provements in the Process of Bleaching Fibrous Material by Aid of Electricity.
Year: 1890

page_text: Date of Application, 1st Apr., 1890
Complete Specification Left, 5th May, 1890-Accepted, 5th July, 1890
PROVISIONAL SPECIFICATION
Improvements in the Process of Bleaching Fibrous Material by Aid
of Electricity.
I, CARL KELLNER, of Bartensteingasse 8, Vienna 1, Austria, Chemist, do hereby
declare the nature of this invention to be as follows:-
This invention has reference to those bleaching processes, in which the bleaching
agents are prepared electrolytically, and it has for its objects not only to economise
power in the production of the electric current required for the electrolysis, but also
to economise chemicals.
In those cases where electrolytic processes have been employed in bleaching fibrous
materials in the manufactured or in the raw state, it has been usual hitherto to
prepare the bleaching agents in a separate vessel by the decomposing action of an
electric current, and afterwards to use them in the same manner as bleaching
agents prepared in another way, viz., in the form of baths, in the bleaching
kier &c.
To
Now according to this invention the decomposition of the materials which are to
furnish the bleaching agent is effected in contact with the fibrous material to be
bleached, so as to allow the products of the decomposition to act in the nascent state,
whereby the effect is, considerably enhanced, and, consequently the quantity of
products required for obtaining the desired result, or the amount of mechanical power
necessary for the electrolytic decompositon is reduced in a proportional measure.
this end the fibrous material to be bleached is first impregnated with the solution,
from which the bleaching agent is to be obtained by electrolysis and afterwards the
fibrous material is, in the form of a layer of suitably chosen thickness, carried
through between the two electrodes. In consequence of the small distance
between the electrodes, but little resistance is opposed to the passage of the electric
current, wherefore a current of low electro-motive force will suffice."
The positive electrode or anode must be made of a material which is not attacked
by the evolved bleaching agent, which may be for instance chlorine evolved from a
solution of a metallic chloride, in which case the said electrode should consist of
carbon or platinum.
The best shape to be given to the electrodes is that of revolving cylinders or
rollers, which carry along the layer of material and simultaneously convey the electric
current through the same. An advantageous arrangement consists in a succession of
several pairs of cylinders or rollers in which the anode is alternately situated above
and below, so as to cause the bleaching agent set free by electrolysis to get into
contact with the upper and the lower layer of the material alternately.
In certain cases it will be found advantageous to pass between the electrodes,
together with the material to be bleached, a layer of felt, or simultaneously to move
along two layers of material, either of which is then impregnated with the anion, while
the other is impregnated with the cation.
In order to prevent the escape of those quantities of chlorine which are not absorbed
by the bleaching process, substances capable of absorbing chlorine are added to the
electrolyte such substances are by preference alkalies, such as soda, ammonia, lime,
magnesia, etc.
;

page_text: COMPLETE SPECIFICATION.
Improvements in the Process of Bleaching Fibrous Material by Aid
of Electricity.
J, CARL KELLNER of Bartensteingasse 8, Vienna 1, Austria, Chemist, 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 has reference to those bleaching processes, in which the bleaching
agents, are prepared electrolytically and it has for its objects not only to economise
power in the production of the electric current required for the electrolysis, but also
to economise chemicals.
In those cases where electrolytic processos have been employed in bleaching fibrous
materials in the manufactured or in the raw state, it has been usual hitherto to
prepare the bleaching agents in a separate vessel by the decomposing action of an
electric current, and afterwards to use them in the same manner as bleaching
agents prepared in another way viz., in the form of baths, in the bleaching
kier &c.
Now according to this invention the decomposition of the materials which are to
furnish the bleaching agent is effected in contact with the fibrous material to he
bleached, so as to allow the products of the decomposition to act in the nascent state,
whereby the effect is considerably enhanced, and consequently the quantity of
products required for obtaining the desired result, or the amount of mechanical power
necessary for the electrolytic decomposition is reduced in a proportional measure.
To this end, the fibrous material to be bleached is first impregnated with the solution
from which the bleaching agent is to be obtained by electrolysis, and afterwards the
fibrous material is, in the form of a layer of suitably chosen thickness, ca: ried
through between the two electrodes. In consequence of the small distance between
the electrodes, but little resistance is opposed to the passage of the electric current,
so that a current of low electro motive force will suffice.
The positive electrode or anode must be made of a material, which is not attacked
by the evolved bleaching agent, which may be for instance chlorine evolved from a
solution of a metallic chloride, in which case the said electrode should consist of
carbon or platinum.
The best shape to be given to the electrodes is that of revolving cylinders or
rollers, which carry along the layer of material and simultaneously convey the
electric current through the same. An advantageous arrangement consists in a
succession of several pairs of cylinders or rollers in which the anode is alternately
situated above and below, so as to cause the bleaching agent set free by electro-
lysis to come into contact with the upper and the lower layer of the material
alternately.
In certain cases it will be found advantageous to pass between the electrodes,
together with the material to be bleached, a layer of felt, or simultaneously to move
along two layers of material, either of which is then impregnated with the anion,
while the other is impregnated with the cation.
In order to prevent the escape of those quantities of chlorine, which are not
absorbed by the bleaching process, substances capable of absorbing chlorine are added
to the electrolyte ; such substances are by preference alkalies, such as soda, ammonia,
lime, magnesia.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1. A process for bleaching fibrous material in the manufactured or in the raw state
by aid of electrolysis, the said process consisting in first-impregnating-the-fibrous¯
matarial with-tha-anturion C
F

page_text: electrolysis, and afterwards causing a layer of the impregnated material of suitable
thickness to pass between two opposite electrodes between which an electric current
passes.
2. In the process referred to in the preceding claim the use of a number of pairs
of electrodes, between which the material to be bleached passes in a successive manner,
the anodes of the several pairs being situated alternately above and below as herein
described for the purpose set forth.
3. In the process referred to in claim 1, the use of electrodes in the form of
revolving cylinders, which serve to simultaneously carry along the material and
convey the decomposing electric current through the same as set forth.
4. In the process referred to in claim 1, causing a layer of material to be bleached
and a layer of felt, or two separate layers of the material to be bleached to pass
simultaneously between the electrodes for the purpose of causing one layer to
be impregnated with the anion and the other layer with the cation as set forth.
Dated this Fifth day of May 1890.
חזיז-
KELLNER,
Per L. W.