IMPROVEMENTS IN BLEACHING VEGETABLE FIBRES
Year: 1856

page_text: LETTERS PATENT to Francis Montgomery Jennings, of the City of Cork,
Manufacturing Chemist, for the Invention of "IMPROVEMENTS IN BLEACHING
VEGETABLE FIBRES."
Scaled the 4th April 1856, and dated the 5th February 1856.
PROVISIONAL SPECIFICATION left by the said Francis Montgomery
Jennings at the Office of the Commissioners of Patents, with his Petition,
on the 5th February 1856.
I, FRANCIS MONTGOMERY JENNINGS, of the City of Cork, Manufacturing
Chemist, do hereby declare the nature of the said Invention for IMPROVE-
MENTS IN BLEACHING VEGETABLE FIBRES, to be as follows:-
My Invention consists in bleaching vegetable fibres, either in a raw or
partially prepared state, or as pulp, yarn, thread, or cloth; with regard to
cloth, yarn, or thread, in such manner as to dispense with bleaching in the
open air, or to materially diminish the time of such bleaching. I prepare the
fibres first in the usual way by treating them with solutions of alkalies,
alkaline earths, saponaceous liquids, or by steeping them in water. I then
treat the fibres with a solution of caustic soda, carbonate of soda, bicarbonate
of soda, or any mixture of these, and hypochlorite of soda, commonly
called chloride of soda; after this wash the fibres with water, or with
acid water. These processes, the treating with soda, chloride of soda, and

page_text: the use of acid and water, are employed alternately, until the bleaching be
nearly completed, which is done by finishing with an alkaline or earthy
chloride in the ordinary way. In some cases, it may be desirable to expose
the articles a short time to bleaching in the open air. Instead of soda, potash
may be used, and in the place of the chloride of an alkali, the chloride of an
alkaline earth or a metallic oxide may be used with caustic alkali. In order
to cause the various solutions to permeate the fibres, weights, rollers, or any
other mode of producing mechanical pressure may be employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Francis Montgomery Jennings in the Great Scal Patent
Office on the 24th July 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
MONTGOMERY JENNINGS, of the City of Cork, Manufacturing Chemist.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of February, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign;
did, for Herself, Her heirs and successors, give and grant unto me, the said
Francis Montgomery Jennings, Her especial license that I, the said Francis
Montgomery Jennings, my executors, administrators, and assigns, or such
others as I, the said Francis Montgomery Jennings, my executors, admi-
nistrators, and 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 BLEACHING VEGETABLE FIBRES," upon
the condition (amongst others) that I, the said Francis Montgomery Jennings,
by an instrument in writing under my hand and seal, 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.
NOW KNOW YE, that I, the said Francis, Montgomery Jennings, 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):-

page_text: My improvements consist in bleaching vegetable fibres in the state of cloth,
thread, yarn, or as flax, hemp, jute, China grass, or cloths, known in the trade
as unions, being mixtures of linen and cotton, or such like substances in any
state of preparation, or entirely unmanufactured, or as pulp, by the use of a
solution of hypochlorite of soda, commonly called chloride of soda, in com-
bination or admixture with an excess of caustic, carbonate, or bicarbonate of
soda, or any mixture of those salts, or caustic, carbonate, or bicarbonate of
potash, or any mixtures of those salts of potash and soda; and I am able to use
chlorine in the state of combination or admixture with those substances at an
earlier part of the process of bleaching, than is now found to be either con-
vénient or suitable in the present modes adopted for bleaching the above
substances, especially in the case of heavy linens. I sometimes use chlorides
of the alkaline earths, in which instances, I prefer employing a solution of.
caustic soda or potash, or a mixture of those alkalies, instead of using their
carbonates, so as to prevent decomposition. I can, by means of my Invention,
bleach any of the above-named substances of a perfectly white colour without
exposure to air or light, or on grass, or with far less exposure than has been
hitherto practised, though I may occasionally include grass bleaching as an.
alternation. I find that the strength of the linen so bleached is as great or
rather greater than linen bleached in the ordinary way, owing to the manner
in which the chlorine is used, and owing to the goods not being exposed at all
or much to the air or light. In my plan, chlorine compounds are used in the
earlier stages of bleaching, and render the colouring matters contained in the
vegetable fibres soluble in alkaline solutions, whereas, in the usual way in
which chlorine compounds are now employed by bleachers of linens, were they
to be used in the earlier stage, the colouring matters would be fastened and
rendered insoluble, so that chlorine compounds would not afterwards effectually
remove them, and the colour would become what is called in the trade "set."
In the place of hypochlorite of soda, hypochlorite of potash, or as it is commonly
called chloride of potash, may be used when it can be obtained cheap enough.
In describing my plan, for the sake of brevity, I will take vegetable fibres in
the form of linen cloth, and therefore I shall not have occasion to name
separately the other substances above mentioned, although my improvements
in bleaching will extend to them as well as linen cloth. I take linen cloth and
soak it in water for a time, say twelve hours, or I boil it in lime, or alkali, or
alkali and lime, and then soak it in dilute acid. If lime be used, I prefer
dilute muriatic acid, or I boil it in a solution of carbonate, or caustic soda, or
potash, or mixtures of those substances, or a soap of oil, or grease, or rosin, as
used at present in bleach greens. If carbonate or caustic soda, or a mixture

