Method, apparatus and product

The invention relates to a method and an apparatus for decorating a transparent object and an object comprising a decorated transparent body. Silk—screen printing is known to be used in order to decorate transparent objects, for example objects of glass. The silk—screen printing provides that a plurality of decorating products, all having a particular color, is applied on an object to be decorated. The decorating products are deposited on a face of the object designed to result in view, during the use. The decorating products are applied each after the other, each one by means of a dedicated net, or silk screen. Silk—screen printing further provides that, after the decorating products have been applied, the object is kept a furnace for a certain interval of time, so that the decorating products are fixed to the object.

A drawback of the silk-screen printing is that said silk- screen printing does not enable to obtain particularly accurate decorations.

Actually, first of all, the use of screens provided with meshes through which the decorating products pass does not enable high definitions to be obtained. In addition,, since the object to be decorated interacts. sequentilly with a plurality of nets, or silk—screen, :it ^' .may- result that the interaction of a decorating product already applied on the object with one of the screen arranged downstream of the screen with which such a decorating product has been applied generates wipes and, consequently, compromises the clarity of the decoration.

Another drawback of the silk—screen printing is that said silk—screen printing produces very muddy decorations since, during the firing, the decorating products penetrate into the glass that is partially softened.

A further drawback of the silk-screen printing is that said silk—screen printing requires a rather complex and, consequently, a very expensive system.

Consequently, also regardless of the poor quality of the obtainable decorations, the silk—screen printing may be used for productions in series that involve the achievement of a significant number of objects, so that said high costs can be amortized by a correspondingly high productivity. The use of the silk—screen printing, on the contrary, is not economically convenient in the case of small lots of production and, a fortiori, when each of such production lots comprises only a few pieces.

Stamp printing is further known for the decoration of transparent objects, which stamp printing provides to apply, once at a time, a plurality of decorating products on a object to be decorated.

However, such a printing technique exhibits substantially the same drawbacks already highlighted with reference to the silk—screen printing. The use of transfers is further known, that are applied to an object to be decorated, such object being then maintained within a furnace for a certain interval of time in order to enable the transfers to stably adhere. A drawback of such a decorating mode consists in that the transfers can be used only in the case of objects showing a face to be decorated that is substantially planar. In addition, a dedicated master copy must be provided for every typology of transfer that is desired to be obtained, i.e. a master copy arranged for generating the decorating pattern that has to be produced by the transfer.

Since the production of said master copy implies a significantly high cost, the use of the transfers is economically unadvisable in the case that lots have to be produced comprising an extremely small number of objects. An object of the invention is to improve the decoration of transparent objects.

Another object of the invention is to improve the quality of the decorations that can be obtained on transparent objects. A further object of the invention is to obtain a method and an apparatus for decorating transparent objects that enable decorating patterns to be obtained that are qualitatively of very high value .

In a first aspect of the invention, a method is provided for decorating a transparent object, comprising depositing a UV ink on a face of said object by means of ink—jet distributing means so as to obtain a decorating pattern on said face, further depositing a covering material on said face in order to cover said decorating pattern. In a second aspect of the invention, an apparatus is provided for decorating a transparent object, comprising ink-jet distributing means arranged for depositing a UV ink on a face of said object so as to obtain a decorating pattern on said face and distributing means arranged for further depositing a covering material on said face in order to cover said decorating pattern. In a third aspect of the invention, an object is provided, comprising a transparent body, a UV ink deposited on a face of said transparent body in order to obtain a decorating pattern and a layer of covering material deposited on said UV ink. _ Owing to these aspects of the invention, a transparent object can be obtained provided with an aesthetically very valuable decoration.

First of all, the use of ink-jet distributing means enables decorations to be obtained having a very higher definition than those obtainable with the printing methods according to the State of the Art .

Furthermore, the use of ink—jet distributing means provided in the context of a digital printing device - enables lots to be produced also comprising a very small number of objects, without that is economically disadvantageous, as that occurs with such printing

techniques that, for any decorating pattern to be obtained, require a dedicated screen, or master copy. Actually, the ink—jet distributing means enables a desired decorating pattern to be obtained on any number of objects without that involves modifications of the ink—jet distributing means, or, more in general, the digital printing device. In addition, the use of a UV ink enables particularly bright decorations to be obtained. The ink—jet distributing means, furthermore, also enables to print on corrugated, irregular surfaces, which are provided with very deep grooves and/or quite high ridges, that contributes to animate the decorating pattern, by improving the aesthetic appearance of the object. Furthermore, owing to these aspects of the invention objects can be obtained wherein the decorating pattern is not made on a face designed, in the use, to result in view, but on a face opposed to the face designed to result in view. In this case, the decorating pattern results visible through the transparent object, that contributes to give a depth effect to the decorating pattern self.

