Method and system for decorating a ceramic article

Abstract

Decoration method and system (1) for automatically applying a predefined image on a base ceramic article (2) by means of decal (3) using one single multi-tool application apparatus (7) comprising a movable support structure (8) carrying a gripping tool (10) and a dispensing tool (11) which is controlled by a control unit (CU) controlling the activation of the movable support structure (8) and selectively enables / disables the tools (11, 10); the method provides for: an application step, during which a layer of water-based glue is applied by the dispensing tool (11) on an area (A) of interest of the base ceramic article (2) and a retrieving step, during which the gripping tool (10) retrieves a decal (3) and lays it on the area (A) of interest.

Description

[0001] "METHOD AND SYSTEM FOR DECORATING A CERAMIC ARTICLE"

[0002] Cross-Reference to Related Applications

[0003] This Patent Application claims priority from Italian Patent Application No. 102024000021126 filed on September 23, 2024, the entire disclosure of which is incorporated herein by reference.

[0004] Technical Field

[0005] The present invention falls in the field of the decoration of ceramic articles, in particular, sanitary ware made of ceramic material (such as washbasins, tanks, bidets, toilet bowls, etc.) , to which the following description will explicitly refer without thereby losing generality.

[0006] Even more in particular, the present invention relates to the decoration of ceramic articles by laying a predefined image, for example a logo or a QR code, on a ceramic article using transferable decorative labels, known as decals.

[0007] Background of the Invention

[0008] In the field of manufacturing ceramic articles, in particular sanitary ware (such as washbasins, tanks, bidets, toilet bowls, etc.) , it is known to lay predefined images on the outer surface of enamelled but not yet fired ceramic articles, for example showing the logo or name of the manufacturer, or identifying signs, for example a QR code, or any other information or decoration considered of interest .

[0009] Such predefined images are generally applied using transferable decorative labels, known as decals. The term "decal" is known to be used to refer to transferable decorative labels formed by: at least one support layer, typically made of siliconi zed paper, on which a predefined image is printed, by means of known printing techniques , for example silk-screen printing or lithography (based on the needs and on the type of support layer ) ; and, in some cases , water-activatable glue applied to the support layer , on the side opposite the printed image , and adapted to facilitate the adhesion of the decal on the surface of the article to be decorated .

[0010] Currently, the application of such decals to the surface of the not yet fired ceramic article is carried out manually by speciali zed operators who retrieve a decal from special ly provided decal feeders , position it on the article , possibly after having previously applied a layer of glue and hold it pressed on the ceramic article until the decal adheres to the article .

[0011] Such process , although applied for many years , has numerous disadvantages .

[0012] The retrieving and application steps of the decal must be carried out in an extremely accurate and precise manner, in order to avoid the risk of damaging the decal , for example , when retrieving the decal and / or when applying it on the ceramic article . In fact , to retrieve and move the decal , the operators use doctor blades or scrapers , which if not manoeuvred suitably can scratch and / or deteriorate the printed image , compromising the success of the operation and / or the ceramic article during installation .

[0013] The operation of positioning the decal on the ceramic article is also extremely delicate . In fact , it must be carried out with extreme precision to place the decal in the correct position, possibly after making reference marks on the article . Furthermore , during the positioning, the operator must very carefully calibrate the force to be applied to ensure the adhesion of the decal to the article while avoiding the risk of damaging and / or deforming the ceramic article which, having not been fired yet , has limited mechanical resistance . In addition, especially when the positioning requires the application of a layer of glue , such operation must be carried out quickly to avoid the risk of the layer of glue drying out and becoming inef fective .

[0014] It is understood, therefore , that such operations , besides requiring the use of highly quali fied personnel , with a consequent increase in production costs , generally require fairly long processing times , often incompatible with the more modern ceramic article production lines .

[0015] Furthermore , the process described above is subj ect to all the limits in terms of precision and repeatability inherent in manual operations .

[0016] A known system for the decoration of ceramic articles is , for example , described in EP1052175A2 .

[0017] The obj ect of the present invention is to provide a method and a system for decorating ceramic articles , which allow at least partly overcoming the disadvantages of the prior art , allowing laying a predefined image on the surface of a ceramic article by means of decals , in a simple , precise and cost-ef fective manner, reducing execution times and the likelihood of application errors .

[0018] Summary

[0019] In accordance with the present invention, a method and a system for decorating a ceramic article are provided for applying a predef ined image on a ceramic article by means of a decal , according to what is described in the appended independent claims , and preferably, in any of the claims directly or indirectly dependent on the mentioned independent claims .

[0020] The claims describe preferred embodiments of the present invention forming an integral part of the present description .