page_text: of those substances is used, I prefer a solution of about three to five of
Twaddle's hydrometer, and boil the cloth from four to six hours. Then I boil
again until the whole or the greater part of the soluble portion of the colouring
matter is dissolved in the common way, as at present in use. I then wash the
linen cloth, above named, and put it into a solution of caustic carbonate or
bicarbonate of potash, or soda, or any mixtures of those salts. I prefer about the
specific gravity of one thousand and twenty-five, or five Twaddle's hydrometer,
of carbonate of soda of commerce, as used by soap makers or bleachers, slight
impurities not affecting the result (pure carbonate acts as well), and add a
solution of chloride of soda of commerce, more properly called hypochlorite of
soda, of such a strength that it would make the total solution of about from
one to two Twaddle, calculating as if the above were water, or calculated by
adding in the chloride of soda, so as to increase the specific gravity by the
addition of the chloride of soda. I generally observe about that proportion in
the mixtures, though stronger or weaker will produce an effect. In this
solution I put the linen cloth, above named, and leave it in for some hours, and
I prefer using rollers, or some other mechanical means, such as pressing with
a weight, so as to make the solution permeate, and cause fresh portions of
the liquor to pass into and through the material, by some such suitable means;
this operation may be brought to a close in about three or five hours, more or
less. I then wash the linen cloth very well, and soak it in dilute, sulphuric, or
muriatic acid, or other suitable acid; and I also prefer some similar mechanical
arrangement to the before mentioned for making the acid permeate the cloth.
The strength may be that generally used, about from one thousand and ten to
one thousand and twenty specific gravity, or from two to four of Twaddle's
hydrometer. I then wash in water the linen cloth, and boil it, as above stated,
in the usual way from six to ten hours. Again put it through the chloride and
carbonate of soda solution (or whatever other solution is used), having added
some more chloride, about one-fourth to one-fifth of the former quantities, and
work on as before, washing, soaking in acid, and boiling, as I have previously
described in the first operations. These operations continue to alternate for
about three, four, or five times, until the linen cloth assumes an appearance
almost perfectly white. I here prefer, in place of the mixture of extra excess
of alkali to hypochlorite, to employ the usual hypochlorite of soda or lime,
commonly called chloride of soda or lime, of about one thousand and one to
one thousand and two specific gravity, or from one-fifth to about one-third
degree of Tweddle's hydrometer, and after washing, use the acid above named
Then I wash in water, or in soap and water, or with what are called the rubbing
beards, or I use the rubbing boards and soap, or soap and alkali, between the

page_text: other processes, where the materials are woven, or where they would not be
injured. I can use grassing or exposure to the air when necessary between
any of these processes or not, as I like, or leave out the acid dip or alternate,
as I think fit, and make use of soap or any saponaceous substances in the
boilings; or I can use any other means of producing those solutions of chlorine
with caustic, or carbonate, or bicarbonate of soda in excess, by passing in the
chlorine directly with those salts, or any of them, but so as to keep the alkalic
in excess over the chlorine; or I can use chlorides of the alkaline earths, in
which cases, however, I prefer the solution of caustic soda or caustic potash.
I am more careful, towards the end of the process of bleaching, as to the relative
quantity of chlorides I employ, than is necessary at first. I can use the
bypochlorite of soda with excess of soda in the first process before boiling with
alkili, or lime, or any other substance. The solutions of chlorides, and also the
acids, may be used warm.
Having thus described the nature of my Invention, and the best means with
which I am acquainted of performing the same, I hereby declare that I claim
the conjoint use of hypochlorites, commonly called chlorides and alkalies, in
manner herein-before described, for the purpose of bleaching vegetable fibres
in the state of cloth, thread, yarn, or as flax, hemp, jute, China grass, or such
like substances, in any state of preparation, or entirely unmanufactured, or as
pulp.
In witness whereof, I, the said Francis Montgomery Jennings, have
heretofore set my hand and seal, this Twenty-third day of July, in the
year of our Lord One thousand eight hundred and fifty-six.
FRANCIS M. JENNINGS. (L.8.)