An Improved Finely Granulated Paper, and Process of Producing the same.
Year: 1893

page_text: Date of Application, 6th Dec., 1893-Accepted, 17th Mar., 1894
CODE DIN DIDOITRATION.
An Improved Finely Granulated Paper, and Process of Producing
the same.
A communication by CARL SCHÄUFFELEN, of Heilbronn on the Neckar,
in the Empire of Germany, Engineer.
1, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors 6 Lord Street, Liverpool and 6, Bank Street,
Manchester, both in the County of Lancaster and 323 High Holborn, in the
County of Middlesex, 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 ascertained in and by the following statement :-
This invention has for its object a process for producing a granulated paper which,
whilst differing from that described in Patent No. 14756 of September 1st, 1891,
which had for its object the production of a granulated paper with a uniform
grain of pyramidal form, has also a uniform grain of pyramidal or even of a
truncated-cone form, but with the graining in the form of depressions instead of in
relief, and is preferably intended for lithographic and photolithographic purposes,
and also for sun printing and platinotype printing. The pyramidal or truncated-
cone shaped depressions in the paper have a regular surface (circle or regular
polygon).
As in the Patent referred to for pyramidal granulated paper with grains in relief,
in this paper, the depressed grains are arranged at an exactly uniform distance
apart, and, according to the fineness of the grain, there are 750, 1000, 1500, 2,500,
etcetera, grains per square centimetre. The production of this depressed grain
takes place in the simplest manner, preferably by means of a powerful calender,
one of the rollers of which is of steel with uniform projections which correspond
to the depressions which are to be impressed in the paper, whilst the other roller
bas a paper or other covering. Instead of a calender, plates having the
necessary projections may of course also be employed, but not so advantageously
and in such case the paper is placed on the plate and both are passed through
two smooth calender rollers.
As before mentioned, this improved negative pyramidal granulated paper may
be employed, more particularly for photographic and lithographic purposes, and
especially for all processes which necessitate the use of a transfer plate. It is,
however, especially advantageous for sun printing and platinotypes, and, in order
to be used for these purposes, it is treated with chromate salts, gelatine or the
like, exactly in the same way as the ordinary papers hitherto employed, and also
as the pyramidal granulated papers hitherto used were prepared. The effect of
the uniformly depressed (intaglio) grains is exactly the same as that of uniform
grains in relief, only the light and shade are reversed. Much softer shades or
reflections of light are obtained both with the hitherto employed positive or with
the negative pyramidal granulated paper, than is the case with ordinary papers.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is:-
1. A process for producing pyramidal granulated paper with recessed or depressed
grains characterised by the grains which are placed at a uniform distance apart
being depressed (intaglio) instead of being raised or in relief as in the process
described in Patent No. 14756", but which are, however, produced in au exactly
similar manner to the raised grains, by one of the two calender rollers between

page_text: which the paper passes, namely, the steel roller, having pyramidal or truncated-
cone shaped projections instead of recesses on its surface, which projections are
impressed in the paper when it passes under the roller, or both rollers may remain
smooth, and the paper be laid on a plate provided with pyramidal or truncated-
cone shaped projections and passed, together with this plate, through the two
smooth calender rollers.
2. As a new industrial product, a granulated paper with depressed grains.
produced by the process herein before described, which paper may be employed for
all technical purposes, such as, for instance, lithography, photolithography and the
like, also for sun printing (heliography) and platinotyping, by preparing it in the
usual manner by means of chrome salts, gelatine or the like.
Dated this 5th day of December 1893.
WM. P. THOMPSON & Co.,
Agents for the Applicant.