[0021] Brief Description of the Drawings

[0022] The invention i s described in the following with reference to the accompanying drawings , which illustrate some non-limiting example embodiments thereof , wherein :

[0023] - Figure 1 is a schematic perspective view of a system for decorating ceramic articles adapted to apply a predefined image on the surface of a ceramic article by means of a decal , in accordance with an embodiment of the present invention;

[0024] - Figure 2 is an enlarged view of the decal application apparatus of the decoration system of Figure 1 to better visuali ze the components thereof ;

[0025] - Figure 3 is a schematic perspective view of a system for decorating ceramic articles for applying a predefined image on a ceramic article by means of a decal , in accordance with a further embodiment of the present invention;

[0026] - Figure 4 is an enlarged view of a part of the system of Figure 3 , to better visuali ze the decal application apparatus of the system of Figure 2 ;

[0027] - Figures 5 to 8 are schematic perspective views of the decoration system of Figures 1 and 2 during subsequent steps of the decoration process of a toilet bowl by applying a predefined image by means of a decal , in which the automatic application apparatus has been schemati zed .

[0028] Detailed Description

[0029] In the accompanying figures , reference numeral 1 indicates, as a whole, a system for decorating base ceramic articles 2, in particular sanitary ware, for applying a predefined image using decals 3 for ceramic, namely transferable labels for ceramic.

[0030] In particular, the present discussion will explicitly refer to the decoration of sanitary ware 2 made of ceramic material, such as washbasins (as in the accompanying figures) , toilet bowls, etc. without thereby losing generality. In other words, in the present discussion, the expression "base ceramic articles 2" (hereinafter for the sake of brevity only "ceramic articles 2") is intended to refer to sanitary ware already formed, generally by means of moulding processes under pressure, dried and possibly enamelled, but not yet fired and intended to form finished ceramic articles after firing, in particular sanitary ware; even more in particular decorated sanitary ware 2.

[0031] It should be noted that in the present discussion the terms such as "upper", "lower", "side", "right", "left", "front", "rear", are used with reference to the decoration system 1 of base ceramic articles 2 located lying on a horizontal plane, for example on the ground. Therefore, for example, the term "above" or "below" means, respectively, "that it is above" or "that it is below" relative to another component of the decoration system 1 of base ceramic articles 2. Furthermore, within the scope of the present description, the term "second" does not necessarily imply the presence of a "first". Such terms are sometimes used as labels to improve clarity .

[0032] With particular reference to the accompanying figures (see in particular Figures 1, 3, 4-8) , the decoration system 1 comprises: a feeder 4 (known per se and not described in detail herein) located at a feeding station 5 and configured to contain at least one decal 3 trans ferable onto ceramic, more advantageous ly, a plurality o f decals 3 ; and a support 6 , for example a workbench ( as is illustrated in Figure 1 ) or a conveyor as in Figures 3- 8 ) , for receiving at least one ceramic article 2 having a peripheral surface provided with an area A of interest to be decorated, i . e . intended to receive the aforementioned predefined image ; more advantageously a plurality of ceramic articles 2 ( as is illustrated in Figures 3- 8 ) .

[0033] In detail , the ( or each) decal 3 , known per se and not described herein in detail , in turn comprises at least one support layer, typically made of siliconi zed paper, on which the predefined image to be applied to the ceramic article 2 is printed, for example by silk-screen printing or lithography . Advantageously but not limitedly, the decal 3 further comprises a layer of water-activatable glue which can be applied to the support layer, on the opposite side , to the predefined image or embedded in the support layer and which is adapted to facilitate the adhesion of the decal 3 on the surface of the ceramic article 2 to be decorated .

[0034] According to some advantageous but non-limiting embodiments , the glue is incorporated in the decal and is composed of carboxymethyl cellulose , kon j ac gum and acrylic binder .

[0035] Alternatively or in addition, the feeder 4 comprises a vessel for containing the decals 3 , which container comprises a certain amount of water and according to some advantageous but non-limiting embodiments a synthetic wool pad and a net resting on the pad to support the decal 3 . More in particular, the container comprises an amount of water such as to ensure that the decal 3 , laid on the pad, is at least partially immersed in the water so as to activate the above- mentioned glue .

[0036] It is understood that the structure of the feeder 4 and the decal 3 could be modi fied without thereby departing from the scope of the present discussion .

[0037] Advantageously, the decoration system 1 further comprises : an automatic application apparatus 7 configured to apply the predefined image on the area A of interest of the ceramic article 2 and at least one control unit CU, only schematically illustrated in Figure 1 , to control the automatic application apparatus 7 .

[0038] With particular reference to the accompanying figures ( see for example Figure 2 ) , the application apparatus 7 comprises : a movable support structure 8 activatable to move in space ; and a multi-tool head 9 which is connected to the movable support structure 8 in a rotary manner and is provided with at least one gripping tool 10 , configured to retrieve the above-mentioned decal 3 , and with a dispensing tool 11 , configured to dispense a first material comprising ( in particular, consisting of ) a water-based glue on the area A of interest of the ceramic article 2 .

[0039] Advantageously, the control unit CU is configured to control the movement of the movable support structure 8 so as to move the multi-tool head 9 from a first position, in which the multi-tool head 9 is at the feeding station 5 , to a second position, in which the multi-tool head 9 is at the support 6 , and vice versa .

