DE4013758A1 - Flashed glass prodn. - by spray coating commercial glass with coloured glass frit - Google Patents

Abstract

Flashed glass is produced by flame spraying commercial glass with coloured glass first of grain size 70 x 10 power (-3) to -150 x 10 power (-3). The substrate is preheated to at least the softening temp. of the glass. Pref. the coating can be complete a partial using a pattern plate. It can be glassy, partially crystalline, crystalline, while, colourless, or coloured, transparent, semi-opaque or opaque. The coating thickness is pref. 0.1-0.5mm. Mixed colouring and colour overlapping can be achieved by using several overlapping spray coated layers. The sprayed coating may have a lower thermal expansion coefficient than the substrate to produce a prestressed coating after cooling. Alternatively the coating may have a higher expansion coefficient so as to produce a cracked affect after cooling. ADVANTAGE - By mixing the spray material and varying the coating thickness, an almost unlimited colour range is achievable at low cost as only these coatings are required.

Description

The invention is applicable for the production of flashings and for applying colored or colorless, preferably glassy coatings for decoration or color design of commercial glass. It can be particularly advantageous are used for the production of new types of overlay glasses that are partially or fully coated and allow new design effects.

A detailed description of flame spraying, its Application that is spraying materials and equipment used in Appen, A. A .; Petzold, A .; Heat-resistant corrosion, Heat and wear protection layers; VEB publishing house for reason Stoffindustrie Leipzig, Leipzig 1984 and in Kretzschmar, E .: Metal, ceramic and plastic syringes; VEB-Verlag Technik Ber lin, Berlin 1970, included. The use of flame spraying for glasses is neither as a glass base nor as a spraying unit proven substance. Further information on the application of the Flame spraying of powders are available from Krauskopf, F; Berthold, A. E .: Possibilities for using flame spraying with powdered filler materials; Technical information 78 (1985) Issue 8, pp. 380-388. The usual one so far Application of flame spraying is in the generation of ver wear, heat and / or corrosion protection layers on me tall underground. A major difference of the "glass flame spraying "to the previous flame spraying is the hot one Substrate that is necessary when applying layers of glass is. Injected ceramic layers also have a counter to glassy layers always a share of open Porosity (often <10%). Through various measures one tries to reduce the disadvantages of porosity. The Spray layers are therefore soaked to close the pores seal (with metals, glasses and enamels, inorganic substances and decomposable salt solutions).  

For the technical task of producing overlay Hollow glass and colored commercial glass are different ver drive in use and known. Most of the colored ones Glasses are either completely dyed through or as a thin coating layer by overlaying or enamelling upset. Decorating glasses with glass colors shoots through colored, mostly borosilicate glasses. By painting Spraying (cold spraying of colored glass powders with organic Adhesion promoters who guarantee liability until they are burned in afford) or by printing the colors are applied. The Glass colors become white or colored in transparent, half opaque or opaque design used. In one after The next step is the applied layers of paint baked between 500 and 660 ° C [author collective: ABC Glass, VEB German publishing house for basic material industry, Leipzig 1983].

More recently, centrifugal casting processes have also been used, where two differently colored glass items below Influence of gravity and surface tension to one out the best of both glasses in a defined mutual arrangement the related items, and deformed by spinning (DD 2 20 017).

For the creation of bubble and streak decorations "proced for refining huts in the feeder "[see also Klein, J .; Wawek, R .: Intensification in machine manufacturing of large-volume commercial and lighting glass products sen; Silikattechnik 39 (1988) Issue 9, pp. 301-305]. These Procedures allow during glass conditioning melt in the feeder, during shaping and the edge bear processing of the products simultaneously in one process stage To achieve finishing effects. You are in the "procedure and Device for the production of bubble-decorated glasses "(DD WP 1 41 513) patented.

For the production of colored effects are "crumbly decorated glasses ser "has been developed: the" process for the production of industrially processed mechanically blown in seamlessly large-volume hollow glass and device for carrying out the  Procedure "(DD WP 1 46 279). By an electropneumatic Controlled device are glass crumbs on the press ram brought before the glass post is put down. The decoration medium melts into the glass item after the drop and is after the pressing process on the bottom of the Circuit board. This is followed by the further usual shaping process zeze.

These procedures leave the search for expansion of color and decor design recognize, but they differ essentially from the "glass flame spraying" according to the invention. The In addition, flame spraying of glass has so far not been available achievable variety of design options, in addition to the Mixing colors the layer thickness can be varied which can influence the color intensity. To Additional effects are due to the influence of the bladder content and by adding non-melting components reachable.

The aim of the invention is to apply the Powder flame spraying coatings that are preferably glassy and are colored to apply to commercial glass. The Erfin is when using templates or with partial coating suitable to achieve decors or design effects. In addition, the invention enables the miscible speed and different layer thicknesses are almost uncompromising limited color palette with cheaper production, since only small Layer thicknesses are required and that in the production of Flashed glass high expenditure is eliminated. More creative Effects are due to the addition of non-melting stock parts reachable to the wettable powder, furthermore the Bla content of the sprayed layer can be varied and thus allow additional design options. The other Coming spray layers can be glassy, partly crystalline lin or crystalline, white or colored, transparent, half be opaque or opaque.

With the introduction of flame spraying on glass, it is with simple, easy-to-use means possible, perfect  to produce new colored and flashed glasses and decors.

