PT1266734E - Method and apparatus for the making of tiles, in particular for venetian floor tiles and the like - Google Patents

Abstract

A method for the making of tiles able to be used as surfacing and support plane, which reproduce, in their motifs and techniques employed, so-called Venetian style floors, comprises the phases of: laying a first layer of grout on a planar support; vibrating the grout; placing a quantity of gravel on the surface of said first layer of grout; subjecting said support to sussultatory vibrations, determining the partial burying of the gravel in said first layer of grout; laying, onto said first layer of grout, a second layer of grout obtaining a semi-finished tile; vibrating the whole semi-finished tile; and drying said semi-finished tile. <IMAGE>

Description

Description and method for the manufacture of tiles, namely Venetian tiles and the like &quot; The present invention relates to a method of manufacturing tiles and other similar boards, intended to be applied as flooring and flat support surfaces, and which reproduce the so-called Venetian mosaics through the motives and techniques applied. The invention also relates to a machine for creating tiles and a plant for their manufacture.

This type of pavement, known for its aesthetic qualities, consists of the application, directly on top of the surface substrate that receives the floor, of a layer of a semifluid insulating material. Said material, well known to those skilled in the art, as well as those based on this type of flooring, should be referred to by its conventional name of fine mortar. It is a mixture essentially of water, cement, marble powder, etc. The characteristics of the blend may vary in order to satisfy the requirements of the application process, in particular with respect to porosity, color, specific weight and the like.

In solidification, it acquires considerable properties of stiffness, strength, ability to be smoothed and polished, producing a shiny surface. In the liquid state, it has the properties of a molten plastic fluid with a reduced viscosity that allows it to drain.

In the mortar layer applied to the substrate with a uniform thickness discrete gravel elements are placed, and this operation is conventionally called gravel placement, these elements being composed of fragments, of different shapes and sizes, of rocks, marbles, granites , glass, etc., selected according to the color, size and effect to be created on the floor.

It is known that by applying said gravel it is possible to obtain a mixture of different colors and stones, as well as a well-ordered and precise drawing according to the pattern of a mosaic, as well as all possible intermediate solutions.

After application of the gravel, an additional layer of mortar is thoroughly applied, which will air dry, a process that can last for several days.

When the entire layer applied to the substrate reaches sufficient stiffness and density, after complete curing of the cement, which lasts for at least one month, it can be smoothed and polished, starting with coarse-grained discs and ending with polishing discs. The elimination of the uneven surface previously obtained allows, on the one hand, to obtain a flat, smooth, shiny and compact surface with a high resistance as a road surface against impacts and other types of friction, infiltration of liquids and other elements harmful. On the other hand, polishing causes the gravel layer to emerge completely, allowing the motifs created during the application phase of the layers to be fully visible, with all their aesthetic grandeur and, in many cases, artistic impact.

From the foregoing description, it is understood that this type of pavement, distinguished by its high value, is reserved for those who can bear the high costs and time associated with such a complex operation as is the application process.

Thus, methods have been developed which are known in the art for creating tiles which, once applied, are capable of simulating the type of floor described above.

These methods usually derive from the formation of a conglomerate of mortar and gravel which, once dried, can be cut into tiles.

Another method is to use a flat support surface on which mortar and gravel are introduced.

However, this method allows only the production of marbled tiles or blocks with stones in the interior, which is notoriously different from the so-called Venetian mosaics. 4

For example, Japanese Patent No. 04 112003 A protects the use of a mold in which a first layer of concrete is formed, while decorative stones are being placed, allowing the vibration to uniform the upper ends up to the same height. Finally, a second layer of concrete is poured. U.S. Patent 3,324,213 describes a method for creating decorative tiles by using a mixture of resins and decorative stones poured onto a support and carrying out a step which consists in moving a pressing and vibrating element on the surface of said mixture, in order to standardize the distribution of the stones.

In addition, this system allows to produce tiles, whose gravel is distributed according to a disordered matrix, without the ability to obtain drawings. Moreover, once the tiles are completed while minimizing the thickness of the slit, the transition from one tile to the other is nonetheless perceptible because of the irregular arrangement of the cut of the tiles in correspondence with the edge of the tile itself next to another .

These disadvantages, in spite of the reduction in costs associated with the application process, which is thus reduced to a simple laying of tiles, are such as to considerably limit the use of this type of flooring. The technical problem which forms the basis of the present invention is to provide a method for the manufacture of tiles which makes it possible to overcome the aforementioned disadvantages with respect to the prior art.

This problem is solved by a method, as specified in claim 1, which comprises the following steps: • Apply a first layer of mortar on a flat base; • Place a small amount of gravel on the surface of the first layer of mortar; • Subjecting said base to vertical vibrations, determining the partial burial of the gravel in the first layer of mortar. • Apply, on top of the first layer of mortar, a second layer of mortar, obtaining a semi-finished tile; • Vibrate the semi-finished tile; and • Dry the tile.