[0040] The control unit CU is further configured to selectively enable / disable ( in particular alternatively) the gripping tool 10 and the dispensing tool 11 (more advantageously but not limitedly, to enable / disable the operation of the gripping tool 10 and the dispensing tool 11 ) so that the dispensing tool 11 dispenses a layer of the above-mentioned first material on the area A of interest ( in particular, when the multi-tool head 9 is in the second position and the dispensing tool 11 is enabled) , and the gripping tool 10 retrieves at least one decal 3 from the feeder 4 ( in particular, when the multi-tool head 9 is in the first position and the gripping tool 10 is enabled) and positions it on the ceramic article 2 at the area A of interest bearing such layer of water-based glue ( in particular, when the multi-tool head 9 is in the second position and the gripping tool 10 is enabled) so as to apply the predefined image on the ceramic article 2 .

[0041] Advantageously but not limitedly, the control unit CU comprises ( in particular, contains ) a memory, advantageously but not limitedly writable , configured to contain a programming of the decoration operations to be carried out , i . e . at least one list of the predefined images to be applied on the ceramic article 2 ( on each ceramic article 2 placed on the support 6 ) and of the laying position on the ceramic article 2 and the control unit CU controls the various components of the decoration system 1 ( in particular, controls at least the automatic application apparatus 7 ) as a function of the decoration operations to be carried out , as will be more evident in the following .

[0042] Even more advantageously but not limitedly, the above- mentioned memory contains a plurality of instructions for moving ( in particular, rotating) the multi-tool head 9 relative to the movable support structure 8 and a plurality of instructions for enabling / disabling the gripping tool 10 and the dispensing tool 11 and is configured to transmit such instructions to the automatic application apparatus 7 so as to apply the predefined image on the ceramic article 2 .

[0043] Advantageously but not limitedly, the application apparatus 7 further comprises a locali zation system (not visible in the accompanying figures ) ; more advantageously but not limitedly, mounted on the multi-tool head 9 , and configured to provide data concerning the position of at least the multi-tool head 9 , relative to the remaining part of the components of the decoration system 1 ; even more advantageously but not limitedly, with a precision of at least about + / -30mm . In this case , advantageously but not limitedly, the control unit CU controls the activation of the application apparatus 7 , conveniently activating the movable support structure 8 also as a function of what detected by such detection system and advantageously but not limitedly as a function of the above-mentioned programming of the decoration operations .

[0044] Even more advantageously but not limitedly, the decoration system 1 further comprises a detection system ( known per se and not described in detail or illustrated herein) configured to detect , advantageously but not limitedly continuously, the position of the ceramic article 2 relative to the remaining components of the decoration system 1 and the control unit CU is configured to control the application apparatus 7 ( in particular at least to control the movable support structure 8 ) also as a function of what detected by such detection system .

[0045] According to some advantageous but non-limiting embodiments , such as for example those illustrated, the multi-tool head 9 comprises a substantially flat support frame 12 connected to the movable support structure 8 through the interposition of a rotation j oint 13 ( only partially visible in the accompanying figures - see , for example , Figures 2 , 3 , 5 ) and configured to enable the frame 12 to rotate around a rotation axis R perpendicular to the frame 12 and the control unit CU is configured to control the rotation of the frame 12 relative to the movable support structure 8 , based on the operations to be carried out , and to the enabled tool (between the gripping tool 10 and the dispensing tool 11 ) , so as to move the dispensing tool 11 or the gripping tool 10 with extreme flexibility .

[0046] According to some advantageous but non-limiting embodiments , the gripping tool 10 is carried, in a proj ecting manner, by the frame 12 to protrude , on the side opposite the j oint 13 , along a first direction B orthogonal to the frame 12 and parallel to the rotation axis R; and the dispensing tool 11 is carried, in a proj ecting manner, by the same frame 12 and protrudes therefrom, always on the side opposite the j oint 13 , along a direction B' , which is parallel to the direction B and the rotation axis R, and, more advantageously but not limitedly, by a distance suf ficient to avoid the risk that , when dispensing, the first material sprayed by the dispensing tool 11 can incidentally hit and dirty the gripping tool 10 .

[0047] More advantageously but not limitedly, according to some embodiments , such as for example those illustrated, the frame 12 is a plate having a peripheral edge P, a transverse development direction X, and a longitudinal development direction Y, which lies in the same plane as the transverse development direction X, and is transverse ( in particular, orthogonal ) thereto . The dispensing tool 11 and the gripping tool 10 are carried, in a proj ecting manner, by the plate (which constitutes the frame 12 ) and connected to such plate along the peripheral edge P .

[0048] In greater detai l , advantageously but not limitedly, the dispensing tool 11 is connected to the plate (which constitutes the frame 12 ) at the intermediate area of a first side LI of the peripheral edge P, which is parallel to the transverse development direction X . More advantageously but not limitedly, the gripping tool 10 is connected to the plate (which constitutes the frame 12 ) near ( close ) to a vertex of the peripheral edge P, at which a second side L2 , substantially parallel to the first side LI , and a third side L3 , perpendicular to the sides LI and L2 and parallel to the longitudinal development direction Y, intersect ( in particular, end) . The arrangement of the gripping tool 10 near to the vertex of the plate (which constitutes the frame 12 ) advantageously allows the decal 3 to be positioned also near to planes or edges of the ceramic article 2 , increasing the flexibility of the decoration system 1 .

