Improved Process or Means of Producing a Orystalline Effect on the Surface of Glass or other Vitreous Substance.
Year: 1887

page_text: Date of Application, 24th Nov., 1887
Complete Left, 20th Mar., 1888
Complete Accepted, 20th Apr., 1888
RESERV
Improved Process or Means of Producing a Orystalline Effect on
the Surface of Glass or other Vitreous Substance.
I, GEORGE JONES ATKINS, of 115 Cannon Street, in the City of London,
Manufacturer do hereby declare the nature of this invention to be as follows :-
It has long been known that when the chemically clean surface of a sheet of glass
is covered with a gelatinous substance, the contraction of the latter, as it dries, tears
up the surface of the glass, and produces a frosted or cystalline appearance thereon,
which can be utilized as a means of decoration. It has been found, in the practical
application of this process for the purpose of producing a crystalline effect on glass
and other vitreous substances, that the contractile action of the gelatine on the glass
not only tears up the surface but bends the sheets of glass submitted to its action,
and in the majority of cases, breaks them in pieces, rendering them useless for the
intended purpose.
The object of my invention is to provide means whereby the
tearing up, and consequent crystalline effect on the surface can be produced without
incurring the risk of breaking the object operated upon, thereby rendering the
manufacture more certain.
For this purpose I mix with the glue or gelatine intended to be spread over the
surface of the glass or other vitreous surface to be acted upon, or apply to such
surface after it has been coated with glue or gelatine, one or more of the following
substances, or others of a similar character that will bring about the same action viz. :-
Chrome alum, tannin, alcohol, or bichromate of ammonium, potassium or sodium.
Chrome alum has the effect of rendering the glue or gelatine insoluble in water
after it has once been dried; it also renders the coating of glue or gelatine more
contractile and less hygroscopic than glue or gelatine used alone as heretofore.
Alcohol volatilizes quickly, facilitates the drying of the glue or gelatine, and
increases its contractile power.
The bichromate salts are, as is well known sensitive to light. 1 mix them with the
glue or gelatine, and apply the mixture to the glass or other vitreous surface. I then
dry, and afterwards expose the surface so covered to the action of light. The light
oxidizes the chromium salt and renders the organic matter with which it is mixed
insoluble in water, thereby making it less hygroscopic and more contractile.

page_text: By the addition of the above matters to gelatine or glue its hold or grip of the
surface is greatly increased, and the breaking up of the said gelatine or glue is
assisted, as numerous points for its rupture are formed and the fractures are localized
and distributed more evenly and uniformly over the surface to be operated on, and
the danger of bending and ultimately breaking the sheet or other object is thereby
materially reduced. Another advantage arising from the use of the above matters
is that they facilitate the use of common glue in place of the more expensive
gelatine, and prevent the glue or gelatinous surface, when once dried, from absorbing
moisture from the atmosphere and thereby losing their contractile power.
After the surface is coated with the mixture of gelatine or glue, with one or more
of the matters above mentioned, or their equivalents, and allowed to set firm, I place
the object in a room or chamber in which a temperature not exceeding 100° Fahrenheit
is maintained, and I dry the coating by submitting it to a hot or cold current of
preferably dry air. By these means I avoid undue expansion of the glass or other
substance while the excessive contractile action of the material covering the surface is
going on at one side, and thereby I obtain a further security against breakage which
is found to be very common under the process of drying by stoving heretofore
employed, by reason of the undue expansion of the glass caused by the excessive heat
of the stove acting in opposition to the contractile effect of the gelatine coating on
one side. I also thereby avoid another effect of excessive stoving, namely the frying
up and consequent general weakening of the contractile power of the gelatinous
surface which take place when a certain temperature is reached.
Dated this 23rd day of November 1997
G. J. ATKINS.
Per W. H. Beck,
115, Cannon Street, London, E.C.,
Agent for Applicant.

