Improvements in the Process of Dyeing, Tanning, and Mordanting Leather, Teaseled Fabrics, or other Porous Materials, and in Apparatus employed therefor.
Year: 1891

page_text: Date of Application, 10th Nov., 1891
Complete Specification Left, 18th Feb., 1892-Accepted, 2nd Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Process of Dyeing, Tanning, and Mordanting
Leather, Teaseled Fabrics, or other Porous Materials, and in
Apparatus employed therefor.
I, ISIDOR GOLDSCHMIDT, of Fürth, in the Kingdom of Bavaria, Empire of
Germany, Engineer do hereby declare the nature of this invention to be as
follows:-
My invention aims to improve the usual processes of dyeing, tanning, and
mordanting porous materials, as leather, teaseled fabrics and the like, by securing a
more uniform, effective and expeditious distribution of the dye, mordant, etc. than
hitherto.
Heretofore the uniform distribution of the dye etc. was obtained by the applica-
tion of centrifugal force or by means of rolls, or brushes. By a repeated applica-
tion of the latter the grain-side of the leather was injured, and the method besides
only allowed a slow impregnation of the material by the dye; moreover it was
impossible to steep in one vat more than one hide or a series of the same lying in
the same plane.
I attain the desired object. by effecting the distribution of the dye, mordant and
the like by means of compressed air, and, in addition to the advantages already
stated, I obtain a very vivid coloration of the hides, the back side of the same
remaining entirely white, and I am also enabled to expose a great number of hides
at one time to the action of compressed air, thus simplifying the process and
reducing its cost and duration.
In carrying out my invention, I employ the apparatus shown in the accompanying
drawings, in which:
Fig. 1 is a general view of the several parts, the vat A, in which the hides are
placed, being shown in section.
Fig. 2 is a top view of the vat A, the cover being a little removed to the side.
Fig. 3 is a front elevation of the same with its fittings.
Similar letters refer to similar parts throughout the several views.
As shown in Fig. 1 the apparatus consists of the following parts
1. The pump L for compressing the air.
2. The air reservoir M, communicating with
3. The smaller air reservoir N.
4. The recipients al a² a³ a, containing the dye or mordant, and communicating
with the compressed-air pipe R, and provided with tubes of india-rubber g¹ 9² g³ g².
5. The vat A, in which the hides are dyed, and communicating with a small
auxiliary air-pump L'.
The vat A has the shape of a short cylinder with a slightly curved bottom.
The lower part can be hermetically closed by the cover D, which is also of slight
curvature, and by means of the bowk, the threaded spindle s, the hand-wheels h¹
and and the screws d. The cover D being loosened by unscrewing the spindle s
and the screws d can be moved to the side by means of a small crane p, in order
that the hides can be placed into the vat A.
In the center of the bottom there is loosely pivoted a plate T serving to support
a number of discs to and arranged in such a manner that each disc can be
readily inserted and removed, and a sufficient space left between the same.
The inner surface of the vat A is covered with sheet-zinc in order to avoid
stains or rust.
The admission of compressed air from the pipe R, which may also lead to several
vats A, can be stopped at any time.

page_text: The small air-pump L', actuated by hand, is only to be used in case the air-
pump L and the reservoirs and pipes communicating with the same should be
disabled. This pump L' is connected directly with the vat A and reservoir N by
means of suitable pipes. The outlet cock o, provided at the bottom of the vat,
and the safety air-valve r, can be adjusted for different pressures, and a manometer m,
are accessory parts which cannot be dispensed with.
The process for dyeing leather, is as follows:
The first of the hides to be dyed is carefully laid on the bottom disc ¹ and
rubbed flat, the back side being closely applied to the disk; then one of the
cocks allowing the entrance of air from the pipe R to the recipients a' a² a³ a¹ is
opened, and the necessary amount of mordant and of dye is let on the hide through
one of the india-rubber tubes g¹ 92 93 g and is uniformly distributed over the
hide by turning the plate i¹. A second hide is prepared in the same manner after
inserting the disc 2, and the remaining hides are placed in succession on the disks ³
and so on, and impregnated with dye and mordant as described. The vat A is
closed by means of the bow k, spindle s, hand-wheels hand h², and screws d, and
the hides are for a short time subjected to the action of compressed air admitted
from the pipe R, the pressure varying according to the nature and to the thickness
of the leather, and the safety air-valve v being adjusted to suit this pressure,
which is indicated by the manometer m.
I have ascertained by numerous trials that a space of one or of a few minutes is
sufficient to impregnate the leather with dye or with mordant to the required
extent. After the cover D has been removed and the dyeing is found to be
thoroughly effected, a fixing agent may be let over the leather and the fixation of
the colours performed in the same manner in which the dyeing was conducted;
and, finally, still using the same apparatus and manipulations, the coloured side of
the leather may be washed with water, after which the hides are rubbed smooth
and dried as usual.
All injury to the leather is avoided in my process, and it is most economical not
only in consequence of the reduced space of time it requires, but also owing to the
small quantity of dye and mordant employed, as compared to the amount used
hitherto, and owing to the possibility of preparing a great number of hides at the
same time in one and the same vat.
The process is of course applicable for all similar operations, and for impregnating
fabrics, leather and the like, with any solution or liquid, I have described the
method as applied to leather only in order to illustrate the same as an example.
Dated this 9th day of November 1891.
H. F. BOUGHTON,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Process of Dyeing, Tanning, and Mordanting
Leather, Teaseled Fabrics, or other Porous Materials, and in
Apparatus employed therefor.
I ISIDOR GOLDSCHMIDT of Fürth in the Kingdom of Bavaria Empire of
Germany Engineer 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 :-
My invention aims to improve the usual processes of dyeing tanning and mordanting
porous materials as leather teaseled fabrics and the like by securing a more uniform
effective and expeditious distribution of the dye mordant etc. than hitherto.
Heretofore the uniform distribution of the dye etc. was obtained by the applica-
tion of centrifugal force or by means of rolls or brushes.
By a repeated application of the latter the grain-side of the leather was injured
and the method besides only allowed a slow impregnation of the material by the

