Improvements in the Manufacture of Matrices for Stereotype Casting.
Year: 1899

page_text: Date of Application, 12th Oct., 1899
Complete Specification Left, 12th July, 1900-Accepted, 12th Oct., 1900
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Matrices for Stereotype Casting.
JOSEPH LUDWIG WINTER, of 25, Kl. Drehbahn, Hamburg, in the Empire of
Germany, Foreman Machinist, do hereby declare the nature of this invention
to be as follows:-
-
The plates in the form of thin sheets of paper or papier maché which are used
for receiving the impression of the type in stereotype casting are at present made
of a number of sheets of tissue or silk paper copper-plate paper or of so-called
cover-paper attached together with paste. These have to be made use of as soon
as made and while yet in a damp condition in order to anticipate any drying of
the paste and consequent unfitness of the plates in question to receive and to
keep the impressions made in them. They have besides after having been im-
pressed to be dried by being kept under heated press plates for 6 to 10 minutes
or over a fire before they can be used as a mould or matrix for the stereotype
plate in the casting apparatus.
Apart from the fact that this process is wasteful of time especially in that
branch of printing which has to be carried out with unusual expedition that is
in the printing of newspapers the degree of sharpness obtained in the impression
will always be dependent upon a definite amount of dampness in the material
and this is in consequence of external influences-variations of temperature and
of the hygroscopic condition of the work-room etcetra-not always to be attained
with exactness. Also the changes in the dimensions of the plate which neces-
sarily result from the drying process may under some circumstances be detri-
mental as is also the so-called warping which may arise from unequal heating
or want of uniformity in the thickness at particular places. A further defect is
the adherence in places of the material of the matrix to the type side of the cast
plate and the necessity of removing the adhering pieces with the greatest care.
To avoid these defects attempts have been made to produce a material for the
moulds or matrices which shall possess sufficient permanent elasticity to render
the continued dampness unnecessary. The plates have been made porous and
elastic by generating gas in their interior by the use of salts of carbonic acid and
treatment with acids which are injurious and other adhesive substances have been
used as a substitute for the paste which only need to be subjected to a less extent
to the drying process or presumably not at all. All these methods however have
not attained any practical significance for a certain amount of dampness has always
continued to be necessary to the paper material thus made.
The present improvements not only render the last named condition unneces-
sary but require absolute dryness for the attaining of a good result in their use.
In regard to this it enables the sharpest possible impression obtainable without
any previous preparation as well as a repeated pouring-on of the stereotype metal
without material deterioration of its condition.
The fibrous material used for the making of this improved kind of papier
maché mould or matrix is in the form of absorptive blotting paper free from

page_text: lumps made to adhere together by a paste which is inserted between which gives
a permanent elasticity to the whole mass. This paste is most efficient when com-
posed of 40 per cent. starch-flour 35 per cent. potato-flour and 10 per cent. dextrine
to which after careful mixing about 10 per cent. glycerine is added. To the dough
thus obtained 5 per cent. gelatine dissolved in cold water is to be added and the
whole before use is to be diluted with sufficient water at about 60° for it to be
easily spread with a soft brush over the sheets of paper which are to be laid one
on another the uppermost and lowest being covered only on the insides and the
middle one or middle ones covered on both sides with the stuff. After gently
squeezing not pressing of these layers and after the side of the paste-board thus
made which is intended for the reception of the impression has been covered
with a thin layer of this paste which for this purpose should be mixed with milk
or glycerine-solution it is dried for several days at the end of which time the
material may be impressed without any previous preparation and in its normal
condition may be applied several times in succession to this purpose. The per-
centage composition stated for the mixture is that which experiment has shown
to be most efficient it may however be deviated from without detracting from the
essence of the invention.
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.
improvements in the manufacture of matrices for Stereotype Casting.
I, JOSEPH LUDWIG WINTER, of 25, Kl. Drehbahn, Hamburg, in the Empire of
Germany, Foreman Machinist, 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 present invention relates to a process for producing a stereotype matrix
to be used dry and composed entirely of papier maché, which is produced in a
special and novel way by means of potato flour paste,.and which offers the advan-
tages specified herein, as compared with the matrices hitherto used composed
mostly of tissue-paper and writing paper and used in a damp condition.
The matrix here described is formed from fibrous material in the nature of
absorbent blotting-paper free from lumps, a number of sheets of which are
attached together by a binding material or paste which imparts to the entire
product a permanent elasticity. This paste is composed most advantageously of
potato flour gelatine and glycerine.
The quality of the new matrix depends essentially on the method of preparing
the paste. This is as follows:-
Dry potato flour is mixed with dissolved and much diluted gelatine. Then
boiling water is poured into the mass whilst constantly stirred. This dough is
then violently beaten until it has become quite plastic. Boiling water is again
poured on to it, it is again beaten and this is continued uninterruptedly until a
substance is obtained which can be easily spread and to which finally a quantity
of glycerine is added.
Suitable

page_text: This paste is spread by means of a soft brush over the sheets of blotting paper
which are laid one over another the upper and under sheets being covered only
on their inner sides, but the middle sheet or sheets are covered on both sides
with the paste. After these sheets have been gently pressed together (not heavily
pressed) and after the surface of the matrix which is intended to receive the im-
pression has been covered with a thin layer of this paste it is dried for several
days at the end of which time the matrix may be used to take an impression
without requiring any of the preparatory processes hitherto requisite and the
matrix may be used in its ordinary state several times in succession for making
a cast from.
Matrices prepared with a paste of this description possess the following
advantages:
Before taking the impression no kind of preparatory process is needed. During
the calendering the matrix, is laid upon a felt (or blanket) resulting in a very
sharp deep clear impression free from blotches. As the impression is readily pro-
duced while laying on a felt the type is not liable to injury as has been the case
with the matrices hitherto in use when being beaten with a brush or when being
rolled direct.
After the impression has been made the matrices are at once ready for taking
the cast and bubbles are entirely avoided which frequently occur when the
matrices are dried by steam or fire after the wet process. The cast produces a
distinct and clear image of the type, the paper of the mould not being liable to
tear out consequent upon its close texture. After the casting the matrix remains
unchanged so that any desired number of casts may be taken and if required the
matrix may be preserved for years for this purpose.
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:
1. The production of a stereotype matrix to be used in a dry state consisting
of several sheets of absorbent blotting-paper held together by a paste of potato
Hour which permits of a penetrating clear impression as with the moulds which
are beaten while wet, and which is ready for casting from immediately after. being
impressed substantially as described.
2. The process for making a paste for preparing the dry stereotype matrix
named and characterised above, in which potato flour is used mixed with diluted
boiling gelatine and glycerine substantially as described.
3. stereotype matrix prepared substantially as described.
Dated this 11th day of July 1900.
WM. P. THOMPSON & Co.,
Manchester, Liverpool, London & Birmingham,
Patent Agents.