According to a prototype of the invention, the method includes the further step of polishing the surface of said semi-finished tile until a predetermined degree of finish is achieved. In any case, the smoothing and polishing phases can also take place after application to a suitably prepared substrate. Partial polishing of said surface is also possible. In this case, a method of laying the tiles obtained as described above allows placing an additional thin layer of mortar on the seated tiles, where the limited thickness of that additional layer allows rapid drying followed by a polishing process which eliminates any trace of crack between the tiles.

In any case, the transition between one tile and another is difficult to detect given the absence of irregularities at the edge of the tile. The placement of the gravel in the method corresponding to the invention can occur at any level of precision. It can range from a mechanical and automated application to a manual application, which, among other advantages, allows obtaining well-defined mosaics and designs.

According to the same inventive concept, a machine for forming tiles and other similar Venetian mosaic tiles includes: A mold structure capable of containing semi-fluid mortar; • Means for placing the semi-fluid mortar in said structure; 7 • A vibrating element on which the structure rests; and • Means for producing vertical vibrations.

A plant for making Venetian tiles and the like according to claim 9 includes the machine defined above, means for drying semi-finished tiles and means for effecting the finishes on the rough surface of the tile. The present invention will be described below in accordance with a prototype, together with some variations, provided in the form of numerous examples with reference to the accompanying illustrative drawings, in which: Figures 1 to 6, 7a, 7b, 8a and 8b show schematically some steps of the method corresponding to the present invention in combination with details of a molding instrument; and Figure 9 shows a schematic view of a plant for implementing the method corresponding to the invention.

Referring to Figures 1 to 6, there is partially shown an instrument 1 for creating tiles, limited to the detail in which the tile is formed. 8

This same instrument is composed of a vibrating element 2, a flat bearing element, which is driven by the vibration generating means 8.

At the top of the vibratory element 2, the instrument 1 includes a mold structure 5, which in turn is composed of a flat support base 50 delimited by walls 3, which define a predetermined thickness. Between the vibratory element 2 and the mold structure 5, there is a buffer layer, the function of which will become apparent hereinafter. The instrument 1 includes a distribution means 6 which transfers a certain amount of semi-fluid mortar. This distribution means 6 is conveniently structured in funnel form and receives the mortar from a system which mixes and distributes components of the mortar itself.

With respect to instrument 1, a first step of the method corresponding to the present prototype comprises the step of applying a first mortar layer 70, determined by the application of a first predetermined amount 7 of mortar, through said distribution means 6 (Figure 1).

As soon as the predetermined quantity 7 of mortar is placed inside the mold structure 5, the vibrating element 2 is driven. The vibration generating means 8 is structured so as to encompass a set of off-center elements, conventional in nature and thus not disclosed here, based on mutually parallel shafts which are also parallel to the flat support base 50, in a rotatable manner, for example by means of bearings or bushes, to the vibratory element.

These shafts are arranged in mutually opposite rotations, with the same rotational speed, so as to produce a vertical vibration which will ensure that the application of the mortar layer occurs uniformly from the point of view of density and thickness. The damping layer 4 acts to cancel the effect of any second-order vibration which may be generated together with the necessary vertical vibrations. By the way, the term vertical vibration refers to the vibration which determines reciprocal movement in a direction which is perpendicular to the vibrating element 2, or the flat bearing base 50. The thickness of the first layer of mortar 70 corresponds to about half the thickness determined by the walls 3 of the mold structure 5. In the present prototype, the thickness is 6-7mm (Figure 2).

Once the application of the first layer 70 is completed, the method includes the step of placing a certain amount of small gravel 9 in that first layer. Various methods can be employed in gravel placement; the most accurate method is the manual, where it is possible to obtain, thanks to the specialized technique applied here, a &quot; natural &quot; or, on the contrary, an accurate design, oriented with appropriate standards. It is entirely clear that this step can be carried out through other application processes, in particular by mechanical methods which discharge a predetermined amount of gravel. It is also clear that the gravel in question is composed of irregular fragments of different sizes and possibly even different colors.

With the application process, a structure is obtained where the mortar layer 70 is superficially covered with the gravel, the fragments of which are partially buried in the semi-fluid mortar or laid to the surface (Figure 3).

At this stage, the method according to the present invention includes the method of subjecting said planar support base 50 to vertical vibrations through said generating means 8. Due to the particular nature of the vibrations and the density of the mortar 7, the gravel is partially buried in the first mortar layer 70, with a substantially uniform distribution 10 (Figure 4).

