HU201701B - Method for decorating, marking and engraving objects of enamelled surface preferably domestic objects - Google Patents

Abstract

A process for decorating, marking, engraving or the like of objects with enamelled surfaces by means of laser beams, wherein the enamel or enamel raw materials are mixed with turbidity agents which, due to the action of a laser beam, initiate chemical and physical reactions locally and optically and thereby bring about a colour change.

Description

The present invention relates to a method of decorating, marking and engraving enamelled objects, which is particularly applicable to household appliances having an enamelled surface.

The principle of decorating and marking objects using a laser beam is well known (for example, according to DD 112 841 and DE 3041072) and is mainly used in the glass industry and in the manufacture of stainless steel vessels. Various methods have been developed to ensure accurate decoration of ornaments and markings or inscriptions and to prevent damage to adjacent surfaces, particularly for decoration of glass and ceramic objects. These methods relate, on the one hand, to the temporal variations in radiation power and, consequently, energy impact on objects, and, on the other hand, to a method of temporarily forming a protective layer to prevent surface damage during radiation. In addition, a protective refrigerant at the time of radiation has been proposed to prevent injury. These latter processes can be found in DD 118 251 and DD 212 701.

However, the transfer of these known procedural steps to the decoration, marking and engraving of enamelled objects is only conditionally and only by the use of complex and costly additional measures, but not all of the requirements are met. In particular, it is not possible to create decorations by known methods in the single-layer direct enamel process by the firing process. In addition, such decorations and markings should also be considered hygienically (with regard to the blister structure of the enamel layer) when using such articles for extended periods of time.

DE 2458370 discloses a method of engraving by means of an energy beam, by means of which various recesses are created on an object to be engraved.

This patent discloses an enameled surface or an enamelled surface. it does not cover the decoration, marking and engraving of objects with enamel surface, whether or not burnt.

It is an object of the present invention to enable the use of laser radiation for the decoration, marking and engraving or similar machining of objects having enamel surfaces and to provide optically perfect recognition of irradiated decorations, markings and p insurance.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of machining enameled articles using art-known laser devices and providing them with impeccable appearance, engraving, markings and inscriptions.

In order to solve this problem, we have developed a process for decorating, marking, engraving objects having an enameled surface, preferably household objects, when they are burnt or even hot. you are plastic. an energy beam is directed to the top 2 of the objects with the enamel coating not yet burned. In accordance with the present invention, the laser beam is used as the energy beam and the opacifying agents which are locally and optically dissolved and cause discoloration are mixed with the crude enamel slurry by chemical and physical reactions.

The bleaching agent used may be oxides of titanium, tin, cerium and antimony, alone or in combination.

Preferably, the laser-treated surface or the whole object is subjected to a further heat treatment.

In order to further improve the overall appearance, additional treatment may be carried out as required by applying an additional layer of enamel. This layer may be transparent, opaque or colored enamel. According to a further feature of the invention, the surfaces are covered with additional absorbent absorbent fluids, glossy glaze or highly colored saline solution during laser irradiation, thereby further improving the appearance.

The application of these process steps is possible both for laser treatment of enamel layers applied by conventional methods and for objects treated by direct and double-layer firing processes,

The invention will now be described in more detail by the following examples.

Example 1

An aluminum dish is pre-treated in the usual way and then sprayed with enamel slurry. Enamel slurry has a composition that corresponds to the following ratios:

100 parts glass paste part T1O2 part thickener part water, or

100 parts glass mass part color body part T1O2 part thickener part water.

Spraying of the enamel slurry is followed by burning of the enamel. The finished container is then placed on a laser decorating apparatus. According to a predetermined program, a decorative design is applied to the vessel using a CO2 laser beam while the added T1O2 opacifier dissolves locally or optically according to the laser beam guidance.

Example 2

The cover plate of the gas or electric stove under the switch buttons must be marked with a company sign and instructions for use. According to the invention, this is done as follows.

First, the object is enamelled according to traditional technology. Spraying is then applied to an overcoat containing 20% molten titanium dioxide. After drying, the subject is labeled with a CO2 or YAG laser according to the specified program. Only then should the enamel be fired at a standard firing temperature of the enamel.

HU 201701 Β

Example 3

A steel plate vessel is conventionally provided with a base and top enamel, wherein the top enamel comprises a bleaching agent according to the invention. The enamelled object is then decorated with a laser beam as described in Examples 1 and 2. The colored object is then applied to a colored transparent enamel in the form of a majolica enamel, dried and then burned. In this way, an enameled dish with a beautiful ornamental motif is created, where the outlines of the laser beam translate through the majolica enamel.

The method according to the invention allows the use of laser beams to decorate, mark, engrave objects with enameled surfaces, so far no laser beam has been used for this purpose.

The main advantage of the invention is that it provides extremely high machining speeds (e.g., ten letters / second) and sharp contour lines. In addition, decoration, marking, engraving is done in a non-contact process.

The process allows, at low cost, optically perfect recognition of their decorative motifs, signs and inscriptions without damaging the surrounding surfaces, and the satisfactory hygienic use of the objects so treated. In addition, the process allows for aesthetically pleasing decorative motifs.

Claims (5)

, PATENT CLAIMS A method for decorating, marking, engraving objects having an enameled surface, preferably household objects, when they are burnt or even hot. a beam of energy is applied to the surface of objects coated with a plastic or uncoated enamel, characterized in that a laser beam is used as the energy beam; 2. The process of claim 1 wherein the opacifying agent is selected from the group consisting of oxides of titanium, tin, cerium and antimony, separately or in combination. Method according to claim 1 or 2, characterized in that the laser-treated surface or the whole object is subjected to a further heat treatment. 4. A method according to any one of claims 1 to 5, characterized in that the surface of the laser-treated object is provided with an additional layer of transparent, opaque, non-opaque or colored enamel. 5. A method according to any one of claims 1 to 3, characterized in that the laser beam is applied to the surface by a absorbent material impregnated with fluxing agents, glossy glaze or highly colored saline solutions.