EP0868960B1 - Process for manufacturing control panels,particularly for electrical household appliances - Google Patents

Description

The present invention relates to the field of equipment household appliances, in particular stoves, ovens, dishwashers and microwave appliances with one or more glass panes hardened, generally forming control panels, and relates to a process for producing control panels, in particular for such Appliances.

The glass elements used for this purpose are generally pieces of aesthetics decorated by serigraphy of enamel or ink. The decor includes, more often, a colored background, a brand logo of another color, and indications for positioning the control buttons of the device, as well as, sometimes more or less illuminated symbols indicating the operating status of the device. As a result, it is common to use more than two colors screen printed on a glass element to be used as a control panel for a apparatus.

These elements of the decor respect a precise positioning, either by relative to the edges of the glass; either with respect to holes provided in the element glass and intended for control buttons or push buttons, or relative to the axis of symmetry of the glass.

According to the closest prior art, the symbols, logos, markings, status indications of operation are generally obtained by screen printing operations successive, allowing an impression of the colors on the glass, at the places desired, while respecting the positioning relative to the glass element.

These successive screen printing operations require, however. of machine settings, even changes of screen printing tools, which results tool setting and change times penalizing production and encumbering the cost price of the parts thus produced. This problem is all the more crucial that the production series for aesthetic parts are low, due to the very fact of their variety, in order to cover all market niches.

It has also been proposed, by EP-A-0 391 848, a method of decoration consisting in locally modifying the pigmentation of a layer of coating by means of a laser beam. This process uses a layer of coating particularly suitable for subsequent decoration by laser beam and cannot be used for any coating layer.

Furthermore, JP-A-61 108487 describes a method of engraving by laser beam, in which the glass is protected, in areas that should not be engraved, by a protective coating which is later removed.

Finally, we know, from DE-A-42 02 074 and DE-A-43 20 341 of surface cleaning methods using a laser beam making destruction of unwanted deposits.

These known methods do not, however, allow the realization of decoration on glass surfaces previously provided with a layer screen printed, without deterioration of said glass.

The object of the present invention is to overcome these drawbacks by proposing a method for producing control panels, in particular for household appliances, making it possible to obtain individual blinds personalized by combining screen printing with decorations common to a range of banners with a specific decoration.

To this end, the process for producing control panels, especially for household appliances, essentially consists in carrying out minus a personalized laser engraving on at least one screenprint already applied on a raw basic glass strip, by removing decorations, symbols or corresponding signs in the screen-printed layer, then to cover these engravings a coating of a different color, immediately following the operation of engraving or in a separate operation, by manual or automated filing.

la figure 1 est une vue en plan d'un bandeau en verre de four traité conformément à l'invention par mise en oeuvre d'un bandeau brut suivant la figure 3 ;

la figure 2 est une vue analogue à celle de la figure 1, d'une variante de réalisation du décor de la figure 1, et

la figure 3 est une vue en plan d'un bandeau brut de base.

The invention will be better understood from the description below. which relates to a preferred embodiment, given by way of example, and explained with reference to the appended schematic drawing, in which:

Figure 1 is a plan view of an oven glass strip treated according to the invention by implementing a raw strip according to Figure 3;

FIG. 2 is a view similar to that of FIG. 1, of an alternative embodiment of the decoration of FIG. 1, and

Figure 3 is a plan view of a basic raw strip.

In accordance with the invention, and as shown, by way of examples, Figures 1 and 2 of the accompanying drawing, the method of making control panels, in particular for household appliances, consists essentially to carry out at least one personalized laser engraving of decorations, symbols or signs 1 and / or 2 on at least one screenprint 3 and / or 4 already applied on a raw base 5 glass strip.

Then, the engravings corresponding to the decorations, symbols or signs 1 and / or 2 can be coated with a different color coating immediately following the engraving operation or during a separate operation. by a deposit manual or automated. Thus, for example, the decorations, symbols or signs 1 and / or 2, provided around the holes 6 and 7, are, for example, respectively of white and red in color.

The basic raw headband 5 can be made of tempered glass and the screenprint (s) 3 and / or 4 can be in vitreous enamel.

Figure 3 of the accompanying drawing shows a basic raw strip 5 provided with a screen-printed logo 3, for example ABC, on a background also screen-printed 4, the logo being of a given color and the background of another color, know, respectively in gray and black. In addition, the raw strip 5 can also be provided with two holes 6 and 7.

The realization of such bands with four colors currently requires successively at least four passages of screen printing and four screen settings. The screen printing of the decorations, symbols or additional signs, designated by the references 1 and 2 in FIGS. 1 and 2, requires at least one or two additional screen printing runs, depending on whether or not these decorations, symbols or signs will be of the same color or color different.

In addition, a range of household appliances may well have strips of the same geometry and drilling, with the same bottom and the same logo, but with inscriptions and or other signs, including sizes and the colors are different, or even positioned differently.

