US2916393A - Method of forming a raised metallic design on a vitreous surface - Google Patents

Description

Dec. 8, 1959 A. VELONIS 2,916,393

METHOD OF FORMING A RAISED METALLIC DESIGN ON A VITREOUS SURFACE Filed June 29, 1955 Unite METHQD OF FGRMII IG A RAISED METALLIC DESIGN ON A VETREUUS URFACE This invention relates generally to the art of putting patterns and design on ceramic or glass articles, and more particularly to a novel product and the method of making the same.

It is known to produce a raised pattern or design on a ceramic or glass article, but the means heretofore employed were critical and time consuming, so that the cost of the finished article was relatively high.

It is therefore among the principal objects of the present invention to provide a new article of manufacture and method of making the same wherein raised designs and patterns are obtained in an improved manner accompanied by a reduction in the requirement of skill on the part of the operator.

These objects and other incidental ends and advantages will more fully appear in the progress of this disclosure, and be pointed out in the appended claim.

In the drawing, in which similar reference characters designate corresponding parts throughout the several views I Figure 1 is a view in perspective of a glass article and stencil therefor showing a first step in the present method.

Figure 2 is a perspective view showing the second step in the present process.

Figure 3 is a fragmentary sectional view showing the first heating or firing step.

Figure 4 is a perspective view showing an ensuing step in the application of the second coating.

Figure 5 is a perspective view showing the second c0ating in place.

Figure 6 shows the second heating or firing step.

Figure 7 shows a step involving the removal of the excess second coating.

Figure 8 is a perspective view of a finished article.

The present invention has particular utility in the application of raised patterns on glass or ceramic articles, where the exposed visible layer contains a metallic compound of relatively high cost.

In accordance with prior methods, the design or pattern has been produced in a raised form on the basic article by casting the same with a protuberance where the pattern was desired, or by applying an overlay in such a desired area and subjecting the same to a firing process whereby the projecting material became fused to the basic article. Following this, by stencil or by accurate and fine brush-work, an overlay of a vitreous material was put in place upon the projecting portions of the design. Subsequent firing then made such lastmentioned overlay secure upon the raised foundation upon which it had been applied. The principal difiiculties presented in the old method lay in the fact that the stencil had to be very accurately positioned, otherwise, with a loss of register, the metallic outer exposed layer would not coincide with the projecting portions of the article being treated, and a rejected or unsaleable piece would result. Similarly, the brush-work requires great care and skill so that the reduced speed of producatent 0 2,916,393 Patented Dec. 8, 1959 "ice tion raises the cost of the finished article, or inaccurate application results in inferior and unsatisfactory finished articles.

In accordance with the present invention, only one application is made which must be accurately positioned with respect to the article, and subsequent steps involve no accurate register so that misaligned designs and patterns are impossible.

Turning to Figure l, in accordance with the present method, a basic article 10, may, for example, take the form of a drinking glass 11. A stencil 14 may be composed of any desired material, such as, for example, flexible metal foil, silk net, nylon net, or the like. In other words, any of the well-known stenciling materials normally used for the application of ceramic or low melting-point enamel colors may be used. The stencil 14 is provided with an opening 15 having the shape of the design or pattern 20 (Figure 8) which it is desired that the finished article 25 may have. By way of example, I have chosen the initial A.

The stencil is placed, as appears in Figure 2, in close contact with the outer surface 16 of the article 10. For this purpose the stencil 14 may be mechanically held in place by means not shown, or may be temporarily held in place by an adhesive (not shown). With the stencil in place, as shown in Figure 2, application is made of a flux 30. This flux is intended to mean a clear ceramic flux or ceramic color that can mature (liquify or melt) at a temperature which is substantially below the softening temperature of the base surface. In this case, for example, the softening temperature of the article 10. It is desired that a substantial difference in temperature of softening of the flux exists, and I have found that a temperature difference of at least fifty degrees is effective for this purpose. The layer of the flux 30 is dependent in thickness upon the amount of raised effect desired in the finished article, taking into consideration the shrinkage in the flux which occurs upon firing.

After the flux has set sufiiciently to allow removal of the stencil 14, the stencil is removed and the flux remains in place upon the article 10 with a configuration corresponding to the opening 15 in the stencil.

