IMPROVEMENTS IN TREATING, STEEPING, AND BLEACHING JUTE AND LIKE VEGETABLE FIBROUS MATERIALS
Year: 1873

page_text: LETTERS PATENT to Edward Charles Théodore Blake, of Brixton, in
the County of Surrey, for the Invention of "IMPROVEMENTS IN
TREATING, STEEPING, AND BLEACHING JUTE AND LIKE VEGETABLE FIBROUS
MATERIALS."
Sealed the 19th May 1874, and dated the 20th November 1873.
PROVISIONAL SPECIFICATION left by the said Edward Charles
Théodore Blake at the Office of the Commissioners of Patents, with
his Petition, on the 20th November 1873.
I, EDWARD CHARLES THÉODORE BLAKE, of Brixton, in the County of
Surrey, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN TREATING, STEEPING, AND BLEACHING JUTE AND LIKE VEGETABLE FIBROUS
MATERIALS," to be as follows:-
Hitherto it has been found impossible to bleach jute at such a cost as
to render it commercially available for the manufacture of paper of good
quality or for spinning comparatively fine descriptions of white or dyed
yarns. Now I have discovered that jute and like vegetable fibrous
material of the same botanical character can be successfully bleached

page_text: according to my improvements by means of a series of successive processes,
so as to completely discharge the colouring matter therefrom at a
comparatively small cost, whereby it is rendered available for being
employed in the manufacture of superior paper or for spinning finer
descriptions of yarn than heretofore for manufacturing purposes. For 5
this purpose according to my improvements the jute is placed in trays
and boiled for about four hours in a solution of caustic alkali, the
strength of the solution being regulated according to the quality of the
jute under treatment, but I find for jute of good quality a solution of
caustic alkali of about two degrees specific gravity above water is 1
sufficient. The solution is then run off and the jute is boiled for about
four hours in a fresh but weaker alkaline solution which is then run off,
and the jute is steeped for about two hours or upwards in fresh cold
water so as to discharge the colouring matter and alkali. The jute fibre
at this stage may if requisite be boiled for two hours, the water may 1
then be run off and if the water is still charged with colouring matter
the jute fibre may be boiled again for about two hours in a fresh weak
solution of alkali, it will then be ready for removal from the thank to be
well washed and passed through rollers ready for bleaching.
The jute fibre thus prepared is subjected to the bleaching process by a
immersing it in a tank containing a strong cold solution of chloride of
lime for about an hour and a half, the heat being raised gradually to
about 140 degrees Fahrenheit, the jute and solution being kept in a
constant state of agitation, by preference in the manner described in the
Specification of a Patent granted to William Tongue, dated 19th July
1866, No. 1881. The solution is then run off and fresh cold water is
run into the tank, the jute fibre being moved up and down or agitated
therein for about half an hour; then run off the water and fill up the
tank with a solution consisting of about three pounds of sulphuric acid
to about one hundred gallons of water (taking care to raise the jute fibre a
out of the tank when the acid is put into the water). The jute fibre is
then moved up and down or agitated for about an hour whilst in the
solution, which is then run off and fresh cold water only introduced into
the tank, and the agitation continued for about half an hour. The jute
fibre in this condition is then removed to another tank containing a
weak solution of alkali in which it is boiled for about two hours, the
fibre is then taken out and well washed in clean water and passed
through squeezing rollers ready for being submitted to a second bleaching

page_text: operation. The fibre thus far treated and bleached is subjected to
further treatment for about an hour and a half by placing it in a tank
containing a weak solution of chloride of lime, the temperature of which
is raised to about 140 degrees Fahrenheit. The solution is then run off
and fresh clean water introduced into the tank in which the fibre is
steeped for about half an hour, when it is run off, the fibre being raised
out of the tank and a solution of sulphuric acid of the strength previously
described introduced in which the fibre is again immersed and agitated
as before described for about an hour. The solution is then run off and
fresh clean water added, the fibre being finally washed and passed through
squeezing rollers.
If the fibre treated and bleached as previously described is not
sufficiently white it is subjected to the bleaching process for a third
time by immersing and well agitating it in a weak solution of chloride
of lime, afterwards well washed in clean water, and placed in a weak
solution of sulphuric acid and treated in a similar manner as in the
processes previously described.
According to my experience I find that the bleaching process and
action of the sulphuric acid on the fibre sets free or loosens the colouring
matter, and by boiling in a weak solution of alkali the colouring matter is
principally removed, the subsequent bleaching process acting more
effectually on the fibre, and I also find that by subjecting jute fibre to
the bleaching process with chloride of lime over and over again (without
boiling) it is impossible to bleach it effectually.
I would remark that I do not confine my method of treating and
bleaching jute and like botanical fibrous materials to the exact details
herein before described, as the processes may be considerably varied
without departing from the characteristic feature of my Invention, which
consists in subjecting jute fibre to a series of separate successive repeated
operations or processes substantially in the manner previously described,
in order to effectually bleach and render it fit for the manufacture of
paper or textile fabrics of a character for which it has not hitherto been
adapted.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward Charles Théodore Blake in the Great Seal
Patent Office on the 20th May 1874.
Patent Office on the 20th May 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
CHARLES THÉODORE BLAKE, of Brixton, in the County of Surrey, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of November, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Edward Charles Théodore
Blake, Her special license that I, the said Edward Charles Théodore
Blake, my executors, administrators, and assigns, or such others as I,
the said Edward Charles Théodore Blake, my executors, administrators,
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 TREATING, STEEPING,
AND BLEACHING JUTE AND LIKE VEGETABLE FIBROUS MATERIALS," upon the
condition (amongst others) that I, the said Edward Charles Théodore
Blake, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, 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 Edward Charles Théodore Blake, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :-
:―
Hitherto it has been found impossible to bleach jute at such a cost as
to render it commercially available for the manufacture of paper of good
quality or for spinning comparatively fine descriptions of white or dyed
yarns. Now I have discovered that according to my improvements jute

