An Improved Process for Making Printing Surfaces.
Year: 1892

page_text: Date of Application (in United Kingdom), 8th Jan., 1892
Complete Specification Left. 8th Jan., 1892-Accepted, 19th Mar., 1892
COMPLETE SPECIFICATION.
An Improved Process for Making Printing Surfaces.
1, HENRI CAPELLE, of 52 Rue Mouffetard, Paris, France, Manufacturer of
Galvano-types, 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 :-
The invention consists in obtaining in galvanos of iron (called steel) and of
nickel of the desired thickness, the reproduction of engraved cylinders for printing
earthenware, porcelain, and fabrics, and for embossing leather. It also permits of
obtaining the reproduction of plates engraved on steel or on copper for all kinds of
printing, absolutely identical to the original, which have hitherto only been
obtainable in copper galvanos.
The iron and nickel galvanos have the advantage of being able to print fifty
times the number of copies that can be obtained by the ordinary copper galvanos,
and to dispense with "steeling "which is very expensive. In order to obtain the
above results I proceed in the following manner :-
After having taken the impression or relief in copper galvano or any other
material of an engraved cylinder or of a plate, I place this impression in the iron
bath until the necessary thickness is obtained; afterwards I deposit on the iron a
thin coating of copper in an alkaline cyanide of copper or other bath; then I place
it in an ordinary copper galvano bath to complete the thickness desired. The
reason that I complete the thickness by ordinary copper galvano, is to diminish the
cost; the coat of copper, further, has for its object to make the iron adhere to
the ordinary galvano, and to prevent the action of the acid on the iron.
But it is not sufficient to simply follow the operation in the order indicated; to
obtain good results, it is necessary that the iron and nickel baths be prepared with
care, and in the proportions hereafter indicated; it is this point which has rendered
the experiments hitherto made unsuccessful.
The composition of the iron bath is obtained by dissolving in ordinary water, or
if preferred, distilled water, equal quantities of pure sulphate of iron and of
ammoniacal sulphate of iron. I add sulphate of magnesia in the proportion of
one to a thousand parts. I neutralize with carbonate of magnesia. This bath
ought to weigh from eighteen to twenty degrees Beaumé. It is advisable that the
materials employed be of the best quality.
To obtain cylinders or plates in nickel galvano, I operate in the same manner as
for iron, with the exception that it is unnecessary to deposit a coating of copper
in the alkaline bath, the galvano of ordinary copper adhering perfectly, and the
acid does not attack the nickel.
The nickel bath is composed in the following manner :-I dissolve in distilled
water equal quantities of pure sulphate of nickel and bi or double sulphate of nickel
and of ammonia.
I add two per cent. of sulphate of magnesia and two per cent. of boracic acid in

page_text: flakes; I neutralize with carbonate of magnesia. The bath ought to weigh from
eight to ten degrees Beaumé.
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
The manufacture in galvanos of iron and of nickel of engraved cylinders and
plates, and also the special processes, as well as the materials which enable the
same to be obtained, all substantially as herein described.
Dh0th of Lau 1000
ALLISON BROS.,
Agents for the Applicant.