page_text: 2. The air reservoir M communicating
3. With the smaller air reservoir N.
4. The recipients a¹ a² a³ a containing the dye or mordant and communicating
with the compressed-air pipe R and provided with tubes of india-rubber g² g² g³ g*.
5. The vat A in which the hides are dyed and communicating with a small
auxiliary air-pump L'.
The vat A has the shape of a short cylinder with a slightly curved bottom.
The lower part can be hermetically closed by the cover D which is also
slight curvature and by means of the bowk the threaded spindles the hand-
wheels and h2 and the screws d.
The cover D being loosened by unscrewing the spindles and the screws d can
be moved to the side by means of a small crane p in order that the hides can be
placed into the vat A.
In the centre of the bottom there is loosely pivotted a plate T serving to
support a number of discs to and arranged in such a manner that each disc
can be readily inserted and removed and a sufficient space left between the same.
The inner surface of the vat A is covered with sheet zinc in order to avoid
stains or rust.
The admission of compressed air from the pipe R which may also lead to several
vats A can be stopped at any time.
The small air-pump L' actuated by hand is only used in case the air-pump L
and the reservoirs and pipes communicating with the same should be disabled.
This pump L' is connected directly with the vat A and reservoir N by means of
suitable pipes.
The outlet cock o provided at the bottom of the vat and the safety air-valve v
can be adjusted for different pressures and a manometer m are necessary parts
which cannot be dispensed with.
The process for dyeing leather is as follows.
The first hide to be dyed is carefully laid on the bottom disc and rubbed flat
then one of the cocks allowing the entrance of air from the pipe R to the recipients
a a² as a' is opened and the necessary amount of mordant and of dye is let on the
hide through one of the india-rubber tubes g1 92 93 9* and is uniformly distributed
over the hide by turning the plate i¹.
A second hide is prepared in the same manner after inserting the disc and the
remaining hides are placed in succession on the discs ³ and so on and impregnated
with dye and mordant as described.
The vat A is closed by means of the bow k spindle s hand-wheels h¹ and h³ and
screws d and the hides are for a short time subjected to the action of compressed
air admitted from the pipe R the pressure varying according to the nature and

page_text: to the thickness of the leather and the safety air-valve being adjusted to suit this
pressure which is indicated by the manometer m.
I have ascertained by numerous trials that a space of one or a few minutes is
sufficient to impregnate the leather with dye or with mordant to the required
extent.
After the cover D has been removed and the dyeing is found to be thoroughly
effected a fixing agent may be let over the leather and the fixation of the colors
performed in the same manner in which the dyeing was conducted and finally still
using the same apparatus and manipulations the colored side of the leather may be
washed with water after which the hides are rubbed smooth and dried as usual.
All injury to the leather is avoided by my process and it is most economical
not only in consequence of the reduced space of time it requires but also owing to
the small quantity of dye and mordant employed as compared to the amount used
hitherto and owing to the possibility of preparing a great number of hides at the
same time in one and the same vat.
The process
is of course applicable for all similar operations and for impregnating
fabrics leather and the like with any solution or liquid. I have described the method
as applied to leather only in order to illustrate the same as an example.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what I
claim is-
1. The process of dyeing and tanning mordanting and impregnating porous
materials, as leather teaseled fabrics and the like consisting in letting the liquid to
be employed on these materials and subjecting the same to the action of compressed
air in a closed vat for the purpose as set forth.
2. In the process claimed in 1. The method of letting the liquid on the material
by employing the pressure of compressed air for driving the said liquid out of the
recipients containing the same for the purpose as described.
3. An apparatus for dyeing and tanning mordanting and impregnating porous
materials as leather teaseled fabrics and the like consisting of the pump L the air
reservoirs M and N the recipients a' a² a³ at the compressed air-pipe R the india-
rubber tubes g¹² g³ g₁ the vat A and the auxiliary air-pump L' for the purpose
as described.
4. In an apparatus for dyeing and tanning mordanting and impregnating porous
materials, as leather teaseled fabrics and the like consisting of the pump L the air-
reservoirs M and N the recipients a¹ a² a³ at the compressed air-pipe R the india-
rubber tubes gg2 g³ g¹ the vat A constructed substantially as described and
illustrated by the drawings and for the purpose set forth.
5. In the process claimed in 1. The method of letting the liquid on the material
by employing the pressure of compressed air for driving the said liquid out of
the recipients containing the same, and by rotating the parts on which the
materials are placed for the purpose as described.
Dated this 16th day of February 1892.
.
H. F. BOUGHTON, M.I.M.E.,
Sheffield and Barnsley, Agent.