In addition, the layer of covering material enables the decorating pattern to be highlighted.

In particular, in the case that the covering material is a metallic material constituting a bottom. layer .of the..obj.ect , . - an.-increase of the brightness .of"the ^• decorating pattern is noticed and, consequently, a particularly pleasant aesthetic effect .

The UV ink is fixed to the object without this latter has to be subjected to a thermal treatment. That constitutes a significant benefit with respect to the methods according to the State of the Art, wherein the decorating products are fixed to the object by means of firing in furnace after the application of the decorating products selves. The invention can be better understood and carried out with reference to the enclosed drawings, that illustrate an exemplifying and non-limitative embodiment thereof, wherein:

Figure 1 is a cross section of a decorated transparent object;

Figure 2 is a plan view of decorated transparent objects used as ornamental inserts for tiles; Figure 3 is a cross section like Figure 1 highlighting a decorated transparent object, obtained according to a variation of the invention;

Figure 4 is a diagram of an apparatus for producing decorated transparent objects; Figure 5 is a variation of the diagram of Figure 4.

With reference to Figure 1 an object 1 is shown comprising a body 2 made of transparent material, for example glass.

The body 2 comprises a face 3, designed, in the use, to result in view, and a further face 4, opposed to the face 3. The further face 4 may exhibit a corrugated surface, so as to give the object 1 a more pleasant aesthetic effect.

A UV ink 5 is associated with the further face 4, said UV ink 5 defining a decorating pattern that results visible through the transparent material constituting the body 2, so that a certain depth is given to the decorating pattern that increases the agreeableness of said decorating pattern.

A covering material 6 is associated with the UV ink 5 contributing to set off the decorating pattern. The .covering material 6 may be a layer. of metal covering the glaze UV 5 and highlighting the brightness -thereof . ~ \., ^r

Between the further face 4 and the UV ink 5 a layer 7 of primer may be provided, for example of the type BondAid I, i.e. a UV primer.

Between the UV ink 5 and the covering material 6 a middle layer 8 may be provided.

The middle layer may comprise a transparent paint giving brightness to the UV ink 5 and acting as a bond coat for the covering material 6.

A protective paint 9, for example of the UV type, or an acrylic paint, or a polyurethane paint, or a paint of other type, may be associated with the covering material 6,

preventing the covering material 6 from being deteriorated and detached from the UV ink 5, or from the middle layer 8, when present .

With reference to Figure 4, an apparatus 10 is schematically shown in order to produce decorated transparent objects.

The apparatus 10 comprises a digital printing device 11 provided with ink—jet distributing means providing to deposit the UV ink 5 on the further face 4 of the body 2, as that was disclosed above. The digital printing device 11 comprises transport means that carry the body 2 - or a plurality of bodies 2 - to interact with ink distributing nozzles with which printing heads are provided with which the ink—jet distributing means is equipped. The ink—jet distributing means may be of the type with eight steps of printing and with variable drop.

The ink—jet distributing means performs a double pass on the body 2 so as to obtain good contrast and high covering power. The digital printing device 11 comprises one, or more, UV rays lamps providing to fix the UV ink 5 to the body 2 as soon as said UV ink 5 is deposited by the ink—jet distributing means. The digital .printing device 11 can operate in six—color_ 'printing - ^" and enables -decorating .patterns < ,to be obtained having a resolution up to 1200 x 2400 DPI.

The apparatus 10 further comprises a metallizing device 12, arranged downstream of the digital printing device 11, said metallizing device 12 depositing the covering material 6 on the body 2 , so as to cover the UV ink 5 , i.e. a layer of metallic material, or a metallizing ink, or a compound, capable of giving a metallic appearance to the substrate to which it is applied. The metallizing device comprises a dispensing device, or applicator, that applies the covering material 6, in form of a metallizing ink, or compund. The dispensing device, or

applicator, may be, for instance, a silk-screen device, or a spraying device.

The metallizing device 12 may comprise a kiln in which the body 2 is arranged in such a way as the face 4 of the body 2 does not rest on the support of the kiln. Subsequently, the body 2 is kept at a preestablished temperature for a given time interval, in order to fix the metallizing ink to the UV ink 5 permanently. Alternatively, a layer of metallic material may be applied on the UV ink 5 by means of cathodic deposition from an electrolytic solution containing dissolved ions of salts of the metallic material that is intended to be applied. The metallic material may also be applied by precipitation from a saturated solution of dissolved ions of salts of the material that is intended to be applied. The precipitation may be brought on by adding appropriate quantities of precipitant substances to the saturated solution. In an alternative embodiment, the metallizing device 12 comprises a chamber, i.e. an autoclave, within which a very high vacuum is obtained.

