Process of Tanning and Colouring Hides or Skins of Animals and the like.
Year: 1898

page_text: Date of Application, 27th June, 1898-Accepted, 24th June, 1899
COREL DRIE DI MUITIVATION.
Process of Tanning and Colouring Hides or Skins of Animals and
the like.
I, GEORGE DEXTER BURTON, of 138, Lincoln Street, Boston, in the County of
Suffolk and State of Massachusetts, Electrician, 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 invention consists in subjecting the skins or hides to be tanned to the
action of a suitable tanning solution and a current of electricity, which is passed
through the solution in which the hides or skins are placed, as hereinafter
described.
In the accompanying drawings, Figure 1 is a side view of a tank containing
the solution, showing one side of the tank removed. The same figure also shows
the generator for furnishing current to the tank, and also the controlling switch,
as well as the device for stirring and keeping the solution in circulation.
Figure 2 is a top plan view of the same.
Figure 3 represents a section of the tank on the linear of Figure 2.
Referring again to Figure 1, A. is the tank containing the solution. Bis the
solution, and CC screens, to prevent the skins or hides from coming into contact
with the electrodes D D. E represents a screen at the bottom of the tank, to
prevent the skins coming into direct contact with the bottom of the tank and
for the purpose of allowing the liquid to circulate underneath the skins. F is
the switch, for controlling the electric current. G represents an electric
generator. H H are conductors to the electrodes D D. JJ are the conductors
leading from the electric machine to the switch.
Means are provided, as shown in Figures 1, 2 and 3, for agitating or keeping
the solution within the tank or receptacle in circulation.
As shown in Figure 2, a pulley K is attached to the shaft of the dynamo and
connected by a belt L to a pulley M, which is connected to a shaft which runs
through one end of the tank. To this shaft are attached fans or projections a aaa
for stirring or agitating the solution. Where the shaft enters into the tank it is
provided with a stuffing box N, to prevent leakage. A collar O is placed on
the inside of the tank, to keep the shaft in position. The shaft is held in place
on the other side of the tank by a recess cut into the inside wall of the tank.
Qrepresents a skin or hide, to be colored or tanned, lying in the solution in
the tank.
The object in circulating the solution is to prevent the tanning or coloring
material from settling in the tank, and also to cause an even distribution of said
materials throughout the tank, causing a more rapid action of the solution upon
the hides or skins.
My process and apparatus for the tauning of all kinds of animal hides or skins
consists of a tank composed of wood, or other non-conducting substance, into which
I place a suitable tanning or coloring solution, and at each end of a tank,
containing about seventy gallons of solution, two carbon plates, one-half inch
thick and twelve by sixteen inches, are properly connected to a suitable source
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page_text: of electricity, preferably that consisting of a current of electricity varying from
twenty to five hundred volts and from ten to one hundred amperes, according to
the size of the tank, the gravity of the solution and the number of skins or
hides to be tanned. In a solution consisting of seventy gallons of water I add
two quarts of tannic acid, or extract of chestnut, oak or hemlock bark, together
with four ounces of chloride of sodium, making the solution, after the acid or
bark liquid and chloride of sodium are added and thoroughly dissolved and mixed,
of a specific gravity of 1030 at 6:30 Fahrenheit, which is accomplished by stirring
the solution briskly for a few minutes. I then place in such bath or solution
four dozen skins to be tanned, or one dozen hides, which have previously been
prepared by other methods for the proper step of tanning.
Such skins may
consist of goat skins, kangaroo skins, calf skins, ox or cow hides etc. I allow the
skins to be tanned to remain in the bath from two to four hours and the hides
from six to eight hours. When the skins or hides are removed from the bath
or solution the customary processes of further treatment to the skins are proceeded
with. The old process of tanning requires the skins to remain in solution from
twelve days to five weeks, according to the color and the character of the process
employed.
The essential feature of my process of tanning hides or skins consists of making
a solucion in the proper proportions, such as herein described, and passing a
suitable electric current through the bath containing the hides or skins to be
tanned. The proportions, of course, may be varied, in accordance with the size
of the tank, the number of skins or hides to be treated at one time and the
quantity of liquid used. The screen at the bottom of the tank is about two and
one-half inches therefrom, is made of a non-conducting substance and has a per-
forated bottom, best shown in Figure 3, which prevents the skins or hides from
coming into direct contact with the bottom of the tank and also allows a free
circulation of the liquid underneath the skins or hides during the tanning
process.
By adding suitable coloring material to the tanning solution hereinbefore
described, in the proportion of two pounds of crystalized logwood, three-quarters
of a pound of sulphite of iron and one-half pound of sulphite of copper, the hides
or skins may be tanned and colored at one operation, without removing them from
the tank or receptacle.
I may also add to the above solution, as a modification of the coloring solution,
two ounces of iodide of potassium and one-half pound of bichromate of potassium
which will change the color from a purple to a black.
One of the essential features of my process of tanning and coloring hides or
skins consists of placing the skins or hides in a solution containing the tanning
and coloring materials and passing a suitable electric current of sufficient
volume and pressure through such solution for the purpose of opening the pores
or fibres of the hides or skins and forcing the tanning liquid into and through
the skins or hides, as well as the coloring material.
It is generally known that the hide or skin of an animal is porous as well as
fibrous. The action of the current upon such skins or hides causes the opening of
the pores or fibres and allows the tanning or coloring material to quickly penetrate
the pores or fibres of such skins or hides as are placed in the solution.
I have stated in this specification a suitable tanning material, as well as a
suitable coloring material; of course other materials can be used if different
colors are to be produced, and different tanning materials can be used; all of
which would come within the scope and features of my invention.
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 process of tanning and colouring hides or skins, which consists in
placing the hides or skins in a tanning solution, passing an electric current

page_text: through said solution containing the hides or skins, then adding colouring matter
to said solution, and again passing the electric current therethrough.
2. The process of tanning and colouring hides or skins, which consists in
placing the hides or skins in a tanning solution, passing an electric current
through said solution containing said hides or skins, then adding colouring matter
to said solution, again passing the electric current therethrough, and subjecting
said solution to mechanical agitation during the whole or a part of the time
occupied by the tanning and colouring operation.
3. The process of tanning hides or skins, which consists in subjecting the hides
or skins to the action of a solution containing tanning material, extraneous
colouring matter and a dissolved solvent as specified which adds density and
conductivity to the solution, and passing an electric current through said solution
in which the hides or skins are placed.
In testimony that I claim the invention above set forth I affix my signature
in presence of two witnesses at Boston, Mass., U.S.A., May 13th, 1898.
Witnesses:
E F. PHILIPSON.
GEO. STEINER.
GEORGE DEXTER BURTON.