WO2012066166A1 - Method and equipment for decorating ceramic pieces and product thus obtained - Google Patents

Abstract

The present invention is based on improvements to patent WO 2004/014624. Said improvements relate to the method and also to the resulting product. As regards the method, the latter is characterized in that, in the step of filling cracks in the initial biscuit of the ceramic piece to be obtained, at least a first material (15') is poured over the bottom of said cracks (5), followed by a second, transparent grain material (15''), mixed with dry glue, the decoration of the first material (15') poured on the bottom of said cracks (5) being visible through said transparent grain material. The resulting product is itself characterized in that the crack filler comprises at least a first material and a transparent second material that leaves the first material visible.

Description

 METHOD AND EQUIPMENT TO DECORATE CERAMIC PARTS AND PRODUCT

 OBTAINED OBJECT OF THE INVENTION

 In the present invention, as expressed in the statement of this specification, it refers to a method and equipment for decorating ceramic pieces and product obtained.

 As in the Invention Patent No. 200201785, during the pressing stage of the earth (materials or components of the cake of the pieces to be obtained) inside a mold, slits are made in the exposed face of such pieces, slits that They are then filled with a decorative material, such as granilla or others, which includes a dry glue in its composition that improves its adhesion.

 At the end of the process, after introducing the ceramic pieces into an oven and subsequent grinding of the exposed face, it will have a completely flat and flush surface.

 The method allows us, if desired, to make projections or ribs on the bottom of the grooves in the pressing process that will be visible as long as the filling granule of such grooves is made of transparent material, so that the incorporation of such ribs or projections on the inside of the grooves constitute new elements of great originality and aesthetically very striking and decorative.

 Starting from this premise, the novelty of the invention focuses essentially on the method and also on the product obtained, achieving a greater range of possibilities thanks to the fact that the filling of the grooves can comprise a first material that is poured on the bottom of the grooves and a second transparent material that shows the decoration of the first material poured and introduced on the bottom of the grooves.

The cooking cycle is also the subject of the invention. of the initial cake together with the filling of the slits.

 BACKGROUND OF THE INVENTION

 Currently there are different types of ceramic pieces for cladding and paving that have different types of decoration on their faces, made through processes and methods of screen printing, among others.

 In some cases, the faces seen from the ceramic pieces are coated with varnishes and then introduced into an oven as a final stage of the process.

 In other cases, such as in porcelain stoneware type ceramic pieces, in one of the stages of the process, grooves are made that will be filled after a liquid product (colored enamels or not) that will overflow or be It is necessary to extend the entire surface of the face seen from the ceramic piece.

 Then, this piece will be introduced into an oven and later a grinding will be done on the entire surface of that face in order to try to achieve uniformity and flatness in that face, since the areas where the grooves are normally found produce contractions of the material resulting in bas-reliefs, which must be flush with the rest of the surface.

 This grinding on all that surface of the face seen of the ceramic piece implies a high cost due to the wear of the abrasive elements, as well as the time spent in such polishing operation.

 In the end, in addition, the product obtained although it could be of great aesthetic appeal, will be excessively expensive and possibly unprofitable.

Also known is Invention Patent WO 2004/014624 which forms the basis of the invention at hand. DESCRIPTION OF THE INVENTION

 In order to achieve the objectives and avoid the inconveniences mentioned in the previous sections, the invention proposes a method and device for decorating ceramic pieces and product obtained.

 The method comprises in principle an initial stage of pressing a conglomerate of component materials of an initial sponge cake obtained in a press that has a lower plate with a cavity where such a conglomerate of materials is housed and an upper plate that presses on those materials to form the initial sponge cake, from which the ceramic piece will finally be obtained by going through a baking phase.

 In this initial stage of pressing simultaneously conforms to the formation of the cake by pressure of the upper plate on the conglomerate of the lower plate, slits by means of male elements integral with the upper plate, emerging upwards in this pressing operation on the initial cake a perimeter partition that borders such grooves protruding above the upper face seen of such a cake, which then corresponds to the decorative face of the ceramic piece obtained.

