FI72304B - PROCEDURE FOR THE FRAMEWORK OF THE STRUCTURE OF THE STRUCTURE AND OF THE GLASMELLANSKIKT - Google Patents

Abstract

1. Method for producing light dispersing and structured surfaces in an intermediate glass layer in which the surface of the base glass of a parison is roughened and coated with a second glass layer after the treatment, characterised in that the parison preformed of crystal or lead glass is sandblasted after cooling down to about 500 to 600 degrees C, whereafter a short-term reheating occurs in order subsequently to coat the roughened surface of the base glass with the second glass layer ; after finishing the forming and a further cooling down the glass object is tempered in the cooling furnace.

Description

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Method for forming light scattering and structured surfaces in an intermediate layer of glass Förfarande för framställning av 1jusspridande och structurerade ytor i ett glasmellanskikt

The invention relates to a method for forming light-scattering and structured surfaces in an intermediate layer of glass, according to which the surface of the base glass is roughened and, after treatment, coated.

DE-PS 15 96 826 discloses such a method in which the surface of a hot glass blank is roughened by either placing this blank in a rough glass mold or sprinkling glass flour on it. Instead, the blank can also be coated with a small amount of foam glass. Thereafter, the still hot glass preform is treated with sublimable metal compounds using reduction so as to subsequently cause sublimation under glass. Thus, the pretreated blank is then coated with a flowing glass. However, with this method, roughened surfaces are obtained in a rather complex way. Above all, no ornaments or artistic decorations can be created in this way.

The object of the invention is therefore to provide a method of the above-mentioned type by means of which it is possible to obtain glass with a plastic decorative effect simply and quickly.

According to the invention, this object is achieved by subjecting a crystal or lead glass preform, after cooling to about 500 to 600 ° C, by sandblasting, followed by short-term reheating, and then coating the roughened surface of the base glass with said second glass layer and final glass and after further cooling, temper in a cooling furnace.

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Some other alternatives for the method of manufacturing a hollow glass article according to the invention are obtained from the dependent subclaims. Multiple sandblasting and coating provide stepped shades that give a plastic impression. According to another measure of the invention, sand of different grain size is blown onto the hot outer surfaces of the blank to provide structurations, or the surface is covered with templates to form geometric ornaments or motifs.

The advantage of sandblasting is that structured surfaces are obtained in a simple manner, on which entrapped air bubbles are formed when the preform is subsequently coated with flowing glass, whereby a mist formed by small bubbles develops, which causes an effective effect in the viewer. Glass blown in this way gives an excellent effect, especially when light rays fall obliquely into the glass. The contrast between clear and frosted glass is also quite impressive. Various effects can also be achieved by partially covering the basic decoration provided by the veil formed by small air bubbles and using sand with a second grain size for finishing, or by staining the veil with metal oxides. Another preferred embodiment of the method according to the invention is also based on the fact that by placing templates various subjects are developed. Thus, glass decorations with a plastic effect can be formed in a rational way, especially in the case where reliefs are obtained, e.g. small patterns. The method can simply be carried out with a sandblasting device.

As described in detail, the method for making both hollow glassware, such as vases or boxes, and also for sealing glassware, such as plates and bowls, can be carried out as follows:

II

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A preform is taken from a glass melt with a temperature of 1250 ... 1400 ° C by means of a blow tube. For example, to make a vase, such a blank has a diameter of 6 cm and a height of 9 cm. After cooling, corundum sand or steel sand is blown into a hot blank at about 550 ... 600 ° C, whereupon individual particles under high pressure are thrown onto the glass surface, which strikes small particles from the glass surface. In this case, the operation becomes dim. Sandblasting as a means of artistic glass design is not new in itself, but now a combination of dimming and a structured surface is achieved in a hot blank, whereby in addition to the small air bubbles formed, other optical effects of veil glass are obtained during coating. After sandblasting, the surfaces must be completely clean so that the blank is blown clean with compressed air. The sand-blown blank can also be treated by treating other surfaces with different sands with different grains, creating an ornament, resp. subject. By superimposing different patterns, subjects can be obtained, e.g. leaves with different relief depths, especially in the area of the stem or flowers. A special effect is also achieved when such objects are illuminated. In this case, such objects formed by sandblasting have a fascinating plastic effect. By superimposing different models, two or more shades can be achieved at separate points or by multiple sandblasting and coatings. Sand blasting after the work is heated preform for a short time, for about half a minute to 1000 ° C to melt slightly roughened surfaces together, respectively, hiekanpuhalluksesta from the closed-adhered particles sticking to hot glass. It is then coated with a second layer of glass. It is also conceivable to engrave sandblasted decorations by hand afterwards and thus give the small series different characteristics. This gives even more craftsmanship. After coating, the cup is freely shaped in this example, and a cavity is created by pushing the iron spindle into the blank. The 4 72304 pre-blown article is then allowed to cool in the blow tube to about 650-700 ° C, after which the article is separated and allowed to temper in a cooling oven for about 16 hours at about 540 ° C. The bottom is then ground or edge treated. In the same way, a plate is made, in which the blank is spun freely open. Other manufacturing methods such as centrifugation or pressing can also be used.

It is clear that the method according to the invention provides a number of design possibilities which are not illustrated by the example presented here. The glass articles according to the invention can be manufactured in a high-tech manner so that the blank is formed by pressing and blowing in known devices.

Claims (4)

72304 A method of forming light scattering and structured surfaces in an intermediate layer of glass such that the surface of the preformed glass is roughened and, after treatment, coated with a second layer of glass, characterized in that from crystal or lead glass to a preformed preform after cooling to about 500-600 ° C; , sandblasting is followed, followed by a brief reheating, and then the roughened surface of the base glass is coated with said second glass layer, and after final shaping and further cooling, the glass article is tempered in a cooling furnace. Method according to Claim 1, characterized in that the sandblasting and coating are repeated several times. Method according to Claims 1 and 2, characterized in that different grains of sand, i.e. different models, are used to cover the sand-blown surfaces. A method according to claim 1, characterized in that the relief-like surfaces of the base glass are coated with said second glass layer.