Improvements relating to Printing Cylinders.
Year: 1898

page_text: Date of Application, 21st June, 1898
Complete Specification Left, 28th Oct., 1898-Accepted, 3rd Dec., 1898
PROVISIONAL SPECIFICATION.
"
Improvements relating to Printing Cylinders.
I, EMILE LOUIS SALLES, of No. 248, Faubourg St. Honoré, Paris, in the Republic
of France, Civil Engineer, do hereby declare the nature of this invention to be as
follows:
The present invention relates to cylinders for printing cloth, paper,
and similar
materials, which cylinders, being made of glass or crystal, are intended to replace
steel or copper cylinders generally employed for this purpose.
These new printing cylinders are strengthened with a metal axle conveniently
adjusted. They can be solid, or in the form of a sleeve furnished inside with a
core of wood, plaster, &c., in which is embedded the metallic axle.
In any case, I make the printing cylinder of glass or crystal in the following
manner:
The surface of the cylinder, which has been "ground, is coated with spirit of
turpentine; it is then covered with an envelope of paper, cardboard, or the like;
which is cut open to expose the parts on the surface of the cylinder that are
intended to be protected against the biting of the acid used for attacking this
surface.
-
There is, moreover, prepared an impalpable powder composed of asphalt and
gum mastic, in the proportion of one part gum to six of asphalt. This powder
is applied, with the aid of a very fine sieve, on all the open parts of the cut sheet
enveloping the cylinder. The latter, thus prepared, is submitted to a gentle heat.
The above-named powder with which it is coated, being heated, mixes perfectly
with the spirit of turpentine, and forms a closely adhering layer, following the
outline of the powder.
The cut sheet, which has served to cover the remainder, is then carefully removed,
and the cylinder, thus prepared, is covered uniformly over all its surface with a
layer of mastic, either reduced to an impalpable powder, or dissolved in a solvent
such as, for example, spirit of turpentine.
The preparation of the cylinder is now complete, and it only remains to immerse
it in a bath of hydro-fluoric acid of convenient strength, formed of acid diluted
with water in the proportion of a third of its volume.
After a period of immersion sufficient to produce an adequate attack, that is to
say, about 40 to 50 minutes, the substances which cover the surface of the glass
are removed with the aid of a solvent, and the cylinder is then ready to be used.
Such cylinders are very advantageously employed for printing cloth or paper
in place of metal or other cylinders hitherto employed. They are capable of the
same finish. The attack by the acid, effected under the conditions I describe, is
of great distinctness, and gives perfect regularity of design. The acid never
spreads beneath the edge of the resist, as is the case with processes of eating away
glass commonly known.
The engraved surfaces take the ink as well as a metal surface, and give an'im-
pression equal thereto.

page_text: Cylinders of glass or crystal, according to my invention, have the advantage of
being absolutely unchangeable, and very durable, as well as being cheaper than
rollers hitherto employed.
NEWTON & SON,
Agents for the Applicant.
Improvements relating to Printing Cylinders.
I, EMILE LOUIS SALLES, of No. 248, Faubourg St. "Honoré, Paris, in the Republic
of France, Civil Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed; to be particularly described and ascer-
tained in and by the following statement:-
The present invention relates to cylinders for printing cloth, paper, and similar
materials, which cylinders, being made of glass or crystal, are intended to replace
steel or copper cylinders generally employed for this purpose.
These new printing cylinders are strengthened with a metal axle conveniently
adjusted. They can be solid, or in the form of a sleeve, furnished inside with a
core of wood, plaster, &c. in which is embedded the metallic axle.
In any case, I make the printing cylinder of glass or crystal in the following
manner:
The surface of the cylinder, which has been ground, is coated with spirit of
turpentine it is then covered with an envelope of paper, cardboard, or the like,
which is cut open to expose the parts on the surface of the cylinder that are
intended to be protected against the biting of the acid used for attacking this
surface.
There is, moreover, prepared an impalpable powder composed of asphalt and
gum mastic, in the proportion of one part gun to six of asphalt. This powder
is applied, with the aid of a very fine sieve, on all the open parts of the cut sheet
which envelopes the cylinder. The latter thus prepared is submitted to a gentle heat.
The above-named powder with which it is coated, being heated, mixes perfectly
with the spirit of turpentine, and forms a closely adhering layer following the
outline of the powder.
The cut sheet which has served to cover the remainder, is then carefully removed,
and the cylinder, thus prepared, is covered uniformly over all its surface with a
layer of mastic, either reduced to an impalpable powder, or dissolved in a solvent,
such as, for example, spirit of turpentine.
The preparation of the cylinder is now complete, and it only remains to immerse
it in a bath of hydro-fluoric acid of convenient strength, formed of acid diluted
with water, in the proportion of a third of its volume.
After a period of immersion sufficient to produce an adequate attack, that is to
say, about 40 to 50 minutes, the substances which cover the surface of the glass
are removed with the aid of a solvent, and the cylinder is then ready to be used.
Such cylinders are very advantageously employed for printing cloth or paper
in place of metal or other cylinders hitherto employed. They are capable of the
same finish. The attack by the acid, effected under the conditions I describe, is
of great distinctness, and gives perfect regularity of design. The acid never
spreads beneath the edge of the resist, as is the case with processes of eating away
glass commonly known.
The engraved surfaces take the ink as well as a metal surface, and give an im-
pression equal thereto.

page_text: Cylinders of glass or crystal, according to my invention, have the advantage of
being absolutely unchangeable, and very durable, as well as being cheaper than
rollers hitherto employed.
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. As an industrial product, cylinders for printing cloth, paper, and the like,
formed of glass or crystal, solid or hollow, the ground surface of which is treated in
such a manner as to leave in relief the parts which are to form the design, such
parts being protected, during preparation, in the manner hereinbefore explained.
2. The process of obtaining cylinders such as form the subject of the 1st claim,
consisting in making a resist of a mixture of asphalt and gum mastic applied in
an impalpable powder to the surface of the glass which has been treated uniformly
with spirit of turpentine, all the surface being subsequently covered with a layer
of mastic, and submitted to the action of hydrofluoric acid, the said process having
the advantage of giving to the parts left in relief, edges perfectly clean and favour-
able for a good impression, substantially as explained and specified above.
Datad this 28th day of October 1898
NEWTON & SON,
Agents for the Applicant.