It is preferable to remove the stencil before the firing of the flux 30, and this step is shown in Figure 3 where a suitable source of heat 33 is employed while the glass 11 is disposed within a kiln 34. Depending upon the nature of the flux 30, other heating methods may be used, such as electrical induction, electrostatic loss and/ or infrared radiation. The flux which constitutes the first layer or first coating in the practice of this invention is preferably a clear ceramic flux which contains, as a major ingredient, a frit composed of powdered low melting point glass. Thus, for example, such frit may have a melting point of one-thousand degrees Fahrenheit, as against, for example, a melting point for the glass 11 of thirteen hundred degrees Fahrenheit. If, for example, the glass 11 has a melting point of one-thousand degrees Fahrenheit, then the melting point of the glass frit as embodied in the first layer or coating, should not exceed nine-hundred and fifty degrees Fahrenheit, and may be lower. The flux constituting the first layer or coating may include a carrying element in the form of Damaar varnish, or other fossil resins in a suitable oil vehicle. These organic constituents of the second layer or coating being primarily carbonaceous, burn off during the firing so that the frit particles sinter to each other and to the base, such as the glass 11.

After the low temperature glass frit or flux 30 has been fired, and is securely matured or fused to the glass 11, an unfluxed metallic material is applied. This unfluxed metallic material forms a secondary layer or second coating and depending upon the color desired, is composed of a form of metal which, upon firing, will become apparent.

For example, when it is desired that the finished design 20 present the appearance of gold, the metallic material applied as the second coating may be unfluxed gold resinate.

Thus, for example, a concentrated solution of gold resinate devoid of organic metal soaps which are normally used as a fixing agent or bridging adherent to vitreous surfaces, may be used. Despite the lack of flux, the gold adheres to the first or primary coating but has a relatively weak adherence to the outer surface of the glass 11. This step is shown in Figures 4 and 5, where the second coating 31 is shown being applied. Because the application at this point may be by brushing, roller coating, wiping, screening, dusting or spraying, the second coating may be applied so that it extends beyond the outlines of the first coating 30. Thus, no second identical stencil operation is required, and hence the problems of obtaining absolute register by the use of a second stencil are avoided. The second coating may be quickly applied and with substantially no skill. As seen in Figure 5, the second coating 31 extends not only on the first coating 30, but also on the neighboring glass area 11.

The second coating, when it is of gold, may be what is commercially known as liquid bright gold such as one containing an organic gold compound with about 8 to 20 percent in actual gold which has been converted into a resinate and dissolved in volatile oils and solvents. The second coating contains no metal organic fluxes so that unless it becomes bonded by the vitreous first coating, it does not become attached to the body of the article being treated.

Following this, the article 10 is placed into a kiln 35 where a source of heat 32 is regulated so that the first layer 30 just reaches its melting temperature. This results in a fusion or welding of the gold or other metal in the second coating, and a permanent bond thereat.

The gold has already been liberated from its resinate form by the initial heat so that a metallic appearance occurs as well.

Next, the article 10 is removed and as soon as the first coating 30 has cooled sufliciently to set, the remainder of the second coating 31 may be easily removed, as for example, by washing with water and light brushing, and/ or wiping or brushing, or bulfing. This step is seen in Figure 7, and after such cleaning operation, the finished article appears as shown in Figure 8.

I Wish it to be understood that I do not desire to be limited to the exact details of construction or steps in the method shown and described, for obvious modifications will occur to a person skilled in the art to which the present invention pertains.

I claim:

The method of forming a raised design upon a vitreous surface of a decorative article comprising the steps of: (1) applying in a predetermined area a first coating of a vitreous flux having a melting point which is substantially lower than the melting point of said article; (2) heating said article and said first coating to a temperature at which said first coating adheres to said article; (3) applying a second coating of untluxed metal resinate upon said first coating and the area adjacent said coating; (4) heating the combined article and first and second coatings to a temperature at which said second coating adheres to said first coating; (5) removing the unadhered portions of the second coating from the area of the surface of the article upon which said second coating has been applied and outwardly of the area of said first coating.

References Cited in the file of this patent UNITED STATES PATENTS 296,226 Berge Jan. 11, 1884 310,042 Gehring Dec. 30, 1884 912,171 Rock Feb. 9, 1909 1,334,301 Hasburg Mar. 23, 1920 1,641,820 Lewis Sept. 6, 1927 2,701,214 Velonis Feb. 1, 1955

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