With the delivery means 6, at a subsequent stage of the present manufacturing method, a second predetermined quantity of mortar is released, to fill the mold structure 5 upwards (Figure 5). This second quantity of mortar then becomes a second layer of mortar, applied above the first, to give rise to a semi-finished tile 12.

To achieve this point, the mold structure is again subjected to vertical vibrations, which determine the application of the added mortar and the uniform distribution of the mortar 9 over the entire thickness and the entire surface of the semi-finished tile 12 (Figure 6) .

At this stage, for the semi-finished tile to face all subsequent processes, it is subjected to a drying step. The drying process can occur naturally or in an environment which promotes dehydration and curing (crystallization) of the mortar, for example by means of temperature controlled drying ovens.

During this process, the semi-finished tile 12 is contained in the mold structure 5, which will then be eliminated, if it is disposable, or reused. The separation of the tile about to be finished from the mold structure 5 can be facilitated by lubricating the inner surface of the mold structure 5 prior to the application of the first layer of mortar. 12

It should be noted that no gravel fragment will pass beyond the edges of the semi-finished tile, as when a whole block of mortar and solidified gravel is cut to produce tiles in this way. The presence of these fragments would allow an attentive observer to detect the presence of a slit, although tenuous, between the tiles, after the application process has finished. In addition, uniform distribution prevents the edge of the tile from being identified due to a thinning of the gravel at the edges. These characteristics are highly appreciated because they allow the flooring acquired by the tile settlement to approach the floor acquired through traditional methods, where the mortar and the gravel are applied directly to the substrate.

It should also be noted that this traditional effect can therefore be achieved by avoiding a specific preparation of the substrate and the long waiting period for drying the floor, all with a reduced tile thickness of less than 20 mm. The finish of the semi-finished tile 12 can cover different phases, which depend on the type of application depending on the location for which the tiles are intended. In general, the finish goes through a series of polishing operations, using discs with progressively thinner granulation, until a shiny surface is obtained. The purpose of the polishing process is also to level and regularize the gravel fragments emerging from the surface of the semi-finished tile. The finish passes through a first general polishing step with the first disk 14 acting on a rough tile P, based on a support base 13. An irregular surface 15 is obtained, which can be exploited during the application process. The rough tile P can be applied in a normal manner, obtaining a uniform surface, although not shiny.

On this same surface, it is possible to apply a thin layer of mortar, using traditional methods with spatulas, capable of drying very quickly. Subsequently, the obtained flooring can be polished until the glossy finish is obtained, eliminating any type of slit or junction between the tiles.

If the aim is a further improved tile, it is possible to proceed to a second polishing step with the second, finely fine, fine-grained polishing disk 16 to provide a shiny surface 17 (Figure 9). With this tile, it is possible to execute a fast application, in everything similar to the one executed with ceramic tiles, obtaining a Venetian pavement.

Referring to Figure 9, there is described an installation 20 for the manufacture of Venetian tiles according to the method described above. This installation includes an assembly line 22, along which the mold structures 5 move through a series of substations, some of which are provided with vibration generating means 8.

This line 22 includes a kind of inlet 21, which receives the blank 5. There follows the first substation 35, where the mold structures are lubricated, and the second substation 36 for the application of the first mortar layer 70. For this purpose, the plant includes tanks 25 with fluid material for the composition of the mortar in proportions predetermined. These tanks 25 are connected to the mixing tanks 26, where the mortar is mixed and fed into an inlet pipe 27, which, in turn, feeds two delivery pipes 23 and 24 to respectively apply the first and second layers of mortar 70.

In this part of the installation, the coloring of the mortar is determined; this same coloration usually remains the same for a certain group of tiles. In any case, maximum flexibility is allowed. The lubrication process can be manual or automatic. The first manifold 23 supplies mortar to said second substation 36, which is followed by a third substation 37, where the vibration generating means 8 is used to uniform the first mortar layer 70.

In a fourth substation 38, the gravel is distributed to the surface, preferably by the manual method by a skilled worker, using patterns to guide the application.

It should be noted that this approach allows the production of individual pieces for the composition of floors which may have extremely complex designs. The operator will then be able to apply the standards, made of for example carton, produced automatically through a computerized CAD / CAM system, through which the floor itself is drawn and drawn.

At a fifth substation 39, the vibration generating means 8 contributes to burying the gravel in the mortar by a correct procedure, and the operator will be able to immediately check that the gravel, which is substantially fixed to the mortar at this stage, assumes the desired arrangement.

In all the phases where the vibration is applied, and in particular in which the gravel will be buried in the mortar, the duration of the same application can be controlled tile by tile by the worker, to obtain a uniform quality level also to vary the amount of gravel, piece size, gravel density, design complexity, etc. 16

In other cases, for large-scale productions, the duration of the vibration can be pre-established.