[0049] Even more advantageously but not limitedly, with particular reference to Figure 2 , the dispensing tool 11 is at a first distance DI from the rotation axis R, along the longitudinal development direction Y, and at a second distance D2 , advantageously but not limitedly zero , from the rotation axis , along the transverse development direction X ; whereas , the gripping tool 10 is at a third distance D3 from the rotation axis R, along the longitudinal development direction Y, and at a fourth distance D4 from the rotation axis , along the first transverse development direction X . More advantageously but not limitedly, the first distance DI is greater than or equal to the third distance D3 .

[0050] The particular conformation of the multi-tool head 9 advantageously enables di f ferent positions of the outer surface of the ceramic article 2 to be reached with greater ease .

[0051] According to some advantageous but non-limiting embodiments , such as for example those illustrated in Figures 1 and 2 , the plate (which constitutes the frame 12 ) comprises ( in particular, consists of ) an "L"-shaped profile comprising a first branch, having a greater development direction parallel to the longitudinal development direction Y, and a second branch, which extends from the first branch along the transverse development direction X . In this case , advantageously but not limitedly, the dispensing tool 11 is connected, in a proj ecting manner, to the first branch at the median area of a lower side LI of the first branch, on the side opposite the second branch, and the gripping tool 10 is connected, in a proj ecting manner, to the second branch at the outer vertex of the second branch . Such configuration of the plate (which constitutes the frame 12 ) , besides reducing weights and dimensions , enables further increasing the versatility of the multi-tool head 9 , in terms of positions which the multi-tool head 9 can assume .

[0052] According to some advantageous but non-limiting embodiments , such as for example those illustrated, the movable support structure 8 comprises ( in particular, consists of ) an anthropomorphic robot , for example in the case illustrated with 6 axes ; even more advantageously but not limitedly, a collaborative anthropomorphic robot . The use of an anthropomorphic robot enables ( together with the particular structure of the multi-tool head 8 ) laying the decal 3 , and therefore making the predefined image mentioned above , in any part of the peripheral surface of the base ceramic article 2 , even near ( close ) to end areas and / or close to the support surface and / or inner parts of the base ceramic article 2 , increasing the flexibility of the decoration system 1 .

[0053] It is understood that according to other embodiments not illustrated, the movable support structure 8 could be constituted by a Cartesian robot , or by any other type of robot or even a support structure with guides , as long as it enables the movement of the multi-tool head 9 in the di f ferent movement directions .

[0054] According to some advantageous but non-limiting embodiments , such as for example those illustrated in the accompanying figures , the gripping tool 10 comprises ( in particular, consi sts of ) : a vacuum gripping unit configured to exert , by contact , a gripping action upon the decal 3 ; and a pressure generator (not vi sible in the accompanying figures ) , which is in fluid connection with the vacuum gripping unit and is activatable to shi ft from a gripping configuration, in which it trans fers a depression of at least about - 0 . 2 bar to the gripping surface to facil itate the gripping of the decal 3 , to a release configuration, in which it generates a pressure of + 0 . 4 bar to facilitate the release of the decal 3 .

[0055] More advantageously but not limitedly, the pressure generator comprises a compressor adapted to generate a flow of air under pres sure , in particular at a pressure of about 4 bar, a first conduit for putting the compressor in fluid connection with the gripping surface , in particular through the above-mentioned holes ; and more advantageously but not limitedly, a second conduit , provided with a Venturi tube located and configured to induce a lowering of the pressure so as to trans fer the above-mentioned depression of at least about - 0 . 2 bar at the gripping surface . In this manner, it is possible to obtain both the desired positive pressure and depression with one single generator .

[0056] Alternatively, according to other advantageous but nonlimiting embodiments , the gripping tool 10 comprises ( in particular, consists of ) : a vacuum generator configured to generate the above-mentioned depression of at least about - 0 . 2 bar and a compressor configured to generate the above- mentioned pressure of about 0 . 4 bar .

[0057] Even more advantageously but not limitedly, the vacuum gripping unit comprises ( in particular, consists of ) a gripping surface , provided with at least one hole through which it is placed in fluid communication with the above- mentioned pressure generator ; more advantageously, the gripping unit is provided with a plurality of holes through which such gripping surface is placed in fluid connection with the pressure generator and configured to enable the trans fer of the above-mentioned pressure or depression, avoiding, at the same time , the ri sk of sucking part of the decal 3 therein, damaging or wrinkling it when gripping .

[0058] Furthermore , according to some advantageous but nonlimiting embodiments , the gripping unit also comprises a layer of porous material , for example made of sponge or polymeric foam, to evenly distribute the above-mentioned depression over the entire gripping surface , so as to reduce the risk that the decal 3 is subj ected, along the gripping surface , to di f ferent pressures which could damage it , bend it , compromising the success ful application . Alternatively or in addition, advantageously but not limitedly, the automatic application apparatus 7 ( in particular, the gripping tool 10 ) comprises a spring compensator 14 interposed between the frame 12 and the vacuum gripping unit configured to act on the gripping unit and to compensate for possible positioning errors and trans fer a pushing action onto the decal 3 , when this is positioned on the above-mentioned area A of interest of the ceramic article 2 . This advantageously allows applying a certain force and therefore positioning the decal 3 with greater stability on the ceramic article 2 . When provided for, the abovementioned layer of porous material , contributes ( together with the spring compensator 14 ) to trans fer a uni form pushing action onto the decal 3 , when it is positioned on the above- mentioned area A of interest of the ceramic article 2 , so as to guarantee the adhesion thereof .