 The method also includes a step of filling the slits as well as a stage where the cake together with the filling of the slits is introduced into a furnace in order to dissolve at least a part of the filling of the slits, at the same time which transforms the initial cake into the ceramic piece itself.

 In another stage the ceramic piece extracted from the interior of the oven is subjected to a grinding on its face in order to eliminate the corresponding raised elevations with the filling of the grooves and perimeter partitions that border such grooves in its mouth.

The method is characterized because at the stage of the filling of the grooves it is first poured into them at less a first material on the bottom of such grooves and a second transparent granule material mixed with dry glue, said granule material being seen decorating the first material poured at the bottom of the grooves, once the oven phase has been overcome .

 The method is also characterized in that the cooking cycle of the initial cake together with the filling of the slits comprises:

 A first progressive rise from an ambient temperature to a temperature of 500 ° C;

 A second rise at a rate of 25 ° C per minute from 500 ° C to 1250 ° C;

 Maintenance of those 1250 ° C for a time ranging from 5 to 7 minutes;

 - A progressive drop in temperature from

1250 ° C to 590 ° C;

 A second temperature drop at a rate of about 5 ° C per minute to reach 490 ° C;

 A third progressive drop in temperature to reach 25 ° C.

 The product obtained comprises, in principle, a body with a decorative face that includes the slits occupied by the corresponding filling.

 The product obtained mentioned is characterized in that the filling of the grooves comprises at least a first material located at the bottom of the grooves and a second transparent material that shows the decoration of the first material previously poured on the bottom of such grooves.

 The product obtained is further characterized in that the first filler material comprises at least one body that maintains its structure unchanged after passing through the oven.

Another particularity of the product obtained is that the first filler material comprises a material of granilla mixed with at least one dry glue.

 Another alternative of the product obtained is that the first filling material comprises a granule material mixed with dry glue and coloring pigments, the proportion of which ranges from 3 to 10%.

 Another possibility of the invention is the incorporation of products to fill the slits, at least partially, to obtain metallic effects in the ceramic piece to be obtained. Thus, it will present in its face a decoration that will include metallic tones with veined effects with depth, opalescence and transparency, resulting in all this a ceramic piece with a high added value, both from the technical and aesthetic point of view.

 The metallic effect or tone can also be obtained by applying certain pigments incorporated together with the granule material with which the grooves are filled.

 Another option is that the material used to achieve the metallized effect is placed in some parts of the slit without the transparent granule, so that the slit locations that do not have the metallized material are decorated only with said transparent cover granule .

 Special care must be taken when filling the grooves with the material that provides the metallic effect, since it must not reach the surface that remains after the polishing stage, otherwise the metallic effect will be eliminated.

Next, in order to facilitate a better understanding of this descriptive report and forming an integral part thereof, some figures are attached in which the object of the invention has been shown as an illustrative and non-limiting nature. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1.- Represents a view showing a ceramic piece in an initial phase of the method of the invention. It is essentially observed a groove with a highlighted perimeter partition obtained in the initial phase of pressing a cake from which the ceramic piece will be obtained.

 Figure 2.- Shows a view of the slot occupied with the filling that overflows slightly above the highlighted perimeter partition that delimits the mouth of such a gap.

 Figure 3.- Shows a view similar to the previous one where the filling of the groove is flush with the free edge of the groove.

 Figure 4.- It shows a perspective view of a filling and pressing machine for the granulation of the holes or crevices of the biscuits made in the initial phase of pressing.

 Figure 5.- Shows a plan view of the machine. Figures 6A-D.- They show different arrangements of pieces that can be decorated in the filling and pressing machine.

 Figure 7.- Shows a view of a decoration added to the slits by an airbrush mechanism or the like.