Subsequently, at a sixth substation 40, fed by the second mortar distribution tube 24, the semi-finished tile carries said second mortar layer 11, and, at a seventh substation 41, the vibration generating means 8 produces a semi- finished with the desired thickness. The fourth substation 38, where the expert technique that the present method explores is concentrated, can be subdivided into multiple substations for the application of different types of gravel. However, it is understood that the same quality can be obtained by a mechanical, active application method, for example, with screens with patterns, for gravel designs, and conventional methods for gravel transport. The same mechanical method can operate with the aforementioned CAD / CAM system for the production of large scale tiles.

After the seventh substation 41, the mold structures are transported in appropriate conditioned spaces 29 to cure the tiles. Conveniently, this space contains a multiplicity of shelves 28 to keep the mold structures stacked, but allowing the circulation of the air and the vapor produced by an appropriate temperature controlled conditioned system. ✓ 17

From the shelves 28, the mold structures 5 containing the cured tiles, ready to be transported to a finishing plant, indicated by the reference numeral 42, are composed of an arm 30, with an apparatus 43 for extracting the tile semi-finished product of the respective mold structure 5, which, if intended to be reused, will be cleaned.

From the extraction apparatus 43, a conveying line is moved which moves the semi-finished tiles through a multiplicity of finishing stations.

In the prototype described here, the finishing plant 42 is successively composed of a first and a second calibration station 31 and 32, provided with high granulation polishing discs, with which it is possible to obtain a rough tile already suitable for be applied with a view to an on-site finish.

Subsequently, the plant has a third finishing station 34, which, with a series of thin, fine-grained discs, produces a glossy surface which renders the tiles ready for the application of a finished floor.

Through the above description, it is readily apparent that the method of manufacture and the installation are capable of producing not only tiles, but also any type of ceramic surface, for example, floor tiles, baseboards, steps, walls, bathrooms , kitchen countertops and bathrooms, decorations of different types, etc.

The formats can be the most diverse and, above all, can be adapted to specific requirements. In particular, the above described mold structures may be fabricated locally, using plastic sheets, capable of being hot molded to the desired shape.

In this way, it is possible to avoid cutting the produced tiles, which would make evident, for the reasons described above, the joints between the tiles.

To the method described above, a person skilled in the art may, in order to satisfy additional and contingent requirements, make numerous modifications and variations, all included within the scope of protection of the present invention, as defined by the appended claims.

Lisbon, October 9, 2006

Claims (12)

Method for the manufacture of tiles and other similar plates, intended to be used for flooring and planar support surfaces, which reproduce the so-called Venetian mosaics by means of applied motifs and techniques, comprising the following steps: a first mortar layer (70) on a flat support base (50); Placing a certain amount of gravel (9) on the surface of said first mortar layer (70); Subjecting said planar support base (50) to vertical vibrations, determining the partial burial of the gravel (9) in said first mortar layer (70); • applying, in said first layer of mortar (70), a second layer of mortar, obtaining a semi-finished tile (12); • vibrate the tile; and • dry the same semi-finished tile (12). A method as recited in claim 1, wherein said first mortar layer (70) is applied through vertical vibrations. 2 A method as recited in claim 1, wherein said second mortar layer is applied through vertical vibrations. A method as recited in claim 1, wherein the application of the gravel is performed according to a drawing and by means of a pattern. A method as recited in claim 1, wherein the polishing step of the surface of said semi-finished tile is carried out until a predetermined finishing level is achieved. A method as recited in claim 1, wherein a partial surface polishing of said semi-finished tile is made. A method as recited in claim 1, wherein the curing step is carried out by means of a temperature controlled oven. A method as recited in claim 1, wherein the planar support base (50) is lubricated prior to the application of said first mortar layer (70). An installation (20) for the manufacture of Venetian tiles, according to the method of claim 1, comprising an assembly line 22, along which the mold structures (5) move, incorporating: a kind of inlet box (21); a first substation (35) where the mold structures (5) are lubricated; a second substation (36) for applying a first layer of mortar (70); a third substation (37), with vibration generating means (8) for uniformizing the first mortar layer; a fourth substation (39) for distributing the gravel (9) to the surface; a fifth substation (33) with a vibration generating means (8) for burying the gravel in the mortar; a sixth substation (40) fed by a second quantity of mortar (11); and a seventh substation (41) with vibration generating means. An installation (29) as recited in claim 9, wherein the fourth substation (38) is subdivided into multiple substations for the application of different types of gravel. An installation as recited in claim 9, comprising conditioning spaces (29) for curing the tiles with a multiplicity of shelves (28) for stacking the mold structures (5), but allowing the circulation of air and steam produced by an appropriate temperature controlled conditioning system. An installation (20) as recited in claim 9, comprising a conveying line for moving the semi-finished tiles through a plurality of finishing stations. Lisbon, October 9, 2006