Resistors are provided within said chamber, which resistors bring metallic wires, for example of copper, or aluminum, or brass, to melt so that metallic vapors are present at the interior of the chamber. The metallizing device 12 further comprises a frame accommodated within the chamber - with which frame edge regions of the body 2 may be fixed.

The metallizing device 12 further comprises moving means that moves - in particular rotates - the frame within the chamber so that metallic particles at the vapor state are deposited on the body 2 so as to cover the UV ink 5. Before the body 2 is inserted into the chamber, a sheet material is applied onto the face 3, which sheet material will be successively removed, so that the layer of metallic material is deposited only onto the further face 4 and is not deposited onto the face 3.

Before the metal is brought to the vapor state, the body 2 is subjected, within the chamber, to a ionic discharge that aids the metallic particles to successively adhere to the body 2. Alternatively, instead of the metal spraying device 12 a distributing device may be provided, that provides to apply a non metallic covering material 6 to the body 2. In a version, the apparatus 10 comprises a dispensing device 13, arranged downstream of the metal spraying device 12, providing to apply the protective paint 9. When the protective paint 9 is of the UV type, the dispensing device 13 comprises one, or more, UV rays lamps that fix the protective paint to the body 2. The protective paint 9 prevents the layer of metallic material from the oxidation, and consequently from the deterioration.

The apparatus 10 may comprises a profiling device 14, arranged upstream of the digital printing device 11, which profiling device 14 gives the further face 4 a desired configuration, in particular a non planar configuration.

The profiling device 14 may comprise a furnace within which a supporting element is arranged, said supporting element being made of refractory material and being provided with a corrugated surface. _ . A 'body 2, having initially a further .substantially -flat face 4, is positioned on the support so that the further face 4 lies on the corrugated surface, a certain amount of sand being interposed between the further face 4 and the corrugated surface, said certain amount of sand preventing, as a result of the thermal treatment in the furnace, a permanent adhesion of the body 2 to the support. Successively, the support and the body 2 lying thereon are introduced into the furnace and maintained at a pre- established temperature for a certain interval of time.

Since the material forming the body 2 softens, the further face 4 adapts itself to the shape of the corrugated surface and takes on a correspondingly corrugated contour. Successively the body 2 is cooled, so that the further face 2 maintains permanently said corrugated contour.

The profiling device 14 is particularly suitable for obtaining corrugated surfaces in bodies 2 of glass. However, by properly adjusting the operating temperatures, the profiling device 14 may also be used for bodies 2 of plastic material, for example of polycarbonate, polymethyl methacrylate and other.

The profiling device 14 may be further provided with an engraving device, for example a sand engraving device, that removes material from the further face 4 in order to obtain cavities defining a particular drawing.

It is to be noticed that the decoration of corrugated surfaces, or surfaces provided with cavities, is a peculiarity of the method and the apparatus according to the invention that is made possible by the use of the ink-jet distributing means. Actually, the known decorating methods, such as silk—screen printing, stamp printing and the application of transfers, can be used only in the case of objects provided with smooth surfaces. The apparatus 10 may further comprise, downstream of the profiling device 14, a cleaning device 15 wherein the body 2 is cleaned before the application of the UV ink 5. Alternatively (Figure 5), the cleaning device 15 may be arranged upstream the profiling device 14, for cleaning the body 2 before the profiling operation and the application of the UV ink 5.

In particular, the cleaning device 15, when arranged downstream the profiling device 14, enables grains of sand to be removed from the body 2 with which grains of sand the body 2 interacted in the profiling device 14 and particles of grease, or dirt in general, that could prevent the UV ink 5 from correctly adhering to the body 2.

The cleaning device 15 may be of ultrasonic type and may comprise three tanks arranged in succession.

Water is contained in a first tank at a temperature of about

50 ⁰ C, to which water a detergent has been added. One or more ultrasonic devices are further associated with the first tank.

Only water, without any additive, is contained in a second tank, arranged for rinsing.

A third tank, containing demineralized water, is further provided, inside which third tank possible scale is removed from the body 2, said scale having been deposited during rinsing that took place in the second tank.

The apparatus 10 may further comprise an applying device 16, interposed between the cleaning device 15 and the digital printing device 11, arranged for applying the layer 7 of primer. In the case that the primer is of the UV type, the applying device 16 comprises one, or more, UV rays lamps fixing the layer of primer 7 to the body 2.

