Improved Process of Tanning Skins and Hides.
Year: 1898

page_text: Date of Application, 17th Mar., 1898-Accepted, 17th Mar., 1899
COMPLETE SPECIFICATION.
Improved Process of Tanning Skins and Hides.
I, JOHANN NUSSBAUMER, of Innsbruck, in the Empire of Austria, Tannery
Owner, 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 new process for quick tanning which forms the object of the present inven-
tion is executed cold and in a very short time by employing the strongest vegetable
extracts with an addition of glycerine and thus avoids all the inconveniences
experienced hitherto in tanning by means of extracts.
At the same time this process enables the tanner to tan in a very reduced space,
without having need of mechanical power or any agitation of the hides or extracts,
and also to manufacture every kind of leather. Moreover, the above system allows
of tanning in two or four weeks without employing mechanical power, and of
fulling after 4 to 10 hours in a fulling-vat with an addition of glycerine.
My system allows one to obtain all qualities and grades of leather in a few
weeks, and to give it a quality and solidity equal to those of leather manufactured
according to the old process which lasted several years; my process also realising
an economy of tanning materials, I have therefore attained the highest degree
of perfection in tanning with extracts, a system which has hitherto not been
practised by anyone with equal success.
It is known that with the different systems of vat tanning with the use of
mechanical power, the skins or hides can be tanned in 48 hours, but it is also
known that through the continual agitating of the unhaired hides in the vat, which
very often have not undergone any preparatory tanning, their fibres stretch so
much that the solidity of the leather suffers greatly.
Through a previous and intense tanning made according to my process by
employing the strong extracts, I can now, by using mechanical power, complete
the tanning in 4 to 10 hours, but without damaging the leather in the least, for
the short duration of the operation and also the partial action of the glycerine do
not produce any injurious effects upon the fibres, and consequently the best
quality of leather is obtainable.
The tanning is effected in the following manner :-
The hair is taken off the hides by a heating process or with sulphuret of sodium,
and when the hides have been soaked for some time, they are afterwards cleaned.
After this preparation the softer hides can be dipped into a glycerine bath
composed of one part of glycerine and 30 parts of water, the hard hides can be
directly put into a strong tanning liquor or ooze where they are left for two days.
After the glycerine bath or the tanning extracts, the hides are immediately
placed in a lye composed of a mixture of extracts at a density of 6 to 32° Beaumé;
these mixtures are composed of:
1 part of extract of fir-bark, and two parts of extract of oak-bark.
1 part of extract of fir-bark, and
1 part of extract of the bark of a
and norte of extract of oak-bark.
parts of extract of hemlock.
South American tree known as quebracho,

page_text: 2 parts of extract of chestnut wood and one part of extract of valonia.
3 parts of extract of chestnut wood and one part of extract of quebracho,
hemlock, fir, or valonia.
These mixtures may also be combined in any desired way.
The hides remain in one of these mixtures from two to six weeks; after this
time they are taken out, washed and prepared.
A modification of the process consists in putting the hides from one to three
weeks in a lye of the above described extracts and afterwards fulling them during
4 to 10 hours, adding lyes of extracts from 6 to 32° Beaumé in a movable
receptacle where raw glycerine must be introduced in the proportion of 1 litre of
glycerine to 10 half-hides.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is;
(1) A process of tanning skins or hides consisting in treating the same first
with a tanning solution, and afterwards with a mixture of strong tanning extracts.
substantially as described.
(2) A process of tanning skins or hides consisting in treating the same first
with a solution of glycerine, and afterwards with a mixture of strong tanning
extracts, substantially as described.
(3) A process of tanning skins or hides consisting in treating the same first
with a strong ooze, and afterwards with strong tanning extracts, substantially
as described.
(4) A process of tanning skins or hides consisting in soaking the same in a lye
of strong tanning extracts and fulling them afterwards under addition of strong
tanning extracts and glycerine.
S. S. BROMHEAD.
Agent for Applicant, 171, Queen Victoria Street, London, E.C.