DD215776A1 - METHOD FOR PRODUCING COLORED IMAGES ON GLASS - Google Patents

Abstract

The aim of the invention is to provide a highly effective variable method for producing resistant colored images on glass substrates. The task is the development of a method that can be used to produce scales, decorations and labels of different dimensions for different combinations of glasses and diffusion colors. This method is characterized in that diffusion colors are heated by means of high-energy radiation, preferably by means of a weak infrared laser beam according to the intended contours of the image simultaneously with the glass surface and convective and introduced by diffusion into the glass surface, with a permanent acid and alkali-resistant, for normal-sighted Eyes consistent color trail arises.

Description

Inventor: Dr. R. Ziermann, Jena

Dr. H. Müller, Neulobeda-East I. Geiling, Naumburg St. Muller, Ilmenau

Serving Agent: '

VEB Kombinat Technical Glass Ilmenau - Central Office for Property Rights - -

6300 Ilmenau

PO Box 303,,

IPK: C 03 C, 21/00

Title of the invention: Process for producing colored images on glass Field of application of the invention:

The invention relates to a process for producing colored images on glass using diffusion paints, preferably for the production of scales on thermometers and other glass measuring devices and of decorations and labels on glass articles and glass parts, in particular in the chemical industry, food industry and the like. Industries apply.

Characteristic of the known technical solutions:

The requirement to produce durable images on glass substrates, has long been a problem. For the production of durable images on glass substrates are known according to DD-WP 100 928 and DD-WP 101 376 methods in which by diffusing into the surface ions, eg , As silver (yellow-brown, brown) or copper (red, black), a color is achieved. The contrast images and true-to-life images produced in this way can only be eliminated by removing the surface layer covered by the diffusion. They are thus resistant to normal ambient conditions, to oils and organic solvents, but also to lyes and acids which do not attack the glass.

However, these methods have several disadvantages:

The diffusion of the ions into the glass surface is a temperature and time dependent process. In addition, the color or tint and contrast of the images are dependent on the charge and coordination of the diffusing ions. Thus, in addition to the selection of a suitable glass matrix, a usually complicated and energy-intensive process is necessary, to which the entire glass part is subjected. Thus, e.g.

with silver-containing inks, burn-in at about 480 ° C. (diffusion), and if the glass matrix does not contain the contrast-enhancing arsenic or antimony-based ion, a reducing after-treatment of the glassware or part is usually at about 450 ° C. (" Development ") necessary. Depending on the color to be achieved, copper requires up to three thermal treatments at even higher temperatures. This makes high demands on the kiln guide during firing or thermal aftertreatment. The temperatures for a sufficient diffusion are in the range of Transformat ion temperatures or even the softening temperatures of the glasses. For "normal" glasses with tg of 450 ... 550 ^e C and E 600 * C only relatively expensive colors based on the coloring silver ion come into consideration.

A further limitation experienced by these techniques in that the colors must be applied directly or indirectly by .Siebdruckverfahren. Thus their variability is severely limited. For small numbers or e.g. for precision scales,

Built on the basis of multiple calibrations, these methods can not be used economically because the Umspann- and adjustments dominate. _x

Therefore, the etching technique is still preferred for these applications, consisting of the steps

- ingrowth of the glass parts

- Label (remove wax with a pricking tool)

Etching the exposed glass e.g. with hydrofluoric acid

- Dewaxing

- Add the color to the etched wells and remove

the excess color - drying the paint

The etching process is in spite of rationalization, especially the labeling, very expensive and connected by the etching environmentally hazardous and therefore with high safety regulations.

These disadvantages are considerably eliminated according to DD-WP 112 941 by a method of laser engraving. By use of microcomputer-controlled moving devices in commercial lettering systems, the first four steps of the etching process can be rationally summarized.

A further improvement experienced by the latter method in that either according to the 3A-PS 49-43 252 an on the glass body previously applied enamel color with the laser beam immediately nachführ'r dye jet is fused with the liquid laser track.

