PROCESS FOR THE DECORATION OF WALL-TILES AND FLOOR-TILES

Description

PURPOSE OF THE INVENTION

[0001] The present invention refers to a new process for the ornamentation of wall and floor tiles by making it possible to reproduce any type of design, especially photographic motifs or images, on them.

[0002] The procedure permits the reproduction of such images in black-and-white as well as colour.

ANTECEDENTS OF THE INVENTION

[0003] At the present time for the ornamentation of ceramic surfaces the following processes are employed:

• Single firing: The entire product is heated in the kiln once so that the unfired base element or bisque receives the enamel using a sprayer and later the decoration, via a serigraphic screen with a type of fixative being used between screens.
• Double firing: First the base or bisque is fired, and then the coats cited above are applied. It is then returned to the kiln.
• Third firing: With this option first the bisque is heated, as in the previous case, and then next, after applying the engobe as in the two previous methods, we proceed to the enamelling and a new firing phase, with the final decoration being applied with screens or by hand (by brush), proceeding finally to the "third firing" which gives the process its name. The decoration in this "third firing" system also tends to be done by applying pre-decorated treadles over the enamelled ceramic base.

[0004] There has recently appeared a system by which the entire process of glazing, enamelling, and decoration using rubber rollers or something similar without employing enamel sprayers or serigraphic screens.

[0005] At any rate, these approaches have their own disadvantages which consist mainly in the following:

• The surface area of serigraphic screens is very limited since, physically, the holes where the paste must pass (coloured ceramic + liquid carrier) need to be of large enough diameter for the paste to flow through with the ensuing danger of that the orifices become quickly clogged. To mitigate this problem weaves of very few threads should be used, causing a final image definition that is notably inferior.
• The angling of each serigraphic screen is critical when working with liquid paste, which tends to expand to some degree after passing through the orifice of the screen, depending on the diameter of the points of the weave, the density of the paste, and pressure and speed of the spatula. Other besides inconveniences or defects are also suffered.
• Defects registering the crosses of each screen over the former, due to the very manufacture process, i.e., inherent in the process itself.

[0006] Thus, the present technological state in the area of application of the invention shows an area of difficulty associated mainly with a lack of exact registry and the consequent impossibility of working with elevated weaves in order to obtain high-quality photographic images in the generation of weave points and unequal point density and in the use of larger points in the process, the serigraphic screen, with which still more point definition is lost, since it is probable that a point of photolyte is found in the intersection between two threads of the screen making it impossible to obtain a motif in the serigraphic panel identical to the photolyte.

DESCRIPTION OF THE INVENTION

[0007] The procedure for the ornamentation of wall and floor tiles that the invention proposes more than satisfactorily resolves the problem mentioned above, insuring the perfect engraving of the images selected, in black-and-white as well as colour; in glossy or flat finishes, with maximum durability and resistance.

[0008] For it, and more precisely, in a primary operative phase we proceed, after selecting the image, to the digitalisation and processing of the same for its photography in photolyte.

[0009] Next the transfer paper is laminated and insolated through photolyte four-colour printing. This operation of lamination and insolation should be repeated as many times as the number of colours to be used in the printing make necessary, according to intention whether said printing is monochrome or polychrome, as previously mentioned.

[0010] Next, in a third operative stage, a commonly used transport solution is applied and allowed to dry. The enamelled ceramic support is cleaned, after which it is fired at a maximum temperature of 1,050° C, a firing phase performed at the same time as that of the tile so that the image becomes integrated in its enamel surface.

[0011] In agreement with the other characteristics of the invention, the firing curve is to evolve in the following manner:

[0012] During the first hour the kiln temperature is raised from room temperature to 325° C. At 2h.45min. a temperature of 700° C is reached. After 30 minutes more, the temperature reaches 1,050° C, which is maintained for 10 minutes, only to be lowered afterwards to room temperature for a period of 2h.30min.

