Year: 1898

page_text: Date of Application, 17th Oct., 1898-Accepted, 19th Nov., 1898
A communication from FREDERICK AUGUSTUS TALMAGE MOOR, of 1035, N. Front
Street, Philadelphia, Pennsylvania, United States of America.
I, HAROLD WADE, of 111, Hatton Garden, in the County of Middlesex, 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:-
The objects of the invention are to produce a firm finished product which may
be subjected to the action even of hot water and rapid drying without becoming
brittle or otherwise materially deteriorated, and to provide a process for
producing such a product which shall be expeditious, satisfactory and economi-
cal and which may, if desired, be practiced by means of a single bath. To these
and other ends hereinafter referred to, the invention, generally stated, comprises
fixing tanning materials and the like in hides or skins by means of formaldehyde
or its equivalent which, when thus applied, imparts to the finished product that
property which enables it to withstand the action even of hot water and drying,
as in a kiln, and also imparts firmness to it.
Tawed or tanned skins or hides, or generically, leather in the ordinary meaning
of that term if subjected to the action of water, more especially of hot water, and
of drying, more especially under the influence of considerable heat, tend to lose
some of that material which makes them more or less pliable and which converts
them from the condition of skins into leather. By the application of formalde-
hyde (CH2O) which is gaseous or perhaps more accurately the application of
(CH2
paraformaldehyde (CO
(CH¹ 2
abcut eleven degrees Beauné, the materials or ingredients which convert hides
or skins into leather are so changed, modified or acted upon that they do not wash
out or are fixed. It follows from this that tanned and tawed or equivalently
prepared hides or skins treated as described will withstand the action of water,
hot or cold, and of rapid drying without becoming hard or brittle and will also
be firmer and not so likely to stretch unduly. They are also otherwise improved
and the described treatment does not interfere with the use of coloring matter
which may be employed after the formaldehyde treatment even in a highly heated
state. Leather prepared in accordance with the invention may be subjected to
comparatively hot irons without injury. As much of the formaldehyde solution
may be used as is desired without any deleterious results, but considerations of
economy will, of course invit the amount employed and the tanned, tawed or.
otherwise prepared leather may be subjected to the action of this antiseptic or
fixing material for at any rate a very great length
since time is of value, economy would dictate the use of as short a time as practical.
metal with of time, without injury, but
Good results can be obtained, for example, in connection with sheepskins by using
four pounds of eleven degree commercial formaldehyde to one hundred pounds of
wet sheepskins tanned or tawed in any appropriate manner as by means of gambier,
sumac, bark, salt and alum, or of a vast number of materials known to those skilled
0} which is obtainable commercially as a solution of

page_text: in the art and generally designated tanning materials, that is, materials which
have the property of effecting in connection with skins or hides that change which
is commonly designated leather. It is one of the advantages of the invention that
the skins or hides may be prepared or tanned preparatory to the application of
the formaldehyde by known and widely used tanning processes. Such a solution
appears to produce sufficiently good results for practical purposes by permitting
it to act upon the skins for approximately twelve to fourteen hours, but in this
connection attention is directed to the fact that the considerations which control
the quantity of the formaldehyde solution as well as the time are those of economy
and may therefore be varied widely, one limit being waste and the other improper
or imperfect treatment of the tanned or tawed or equivalently prepared hides or
skins or leather. For the sake of further description, it may be stated that in the
practice of the invention in connection with, for example, sheepskins, good results
have been obtained by tanning the latter in a suitable vessel, either open or
closed, in the usual manner. Gambier happens to have been employed for this
purpose, but the invention is not limited to the use of gambier or to any other
tanning, tawing or leather making solution as they are all well known and in
theniselves constitute no part of the invention. Into the vessel which contained
the one hundred pounds of wet sheepskins and about twelve gallons of the tanning
fluid either with or without colouring matter, is introduced about four pounds of
commercial formaldehyde which is of about eleven degrees Beaumé. Instead of
proceeding in this way, good results may be accomplished by taking the tanned
hides or skins out of the tanning bath or vat and putting them into a separate bath
of the formaldehyde solution. However, the fact that one vessel can be used for
tanning, tawing or the like, treating with formaldehyde, colouring, washing, or in
other words, completing the operation ready for drying, is an advantage that will
be obvious to tanners. The tanned skins and solution containing the formaldehyde
are agitated for about an hour and then permitted to stand for several hours, for
example, over night, and then stirred or agitated again for a little while in the
morning. Where a closed vessel is used it may be turned as a whole or where an
open vessel is used the contents may be agitated by means of a suitable implement.
Afterward the finished material may be washed with water, either hot or cold, and
then dried, dressed, glazed or appropriately treated for sale. The invention is not
limited to the use of either an open or a closed vessel but a closed vessel presents
advantages, for instance, its contents can be easily stirred and economy may be
effected in that gaseous ingredients of the contents may not so readily escape. The
tanned, tawed or otherwise prepared leather may be exposed to the action of
formaldehyde in gaseous or vaporous condition in which case an air-tight room,
chamber or vessel may be employed.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondent and in what manner the
same is to be performed, I declare that what I claim is:-
In the manufacture of leather that improvement which consists in subjecting
tanned, tawed or equivalently prepared hides or skins to the action of formalde-
hyde, substantially as described.
111
Cintahan 100Q