page_text: I, GEORGE JONES ATKINS, of 115 Cannon Street, in the City of London,
Manufacturer do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
It has long been known that when the clean surface of a sheet of glass is covered
with a gelatinous substance the contraction of the latter, as it dries, tears up the
surface of the glass, and produces a frosted or crystalline appearance thereon, which
can be utilized as a means of decoration. It has been found, in the practical
application of this process for the purpose of producing a crystalline effect on glass
and other vitreous substances, that the contractile action of the gelatine on the glass
not only tears up the surface but bends the sheets of glass submitted to its action,
and, very often breaks them in pieces, rendering them useless for the intended
purpose. The object of my invention is to provide means whereby the tearing up and
consequent crystalline effect on the surface can be produced with much diminished
risk of breaking the object operated upon, thereby rendering the manufacture more
certain.
For this purpose I dissolve in water the glue, gelatine or other similar substance
intended to be spread over the surface of the glass or other vitreous surface to be
acted upon, and I either mix with such solution before spreading, or apply to such
solution after it has been spread over the surface of the glass, or other vitreous
surface, one or more of the following substances, or others of a similar character that
will bring about the same action, namely: Chrome alum, alcohol, or bichromate of
ammonium, potassium, or sodium.
Chrome alum has the effect of rendering the glue or gelatine more or less insoluble
in water after it has once been dried; it also renders the coating of glue or gelatine
more contractile and less hygroscopic than glue or gelatine used alone as heretofore.
Alcohol volatilizes quickly; facilitates the drying of the glue or gelatine, and
increases its contractile power.
The bichromate salts are, as is well known, sensitive to light when combined with
organic matter, and I have found that when such salts are mixed with glue, gelatine
or other similar substance, and the mixture is applied to the glass, or other vitreous
surface, and dried, and then exposed to light, the latter acts upon the combination of
chromium salt and organic matter (the glue or gelatine for example) and renders the

page_text: latter more or less insoluble in water, thereby making it less hygroscopic and more
contractile.
Tannin is another substance that may be used in combination with the solution. It
forms an insoluble compound with glue, gelatine and similar substances, and there-
fore renders them less hygroscopic and more contractile. It must be applied to the
solution after it has been spread on the glass or other vitreous surface.
By the addition of any of the above substances to glue or gelatine, its hold or grip
of the surface is greatly increased, and the breaking up of the said glue or gelatine is
assisted, as numerous points for its rupture are formed and the fractures are localized
and distributed more evenly and uniformly over the surface to be operated upon; and
the danger of bending and ultimately breaking the sheet or other object is thereby
materially reduced. Another advantage arising from the use of the above matters is
that they facilitate the use of common glue in place of the more expensive gelatine,
and prevent the glue or gelatinous coating, when once dried, from absorbing moisture
from the atmosphere and thereby losing its contractile power.
After the mixture of glue, gelatine or other similar substance, and one or more of
the matters above mentioned, is spread over the glass or other vitreous surface, it is
allowed to set firm; and this operation may be facilitated by passing a current of
dry air over the surface in order to remove the greater part of the moisture from
the coating. The object is then placed in a room or chamber in which a tem-
perature of about 100° Fahrenheit is maintained in order to complete the drying
operation (this operation may also be facilitated by submitting the coating to the
action of a current of dry air) and when the the coating is thoroughly dry, it
begins to exert its contractile power by tearing up the vitreous surface so as to
produce the desired crystalline effect thereon, but with slight risk of breaking the
object under treatment.
When the coating contains a salt which is sensitive to light when combined with
organic matter, as above described, light is admitted into the heated room or chamber
in which the final drying is effected. This light acts upon the mixture of gelatinous
or other organic matter and salt, rendering the former more or less insoluble, less
hygroscopic and more contractile, and therefore more efficient in tearing up the
surface of the glass as before described.
The effects produced may be varied by varying the proportion of the salts used in
the gelatinous or other similar coating.
The above described effects may be produced on the surface of plain glass, but
I prefer to use glass the surface of which has been ground or otherwise roughened or
abraded.
By the means above described I avoid undue expansion of the glass or other
vitreous substance while the excessive contractile action of the material covering the
surface is going on at one side, and thereby I obtain, to a great extent, security
against breakage which is found to be very common under the process of drying by
stoving heretofore employed, in which the expansion of the glass caused by the
excessive heat of the stove acts in opposition to the contractile effect of the gelatinous
coating. I also thereby avoid another effect of excessive stoving, namely the frying
up, and consequent general weakening of the contractile power of the gelatinous
coating which take place when a certain temperature is exceeded.
Having now particularly described and ascertained the nature of my said inven-
tion, and the manner in which the same is to be performed, I declare that what I
claim is
First. For the purpose of producing crystalline effects on the surface of glass or
other vitreous substance, the use of a contractile coating composed of glue, gelatine
or other similar substance. in combination with chrome alum, tannin, alcohol, bi-
chromate of ammonium, bichromate of potassium, bichromate of sodium, or other
substance of similar character, substantially as hereinbefore described.
Second. The process for producing crystalline effects on the surface of glass or

page_text: other vitreous substance which consists in coating such surface with a mixture com-
posed of glue, gelatine, or other similar substance in combination with one or more of
the chemical substances hereinbefore mentioned, in allowing the said coating to set
firm, with or without the aid of a current of dry air, and in then completing the
drying operation in a room or chamber maintained at a temperature of about
100° Fahrenheit, with or without the aid of a current of dry air, and (when the
coating employed is sensitive to light) in submitting such coating, while in the said
drying room or chamber, to the action of light, substantially as herein before
described.