With correspondingly set differences in the expansion coefficient The sprayed-on layer can be efficiently pre-stressed strengthening (coefficient of expansion lower than Base glass) or for crackling effects (coefficient of expansion higher than base glass) can be used.

The object of the invention is to use commercial glass glassy or semi-crystalline layers, preferably are colored.

The advantages of the invention compared to those already known technical solutions are in

• - a low consumption of colored glass due to the low Layer thickness,
• - high design diversity by varying the Layer thickness, flowing color transitions, mixed colors, Admixing non-melting components,
• - Little effort.

According to the invention, this object is achieved in such a way that that these layers using the powder flame spraying process be applied to commercial glass. The spray application can by means of powder flame spray guns using manual, mechani automated or automated spraying technology.

The following requirements are necessary:

• 1. The substrate must have a temperature <= the softening temperature (T _g ) of the glass during the spraying process
• 2. the wettable powders must be in a form suitable for handling in flame spraying devices (glass frits with a grain size preferably in the range from 70 · 10 ^-3 to 150 · 10 ^-3 mm,
• 3. the expansion coefficients of the base glass and sprayed-on layer normally become approximately the same be great  
• 4. To create a crackle effect, the expansion must coefficient of the sprayed layer correspondingly higher be,
• 5. to generate a pressure bias in the sprayed Layer, the coefficient of expansion must be correspondingly lower be to achieve a solidification effect.

With the aid of the powder flame spraying process, colored glass frits which correspond to the requirements of the spray guns (grain size preferably in the range from 70 · 10 ^-3 to 150 · 10 ^-3 mm) are preferably applied to commercial glass. The spray application is carried out using the KMP 64, KMP 64/1 flame spray gun or devices with the appropriate power. The surface must have a temperature <= the softening temperature (T _g ) of the glass (approx. 500 to 600 grdC) and be free of impurities. For energetic reasons, the spray order is classified in the manufacturing process so that the glasses still have the necessary temperature through the manufacturing process. The distance between the spray gun and the underground is about 100 to 200 mm. The spray application can be done manually or mechanized or automated. Several spraying processes can be carried out in succession or next to each other with different colors and layer thicknesses. The layer thickness will preferably be in the range of 0.1 to 0.5 mm. It is possible to achieve partial coatings and decorative effects using stencils. Mixing colors and varying layer thicknesses allows an almost unlimited range of colors. Additional effects can be achieved by adding non-melting components.

The sprayed-on layers can be glassy, partly crystalline to crystalline, white or colored, in transparent, half opaque or opaque versions are used. The embodiment of the invention is illustrated by the following examples explained.

• 1. Hollow glass products, for example drinking vessels, are covered with a layer, which is preferably glassy and colored, while they are still hot (temperature <= softening temperature T _g ). The layer is applied using powder flame spray guns, the spraying distance is approx. 100 to 200 mm to the substrate. The spray application can be carried out on the entire outer surface or only partially. Stencils or masking can be used for decorative effects.
• 2. Illuminated glass products, for example lamp shells, are coated with a spray application after the shaping, while still hot (temperature <softening temperature T _g ), the coefficient of expansion of which is considerably greater than that of the substrate. Krakelee structures can thus be reached.
• 3. Hollow glass products, such as drinking vessels, are completely covered with a glassy spray application after the shaping, while still hot (temperature <= softening temperature T _g ), the coefficient of expansion of which is less than that of the substrate. The spray application is done by powder flame spraying devices, the spraying distance is about 100 to 200 mm. After cooling, a compressive stress occurs in the sprayed-on layer, which causes a consolidation effect.
• 4. Illuminated glass products, for example lampshades, are coated with a partially crystalline or crystalline coating, the coefficient of expansion of which is matched to the substrate (difference in coefficient of expansion not exceeding 0.7 · 10 ^-6 K ^-1 ). This enables new types of cloudy glass to be produced.

Claims (9)

1. A process for the production of flashed glass and for applying colored and colorless layers and decorations on industrial glass, characterized in that layers are brought onto industrial glass by the powder flame spraying process. 2. The method according to item 1, characterized in that the glass to be coated has a temperature during the spraying process <= the softening temperature (T _g ). 3. The method according to items 1 and 2, characterized in that colored glass frits are preferably used as the spraying material, in a grain size suitable for the spraying devices, grain size approximately in the range from 70 · 10 ^-3 to 150 · 10 ^-3 mm. 4. The method according to items 1 to 3, characterized in that that the coating takes place partially or completely, at partial coating can be used to achieve decorative Effects stencils can be used. 5. The method according to items 1 to 4, characterized in that that the sprayed layers are glassy, partially crystalline or crystalline, white, colorless or colored, transparent, half are opaque or opaque. 6. The method according to items 1 to 5, characterized in that that the layer thickness is preferably 0.1 to 0.5 mm. 7. The method according to items 1 to 6, characterized in that that mixed colors and color transitions through multiple and overlapping spray application can be achieved. 8. The method according to items 1 to 3, characterized in that that the sprayed layer against the base glass one has so much lower coefficients of expansion that after  the cooling has a solidifying effect. 9. The method according to items 1 to 7, characterized in that that the sprayed layer is so much higher Expansion coefficient has that after cooling to Crackle effect is coming.