page_text: and like vegetable fibrous material of the same botanical character can
be successfully bleached by means of a series of successive processes so as
to completely discharge the coloring matter therefrom at a comparatively
small cost, whereby it is rendered available for being employed in the
manufacture of superior paper or for spinning finer descriptions of yarn
than heretofore for manufacturing purposes. For this purpose according
to my improvements the jute is placed in trays and boiled for about
four hours in a solution of caustic alkali, the strength of the solution
being regulated according to the quality of the jute under treatment,
but I find for jute of good quality a solution of caustic alkali of about
two degrees specific gravity above water is sufficient. The solution is
then run off and the jute after being passed through squeezing rollers is
boiled for about four hours in a fresh but weaker alkaline solution which
is then run off, and the jute (which I prefer to pass through squeezing
rollers to discharge the liquid after each process) is steeped for about
two hours or upwards in fresh cold water so as to discharge the coloring
matter and alkali. The jute fibre at this stage may if requisite be boiled
for two hours, the water may then be run off and if the water is still
charged with coloring matter, the jute fibre may be boiled again for
about two hours in a fresh weak solution of alkali, it will then be ready
for removal from the tank to be well washed and passed through
squeezing rollers ready for bleaching.
The jute fibre thus prepared is subjected to the bleaching process by
immersing it in a tank containing a strong cold solution of chloride of
lime for about an hour and a half, the heat being raised gradually to
about 140 degrees Fahrenheit, the jute and solution being kept in a
constant state of agitation, by preference in the manner described in the
Specification of a Patent granted to William Tongue, dated 19th July
1866, No. 1881. The solution is then run off and fresh cold water is
run into the tank, the jute fibre being moved up and down or agitated
therein for about half an hour, I then run off the water and fill up the
tank with a solution consisting of about three pounds of sulphuric acid to
about one hundred gallons of water (taking care to raise the jute fibre
out of the tank when the acid is put into the water). The jute fibre is
then moved up and down or agitated for about an hour whilst in the
solution, which is then run off and fresh cold water only introduced into
the tank and the agitation continued for about half an hour. The jute
fibre in this condition is then removed to another tank containing a weak

page_text: solution of alkali in which it is boiled for about two hours, the fibre is
then taken out and well washed in clean water and passed through
squeezing rollers ready for being submitted to a second bleaching
operation. The fibre thus far treated and bleached is subjected to
further treatment for about an hour and a half by placing it in a tank
containing a weak solution of chloride of lime, the temperature of which
is raised to about 140 degrees Fahrenheit. The solution is then run off
and fresh clean water introduced into the tank in which the fibre is
steeped for about half an hour when it is run off, the fibre being raised
out of the tank, and a solution of sulphuric acid of the strength
previously described introduced in which the fibre is again immersed
and agitated as before described for about an hour. The solution is
then run off and fresh clean water added, the fibre being boiled again for
about two hours in a weak solution of alkali, and finally washed in clean
water and passed through squeezing rollers and dried by preference in
the open air or in a shed without the aid of artificial heat.
If the fibre treated and bleached as previously described is not
sufficiently white it is subjected to the bleaching process for a third time
by immersing and well agitating it in a weak solution of chloride of
lime, afterwards well washed in clean water and placed in a weak solution
of sulphuric acid, and treated in a similar manner as in the processes
previously described.
According to my experience I find that the bleaching process and
action of the sulphuric acid on the fibre sets free or loosens the coloring
matter, and by boiling in a weak solution of alkali the coloring matter
is principally removed, the subsequent bleaching process acting more
effectually on the fibre, and I also find that by subjecting jute fibre to
the bleaching process with chloride of lime over and over again (without
boiling) it is impossible to bleach it effectually.
I would remark that I do not confine my method of treating and
bleaching jute and like botanical fibrous materials to the exact details
herein-before described as the processes may be considerably varied with-
out departing from the characteristic features of my Invention, and my
claim consists in subjecting jute fibre to a series of separate successive
repeated operations or processes substantially in the manner previously
described in order to effectually bleach and render it fit for the manu-

page_text: facture of paper or textile fabrics of a character for which it has not
hitherto been adapted.
In witness whereof I, the said Edward Charles Théodore Blake,
have hereunto set my hand and seal, this Fifteenth day of
May, in the year of our Lord One thousand eight hundred and
seventy-four.