The latter methods allow a high variability, but the images produced therewith are not resistant in the aforementioned sense. Only mechanically and chemically unstable air-drying inks or enamel colors of the N-series (N = non-resistant) can be used for the "normal" glasses.

Object of the invention:

The aim of the invention is to develop a method in which these disadvantages are eliminated and colored with the highest efficiency.

sistente images are produced, with 'economically favorable dye combinations are applied.

   Presentation of the essence of the invention:

The invention has as its object to develop a process for the production of resistant colored images on glass, with the scales, decorations and labels different, often changing, extreme dimensions using different, even for certain types of glass previously not applicable diffusion colors are produced and with the In addition, different colors are possible. '

According to the invention, the object is achieved in that the method for producing colored images on glass is characterized in that uniformly over the entire surface of the image on the glass carried diffusion dye by means of high-energy fol ^ ussierter radiation, preferably by means of infrared laser beams by a controlled relative movement of Laser beam to Glasob'erfläche corresponding to the intended contours of the image, is heated simultaneously with the glass surface locally. In the process, the glass surface is melted and the diffusion color is mixed convectively into the molten glass. According to the invention, color ions are diffused by the heating immediately and also after the laser beam has continued to cool down in the area of the thermal aftereffect from the diffusion paint into the glass surface, so that it produces a uniform and permanent color track without engraving or other damage to normal-sighted eyes leave the glass. '

Only compositions with diffusible and coloring ions are suitable for the process, glaze-based enamel colors are unsuitable. The colors suitable for screen printing are usually thinned and applied evenly to the glass surface. The laser beam cuts off the contours of the future image. The image data are preferably stored in a microcomputer which controls a cross table plus a laser beam dropout device or a mirror deflection system plus blanking.

The partially mixed with the color in the laser track convective organic. Color components provide for reducing conditions

  · "I.

The advantages of the method are also that it is guaranteed by an optimal adjustment of laser power and feed that the glass does not evaporate, that no fragments are torn out of the glass surface and that no hairline cracks occur in the glass interior. The glass, heated and molten by the laser beam, retains due to its poor thermal conductivity.

, Relatively long a high temperature. The initially very high diffusion rate of the coloring ions in the heated laser track guarantees that the initially generated by convection

'' ν

Uneven mixing of the color at the end of the process results in a uniform color for normal eyes. This appears in its final form after removing the excess color. .

Furthermore, the method is characterized; that the glass surface is heated by the infrared laser beam locally to temperatures above the softening temperature of the glass and the color ions can be introduced at temperatures of appreciable diffusion above the transformation region of the glass in the glass surface. This makes it possible to apply even to glasses with low transformation and softening temperature colored, resistant scales, labels or decors with such colors, which have a high diffusion temperature, without deforming the glassware or objects. This is a replacement of the expensive silver. Furthermore, the method is also characterized in that the production of multicolor images in a main process step is possible by simultaneously applying a plurality of diffusion colors of identical or different diffusion temperatures to the glass surface

and by means of the infrared laser beam in a process.

The process can be carried out both on flat glass and on round material. In the case of low beam divergence, in the latter case neither unrolling is the same as in screen printing nor is focus tracking

(z-coordinate setting) necessary.

In addition, the method is characterized in that the laser beam · in the case of burnt enamel paints, preferably coated with lead-containing enamel, coated glass underlays the Oxida-, 5 tion state of the coloring ions locally and thereby a different-colored, but o.g. Definition of non-resistant track generated. Burning traces are obtained by reduction or other chemical reactions of mostly heavy metals.

Preferably, lead-containing black pigments of the series ΝΙΟ produce white-black traces. When using such coated glasses, the so-called substitution glasses, it is possible, with the aid of laser technolo- gy, to replace the expensive opaque glass (frosted glass) with precision scales. '

Furthermore, it is möglieh with the erfindungsmäßigen method also possible that the laser beam stood in already colored glasses the Oxidationszü, the coordination or distribution of the color ions · locally changes and produces a different colored track so that color images can be made on colored glass.