Thus, obtaining by screen printing the strips according to Figures 1 and 2, is only possible by using a single common screen printing screen, know that of the logo 3. The screen printing screens of the bottom 4, as well as the decorations. additional symbols or signs, designated by references 1 and 2 on the Figures 1 and 2, cannot be common, so that with each production of these bands, a change of the screen printing tools, with times and, by corresponding adjustment costs to be charged to the quantity produced per batch of each product.

The invention proposes to produce the headbands from a raw strip 5. For this purpose, the decorations, symbols or signs 1 and / or 2 are engraved by a laser cut of the bottom 4. Such a cut can be done in seconds. Thus, the embodiments according to Figures 1 and 2 can be obtained very quickly and without the use of tools particular.

Applying different color plaster in engravings corresponding to the decorations, symbols or signs 1 and / or 2 of the background 4 will be carried out quickly, either manually or automatically, for example with ink fast drying.

The cutting of the engravings corresponding to the decorations, symbols or signs 1 and / or 2 is advantageously carried out by means of a laser numerical control. This results in great flexibility with regard to the decors, symbols or signs 1 and 2 to be produced as well as a perfect execution of these decors, symbols or signs 1 and 2. In addition, the number of variants in a range becomes unlimited. Thus, the process has only been described with regard to etching. from the bottom 4, however, the engraving of the logo 3 is also possible. for example to modify its appearance. It is also possible to realize the logo 3 directly on the bottom 4, by laser engraving. In such a case, only the background 4 would be screen printed on the raw banner 5.

The process according to the invention therefore makes it possible to personalize infinity within a very short time of the raw bands 5 kept in stock and which can form the basis of a range of glass elements for device control. These raw headbands being common to many variants of headbands. they can be produced in large quantities, with reduced costs for series produced.

The raw headband of base 5 may consist of a glass with a reflective layer on the front face. this reflective layer being provided with decorations, symbols or signs by etching laser, said decorations, symbols or signs may be covered with a coating of color deposited on the back. So, by this cutting in precise places, in more than the enamel cut on the back, the decorations, symbols or signs are perfectly highlighted, due to the filling of the corresponding engravings by the color coating, without being attenuated by the reflective layer. This mode of realization allows to obtain bright colors deposited on the back of glasses reflective, replacing front and back screen prints on the same glass element.

Cutting the background decoration by laser with digital controls followed by a quick-drying color application on the cut areas, allows endless personalization of products, in a short time, while quantity even per unit, repetitively or not, without tooling cost significant, nor prohibitive setting time for weak series.

Thanks to the invention, it is possible to produce, at reduced cost and in particularly short deadlines, for example just-in-time, on demand, from raw strips, device control strips custom appliances to cover market niches.

These raw strips, which can be stored ready to be can already be fitted with their fixing elements, such as brackets, glued covers, bifaces or a glue deposit. The process thus avoids the delays caused by these installation and bonding operations. as well as the polymerization times of the corresponding adhesives.

In addition, the method according to the invention does not provide for a glass etching by laser, but a simple removal of part of the layer of screen-printed coating, without deterioration of the glass detrimental to the aesthetics, this etching being followed by deposition of a layer of a coating of another color.

Of course, the invention is not limited to the embodiment described, nor to the oven or non-tempered glass oven strips. She may very well apply to glass baking plans also screen printed. Of modifications are still possible, particularly from the point of view of the design of raw parts to undergo laser cutting of part of their decoration, without however, depart from the scope of protection of the invention, such as defined in the claims.

Claims (5)

1. Process for the production of control strips, notably for household electrical appliances, in which at least one serigraphic surface (3, 4) is applied to a plain base panel (5) made of glass,
   characterized in that
   it consists in producing at least one laser engraving in at least one serigraphic surface (3 and/or 4) by removing corresponding decorative features, symbols or signs (1 and/or 2) from the said serigraphic layer and then covering the engraved areas with a coating of different colour, immediately after the engraving option or in a separate operation, the coating being deposited either manually or automatically.
2. Process according to Claim 1,
   characterized in that
   the differently coloured coating over the engravings corresponding to the decorative features, symbols or signs (1 and/or 2) is applied in the form of a quick-drying ink.
3. Process according to Claim 1,
   characterized in that
   the engravings corresponding to the decorative features, symbols or signs (1 and/or 2) are cut out by means of a numerically controlled laser.
4. Process according to any of Claims 1 to 3,
   characterized in that
   the plain base panel (5) consists of glass with a reflective layer on its front surface, the said reflective layer being provided with decorative features, symbols or signs by means of laser engraving, and the said decorative features or signs being covered if desired by a coloured layer deposited on the back surface.
5. Process according to any of Claims 1 to 4,
   characterized in that
   the plain base panel (5) consists of tempered glass and the serigraphic surfaces (3 and/or 4) are of vitrified enamel.

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