NL8503201A - METHOD FOR DECORATING, MARKING AND ENGRAVING OR SIMILAR ARTICLES WITH ENAMELED SURFACES BY LASER BEAM - Google Patents

Description

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Method for decorating, marking and engraving or the like of objects with enamelled surfaces by means of a laser beam_

The invention relates to a method for decorating, marking and engraving or the like of objects using laser beams, which is particularly suitable for household objects with an enamelled surface.

Decorating and marking objects using laser beams is known in principle and takes place above all in the glass industry and in stainless steel dinnerware applications (DD-P 112 941, DE-OS 304 1072). To achieve an exact effect of decorations and markings resp. A description and in order to avoid damage to the adjacent surfaces, various methods of implementation have been developed for this purpose, in particular for decorating glass and ceramic articles. These concern, on the one hand, 15 lateral changes in the radiation yields and thus the energetic effect on the objects; on the other hand, it has become known to simultaneously apply a protective layer for preventing damage to the surface during the irradiation. It has further been proposed to avoid a protective cooling medium during irradiation (DD-P 118 251, DD-P 212 701) to avoid destruction.

A transfer of these known method steps to decorating, marking and engraving or the like of objects covered with an enamel layer is only limited and only possible with extra complicated and extensive measures, whereby an image which satisfies all requirements is moreover to be shown. is not available. In particular, it is not possible to obtain decorations in the baking method in the direct single-layer enamel with the known method. In addition, such decorations are resp. markings with longer use of the corresponding objects hygienically not without concerns (blowing structure of the enamel layer).

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The method steps according to the invention will make it possible to use the laser irradiation for decorating, marking and engraving or the like of objects with an enameled surface layer and, with little effort, an optical problem-free recognition of the irradiated decorations, drawings and writing lines and without the danger of damage to the adjacent surface, as well as hygienic use of the objects are ensured without any objection.

The object of the invention is to develop a method which, when using known laser devices, satisfies requirements for processing enamelled objects and for obtaining a problem-free display of decorations, engravings, markings.

According to the invention, this object is achieved in that the enamel coating is mixed with clouding agents such as oxides of titanium, tin, cermets and antimony, which dissolve locally and optically by the direct action of their laser beam as a result of chemical and physical reactions, whereby a color change of the irradiated area occurs and thereby a problem-free recognition is achieved.

The irradiation is thus applied to an already baked enamel surface layer as well as to an unbaked enamel coating, as well as to still hot and / or hot. plastic enamel possible. According to a further feature of the invention, the edges created by the laser irradiation can be fused by re-acting a laser beam with altered energy effect or by heating the entire object by means of known heat sources. In order to further improve the whole tone image, according to the requirements, a further treatment by tracing with an additional enamel layer is carried out. This layer can consist of transparent, clouded, non-clouded or colored enamel. According to a further feature according to the invention, during the laser irradiation, the surfaces can be covered additionally by a material absorbent / with liquids, brightener or a strong coloring salt solution, so that the image can be influenced more positively. .

The use of these method steps is possible both for laser treatment of enamel layers applied by conventional methods and for articles treated directly or by the two-layer baking method.

The invention will be elucidated below on the basis of a few examples.

EXAMPLE 1:

An aluminum crockery is pretreated in the usual manner and subsequently sprayed with an enamel mud. The mud has the following composition: 100 parts glaze or 100 parts glaze 15 parts Ti02 5 parts paint 15 parts hardener 5 parts T1O2 20 40 parts water 15 parts hardener 40 parts water

After the mud has been sprayed on, the enamel is fired. The baked crockery is now adjusted on a laser decoration device. According to a pre-program, a laser beam and decoration is applied to the crockery by means of a CO2, the accompanying clouding agent T1O2 being applied locally or. dissolves visually according to the guidance of the laser beam.

30 EXAMPLE 2:

The valve shield of a gas resp. the electric stove must be provided with the company sign and with operating instructions. According to the invention this is done in the following way:

First of all, the ground enamel of the object takes place according to the known technology. Then a spray is applied by spraying 5 · Λ * - · i "" W · *** j * ι \ Λ -4- containing 20% of titanium dioxide melted therein. After drying, the desired description of the object is again carried out with a CO2 or YAG laser in accordance with a predetermined program. Only then is baking of the object again carried out at a baking temperature customary for the enamel.

EXAMPLE 3;

A tin plate service is conventionally enameled and deck enamelled, the enamel containing a clouding agent according to the invention. The enamelled object is now again decorated by means of a laser beam, as already described in Examples 1 and 2. A colored, transparent enamel in the form of a majolika enamel is now again applied to the decorated object, dried and baked. This creates an enameled tableware with a beautiful decoration, where the contours of the laser beam shine through the majolika enamel.

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Claims (5)

1. Method for decorating, marking and engraving or the like of objects with enamelled surfaces by means of a laser strip, characterized in that the enamel resp. the enamel raw material mixture by the action of the laser beam as a result of locally and optically dissolving by means of chemical and physical reactions dissolving locally and optically causing clouding agents such as the oxide of titanium, tin, cermets and antimony, are mixed. A decorating, marking and engraving method or the like according to claim 1, characterized in that the irradiation by means of a laser is carried out both with baked and also with an unbaked enamel surface layer. 3o. A method for decorating, marking and engraving or the like according to claim 1, characterized in that the irradiation by means of the laser is still under hot resp. plastic enamel surfaces take place. 4. A method of decorating, marking and engraving or the like according to claims 1, 2 or 3, characterized in that the surfaces treated by means of the laser and / or laser. the whole object is subjected to a further heat treatment. Method of decorating, marking and engraving or the like according to any one of claims 1 to 4, characterized in that the surface of the laser-treated object of a further layer made of transparent, cloudy, not cloudy or painted enamel is provided. 6. A method of decorating, marking and engraving or the like according to any one of claims 1 to 3, characterized in that during the laser irradiation the surface is covered by a well-absorbing material, which is with liquid agents, brighteners or strong coloring salt solutions. drenched. Λ 5 Λ -: v,> ·; -¾ W w ** ** * +