[0013] A glossy or flat finish is achieved by incorporating more or less flux into the ceramic colours so that they melt with more or less facility in order to obtain more or less brilliance.

PREFERABLE EMPLOYMENT OF THE INVENTION

[0014] According to a preferred example of the practical use of the invention and when dealing with the ornamentation of wall and floor tiles and with images in colour, the image to be applied onto the ceramic piece in question is digitised and processed. More exactly, filming in photolyte at 200 lines per inch, which equals 78.74 points per cm² is done.

[0015] The transfer paper is laminated and insolated by magenta four-print photolyte. The protective plastic is removed from the treadle sheet to apply the powdered magenta ceramic colour and the probe or treadle is instantly cleaned with anti-static gauze.

[0016] Next this operation is repeated, i.e., a second lamination and insolation is performed, following the same process, with cyan photolyte colour, a third with yellow and a final one with black.

[0017] Afterwards, a commonly used transport solution is applied, either by brush or serigraphic screen. After drying, the enamelled ceramic support is cleaned. Then the probe or treadle is submerged in water to loosen the image from the cardboard support. Once loosened, it is applied onto the ceramic piece, eliminating the water and the air with a rubber spatula.

[0018] Once again, it is allowed to dry and then fired at high temperature, concretely at 1,050° C in order to fire the colour of the image together with the tile and integrate the image with the enamel of the latter. More or less flux is incorporated into the ceramic colours according to the desired gloss.

[0019] When dealing with black-and-white images or sepia, the procedure is exactly the same as described for obtaining those of colour except that only one phase of lamination and insolation is carried out, i.e., in black or sepia.

[0020] In obtaining black-and-white images as well as those in colour the firing curve is the following:

a) 350° C increase in one hour.

b) 700° C increase in 4'45''.

c) 1,050° C for 30 minutes more.

d) Maintenance at 1,050° C for 10 minutes.

e) Reduction to room temperature in 2h.45min.

[0021] As may be deduced from the above, the use of colours capable of supporting the high temperatures mentioned is necessary in order to achieve greater durability and resistance in the finish.

[0022] It is not considered necessary to elaborate this description any further for any expert in the field to understand the achievement of this invention and its advantages.

[0023] The terms in which this memorandum is made should always be taken in the most ample and least limited sense.

Claims

1. Procedure for the ornamentation of wall and floor tiles, which serves the purpose of transferring all types of images, especially photographic ones, to the same, is characterised according to the following established operative phases:

- The selected image is digitised and processed into photolyte photography.

- The transfer paper is laminated and insolated via four-print photolyte, eliminating the plastic protector of the probe or treadle sheet for applying the selected powdered ceramic colour, followed by cleaning the probe with anti-static gauze.

- A commonly used transport solution is applied. After drying, the enamelled ceramic support is cleaned, submerging the treadle in water to loosen the image from the support previous to its application onto the ceramic piece, eliminating the water and air with a rubber spatula.

- After drying again, it is fired at a high temperature, so that the colour of the image remains integrated into the enamel of the tile during the firing of the latter.

2. Procedure for the ornamentation of wall and floor tiles according to 1^st claim, characterised by, in the case of obtaining polychrome images, the lamination and insolation phase may be repeated as many times as the number of colours or photolytes to be executed require.

3. Procedure for the ornamentation of wall and fllor tiles, according to previous claims characterised by a firing temperature of approximately 1,050° C.

4. Procedure for the ornamentation of wall and floor tiles according to 1^st, 2^nd and 3^rd claims characterised by the fact that the firing curve during firing is such that it reaches 350° C temperature the first hour, 700° C temperature at two hours and forty-five minutes (2h.45min.), 1050° C temperature in the thirty (30) following minutes at which temperature is maintained for ten (10) minutes, and finally return to room temperature over a period of two hours and thirty minutes (2h.30min.).

5. Procedure for the ornamentation of wall and floor tiles, according to previous claims, characterised by the fact that the resulting level of gloss is obtained according to the quantity of flux added to the ceramic colours.