[0059] In more detail , advantageously but not limitedly, in order to avoid the risk of damaging the decal 3 when gripping, advantageously but not limitedly, the gripping unit ( in particular the gripping surface ) has a transverse section of shape and dimensions substantially similar to that of the decal 3 , in particular the face of the decal 3 which it is intended to grip by contact .

[0060] According to some advantageous but non-limiting embodiments , such as those illustrated, the dispens ing tool 11 is a spray gun configured to spray the water-based glue on an area A of interest .

[0061] More advantageously but not limitedly, the dispensing tool 11 is connected to a containment tank (not visible in the accompanying figures ) for containing the first material and comprises a pumping system ( also not visible in the accompanying figures and known per se ) for dispensing a j et of air under pres sure together with the first material so as to nebuli ze the f irst material on the area A of interest of the ceramic article 2 .

[0062] According to some advantageous but non-limiting embodiments , the pumping system of the dispensing tool 11 comprises (more in particular, coincides with) the pressure generator of the gripping tool 10 . In other words , advantageously but not limitedly, the gripping tool 10 and the dispensing tool 11 share the same pressure generator . This advantageous ly enables reducing weights , dimensions and costs of the automatic application apparatus 7 .

[0063] According to some advantageous but non-limiting embodiments not illustrated, the decoration system 1 comprises a first vision device (not visible in the accompanying figures and known per se ) , for example a camera or another image acquisition or detection system, configured to detect the position of the decal 3 at the feeding station 5 and trans fer data on such detected position to the control unit CU and the control unit CU is configured to control the movement of the movable support structure 8 in such first position, i . e . at the feeding station 5 , also as a function of what is detected by the above-mentioned first vision device .

[0064] Alternatively or in addition, advantageously but not limitedly, the decoration system 1 comprises a second vision device configured to detect the position of the decal 3 relative to the ceramic article 2 and to send an error signal to the control unit CU i f the detected position does not correspond to a reference position, advantageously contained in the above-mentioned memory of the control unit CU . More advantageously but not limitedly, such second vision device is in communication with the control unit CU, which control unit CU is configured to calculate also based on the error signal received ( as well as based on the data received from the locali zation system and / or from the detection system) the new traj ectory along which to move the multi-tool head 9 so as to correctly position the decal 3 and consequently appropriately activate the movable support structure 8 .

[0065] According to a further aspect of the present invention, a decoration method is proposed for applying a predefined image on a ceramic article 2 using a decal 3 of the type described above .

[0066] Advantageously, the decoration method comprises the following steps : a first preparatory step, during which at least one base ceramic article 2 is provided, advantageously but not limitedly placed lying on a workbench ( see for example Figure 1 ) or on a conveyor ( see , for example , Figures 3 to 8 ) ; a further preparatory step, during which at least one decal 3 trans ferable onto ceramic of the type described above is provided at a feeding station 5 ; an application step, during which a layer of a first material comprising ( in particular, consisting of ) a water-based glue is applied on an area A of interest of a peripheral surface of the ceramic article 2 ; and a retrieving step, during which the decal 3 is retrieved from the feeding station 5 and laid on the peripheral surface of the ceramic article 2 at said area A of interest .

[0067] According to the invention, advantageously, the above- mentioned application and retrieving steps are automatically carried out by a single automatic application apparatus 7 , which comprises a movable support structure 8 carrying a gripping tool 10 , configured to retrieve the decal 3 , and a dispensing tool 11 , to apply the first material . More advantageously but not limitedly, the decoration method is actuated with a decoration system 1 as that described above .

[0068] The decoration method further provides for a control step, during which a control unit CU, which controls the activation of the automatic application apparatus 7 , controls the activation of the movable support structure 8 and selectively ( in particular, alternatively) enables / disables the gripping tool 10 and the dispensing tool 11 .

[0069] More advantageously but not limitedly, the method also comprises a detection step, at least partially prior to the control step, during which a detection system ( known per se and not described in detail herein ) detects , advantageously but not limitedly continuously, the position of the ceramic article 2 ( in particular, relative to the other components of the decoration system 1 used to actuate the decoration method) and during the above-mentioned control step the control unit CU controls the application apparatus 7 ( in particular, at least the movable support structure 8 ) as a function of what detected in such detection step and, when there is also a locali zation system integral with the application apparatus 7 , also as a function of what is detected by the locali zation system .

[0070] As set forth above in relation to the decoration system 1 , advantageously but not limitedly, the gripping tool 10 and the dispensing tool 11 are mounted on one single multitool head 9 connected to the movable support structure 8 in a rotary manner ; more advantageously, such multi-tool head 9 comprises a substantially flat frame 12 , advantageously as that described above in relation to the decoration system 1 , and is mounted on the movable support structure 8 by means of a j oint 13 to allow the rotation of the multi-tool head

[0071] 9 around a rotation axis R substantially orthogonal to the frame 12 .

