Improvements in the Manufacture of Decorated Glass Sheets.
Year: 1898

page_text: Date of Application, 15th Dec., 1898-Accepted, 25th Feb., 1899
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Decorated Glass Sheets.
I, PAUL THEODOR SIEVERT, of No. 43, Eisenstuckstrasse, Dresden, Saxony,
German Empire, Glass Manufacturer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement : —
Attempts have been made to produce hollow glass bodies, or balloons, and plates
or sheets of glass in variegated colours, plain colours, and with an ornamental
design covering, formed of grains of glass united with the glass body while in a
plastic state (see, for example, l'atents Nos. 11398 of 1884 and 7792 of 1892).
In these attempts, it was, however, impossible to cover plates or sheets of glass
of any considerable size with a layer which was of equal thickness throughout, and
ornamented as desired. The attempts which have been made to strew or fasten
glass grains or pulverized glass on a slab or marver, and then to cast or roll glass
thereon, have been unsuccessful. There was this difficulty, that the glass mass,
which was cast and rolled on the slab, pushed the glass giains, or the particles
of pulverized glass, forward, so that an even attachment thereof to the glass sheet
was unattainable, and the designs were, thereby distorted.
When the attempt was made to apply a ready rolled glass sheet to a slab or
marver strewed with glass grains, or with pulverized glass, and to unite the still
hot glass sheet with these grains, or with this pulverized glass, by rolling or by
pressure, the surface of the glass sheet was found to be too much chilled to effect
a proper union of the grains therewith, entirely independent of the fact that it
caused considerable trouble to apply a large more or less plastic glass sheet to the
grains upon the slab.
The employment of an adhesive substance to fasten the glass grains to the slab
or marver, and to apply to this the hot glass sheet, or to cast plastic glass upon
this, caused the disengagement of glass bubbles, and the formation of blisters
and "blows," which gave the surface of the sheet or covering an undesirable
appearance.
<<
A well known method of blowing a hollow glass body or balloon," and after
rolling this, while hot and still plastic, on a slab or marver strewed with glass
grains, working these into the glass sheet by well-known processes, led to no
favorable results, because the manufacture of ornamented sheets of any consider-
able size thereby was impossible. Glass cylinders for the manufacture of plates
or sheets of glass of any considerable dimensions chill at the
punty" end
to such a degree, that a thorough and exact union of the glass grains with
the cylinder-surface by means of the rolling process was impossible; while the
reheating of such large cylinders in the "drum" to such a degree that the glass
would be plastic enough to adhere to the grains, was out of the question, by reason
of the difficulties inseparable from such a process.
The hereinafter-described invention and process, however, permits the pro-
duction of glass sheets of any desired size, either with an entire covering of glass
grains, or of pulverized glass, or with glass grains, or with pulverized glass, in

page_text: any desired pattern, with sharp outlines and without distortion. To aid in the
technical description of this process, there are four diagrams hereto appended.
The process is as follows;
The glass grains, either colorless, unicolored, or multicolored, as desired, are
fastened with a combustible adhesive substance, either (1) to the cylindrical
surface of a roller or (2) to a sheet or web of paper, or of thin combustible textile
fabric. Where the cynndrical surface of a roller is employed to carry the grains,
the pattern may be outlined thereon with radially projecting ribs of Across
section, in the usual manner; the desired spaces between these ribs a, Fig. 1
(which shows a piece of a roller surface flattened out) may be covered with the
glass grains. The action of the sharp-edged ribs upon the plastic glass mass will
be to impress upon the latter the outlines of the pattern, and thereby make it
sharper and more distinct. But this outlining of the pattern by sharp-edged ribs
is not absolutely necessary or essential to the successful working of my process.
The plastic glass mass e is cast on a slab, marver, or bed, Fig. 4, and, by means
of a roller c, rolled into a sheet of the required thickness. This roller presses at
the same time the powdered or granulated glass unto a plastic sheet of glass for
decorating the latter; and for this purpose the powdered or granulated glass may
have been fixed on the surface of the roller (c), or on the surface of a sheet of
paper, or of textile fabric d, which is so placed with relation to said roller (c) that
the latter presses the covered face firmly upon the still plastic surface of the newly
formed glass sheet or plate.
The operation can also be carried out in the following manner:-Molten glass
can be poured on a table, marver, or slab, and with a roller (b) Figs. 2 and 3
rolled, while plastic, to the desired thickness into a sheet or plate; at the same
time, there is brought into play a second roller c, which bears on its cylindrical
surface the glass grains or the pulverized glass which it is desired to impress
upon the whole, or upon a portion of the still plastic glass sheet or plate. Or the
glass grains or pulverized glass may be attached to the surface of a sheet of paper
or of textile fabric, which is so placed with relation to the second roller c, that
the latter presses it firmly upon the still plastic surface of the newly-formed
glass sheet or plate.
Whether one roller or two be used, or whether the grains be borne directly by
the surface of the roller, or upon a sheet of paper, or of thin textile fabric inter-
posed between the roller and the newly-rolled glass plate, the practical result is
the same: the intimate union of the glass grains, or the glass powder, with the
surface of the sheet or plate. The adhesive material, as well as the paper or
the textile fabric, (where one of these is used), burns quickly to ashes, and as the
resulting gases of combustion have free escape, there are no blisters formed.
The slight amount of ash left may readily be brushed off before the now-
decorated sheet or plate is put in the cooling or annealing-oven; or if this removal
is delayed until after cooling or annealing, or should it not have been thoroughly
effected by the sweeping before cooling, it may be entirely removed by an acid
bath.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is-
-
1. The improved process above described for manufacturing coloured or deco-
rated glass sheets, consisting in fastening powdered or granulated glass upon
molten glass while in a plastic state.
2. The improved process of manufacturing decorated glass sheets, consisting
in fastening powdered or granulated glass upon the surface of a plastic sheet of
glass while the latter is formed by rolling out molten glass, said powdered or
granulated glass being previously attached to the surface of the roller, by which
the rolling out of the molten glass is performed.
3. The improved process of manufacturing' decorated glass sheets, consisting in

page_text: fastening powdered or granulated glass upon the surface of a plastic sheet of
glass while the latter is formed by rolling out molten glass, said powdered or
granulated glass being attached to the surface of a sheet of combustible material,
which is pressed down on the molten glass by the roller, which rolls the molten
glass out into a sheet.
4. The improved process of manufacturing decorated glass sheets, consisting in
fastening powdered or granulated glass upon the surface of a plastic sheet of glass,
while the latter is formed by rolling out molten glass, said powdered or granulated
glass being attached to the surface of a roller, following the roller which rolls
out the molten glass into a sheet.
5. The improved process of manufacturing decorated glass sheets, consisting in
fastening powdered or granulated glass upon the surface of a plastic sheet of
glass, while the latter is formed by rolling out molten glass, said powdered or
granulated glass being attached to the surface of a sheet of combustible material,
which is pressed down on the molten glass by a roller following the roller which
rolls out the molten glass into a sheet.
Dated this 15th day of December 1898
NEWTON & SON,
Agents for the Applicant.