Improvements in and connected with the Recovery of Tannin from Waste Leather.
Year: 1890

page_text: Date of Application, 20th Jan., 1890
Complete Specification Left, 20th Oct., 1890-Accepted, 22nd Nov., 1890
PROVISIONAL SPECIFICATION.
Improvements in and connected with the Recovery of Tannin from
Waste Leather.
I, HARRY GRIMSHAW of the Canal Chemical Works Clayton Manchester in the
County of Lancaster, Chemical Manufacturer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to the utilisation of waste leather and it has for its object
the recovery of the tannin therefrom and thus also to render the waste leather
available in the manufacture of size and for other purposes for which tanned leather
is not suitable but for which untanned leather may be employed.
In carrying out my invention I steep the leather in, or otherwise similarly treat it
with, an alkaline solution of an alkali or of an alkaline earth the tannates of which
are soluble in water. By this means 1 untan the leather and obtain tannates in
solution. The tannin may be recovered from the solution if desired by any known
or convenient means, and the untanned leather may be employed for various purposes
for example those for which hide shavings and other similar animal tissues are
ordinarily used.
Dated this 18th day of January A.D. 1890.
WILLIAM E. HEYS,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and connected with the Recovery of Tannin from
Waste Leather.
I, HARRY GRIMSHAW of the Canal Chemical Works Clayton Manchester in the
County of Lancaster, Chemical Manufacturer, 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 relates to the utilisation of waste leather by the recovery or the
removal of the tannin therefrom thus rendering the waste leather available in the
manufacture of size and for other purposes for which tanned leather is unsuitable but
for which untanned leather may be employed.
In carrying out my invention, I steep the leather in, or otherwise similarly treat it
with, an alkaline solution of an alkali or of an alkaline earth the tannate of which is
soluble in water.
For economical reasons I prefer to employ a solution of the hydrate or of the
carbonate of soda, since such solutions are at once the cheapest and the most readily
available. The strength of this solution not very material but it may suitably
contain about 10 per cent. of the hydrate of soda.
The saturation or similar treatment is continued until the tannin has combined
with the soda or other alkali or alkaline earth and is consequently removed from the
leather.
By this means the leather is untanned and tannates are obtained in solution. The
tannin may be removed from the solution if desired by any known and convenient
means, and the resulting leather, free from tannin, may be washed and employed for
various purposes as for example, those for which hide parings and similar animal
tissues are ordinarily used.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is-
The hereinbefore described process for the recovery or removal of tannin from
waste leather, which process consists in steeping and similarly treating the leather
in an alkaline solution of an alkali or of an alkaline earth substantially as set
forth.
D
uay of October A.D. 1890.
WILLIAM E. HEYS,
Agent for the Applicant.
WILLIAM E. HEYS,
Agent for the Applicant