[0072] Advantageously but not limitedly, the aforementioned control step comprises a switching sub-step, during which the control unit CU trans fers to the automatic application apparatus 7 the movement instructions ( in particular, the rotation instructions ) of the multi-tool head 9 relative to the movable support structure 8 around a rotation axis R and instructions / controls for enabling / disabling the tools 10 , 11 .

[0073] With particular reference to Figures 5 , 7 and 8 , advantageously but not limitedly, the retrieving step comprises , in turn : a gripping sub-step, during which the control unit CU enables the activation of the gripping tool

[0074] 10 and such gripping tool 10 retrieves the decal 3 from the feeding station 5 ( see Figure 5 ) ; a moving sub-step, which is ( at least partially) subsequent to the gripping sub-step, during which the control unit CU controls the movement of the movable support structure 8 in order to move the multitool head 9 from the feeding station 5 up to near the base ceramic article 2 ( in particular, near the support 6 ) ; and a positioning sub-step, which is ( at least partially) subsequent to the moving sub-step, during which the control unit CU enables the activation of the gripping tool 10 and the gripping tool 10 positions the decal 3 in contact with the ceramic article 2 at the area A of interest , more advantageously but not l imitedly, with the predefined image in contact with said layer of a base glue ( see Figure 7 ) . According to some advantageous but non-limiting embodiments , the method ( in particular, the retrieving step ) also comprises a first detection step, at least partially prior to the gripping step, during which a first vision device ( for example a camera or another acquisition or detection system not illustrated) detects the position of the decal 3 at the feeding station 5 . In this case ( i . e . when such detection sub-step is provided for ) , during the gripping sub-step the control unit CU controls the activation of the movable support structure 8 also as a function of what detected in such detection sub-step .

[0075] Advantageously but not limitedly, the gripping tool 10 comprises ( in particular, consists of ) : a vacuum gripping unit ( in particular, a suction cup ) intended, in use , to come into contact with the decal 3 to be retrieved, and a pressure generator in fluid connection with the vacuum gripping unit . In this case , during the gripping sub-step, the control unit CU controls the pressure generator to trans fer a depression of about - 0 . 2 bar at most to the gripping unit , and therefore to the decal 3 , and to keep such depression substantially constant during the moving sub-step and during the application step ; whereas , during the positioning sub-step, the control unit CU controls the pressure generator to trans fer a pressure of about +4 bar at most to facilitate the detachment of the decal 3 from the gripping unit and therefore its release on the ceramic article 2 . This facilitates the gripping of the decal while at the same time reducing the contact and rubbing surface and therefore reducing the risk of damage to the decal .

[0076] According to some advantageous but non-limiting embodiments not i llustrated, the decoration method comprises a stabili zation step, which is ( at least partially) subsequent to the positioning sub-step, during which a flow of air under pres sure is inj ected towards the decal 3 , once it has been placed on the area A o f interest of the ceramic article 2 to facilitate the adherence thereof . More advantageously but not limitedly, such stabili zation step is carried out with the gripping tool 10 , made as described above ; more in particular, during such step the control unit CU controls the pressure generator to trans fer a pressure of at least about 4Xbar towards the decal 3 , thus generating the aforementioned pushing action on the decal 3 .

[0077] With particular reference to Figure 6 , advantageously but not limitedly, during the application step the control unit CU enables the activation of the dispensing tool 11 and the dispensing tool 11 dispenses a defined quantity of first material on the area A of interest .

[0078] Advantageously but not limitedly, the method comprises at least one rotation step, which is ( at least partially) prior to the positioning sub-step and subsequent to the application step, during which the control unit CU controls the movable support structure 8 to rotate the multi-tool head 9 around the rotation axis R so as to reverse the mutual position of the dispensing tool 11 and of the gripping tool 10 relative to the area A of interest of the ceramic article 2 so as to be able to carry out in succession the above- mentioned application step and positioning sub-step, once the multi-tool head 9 with the gripped decal 3 assumes the above-mentioned second position . In other words , in this manner, once the multi-tool head 9 has been moved up to near the support 6 , and more precisely up to facing the area A of interest of the ceramic article 2 , as is illustrated in Figures 6 and 7 , it will be poss ible to apply the layer of first material during the above-mentioned application step and immediately after, without moving the entire support structure 8 , but only by rotating the multi-tool head 9 around the rotation axis R it will be possible to position the decal 3 during the above-mentioned positioning step .

[0079] Advantageously, the application step is at least partially subsequent to the gripping step and ( at least partially) prior to the positioning step . More advantageously but not limitedly, the application step is ( at least partially) subsequent to the moving step .

[0080] Even more advantageously but not limitedly, the application step precedes the positioning step by a time interval of about 5 seconds at most . In this manner, the risk of the water-based glue layer partially or completely drying before laying the decal 3 i s avoided, in thi s manner risking compromising the adhesion of the decal 3 to the ceramic article 2 .

