Patent Publication Number: US-2010119722-A1

Title: Decoration method and system for decorating ceramic products

Description:
TECHNICAL FIELD 
     The invention refers to a decoration method and system for decorating ceramic products, particularly products with multiform concave and convex surfaces, such as, e.g., sanitary ware. 
     TECHNOLOGICAL BACKGROUND 
     Many types of systems are known to exist for decorating ceramic products such as tiles and sanitary ware. 
     Recently, one of the most commonly used decorating techniques for decorating flat-shaped ceramic products, such as tiles and slabs, has been the procedure known as “ink jet”, which is a procedure normally used in the printers connected to computers for printing wording and designs on sheets. 
     According to this technique, one or more colored ink dispensing heads are supported by a frame normally positioned above a product conveyor line. The dispensing heads are connected to their own tank and each has a series of nozzles through which the inks are dispensed that have to be deposited on the visible surfaces of the tiles or the slabs to form a preset design while these run under the frame, conveyed by the conveyor. 
     The dispensing heads are fixed or positionable in fixed positions on the frame in cross directions with respect to the direction of forward movement of the tiles and both the successions and the durations of the ink dispensing operations are coordinated by an electronic control program, according to the designs that have to be reproduced. 
     SUMMARY 
     This state of the art has a number of drawbacks. 
     A first drawback is that it is only possible to decorate flattened products, meaning products that have a flat surface, such as ceramic tiles and slabs. 
     Another drawback is that when the products to be decorated, e.g., the new tiles or slabs, are of very large dimensions, the use is required of a proportionately high number of dispensing heads to be able to quickly decorate the entire surface. 
     This large number of heads creates a further drawback, which is the difficulty in coordinating the functions of each single dispensing head with respect to the others. 
     One object of the invention is to upgrade the state of the art. 
     Another object of the invention is to develop a decoration method and system for decorating ceramic products that also permits using the ink jet technique for products with multiform surfaces, such as, e.g., sanitary ware. 
     A further object of the invention is to develop a decoration method and system for decorating ceramic products that does not create problems with regards to the coordination of the decorating phases. 
     According to one aspect of the invention, a decoration method is provided for decorating multiform ceramic products having multiform surfaces to be decorated, characterized by the fact that it comprises: moving said multiform products and/or said decorator unit with respect to each other in such a way that said decorator unit follows said multiform surfaces to be decorated; dispensing decorating substances during said movement. 
     According to another aspect of the invention, a decoration system is provided for decorating ceramic products, suitable for decorating multiform: products having multiform surfaces to be decorated, comprising: a dispensing unit of decorating substances; a supporting and movement device for said dispensing unit; characterized by the fact that said supporting and movement device comprises movement means for moving in space said dispensing unit along said multiform surfaces. 
     The decoration method and system for decorating ceramic products therefore permit making decorations according to a preset design on products that have multiform surfaces and without there being coordination difficulties between the decoration phases. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further characteristics and advantages of the invention will appear more evident from the detailed description of a decoration method and system for decorating ceramic products, illustrated indicatively by way of non limiting examples in the accompanying drawings, wherein: 
         FIG. 1  is an interrupted schematic view of a decoration system for decorating flat-shaped ceramic products according the known technique; 
         FIG. 2  is an interrupted and schematic side view of a decoration system for decorating ceramic products having multiform surfaces; 
         FIG. 3  is a detailed view of a dispensing unit of decorating substances, in a second possible embodiment. 
     
    
    
     EMBODIMENTS OF THE INVENTION 
     With reference to the  FIG. 2 , a dispensing head  1  can be seen that is supported at a distal end  2  of an arm  3  of a robot  4 . 
     The coupling of the dispensing head  1  has been schematically illustrated with an articulated ball joint  5  for the purpose of indicating that the dispensing head  1  can be moved in space without any limit with regard to direction, driven in a way known to a person skilled in the field. In  FIG. 2 , a piece of sanitary ware  6  has been shown, in this specific case a washbasin  7 , installable on a support  8 . 
     This support  8  can be fixed or movable, so as to arrange the washbasin  7  turned towards the dispensing head  1  in positions that make decorating the latter easier. 
     As can be further seen in the  FIG. 2 , the dispensing head  1  comprises a substantially parallelepiped body  101  having a flat face  102  considered frontal, which has a plurality of sprayer nozzles  9  that can be turned towards the washbasin  7  and ready to dispense ink or glaze jets towards the multiform surfaces of this. 
     The  FIG. 3  on the other hand shows a second embodiment of the dispensing head, indicated by  200 . 
     This dispensing head  200  comprises a prismatic body  201  that defines a series of faces  202 ,  203 ,  204  angled the one with the other and on which are fixed a plurality of sprayer nozzles  209 . 
     This way, the ink or glaze sprays can be directed in different directions and the angles allow the head  201  to also more easily reach hidden points of the multiform surfaces of the products. 
     For a person skilled in the field, it is simple to arrange the angled surfaces according to preferred angles or contemplate for the surface on which are arranged the plurality of nozzles  209 , a cap form, with ellipsoid round profile or according to other convex and concave shapes, to arrange the sprayer nozzles  209  according to required positions. Each sprayer nozzle  9  or  209  is connected independently to one or more ink or glaze storage tanks, normally so it is independent of the other sprayer nozzles  9  and  209 . 
     Furthermore, an electronic program entered in a computer  300  sets and controls both the movement directions of the dispensing head  1  or  201  and the parameters concerning the inks or the glazes to regulate the quantity, the spraying pressure, the speed and the density for each nozzle  9  or  209 , depending on the position of this in space and, therefore, on the distance from the multiform surface of the piece of sanitary ware  6  to be decorated, so as to prevent the formation of drops of excess glaze creating undesired drips. The decoration method comprises positioning a product, e.g., a washbasin  7 , in such a position that every point of its multiform surfaces can be reached by the ink or glaze sprays dispensed by the dispensing nozzles  9  or  209 . 
     In other words, according to the decoration method, and with the decoration apparatus, the dispensing head  101  or  201  can be moved in space with respect to the washbasin  7  by means of the arm  3  of the robot  4 , or the washbasin  7  can be moved with respect to the dispensing head  101  or  201 , or both can be moved with respect to one another. In all cases, the movements of the dispensing head  101  or  201  and/or of the washbasin  7  allow the sprayer nozzles  9  or  209  to spray glazes and inks in a calibrated way keeping preset distances with respect to the multiform surfaces to be decorated, so as to execute preset designs without the formation of drops. 
     The arm  3  of the robot  4 , which can be of the extensible type, e.g., telescopic, supports and moves the dispensing head  101  or  201  in space, causing it to follow the profiles of the multiform surfaces to be decorated so that the front face  102  or one of the faces  202 ,  203 ,  204  is turned towards a multiform surface to be decorated and maintains a substantially constant distance from this, being also able to penetrate inside cavities, as schematically indicated in the  FIG. 2  by broken lines. 
     The computer  300  stores the designs to be executed and, if necessary, a plurality of dispensing heads  101  or  201  can be contemplated, each supported by its own operating arm  3  of a robot  4 , all controlled by the computer  300  which coordinates their movements, the ink and glaze sprays and all the characteristics relating to their operation.