IMPROVEMENTS IN BLEACHING The FIBRES OBTAINED FROM VEGETABLE FIBROUS SUBSTANCES, AND ALSO THE FABRICS MADE FROM SUCH FIBRES.
Year: 1882

page_text: LETTERS PATENT to James Anthony Graham, of 66 Coleman Street, in the
City of London, for an Invention of "IMPROVEMENTS IN BLEACHING The
FIBRES OBTAINED FROM VEGETABLE FIBROUS SUBSTANCES, AND ALSO THE
FABRICS MADE FROM SUCH FIBRES.
"
PROVISIONAL SPECIFICATION, left by the said James Anthony Graham at
the Oflice of the Commissioners of Patents on the 10th November 1882.
JAMES ANTHONY GRAHAM, of 60 Coleman Street, in the City of London,
"IMPROVEMENTS IN BLEACHING THE FIBRES OBTAINED FROM VEGETABLE FIBROUS
SUBSTANCES, AND ALSO THE FABRICS MADE FROM SUCH FIBRES
"
All vegetable fibrous substances in the natural state contain organic coloring
matters which unless extracted or rendered inert (that is rendered capable of
being bleached), are detrimental if the materials are required in a bleached state.
After the raw materials have been subjected to the ordinary boiling or boilings
in alkali or other solvents they still retain an appreciable quantity of these coloring
matters which have resisted the action of the solvents.
It is usual to act upon these residual coloring matters by bringing the materials
in contact with chlorine or an hypochlorite, or both, whereby they are bleached.
My Invention consists in bringing into contact with the materials being treated
(either previous, or at the same time, or subsequent to their treatment with chlorine
or an hypochlorite, or both) nitrate of soda or potash in solution, or any suitable
combination of the same.
The advantages resulting from this addition are :—
1st The nitrate has a solvent action on many of the coloring matters themselves.
2nd It assists in divesting the fibres of insoluble lime salts formed naturally
in the fibres themselves, or obtained from the water or chemicals used in the
previons operations.

page_text: 3rd When bleaching with chlorine or an hypochlorite, or both, bydrochloric acid
is generally formed which if allowed to remain long in contact with the fibrous
substances renders them weak. The presence of a nitrate prevents the detrimental
action of the hydrochloric acid, and thus enables a higher temperature to be used
than would otherwise be safe.
In operating on fibres suitable for paper making the materials are beaten up in
water by the usual machinery. The nitrate may then be added in the solid or
liquid state (together with, or previous or subsequent to the chlorine), and the
solution heated by injected steam or otherwise, so as to raise the temperature to
any requisite degree depending on the nature of the fibre being treated.
In operating on fabrics made from vegetable fibres the nitrate solution would be
either added to the ordinary bleach liquor, or the fabrics might be passed through
the nitrato solution before or after they are passed through the bleach liquor.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Anthony Graham in the Great Seal Patent Office on the
10th May 1883.
JAMES ANTHONY GRAHAM, of 66 Coleman Street, in the City of London,
"IMPROVEMENTS IN BLEACHING THE FIBRES OBTAINED FROM VEGETABLE FIBROUS
SUBSTANCES, AND ALSO THE FABRICS MADE FROM SUCH FIBRES,"
All vegetable fibrous substances in the natural state contain organic colouring
matters which unless extracted or rendered inert (that is rendered capable of being
bleached), are detrimental if the materials are required in a bleached state.
After the raw materials have been subjected to tho ordinary boiling or boilings
in alkali, or other solvents, they still retain an appreciable quantity of these
colouring matters which have resisted the action of the solvents.
It is usual to act upon these residual colouring matters by bringing the materials
in contact with chlorine or an hypochlorite, or both, whereby they are bleached.
My Invention consists in bringing into contact with the materials being treated
(either previous to, or at the same time as, or subsequent to their treatment with
chlorine or an hypochlorite, or both) nitrato of soda or nitrato of potash in solution,
or any suitable combination of the same.
The advantages resulting from this addition are :—
1 The nitrate has a solvent action on many of the colouring matters.
themselves.
2nd It assists in divesting the fibres of insoluble lime salts formed naturally in
the fibros themselves, or obtained from the water or chemicals used in the previous
operations.
3rd When bleaching with chlorine or an hypochlorite, or both, hydrochloric
acid is generally formed which if allowed to remain long in contact with the fibrous
substances renders them weak. The presence of a nitrate prevents the detrimental
action of the hydrochloric acid, and thus enables a higher temperature to be used
than would otherwise be safe.
In all cases where a nitrate is used in conjunction with chlorine or an hypo-
chlorite, the best results will be obtained when the solution is heated, and such
solution may be heated to the boiling point without materially affecting the
strength of the fibres.
My Invention is especially adapted for bleaching fibrous substances which have
been previously treated with sulphurous acid or its compounds, but may also be
employed for bleaching fibrous substances from which the incrusting matter has
been removed by any other suitable treatment.
up
in
In operating on fibres suitable for paper making the materials are beaten
water by the usual machinery. The nitrato may then be added in the solid or
liquid state (together with, or previous or subsequent to the chlorine), and the
solution heated by injected steam or otherwise, so as to raise the temperature to
any requisite degree depending on the nature of the fibre being treated.
In operating upon fabrics made from vegetable fibres the nitrate solution would
be either added to the ordinary bleach liquor, or the fabrics might be passed
through the nitrate solution before or after they are passed through the bleach
liquor.
When the desired result has been attained the fibres may be washed in any
suitable manner.

page_text: Having thus described the nature of my said invention and the manner of
carrying the same into effect, I wish it to be understood that what I claim is :-
The improved process for bleaching the fibres obtained from vegetable fibrous
substances or the fabrics made from such fibres, consisting in the use either of
nitrate of soda or nitrate of potash, or both, in conjunction with chlorine or an
hypochlorite, substantially as herein described.
In witness whereof, I, the said James Anthony Graham have hereunto set
my hand and seal this tenth day of May in the year of our Lord one
thousand eight hundred and eighty-three.
JAMES ANTHONY GRAHAM (L.S.)
Witness.
HERBERT. J. ALLISON Fel. Inst. P. A.
41 Southampton Bdgs
Holborn.