[0081] According to some advantageous but non-limiting embodiments , the decoration method comprises a position control step, which is ( at least partially) subsequent to the positioning sub-step and, advantageously but not limitedly, when provided for, also to the stabili zation step, during which a further vision device ( for example , a camera or another acquis ition or detection system not illustrated) controls the position of the decal 3 relative to the ceramic article 2 and sends an error signal to the control unit CU i f the position does not correspond to a reference position . In this manner, the correct positioning of the decal 3 on the ceramic article 2 before its firing is guaranteed with even greater precision, minimising waste . According to some advantageous but non-limiting embodiments , when during the control step the further vision device sends the above-mentioned error signal , the ceramic article 2 is discarded . Alternatively, according to other advantageous but non-limiting embodiments , when during the control step the further vision device sends the above- mentioned error signal , the decal 3 applied during the positioning sub-step is removed from the ceramic article 3 and a further gripping sub-step, a further moving sub-step and a further positioning sub-step are repeated to apply another decal 3 on the ceramic article 2 , and, in this case , the control unit CU activates the movable support structure 8 ( at least in the above-mentioned gripping and pos itioning sub-steps ) also as a function of such error signal , consequently recalculating the movement traj ectory of the movable support structure 8 .

[0082] The decoration method and decoration system 1 for decorating ceramic articles 2 of the present invention have numerous advantages , among which the following are mentioned .

[0083] The decoration method and the decoration system 1 of the present invention allow laying predefined images , for example logos or identi fication codes , such as QR codes , on base ceramic articles 2 , in an extremely accurate and rapid manner and without the need for the intervention of speciali zed operators , with a consequent reduction in costs and production times .

[0084] Furthermore , thanks to the use of an automatic application apparatus 7 the operation of which can be controlled with extreme precision, the risk of incorrect applications , of involuntary damage to the decal 3 and / or the ceramic article 2 not yet fired, is avoided, minimizing production waste.

Claims

CLAIMS1. A decoration method for applying a predefined image on a base ceramic article (2) using a decal (3) ; the decoration method comprises the following steps:- a first preparatory step, during which at least one base ceramic article (2) is provided;- a second preparatory step, during which, at a feeding station (5) , at least one decal (3) transferable onto ceramic is provided, which decal (3) comprises at least one support layer, on which said predefined image is printed;- an application step, during which a layer of a first material comprising (in particular, consisting of) a waterbased glue is applied on an area (A) of interest of a peripheral surface of said base ceramic article (2) ;- a retrieving step, during which said at least one decal (3) is retrieved from said feeding station (5) and laid on said peripheral surface of said base ceramic article (2) at said area (A) of interest; the method is characterized in that said application and retrieving steps are automatically carried out by one single automatic application apparatus (7) , which comprises a movable support structure (8) , which carries at least one gripping tool (10) configured to retrieve said at least one decal (3) and a dispensing tool (11) configured to apply said first material; the method comprises a control step, during which a control unit (CU) , which controls the activation of said automatic application apparatus (7) , controls the activation of said movable support structure (8) and selectively enables / disables said gripping tool (10) and said dispensingtool (11) .

2. The decoration method according to claim 1, wherein: said retrieving step comprises, in turn: a gripping sub-step, during which the control unit (CU) enables the activation of said gripping tool (10) and said gripping tool (10) retrieves said at least one decal (3) from said feeding station (5) ; a moving sub-step, which is at least partially subsequent to said gripping sub-step and during which the control unit (CU) controls the movement of said movable support structure (8) in order to move said gripping tool (10) and said dispensing tool (11) from said feeding station (5) up to near said base ceramic article (2) ; and a positioning sub-step, which is at least partially subsequent to said moving sub-step and during which the control unit (CU) enables the activation of said gripping tool (10) and said gripping tool (10) positions said at least one decal (3) in contact with said at least one base ceramic article (2) at said area (A) of interest; and during said application step, said control unit (CU) enables the activation of said dispensing tool (11) and said dispensing tool (11) dispenses a defined quantity of said first material onto said area (A) of interest.

3. The decoration method according to claim 2, wherein said application step is at least partially subsequent to said gripping sub-step and at least partially prior to said positioning sub-step.

4. The decoration method according to claim 2 or 3, wherein said application step is at least partially subsequent to said moving sub-step.

5. The decoration method according to any one of claims 2, 3 or 4, wherein said application step precedes saidpositioning sub-step by a time interval of about 5 seconds at most.

6. The decoration method according to any one of the preceding claims, wherein: said gripping tool (10) and said dispensing tool (11) are mounted on one single multi-tool head (9) connected to said movable support structure (8) in a rotary manner; and said control step comprises a switching sub-step, during which said control unit (CU) transfers to said automatic application apparatus (7) movement instructions (in particular, rotation instructions) of said multi-tool head (9) relative to said movable support structure (8) and instructions for enabling / disabling said gripping tool (10) and dispensing tool (11) .