 Figure 8.- Shows a view similar to that shown in Figures 2 and 3, with the difference that the filling of the slit is below the free edge of the highlighted perimeter partition of said slit.

 DESCRIPTION OF THE PREFERRED EMBODIMENT

Considering the numbering adopted in the figures, in an initial stage of pressing, as described in the Patent of Invention WO 2004/014624, the material or component materials of the initial sponge cake 1 and subsequent ceramic piece to be obtained 2, is pressed on such Biscuit 1 housed in a cavity of a lower plane 3 of the press by means of an upper plate 4. This, in turn, performs in this pressing operation, slits 5 on such initial cake 1 thanks to male elements 6 incorporating such upper plate 4, so that in this pressing operation a small raised edge or perimeter partition 7 that borders those recesses 5 emerges upwards as a result of the pressure exerted by the male elements 6 on the initial cake 1.

 Obtaining the raised partitions 7 is possible thanks to grooves 1 'established in the upper plate 4 and which border the male elements 6, raised partitions 7 which are located in the grooves 1' in principle during the pressing operation.

 The recesses 5, as is evident, will be established on the face of the piece or cake.

 Approximately the recesses 5 have a depth of 2.2 mm, while the perimetral partitions 7 raised upwards have an approximate height of 1 mm.

 The slits 5 can incorporate ribs 8, projections, areas in bas-relief or any other decorative element, as well as a rounded surface or a surface formed by several faces in different planes, all depending on the configuration of the male elements 6 integral with the upper plate 4 of the press.

 At a later stage, the biscuits 1 obtained in the press pass to an intermediate stacking station 9 and from there to a bed of rollers 10 that are part of a machine 11 by which a filling 15 is poured and pressed to be poured onto the recesses or indentations 5 of the biscuits 1.

 These biscuits 1 obtained in the first pressing phase could also pass directly to said machine 11.

As it is an automatic process, the stacking station 9 is very good for when there is any decompensation or interruption in any of the mechanisms and devices, whether in the press, machine or any other.

 The machine 11 further comprises a horizontal screen 12 arranged above the roller bed 10 and which incorporates recesses 13 that correspond exactly to the slits 5 of the biscuits 1, so that when these slits 5 and recesses 13 are facing each other , from a longitudinally displaced upper hopper 14, in a first embodiment, grainy materials, dry glue and other materials as filler 15 will fall by gravity to occupy the space of the slits 5 of the biscuits 1.

 The screen 12 can be moved in a vertical direction in order to regulate its approach to the biscuits 1, depending for example on its thickness.

 The hopper 14 can include a single department or several in order to be able to pour the granule of different colors into the slits 5. The material outlet of the hopper 14 will be regulated by one or more chopping boards 16.

 The hopper 14 includes a vibrating mechanism 17 that facilitates the exit of the material, at the same time that it is coupled to small supports 18 in turn coupled in longitudinal guides 19 with interposition of rubber damping elements 20 to absorb the vibrations of the hopper 14 produced by said vibrating mechanism 17.

 The displacement of the hopper 14 to match its outlet mouths with the slits 5 of the biscuits 1 to pour the filling 15, such displacement is carried out through a motor element 21 associated with a chain, belt 22 or similar, which is hooked the hopper at its ends and related to a pinion 23 embedded in the shaft of such motor element 21.

Once the slits or gaps 5 of the initial sponge cake 1 have been filled, it passes to a rear part of the machine where apart from the roller bed 10, there are two upper rollers, one front 24 and one rear 25, which press on the filling 15 for pressing and compacting, the filling 15 being flush approximately with the free edge of the perimeter partitions 7 raised ones that surround the different indentations 5.

 The granulometry of the granule and dry tail of the filling 15 will be located between a minimum value of 5 microns and a maximum value of 1000 microns. In this way, the compaction without empty spaces of the filling 15 inside the recesses 5 will be markedly increased, as will also be increased the quality of the decorative motifs without deformations in such decorative motifs.

