IMPROVEMENTS IN BLEACHING HEMP AND FLAX TOGETHER WITH THEIR STALKS AND SHIVES AND RENDERING THE LATTER FIT FOR PAPER MAKING
Year: 1882

page_text: LETTERS PATENT to Arthur Charles Henderson of 6 Southampton Buildings
Holborn in the county of Middlesex for an invention of "IMPROVEMENTS IN
BLEACHING HEMP AND FLAX TOGETHER WITH THEIR STALKS AND SHIVES
AND RENDERING THE LATTER FIT FOR PAPER MAKING,"-A communication
from abroad by Augusto Demeurs of Huyssinghen in the Kingdom of
Belgium
PROVISIONAL SPECIFICATION left by the said Arthur Charles Henderson
at the Office of the Commissioners of Patents on the 14th April 1882.
ARTHUR CHARLES HENDERSON of 6 Southampton Buildings Holborn in the
County of Middlesex "IMPROVEMENTS IN BLEACHING HEMP AND FLAX TOGETHER
WITH THEIR STALKS AND SHIVES AND RENDERING THE LATTER FIT FOR PAPER
MAKING." A communication from abroad by Auguste Demeurs of Huyssinghen in
the Kingdom of Belgium.
The object of this invention is to bleach hemp and flax and the common
substances such as the stalks and shives thereof which have hitherto resisted
bleaching by simple chlorine, and thus rendering these matters useful in the
manufacture of the finest white paper.
Tho modus operandi is as follows-After the matters mentioned have been
previously submitted to a lixivation more or less powerful according to the quality
of the substances and that they have been suitably bleached in gaseous chlorine,
they are placed in the chloric vat where the paste or stuff receives a first wash in
the usual manner.
When this primary operation has been conveniently effected, that is to say when
the paste or stuff has completely.lost the yellow color (the effect of the gas
bleaching), and that the washing water at first acid has become clear, and so to
speak neutral, the introduction of water is arrested whilst allowing the wash
cylinder to operate until the half stuff in the vat has attained the desired degree
of concentration. This is the time for attacking the stalks and shives, the color of
which by reason of the washing has become nearly black; caustic lye therefore is

page_text: now introduced in the vat, composed of equal parts of carbonate and chloride of
lime. The strength of this bath is regulated according to the nature of the matters
treated, and is generally prolonged for two or three hours; at the end of which
time it is impossible to discover the slightest traces of stalk or other matter in the
stuff.
After a fresh washing, destroying the brown color acquired by the lye, the
bleaching of the stuff is proceeded with by means of a solution of chloride of lime
the quantity of which is reduced in proportion to the amount of bleaching already
effected on the filaments, by the action of the alkali, and sufficient to preclude the
possibility of the presence of those stalks and shives that had resisted the bleaching
action.
This process is in the first place much more economical than the ordinary
methods employed, and moreover has the great advantage of bleaching the stalks
and shives so thoroughly that the stuff may be kept in store with impunity by the
manufacturer.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Arthur Charles Henderson in the Great Seal Patent Office on the
20th September 1882.
ARTHUR CHARLES HENDERSON of 6 Southampton Buildings, Holboro, in the
county of Middlesex. IMPROVEMENTS IN BLEACHING HEMP AND FLAX TOGETHER
WITH THEIR STALKS AND SHIVES AND RENDERING THE LATTER FIT FOR PAPER
MAKING A communication from abroad by Auguste Demeurs of Huyasinghen in
the Kingdom of Belgium.
The object of this invention is to bleach hemp and flax and the common
substances such as their stalks and shives, which have hitherto resisted bleaching
by simple chlorine, and thus rendering these matters useful in the manufacture of
the finest white paper.
The modus operandi is as follows:-After the matters mentioned have boen
previously submitted to a lixivation more or less powerful according to the quality
of the substances and that they have been suitably bleached in gaseous chlorine,
they are placed in the chloric vat where the paste or half stuff receives a first
wash in the usual manner. When this primary operation has been conveniently
effected, that is to say when the paste or stuff has completely lost the yellow color
the effect of the gas bleaching and that the washing water at first acid has become
clear, and so to speak neutral, the introduction of water is arrested whilst allowing
the wash cylinder to operate until the half stuff in the vat has attained the desired
degree of concentration. This is the time for attacking the stalks and shives the
color of which by reason of the washing has become nearly black, caustic lyo
therefore is now introduced in the vat composed of equal parts of carbonate and
chloride of lime. Or carbonate of soda rendered caustic may be used.
The strength of this bath is regulated according to the nature of the matters
treated and is generally prolonged for two or three hours at the end of which time
it is impossible to discover the slightest traces of stalk or other matter in the stuff,
After a fresh washing destroying the brown color acquired by the lye the bleaching
of the stuff is proceeded with by means of a solution of chloride of lime the
quantity of which is reduced in proportion to the amount of bleaching already
effected in the filaments by the action of the alkali, and sufficient to preclude the
possibility of the presence of those stalks and shives that had resisted the bleaching
action.
This process is in the first place much more economical than the ordinary
methods employed and moreover has the great advantage of bleaching the stalks
and shives so thoroughly that the stuff may be kept in store with impunity by the
manufacturer.
The improvements introduced in the application of this novel process consist in
suppressing the bleaching by gaseous chlorine which follows the reduction of the
rags to half stuff, by substituting for it a solution of chloride of lime. By this
means there is a great reduction in the expense of the operation, in the time
occupied and in labour without taking into account the difficulties and many
inconveniences overcome by the suppression of the gas bleaching which is now
alandoned for these reasons by most manufacturers. The improved process
being more advantageous and requiring no fresh works erecting wherein to
conduct it.
In witness whereof I the said Arthur Charles Henderson have hereunto set
my hand and seal this third day of August in the Year of Our Lord
One thousand eight hundred and sighty two