7. The decoration method according to any one of claims 2 to 6, wherein: said gripping tool (10) comprises (in particular consists of) : a vacuum gripping unit intended, in use, to come into contact, through a gripping surface, with the decal (3) to be retrieved and a pressure generator in fluid connection with said vacuum gripping unit; during said gripping sub-step, the control unit controls said pressure generator to transfer a depression of about -0.2 bar at most to said vacuum gripping surface so as to retrieve said decal (3) and to keep said depression substantially constant during said moving sub-step and during said application step; during said positioning sub-step, the control unit (CU) controls said pressure generator to transfer a pressure of about +0.4 bar at most to said gripping surface so as to facilitate the detachment of said decal (3) from said vacuumgripping unit.

8. The decoration method according to any one of the preceding claims, comprising a stabilization step, which is at least partially subsequent to said positioning sub-step and during which a flow of air under pressure is injected towards said decal (3) , once it has been laid on said area (A) of interest of said ceramic article (2) , in order to facilitate the adherence thereof; in particular, said stabilization step being carried out with said gripping tool (10) comprising a vacuum gripping unit and a pressure generator in fluid connection with said vacuum gripping unit and, during said stabilization step, said control unit (CU) controls said pressure generator to transfer a pressure of at least about 4 bar towards said decal ( 3 ) .

9. The decoration method according to any one of the preceding claims, comprising a position control step, which is at least partially subsequent to said positioning substep and during which a vision device controls the position of said decal (3) relative to said base ceramic article (2) and sends an error signal to said control unit (CU) , if the position does not correspond to a reference position.

10. A decoration system (1) for applying a predefined image on a base ceramic article (2) using a decal (3) ; the decoration system (1) comprises: a support (6) for receiving a base ceramic article (2) having a peripheral surface provided with an area (A) of interest intended to receive said predefined image; a feeder (4) located at a feeding station (5) and configured to contain at least one decal (3) transferable onto ceramic, which, in turn, comprises at least one supportlayer, on which said predefined image is printed; an automatic application apparatus (7) which, in turn, comprises: a movable support structure; and a multi-tool head (9) , which is connected to said movable support structure (8) in a rotary manner and is provided with at least one gripping tool (10) , configured to retrieve said at least one decal (3) , and with a dispensing tool (11) , configured to dispense a first material comprising (in particular, consisting of) a water-based glue; and a control unit (CU) configured to control said automatic application apparatus (7) by controlling the movement of said movable support structure (8) so as to move said multitool head (9) from said feeding station (5) up to the area of said support (6) , and vice versa, and by selectively enabling / disabling said gripping tool (10) and said dispensing tool (11) so that said dispensing tool (11) dispenses a layer of said first material on said area (A) of interest and said gripping tool (10) retrieves said at least one decal (3) and positions it on said area (A) of interest, so as to apply said predefined image on said base ceramic article ( 2 ) .

11. The decoration system according to claim 10, wherein said multi-tool head (9) comprises a substantially flat support frame (12) connected to said movable support structure (8) through the interposition of a rotation joint (13) configured to allow the frame (12) to rotate around a rotation axis (R) perpendicular to said frame (12) ; and said control unit (CU) comprises a memory containing, in turn, a plurality of movement instructions (in particular, of rotation instructions) of said multi-tool head (9) relative to said movable support structure (8) and aplurality of instructions for enabling / disabling said gripping tool (10) and dispensing tool (11) and is configured to transmit said instructions to said automatic application apparatus (7) so as to apply said predefined image on said base ceramic article (2) .

12. The decoration system according to claim 11, wherein : said frame (12) is a plate having, in turn: a peripheral edge, a first development direction (X) and a second development direction (Y) , which lies in the same plane as said first development direction (X) and is transverse (in particular, orthogonal) to the first development direction (X) ; said dispensing tool (11) is connected, in a projecting manner, to said plate at the intermediate area of a first side (LI) of said peripheral edge (P) , which is parallel to said first development direction (X) ; said gripping tool (10) is connected, in a projecting manner, to said plate near to a vertex of said peripheral edge (B) , at which a second side of said peripheral edge, substantially parallel to the first side, and a third side of said peripheral edge, which extends along said development direction (Y) , perpendicularly to said first and second sides (LI, L2) , intersect.

13. The decoration system according to any one of claims 10 to 12, wherein said gripping tool (10) comprises (in particular, consists of) : a vacuum gripping unit having a gripping surface and configured to exert, through contact, a gripping action upon said decal (3) ; and a pressure generator, which is in fluid connection with said vacuum gripping unit and is activatable to shift from a grippingconfiguration, in which it transfers to said gripping surface a depression of at least about - 0.2 bar, to a release configuration, in which it transfers to said gripping surface a pressure of + 0.4 bar to facilitate the release of said decal (3) from said vacuum gripping unit.

14. The decoration system according to claim 13, wherein the automatic application apparatus (7) comprises a spring compensator (14) interposed between said frame (12) and said vacuum gripping unit to compensate for any positioning errors and transfer a pushing action onto said decal (3) , when it is positioned on said area (A) of interest of said base ceramic article (2) .

15. The decoration system according to any one of claims 10 to 14, comprising a vision device configured to detect the position of said decal (3) relative to said base ceramic article (2) and to send an error signal to said control unit (CU) , if the detected position does not correspond to a reference position.

16. The decoration system according to any one of claims 10 to 15, wherein said movable support structure (8) comprises (in particular, consists of) an anthropomorphic robot .

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