Improved Process for Tanning Hides.
Year: 1895

page_text: Date of Application, 27th Nov., 1895-Accepted, 18th Jan., 1896
COMPLETE SPECIFICATION.
Improved Process for Tanning Hides.
We, CHARLES KNEES, Tanner, of the Town of Oshawa, in the County of
Ontario, in the Province of Ontario, Canada, and DAVID WATSON ALEXANDER,
Leather Merchant, of 5-7 Scott Street, in the City of Toronto, in the County
of York, in the Province of Ontario, Canada, 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 :-
Our invention relates to an improved process for tanning hides or skins and the
object of the invention is to provide an extremely simple process in which the
leather may be made waterproof, elastic, pliable, heat proof for hot climates and
frost proof that is to say will not crack in frosty weather and in which the slipping
qualities of the leather will be entirely obviated and it consists in the steps
hereinafter explained.
To carry our invention into effect the following ingredients are to be used in
the proportions named below and suitably mixed together.
A composition containing bi-chromate of potash about five per cent. of the weight
of the hide, two and a half per cent. of sulphuric acid, five per cent. of the weight of
the hide of neat's foot oil and the balance of water. There is also used a com-
position of ten per cent. of the weight of the bide of hypo-sulphite of soda with
sulphuric acid seven and one-half per cent., five per cent. of neat's foot oil and the
balance of water.
These two compositions are each to be thoroughly mixed but are kept separate.
After the hide has gone through the regular process of unhairing and flushing
we introduce it into either one of these compositions, which is placed in what
is technically known as a pin wheel and is there treated in the usual manner, so
that the hide is thoroughly permeated with the composition.
After this has been accomplished the hide is taken out of this composition and
placed into the other composition where it undergoes the same treatment in a pin
wheel in the usual manner as hereinbefore stated.
After the hide has been so treated it is left to dry.
It is particularly pointed out that the treatment of the hide in one composition
first and then following with the treatment in the other composition, must be
accomplished and it does not matter which composition is used first in such
treatment. The hide, however, must be subjected to the composition in its entirety
in each case as it would not do to use the ingredients of either composition
separately as we find in practice that the result which we have striven to obtain
can only be effected from the compositions themselves.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is,
A process of tanning skins or hides which consists first in subjecting the
previously prepared skins or hides to the action of a composition comprising
bi-chromate of potash, sulphuric acid, neat's foot oil and water and secondly

page_text: subjecting the skins or hides thus treated to a further composition consisting of
hypo-sulphite of soda, sulphuric acid, neat's foot oil and water as set forth.
Dated this 27th day of November 1895.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.