The apparatus 10 may further comprise a further applying device 17, interposed between the digital printing device 11 and the metallizing device 12 - or the distributing device — arranged for applying the middle layer 8.

The apparatus 10 may further comprise, upstream of the profiling .device 14, _ a .cutting, device 18 wherein a body 2 may -be obtained from a plate-like element,"' said body 2 having any shape, for example a body 2a of polygonal shape, as shown in the left—hand portion of Figure 2, or a body 2b having a star—like shape, as shown in the right—hand portion of Figure 2. The star-like shape is to be understood as merely exemplifying, any other desired shape being capable of being given to the body 2.

In the case that the body 2 is obtained from a sheet of glass, the cutting device 18 may comprise a water—jet device . The more aesthetically agreeable results are obtained by using a glass of extra clear type.

As shown in Figures 2 and 3, the object 1 may be used as a decorating insert for ceramic tiles 20 to be applied to a floor or a wall.

In such a case, by means of a water—jet device a seat 21 may 5 be obtained in the ceramic tiles 20, said seat 21 being arranged for receiving the object 1.

During the thermal treatment taking place in the profiling device 14, as a consequent of the partial softening of the material constituting the body 2, the face 3 may result non- 10 planar, but may exhibit ondulations.

In the case that an insert is made necessary to be associated with a tile 20, said insert having a planar face in view, a further body 22 can be fixed to the body 2, also said further body 22 being obtained in transparent material, 15 which further body 22 exhibits opposing planar faces.

In particular, a first planar face 23 of the further body 22 may be fixed, for example by means of a gluing material, with the further face 3 of the body 2, while a second planar face 24, opposed to the first planar face 23 results in 20 view, in the use.

Furthermore, the further body 22 may be selected so that the addition of the thickness Sl of the body 2 and the further thickness S2 of the further body 22 is substantially equal

.to the thickness S of the ceramic -tile 20

-25 Thus, a same .object 1 may be associated with tiles 20 having any thickness by simply properly selecting the thickness S2 of the further body 22.

In the case that the object 1 is employed as a decorating insert for ceramic tiles 20, a bond coat can be deposited on 30 the covering material 6 - or on the protective paint 9, when present - said bond coat aiding the further face 4 to adhere to a mortar by means of which the object 1 is fixed to a building product.

Owing to the particular aesthetic value given by the use of

35 a UV ink and the high definition of the image obtainable by means of ink—jet printing, the object 1 is particularly

suitable for being employed as a decorating insert, in order to break the monotony of a floor - in particular in the case that such floor is covered by tiles having decorations representing veins, streaks, or spots, in order to look like the natural stones, repeating themselves without substantial differences on any tile — or the coating of a wall. In particular, on the object 1 a word may be transferred, for example a business name, or a trademark, or a drawing, for example a logo, identifying a business or industrial activity.

In such a case the object 1, or a plurality of objects 1, may be associated with ceramic tiles coating a floor or a wall of a building wherein said business, or industrial activity has seat, for promotional purposes. Actually, the object 1 represents an element attracting the attention of the people entering said building remarkably contributing to promoting the memorization by said people of an inscription or a figure identifying the holder of the activity. Owing to the invention, personalized inserts can be obtained at a very reduced cost, since the digital printing device is capable of printing a limited number of pieces', without that involves an increase of the unit cost. In particular, , the costs, may. be .very . limited, _ .since the digital-- printing .device is .capable, of printing... mutually different decorating patterns in a single working cycle on a plurality of bodies 2. For example, in a same working cycle, a pre-established decorating pattern may be printed on a group of bodies 2 and a different decorating pattern may be printed on a remaining group of bodies 2.

Consequently, the objects 1 are economically accessible not only to the buyers requiring many pieces, but also to the buyers needing a small number of pieces, the cost of any object not depending on the overall number of the produced objects. That is not possible in the case of transparent objects decorated with the methods according to the State of

the Art, which methods, in order to be carried out, require heavy costs of plant that can be amortized only in the case of large scale productions. Consequently, the transparent objects decorated with the methods according to the State of the Art are not accessible to prospective buyers that only desire a reduced number of objects properly personalized by means of the printing of an own wording or trademark. The objects obtained with the method and the apparatus according to the invention, can constitute, beside inserts for ceramic tiles, also complements of fittings - such as cornices, plates, ornaments - jewels, table—mats and other. Any time the objects have to be placed in a position accessible to the public, the owner can personalize said objects with a desired suggestion, giving a promotional design to the objects selves.

In particular, in the case that the objects are used as table—mats, said objects may reproduce the name and/or the logo of a restaurant where said objects are used, so as to act as an attracting element of the attention of the customers of the restaurant self.