means (2) in its upper branch (6S), and subsequently in phase relationship with the aforementioned transport line (T) of the tile or ceramic slab (PL), to transfer said design or decoration (D) to the latter. Applicator device according to claim 3, characterized in that it provides a collection plate (36), located immediately below said upper horizontal branches of the belts (33) that define said mobile support surface (31), intended for retain the enamel dust (S) dragged between one belt and another, avoiding its deposit on the underlying ceramic tile or slab (PL). 8 . Applicator device according to claim 1, characterized in that in said dosing unit (3) there is a separation device (7), associated with said plurality of conveyor elements (30), in the area of these where the mentioned drop occurs. gravity of the amount of powdered enamel dosed, said separation device (7) being provided with at least one compressed air expulsion nozzle (70) for each of said conveying elements (30), which can be activated in relation phase with the activation of the latter to reduce the amount of powdered enamel (S) that falls, directing a surplus part (Se) to a recovery tile (71) conveniently located nearby.