A NEW OR IMPROVED METHOD OF BLEACHING ANIMAL AND VEGETABLE FIBRES AND TEXTILES
Year: 1881

page_text: LETTERS PATENT to Walter Alfred Barlow, of 6, St. Paul's Churchyard, in
the City of London, Patent Agent and Engineer, for an Invention of
"A NEW OR IMPROVED METHOD OF BLEACHING ANIMAL AND VEGETABLE
FIBRES AND TEXTILES." A communication from abroad by Laurent Naudin
and Joseph Schneider, both of Paris, France.
PROVISIONAL SPECIFICATION left by the said Walter Alfred Barlow at
the Office of the Commissioners of Patents on the 2nd July 1881.
WALTER A. BARLOW, of 6, St. Paul's Churchyard, in the City of London,
Patent Agent and Engineer. "A NEW OR IMPROVED METHOD FOR BLEACHING
ANIMAL AND VEGETABLE FIBRES AND TEXTILES." A communication from abroad
by Laurent Naudin and Joseph Schneider, both of Paris, France.
Chemical bodies in the nascent state are characterized by special and very
energetic affinities.
Furthermore, the acid alcoline or neutral character of the
medium in which the reactions take place is not without importance in the final
result. It has been found that vegetable and animal fibres (cotton, flax, hemp,
silk, wool, and so forth) may be very rapidly bleached by bringing them in contact
with oxidizing bodies liberated in the nascent state by electrolysis.
In carrying out this Invention it will suffice to place the electrodes of any
electrical source (magneto electric machine, thermo electric batteries of any kind,
and so forth) in a trough or tub containing the fibres to be bleached (such fibres
in the rough state, as threads or manufactured tissues), and a solution of a
compound body which will serve to liberate an oxidizing agent in the nascent
state by electrolysis, as chlorine, oxygen, and so forth.
The solution to be electrolysized are water, the hypochlorites in general, hydro-
chloric acid, and so. forth, the chlorides, bromides, alcaline, iodides, and others
susceptable of setting at liberty chlorine, bromine, or iodine in the nascent state,
these said three bodies serving the role of oxydizing agents, and consequently of
decolorizing agents.
The fibres which are plunged or immersed in the solution during the passage of
the electric current remains therein a sufficient time for the completion of the
operation, but the length of time varies according to the substance to be bleached.
Then they are washed and dried.

page_text: of the vase E, whilst the solution of hypochlorite which has been generated flows
through the overflow pipe D, and proceeds to act on the material to be bleached
contained in the reservoir C.
The safety pipe T adapted to the electrolyser E serves for the escape of the
hydrogen gas produced during the chemical reaction, and to retain in an alkaline
solution the traces of chlorine which otherwise would incommode the operator.
It is conceived that this slow movement of the saline solution in the receptacle C
flowing to the electrolyser and the rapid transformation of this solution into
decolorising chloride and its immediate use on the material to be bleached present
several important advantages.
The chloride of sodium, the first product of chlorine, is obtained at the cost
only of its extraction from sea water, whereas in the actual state of the industry
employing decolorising chlorides, the chloride of sodium has to be brought into the
state of hydrochloric acid, which acid has to react on bioxyde of manganese to
form chlorine which is made to combine with an alkali obtained by the methods of
Leblanc or Solvay.
The object with the inventors has been to suppress all these intermediate
operations, beginning with the initial body, the chloride of sodium, and to draw
the elements of the body to be produced, the hypochlorite, from the chloride of
sodium itself by simply changing by an electric current the order and the position of
the molecules as results from the chemical equation formulated above, and experience
has shown that this is right.
Another advantage for bleaching is to have constantly under hand a solution of
hypochlorite always fresh, having a regular decolorising power ruled by the
electro-motive force of the electric machine.
It must be remembered that the hypochlorites, solid or in solution, lose their
chlorine after a certain length of time, and further, that all the chlorides, bromides,
and iodides can undergo the same chemical transformation by means of an electric
current, and can be utilised for the production of the same results.
For example
Chlorides of potassium.
barium.
"
"5
Bromides strontium.
"
Bromides calcium.
"
Iodides
"
"
aluminum.
magnesium.
Fluorides of iron, and so forth.
When the solution of
Again, sea water containing a mixture of different chlorides, it follows that it
will serve directly as the raw material for bleaching.
chloride of sodium, for example, is deprived of its chlorine by electrolysis, there
remains a solution of caustic soda, which may be usefully employed in operations
of boiling textile fibres.
According to the concentration of the liquor and the temperature to which it is
worked, formation of chlorine may be obtained instead of hydrochloric acid.
Having now described the nature and particulars of the said Invention, I
claim,―
First. The application of electric currents for the purpose of forming at once
decolorising hypochlorites and hypobromites, and so forth, by employing the
electrolysis of alcaline solutions, more or less concentrated, of chlorides, bromides,
iodides, or fluorides, as herein set forth.
Second. The application of the decolorising chlorides made as described for
bleaching of textiles of all kinds, as herein set forth.
Third. The application of the saline solution freed from chlorine, bromine, or
iodine, and constituting the caustic alkali for the boiling of the textiles, as herein
described.
Fourth. The apparatus for the above purpose in combination with an electric

page_text: machine constructed and operating as and for the purpose herein set forth and
shown by the Drawings.
In witness whereof, I, the said Walter A. Barlow, have hereunto set my hand
and seal, this Twenty eighth day of December, in the year of our Lord One
thousand eight hundred and eighty-one.
WALTER A. BARLOW. (L.S.)