 To obtain a better result even if it fits, the first pressing roller 24 rotates at the same speed as the rollers 10 that serve as a bed and seat to the cake 1, while the other even pressing roller 25 will rotate at a slower speed, approximately 10 % less turning speed.

 The pressure exerted by these two pressing rollers 24 and 25, essentially the second, provides a compacting effect without empty spaces in the granule and dry glue filling 15 within the slits 5 of the biscuits 1.

 At a later stage, the cake 1 is removed from the machine 11 to be introduced into an oven where the mixture of granule and dried glue will dissolve to a liquid state reducing its volume somewhat, although its free level will always exceed the surface of the face view of the ceramic piece 2 already formed, where the mixture of the filling 15 will be integrated in such ceramic piece 2 in the rough.

Finally, the ceramic piece 2 will be subjected to a grinding process that will only affect the corresponding highlighted areas with the grooves 5 occupied by the filling 15 of the granules and other materials, together with the solidified dry tail, so that after a period of time the entire surface of the face will be flush to the same level.

 In the case that the design does not require a groove width of more than 5 mm. wide, the same plate of the press will make an intermediate rib being decorative on the product and thus achieve the desired measure without problems of contractions and couplings, so that the length can be as desired.

 The possibility of incorporating one or several airbrushes 26 to paint the lateral surfaces of the grooves 5 is provided in order to achieve a color effect depending on the visual incidence side.

 This operation will be carried out before passing the cake under the hopper for filling its grooves.

 Optionally, the mass of the filling 15 could be constituted by a liquid or pasty material, whereby the pressing rollers 24 and 25 could be dispensed with.

 As is more clearly shown in Figures 2, 3 and 8, a new possibility of the invention at hand is that a first filling material 15 'being poured onto the bottom of the slit occupying only a part of the total volume of the slits 5, the rest of the slot space being then filled with a second filling material 15 '' of transparent granule so that the decoration provided by the first filling material 15 'initially poured onto the bottom of such slits 5 is seen.

In a first option, the first filling material may consist of a granule with the addition of dry glue and as a second option the deposition on the bottom of the slits of small decorative elements that would later be embedded in the granule material could be considered transparent spill occupying the resulting space of the slits, keeping said decorative elements its initial structure unchanged.

 Another possibility of the invention is that the granule material is coated with a pigment according to the desired color.

 Thus, to obtain the colored granules that are placed under the glazing cover, glaze dyes with a temperature range between 920 and 1250 ° C suitable for the firing cycle of the base (porcelain) constituting the initial cake are used.

 The dye pigments are mixed with the granule in low proportions ranging from 3 to 10%, depending on the intensity of the color that was intended to be achieved. To achieve a homogeneous mixing (the dyes completely cover the surface of the granule) the mixture is vigorously stirred for several minutes. In laboratory applications, it was not considered necessary to use a fixative that kept the mixture achieved by this batter technique uniform over time.

 Depending on the effect to be achieved, the number of passes will be regulated, as well as the speed (getting more or less amount of granules deposited) using the filling and pressing machine 11.

 When decorating with colored granule, to achieve the effects under cover, the screen used has a smaller step (depending on the size of the colored granule) trying to leave the minimum amount of color that achieves the effect of depth.

 The granule used for the cover, in this case of larger size, once applied it must exceed the edge of the groove to achieve a correct filling that avoids problems after the polishing operation (the surface presents irregularities giving rise to unpolished forms).

The screens used for this last application have a greater step, and the design must be somewhat larger than the groove. This stage of application must also ensure a Good packing to prevent air from being occluded between the particles of granilla that could be the cause of the appearance of defects by bubbles. The packing density is increased if the piece has vibrated a little.

 Once the granule is applied, the piece passes through the rollers 24 and 25 mentioned above, so that by means of a slight pressure the packing of the granules deposited inside the groove or corresponding grooves 5 is improved.

