A New or Improved Process for Cleaning and Preparing Lithographic Printing Surfaces.
Year: 1887

page_text: Date of Application, 27th Apr., 1887
Complete Left, 28th Nov., 1887
Complete Accepted, 30th Dec., 1887.
TRIDIONAL
A New or Improved Process for Cleaning and Preparing
Lithographic Printing Surfaces.
I, ERNST OTTO SCHMIEL of Gohlis-Leipzig, in the Kingdom of Saxony,
Manufacturer, do hereby declare the nature of this invention to be as follows:-
This invention consists in a new process for rendering lithographic stones or plates
of all kinds, used or unused, soft or lime-stained stones and zinc-plates, fit for use
without grinding the same with sand. This process is performed as follows:
The stones or plates are first freed from impurities or colour by washing with
benzine or an equivalent liquid. Subsequently they are treated with diluted acid
(sulphuric acid, muriatic acid etc.) by which means any former lithographic design or
scripture is removed. The stone or zinc plate is now covered with a strong solution
of chloride of magnesia with which has been previously mixed according to require-
ment 5 to 10 per cent soluble glass, the mixture having been allowed to stand for
about 24 hours. This mixture is allowed to act in the case of stones for 5 to 20 minutes,
in the case of zinc plates for 1 to 2 days on the parts to be treated. Subsequently
the stone is pumiced with the mixture still upon it and cleaned, by which means the
surface is adapted not only to receive but also to bind carbonate of magnesia. A fine
layer is produced by rubbing or pumicing with a little water and carbonate of
magnesia, i.e. by the combination of the carbonate of magnesia with the stone. The
zinc plates however, after the upper layer has been dissolved by the chloride mixture
are coated with dissolved chloride of zinc and carbonate of magnesia instead of with
water and carbonate of magnesia, by which means the adherence of the carbonate of
imagnesia to the zinc plate is attained. After this process the stones and zinc plates
are ready for lithographing and may be used without further grinding with sand.
Dated this 27th day of April 1887.
HERBERT & CO.,
Agents to Applicant.

page_text: 1, ERNST OTTO SCHMIEL, of Gohlis-Leipzig, in the Kingdom of Saxony,
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:-
This invention consists in a new process for rendering lithographic stones or plates
of all kinds used or unused, soft or lime-stained stones and zinc plates, fit for use-
without-grinding-the-same-with-sand. This process is perforined as follows:
The stones or plates are first freed from impurities or colour by washing with
benzine or an equivalent liquid. Subsequently they are treated with diluted acid
(sulphuric acid, muriatic acid etc.,) by which means any former lithographic design or
scripture is removed. The stone or zinc plate is now covered with a strong solution of
chloride of magnesia with which has 1:een previously mixed, according to requirement, 5 to
10 per cent soluble glass, the mixture having been allowed to stand for about 24 hours.
This mixture is allowed to act in the case of stones for 5 to 20 minutes, in the case of
zinc-plates for 1-2 days on the parts to be treated. Subsequently the stone is pumiced
with the mixture still upon it, and cleaned by which means the surface is adapted not
only to receive but also to bind carbonate of magnesia. A fine layer is produced by
rubbing or pumicing with a little water and carbonate of magnesia i.e. by the com-
bination of the carbonate of magnesia with the stone. The zinc plates however, after
the upper layer has been dissolved by the chloride mixture, are coated with dissolved
chloride of zine and carbonate of magnesia, instead of with water and carbonate
of magnesia by which means the adherence of the carbonate of magnesia to the zinc
plate is attained.
After this process the stones and zinc plates are ready for lithographing and may
be used without further grinding with sand or the like.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
A process for cleaning and preparing lithographic printing plates of all kinds and
preparing soft or stained lithographic stones and zinc plates, for lithographic printing,
said process consisting in treating the stones or plates with benzine or equivalent
substance thereafter with a solution of a chloride, and subsequently dressing the stones
or plates (by means of a pumice stone or the like) with carbonate of magnesia
supplied with water or chloride of zinc, substantially as and for the purpose set forth.
TAIGOS
LXXI
LAIGI THIS AUKIKY OLOVOD10or 1XX
E. O. SCHMIEL.
By Herbert & Co.,
18, Buckingham Street, Strand, London, W.C.,
Agents to Applicant.