An Improvement in the Manufacture of Waterproof Paper Material.
Year: 1893

page_text: Date of Application, 21st Aug., 1893-Accepted, 30th Sept., 1893
COMPLETE SPECIFICATION.
[Communicated from abroad by VICTOR BENEDIX, of No. 25/26, Burgstrasse, Berlin,
German Empire, Banker, and AUGUST DE BARY, of No. 7, Urbanstrasse,
Berlin, in the German Empire, Retired Cavalry Captain.]
An Improvement in the Manufacture of Waterproof Paper Material.
I, OLIVER IMRAY, of. No. 28, Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, 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 :-
Waterproof paper materials which are employed in the manufacture of articles
of the most varied kinds, for instance in the manufacture of horse shoes, have up
till now been produced, either by mixing the paper substance, whilst in the state of
pulp, with the necessary waterproofing substances, such as oils, solutions of resin &c.,
and then pressing the articles to be made in one operation from the pulp thus
prepared, or by first making a number of separate sheets of paper, coating them on
one side or on both sides with glue, placing them together and causing them to
cohere by pressure.
The first mentioned method had the disadvantage that in consequence of the
peculiar felt-like consistence of the prepared paper pulp, the pressure of the press
was unable to penetrate with a uniform force to the interior of the articles made,
so that a product was obtained the interior of which possessed less tenacity than
the external shell. The second method mentioned resulted in an approximately
uniformly strong product, but had the drawback that the sticking together of the
separate layers of paper resulted in a laminated or stratified product which, when
employed for articles, such as horseshoes, that are exposed to wear, became useless
by reason of the layers of paper peeling off.
The present invention relates to a method of manufacture of a waterproof paper
material which shall avoid the above mentioned objections, and by means of which
there can be obtained a non-stratified (non-laminated) and perfectly homogenous
product of uniform strength throughout its mass, which shall be capable of being
used for the manufacture of horse shoes, and also for covering floors, walls of sheds
or huts, covering roofs &c.
This method consists essentially in causing the sheets (marked a in the
accompanying drawing) made from the prepared paper pulp, to pass, before they
have become dry, (that is to say, before the agglutinants and the waterproofing
substances contained in the paper have become solidified by the evaporation of
their solvents), in spiral convolutions around a pressure roller A. in such a manner
that the separate layers of paper are caused to lie upon one another and are
pressed together by means of a counter pressure roller. In this way a very strong
homogeneous product is obtained. The intimate mutual adhesion of the separate
prepared sheets of paper and the great strength of this product are dependent upon
two factors. First, as the sheets of paper are pressed together before the oily or
resinous substance and the agglutinants have become dry, the said sheets can unite
intimately with one another without the necessity of using separating layers of
adhesive material.
Secondly, the above described manner of coiling the sheets of paper, has for
result a relatively great density because there are not a number of loose layers of
paper being pressed together at one time, but only one loose layer of paper is
pressed at one time upon one or more layers of paper which have been previously
pressed and thus rendered dense and hard, so that they serve as an efficient support
for the still loose layer to be pressed, because they are only slightly less hard than
the surface of the roller itself. The pressure of the rollers acts only upon a single

page_text: layer of paper at a time, and as it is only of slight thickness, the pressure is
utilised to its fullest extent. The pressure with which each subsequent and as yet
unpressed layer of paper is pressed upon the layers of paper that have already
been united by the pressing operation, is the same in all cases, and the result is a
structureless or homogeneous product of uniform strength or density.
Ordinary gelatine, fish glue or isinglass, chrome-glue, casein, oils, solutions of
resin, solutions of caoutchouc, gutta percha, marine glue, and the like, may be
employed as waterproofing substances and agglutinants, in carrying out the process
hereinbefore described.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The herein described process of manufacture of waterproof paper material, by
forming sheets of paper pulp intimately mixed with waterproofing and binding
agents (such as oils, fats, solutions of resin and gutta percha, casein, marine glue,
chrome-glue and the like) passing such sheets, before the waterproofing and binding
agents have set or dried, between two pressure rollers, and coiling them in a spiral
manner upon one of the rollers in such a manner that the loose layers of paper are
pressed singly and in succession upon the layers of paper that have already been
pressed and thus been rendered hard so as to serve as a support, for the purpose of
obtaining a thoroughly dense and homogeneous product.
Dated this 21st day of August 1893.
ABEL & IMRAY,
Agents for the Applicant.