 The ceramic pieces to be obtained are introduced into a laboratory muffle resistance furnace. The programmed cooking cycle is as follows:

 Progressive rise from an ambient temperature to a temperature of 500 ° C.

 Rise at a rate of 25 ° C per minute from 500 ° C to 1250 ° C.

 Maintenance of those 1250 ° C for a time ranging from 5 to 7 minutes.

 - A first progressive lowering of temperature until reaching 590 °.

 A second temperature drop at a rate of 5 ° C per minute to reach 490 ° C.

 A third progressive drop in temperature to reach 25 ° C.

 The decorative motifs with colored granules contrast with the areas decorated with the cover granule and the enamel at the interface. The granule used for coloring has allowed the color not to be integrated, being able to see in the background the colored particles that have not melted. With the invention at hand, most of the decoration forms allowed by the system are collected.

Claims

 1.- METHOD FOR DECORATING CERAMIC PARTS, which comprises an initial stage of pressing a conglomerate of component materials of an initial sponge cake obtained in a press that has a lower plate with a cavity where such material conglomerate is housed and an upper plate that press on these materials to form the initial sponge cake, from which the ceramic piece will finally be obtained by passing through a baking phase, forming in that initial stage of pressing some slits (5) by means of male elements (6) in solidarity with the upper plate (4), a perimeter partition emerging upwards in this pressing operation (7) that borders such grooves (5) protruding above the upper face seen from such initial sponge cake (1), face that corresponds later with the decorative face of the ceramic piece obtained;  a step filled with slits (5);  a stage where the cake (1) together with the filling of the grooves (5) are introduced into an oven in order to dissolve at least a part of the filling of the grooves, while transforming the initial cake into the ceramic piece proper;  - a stage where the ceramic piece (2) extracted from the interior of the oven is subjected to a grinding on its exposed face in order to eliminate the corresponding raised elevations with the filling of the grooves and also with the raised perimeter partitions that border such grooves; characterized in that at the stage of the filling of the grooves, at least one first filling material (15 ') is poured thereon on the bottom of such grooves and a second filling material (15'') of transparent granule mixed with glue dry, looking at through said transparent granule material the decoration of the first filling material (15 ') poured into the bottom of such slits (5).  2. METHOD FOR DECORATING CERAMIC PARTS, according to claim 1, characterized in that the initial sponge cake cooking cycle together with the filling of the slits (5) comprises:  a first progressive rise from an ambient temperature to a temperature of 500 ° C;  - a second temperature rise at a rate of 25 ° C per minute from 500 ° C to about 1250 ° C; maintenance of those 1250 ° C for a time ranging from 5 to 7 minutes;  a first progressive decrease in temperature from 1250 ° C to 590 ° C;  a second temperature drop at a rate of 5 ° C per minute to reach 490 ° C;  a third progressive temperature drop to reach 25 ° C.  3.- PRODUCT OBTAINED WITH THE DECORATION METHOD CERAMIC PARTS, which in principle comprising a body with a decorative face that includes slits (5) occupied by a filling, is characterized in that the filling of the slits (5) comprises at least a first filling material (15 ') located in the bottom of the slits (5) and a second filling material (15 '') transparent that reveals the decoration of the first material.  4. - PRODUCT OBTAINED WITH THE METHOD FOR DECORATING CERAMIC PIECES, according to claim 3, characterized in that the first filling material (15 ') comprises a body that maintains its structure unchanged after passing through the oven. 5. - PRODUCT OBTAINED WITH THE METHOD FOR DECORATING CERAMIC PARTS, according to claim 3, characterized in that the first filling material (15 ') comprises a granilla material mixed with at least dry glue.  6. PRODUCT OBTAINED WITH THE METHOD FOR DECORATING CERAMIC PARTS, according to claim 3, characterized in that the first filling material (15 ') comprises a granule material mixed with dry glue and also with coloring pigments whose proportion ranges from 3 and 10%.