Exemplary embodiments: ^v

The invention will be explained below with reference to several examples:

l.The production of a precision scale on opaque glass white, for a thermometer:

The cleaned scale carrier from Trübflachga 1s comes to a laser system either with all calibration marks or with a base or ¹ start mark and the data on the remaining marks. The physical relationship, ie the function of the pitch delimiters, is entered as a so-called "mother scale" for the respective device or thermometer type in a computer With the aid of rapid change magazines, the scale carrier to be processed is adjusted after the base point has been adjusted

Apply with diluted, screen-printable diffusion paint, ζ. Β. with silver containing "yellow sets", placed on an xy-processing table. Subsequently, the distances of the calibration marks are entered into the computer and the corresponding scale program is started. While the laser processes one block of scales, the next cutting magazine is prepared and the data is already stored. Thus, the economy of the process co-determining idle times of the laser are minimized. _Does this example become a CO _? Laser used in CW operation, so for the übliehe line width a power under 10 W at the workpiece surface from. As a result, an engraving of the glass or other damage, as z. B. are to be feared in other laser methods with much higher output, almost impossible. If a laser is used in multi-mode operation, despite the power reduction by the focusing optics, a. Laserau s.gangsleistung of about 10 W sufficient .. Thus, the glass surface is only melted by the laser beam, the diffusion color is mixed with the molten glass, at the same time begins the diffusion of color ions, due to the heat storage in the molten

20 'glass even after the removal of the laser beam for a certain time stops. As a result, diffusion paths are achieved, which lead to a uniform distribution of the color ions along the laser track. Instead of the CO laser with a wavelength of approx. 10 pm, ζ. For example, a 1.06 pm Nd-YAG laser can also be used.

After laser processing, the excess diffuse color is recovered, ζ. Β. by peeling, stripping or wiping.

2. The application of a -Skale on round material made of low-softened device glass by means of copper diffusion paint, preferably on a measuring cuvette ο the pipette:

The process is carried out with the same process steps as under Pkfc. 1 performed. Prerequisite for the elimination of a rotating mechanism or a Z coordinate guidance is either the application of a YAG laser or a CO laser with low divergence

(Single-mode operation, optics with long focal length, etc.) ·

3. Applying a precision scale to "substitution glass", a glass coated with white lead enamel:

In contrast to the embodiments 1 and 2, the glass-5 surface is not coated with diffusion paint. By melting the enamel layer with the aid of the laser beam, the lead ions interact locally with the atmosphere in the laser track and are thereby partially reduced, as a result of which the track worn by the laser beam becomes uniformly black. Advantageously, a YAG laser is used, with this the finest tracks are achieved with very good contrast. Otherwise, the procedure is carried out as described in Example 1;

Claims (4)

Invention claim: 1. A process for producing colored images on glass, characterized in that - Apply a diffusion color evenly over the entire surface of the intended image on the glass surface on ge - By means of high-energy focused radiation, preferably
by means of an infrared continuous laser beam it from 1 to 2 0 W by a controlled «relative movement of laser beam
heated to glass surface according to the intended contours of the BiI-des simultaneously with the glass surface
"- convective in the molten glass surface, wherein their color ions immediately and then in the range of thermal aftereffect in the glass diffuse and - As for normal eyes consistent and permanent color trail without engraving or other damage to the glass on the glass surface is visible. 2. Method according to / point / 1., characterized in that the glass surface is locally at temperatures above the softening temperature
of the glass is heated and the color ions with temperatures of noticeable diffusion above the transformation range of the
Glases are introduced into the glass surface. 3. Procedure according to / point / 1. and 2. , characterized in that
multiple diffusion colors of the same or different temperatures of noticeable diffusion simultaneously on the glass surface applied and by means of infrared laser beam at the same
Procedural parameters are introduced. 4. Method according to / point / 1 .. characterized in that on with
baked enamel paints preferably with lead-containing melt colors, coated glass substrates by means of infrared laser beam, the oxidation state of the color ions locally changed and a
different colored track is generated. S.Proceed to / point / 1. , characterized in that. already colored glasses by means of infrared laser beam, the oxidation state, the coordination or the distribution of the color ions locally changed and a different colored track is generated.