IMPROVEMENTS IN WHITENING OR BLEACHING YARNS, FABRICS, AND FIBROUS SUBSTANCES
Year: 1869

page_text: LETTERS PATENT to Walter Noel Hartley, of Litchfield, in the County
of Stafford, Fellow of the Chemical Society, for the Invention of
"IMPROVEMENTS IN WHITENING OR BLEACHING YARNS, FABRICS, AND FIBROUS
SUBSTANCES."
Sealed the 5th April 1870, and dated the 9th October 1869.
PROVISIONAL SPECIFICATION left by the said Walter Noel Hartley
at the Office of the Commissioners of Patents, with his Petition,
on the 9th October 1869.
I, WALTER NOEL HARTLEY, of Litchfield, in the County of Stafford,
Fellow of the Chemical Society, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN WHITENING OR BLEACHING YARKS,
FABRICS, AND FIBROUS. SUBSTANCES," to be as follows:-
This Invention has for its object the whitening or bleaching of yarns,
fibres, or fabrics, and is equally applicable either to linen or cotton, but
it is more especially intended for the bleaching of linen.

page_text: When the linen cloth has been once or twice boiled and scoured it is
steeped in a dilute solution of permanganate or manganate of potash,
soda, or lime, which solution of manganate or permanganate may be
used neutral, alkaline, or acid, but it is found to be preferable to use it
acidified with suphuric acid. After a long enough exposure to the 5
action of the bleaching liquid the cloth should be steeped in a warm
solution of oxalic acid, or oxalic acid mixed with any mineral acid,
whereby the peroxide of manganese precipitated on and adhering to the
cloth is dissolved off, and the linen is found to be whitened.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Walter Noel Hartley in the Great Seal Patent Office
on the 6th April 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WALTER
NOEL HARTLEY, of Litchfield, in the County of Stafford, Fellow of the
Chemical Society, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of October, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Walter Noel Hartley, Her special license
that I, the said Walter Noel Hartley, my executors, administrators, and
assigns, or such others as I, the said Walter Noel Hartley, my executors,
administrators, or assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,"
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN WHITENING
OR BLEACHING YARNS, FABRICS, AND FIBROUS SUBSTANCES," upon the condition
(amongst others) that I, the said Walter Noel Hartley, my executors or
administrators, by an instrument in writing under my hand and seal,
or under the hand and seal of one of them, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Walter Noel Hartley, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, that is to say :-
My said Invention has for its object the whitening or bleaching of
yarns, fibres, or fabrics, and is equally applicable either to linen or
cotton, but is more especially intended for the bleaching of linen.
My improved process of bleaching linen, flax, yarns, or other fibrous
substances
may be best described by dividing it into two operations, that
is to say:
First. The bleaching process proper, or destruction of the organic
coloring matter in the fibres.
Second. The decolorization of the linen or other fibrous material, or
the removal therefrom of the mineral coloring matter resulting from the
previous operation.
To destroy the organic coloring matter I use certain highly oxidised
compounds of manganese which have long been in use by chemists as
oxidising agents, namely, those salts called manganates or perman-
ganates. The salt which I prefer as being the most easily and cheaply
procurable in commerce is mineral chamelon or crude manganate, or a
mixture of manganate and permanganate of soda or potash (the man-
ganate or permangate of lime would answer the purpose). I make a
solution of this salt in water, and in order to get rid of the excess of
caustic alkali in it, and to convert all the manganite into permanganate,
I pass through it a current of carbonic acid until the liquid assumes a
deep red color, or I add a slight excess of sulphuric acid, when the same
change in appearance takes place, and I then neutralize the sulphuric
acid with bi-carbonate of soda, so as to get an excess of carbonic acid
present. I then dilute my solution till I obtain it of such a strength
that about twenty-three thousand parts by weight of the solution will
contain one part by weight of permanganate of potash or soda, that is
to say, a strength of about three grains of the salt to a gallon of water;
but I do not confine myself to the use of a liquid of this strength.
This solution I call solution A.
The method I adopt for ascertaining when the solution A. is of the
proper strength is the following:-I make a solution of pure crystallized
permanganate of potash by dissolving three grains in a gallon of water,

page_text: and I fill a glass tube of about half an inch in diameter with this. I
take a similar glass tube and fill it with a very weak solution of magenta
dye mixed with a little aniline blue to give it the right tint. When the
tubes are alike in depth of tint I keep the one containing the dyes for
my color test. All that is necessary then in order to find the strength
of my solution A. is to place some of it in a similar glass tube, and if it
be too strong I add sufficient water to bring it to the proper tint, noting
the proportion of water added, thus ascertaining how much my solution
must be diluted in order to bring it to the proper strength. I then
make a souring liquid by mixing oil of vitriol with water till the
mixture has a specific gravity equal to 1° or 1° Twaddel, and then add
thereto one per cent. of green vitriol or sulphate of iron, or about the
same quantity of oxalic acid, or a mixture of the two, but the proportion
of oxalic acid or green vitriol may be varied. This sour mixture I call
mixture B. The substances that have to be bleached, as, for example,
a piece of linen) are boiled once or twice with soda ley and soured in
the usual method known to bleachers. After the boiling process I steep
the linen in the solution A. for about seventy-two hours, and then remove
it, when it will be found to be quite brown; I then wash and sour
it in the mixture B. for about six hours, that is to say, until all the
brown oxide of manganese is removed; the linen is then washed,
replaced in the solution A. for forty-eight hours, again washed, soured
in the mixture B. for about twelve hours, rewashed, and then dipped
again in solution A. for about forty-eight hours, and then washed and
soured in the mixture B. for about twelve hours; or I steep it for a
week in the solution A., and then sour it in B. for about twelve hours.
When the cloth has gone so far through the process it is nearly white.
To remove the last traces of color I make a solution (which I call
solution C.) of permanganate similar to solution A., but instead of being
alkaline it is acidified with dilute sulphuric acid till of a specific gravity
equal to one and a half degree on Twaddel's hydrometer. After the
linen has been steeped in solution C. for a period varying from about
twenty-four hours to three days it is removed, washed, and soured in the
sour mixture B. of two degrees Twaddel containing oxalic acid until
white. Some kinds of linen may require longer or shorter treatment
than this in the alkaline dip, but the process is essentially the same for
different kinds of cloth. The amount of permanganate removed from
the solution by the linen and lost in the various operations amounts to
about 2.68 per cent. of the weight of the linen bleached. If I wish to

page_text: roughly bleach and not obtain a full white I simply after boiling use
the dip solution C. and the sour mixture B. alternately until the desired
effect is obtained. If desired, in lieu of using the solution C., the cloth
or other fibrous material after it has undergone the processes herein-
before referred to may be rendered perfectly white by the ordinary
bleaching process.
Having now described and particularly ascertained the nature of my
said Invention, and in what manner the same is or may be used or
carried into effect, I would observe in conclusion that what I consider to
be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is, the use of
highly oxygenised compounds of manganese for the purpose of oxidizing
the organic coloring matter contained in fibrous substances, and the
subsequent removal of the brown manganic oxide therein deposited by
means of solutions of free oxalic acid or of oxalic acid or green vitriol
mixed with dilute mineral acids, substantially as herein-before described.
In witness whereof, I, the said Walter Noel Hartley, have to this
my Specification set my hand and seal, the Sixth day of April
One thousand eight hundred and seventy.
WALTER NOEL HARTLEY. (L.S.)