An Improved Tanning Process.
Year: 1899

page_text: Date of Application, 25th Apr., 1899-Accepted, 17th June, 1899
An Improved Tanning Process.
1, FRITZ SCHEDLINSKY, Tanner, of Pintsch, Luxemburg, in the German
Empire, 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 a tanning process and it concerns that method of
tanning by which the hides or skins are subjected to the action of previously
prepared tanning liquors.
Generally speaking, there are at present only two tanning processes. According
to one process, the skins are spread in tan-pits with material forming tanning
liquor with water whereby leather of the best quality is produced, though with a
By the other process-
somewhat enormous expenditure of time and labour.
known as the "quick process "-rapid tanning is obtained, but at the expense
of the quality of the leather.
The object of my invention is to procure the advantages of both the processes
referred to without their disadvantages; that is to say, the obtainment of leather
of the best quality in the shortest possible time.
To this end, I circulate or pass the tanning liquor through a number of pits
or vats so that the hides or skins contained therein successively absorb the
tannin.
In carrying my invention into practice, I employ a series of pits or vats-
say 30 or 40 in number-arranged and connected so that the tanning liquor may
pass or flow through them successively in contact with the hides or skins, for
which purpose the strong liquor is supplied to the first vat and the last vat is in
communication with the source receiving the spent liquor.
In operation, the hides are suspended in the vats and then the strong liquor
is run into the first vat, whence it flows to the second vat, thence to the third
vat, and so on throughout the total number into the last vat wherefrom it drains
as spent liquor, the tannin having been absorbed by the hides during the passage.
As will be evident, the hides in the first vat absorb the great part of the tannin
and are thereby tanned most, whereas those in the subsequent vats are less and
less tanned. However, as the hides can only take up a certain amount of tannin
in a certain time, it follows that the least tanned hides will absorb the most of
the tannin from the next liquor supplied to the first vat and passing from it and
through the others as before. Thus the new liquor will give up more tannin to
the hides in the second, third and following vats than to the first vat, and so on
succeeding supplies act less and less or not at all in the earlier vats of the series,
the operation being delayed until they reach the later vats.
In this way the tanning proceeds, there being a continual flow of tanning liquor
acting successively on all the hides whereby they are quickly and efficiently tanned
without the necessity for vibrating them to hasten the absorption of the tannin.
Further, by my process, this absorption, as will be understood from the foregoing,
is regulated by the hides themselves.

page_text: As the hides are tanned, they are of course removed and replaced by others
to be tanned.
The strong liquor is delivered to the first vat in such a manner as not to damage
the hides therein; but this will be readily understood by tanners without further
remark.
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. The improved process' or method of tanning conducted substantially as set
forth.
2. In tanning, circulating or passing the tanning liquor through a number of
vats so that the hides or skins suspended therein successively absorb the tannin,
substantially as herein before described.
Dated this 24th day of April 1899.
For the Applicant,
J. A. HARVEY,
Associate Agent.