AN IMPROVED METHOD OF BLEACHING
Year: 1861

page_text: LETTERS PATENT to Thomas Gray, of No. 19, Hill's Cottages, Union Road,
Wandsworth, in the County of Surrey, Manufacturer of Materials for
Making Paper, for the Invention of "AN IMPROVED METHOD OF BLEACHING
Sealed the 13th December 1861, and dated the 17th June 1861.
PROVISIONAL SPECIFICATION left by the said Thomas Gray at the
Office of the Commissioners of Patents, with his Petition, on the
17th June 1861.
I, THOMAS GRAY, of No. 19, Hill's Cottages, Union Road, Wandsworth,
in the County of Surrey, Manufacturer of Materials for Making Paper, do
hereby declare the nature of the said Invention for "AN IMPROVED METHOD
OF BLEACHING COLORED RAGS AND VEGETABLE FIBRES," to be as follows, that is
to say :-
For bleaching rags I take any quantity of linen or cotton rags of any color,
including those colors known as fast colors, videlicet, Turkey reds, indigo blues,
lilachs, and other colors which have hitherto been considered as incapable of
being perfectly discharged, and I first cleanse and boil the rags, and then I pre-
pare a weak mixture or solution composed of muriatic acid and water either in
a cold or lukewarm state, in which mixture or solution I steep or immerse the.
said rags for a short period, the effect of which process is to move or loosen.
the colors in the rags, and I then drain them so that a portion of the above
solution may be retained in them. The rags are then to be submitted to

page_text: the ordinary process of bleaching in chlorine liquor. By this double process
the colors in the rags are completely discharged and the rags become perfectly
white and the fibres remain uninjured. The rags are then as fit for the
purpose of making white paper as ordinary undyed linen or cotton rags now
are. The above double process is also applicable for bleaching straw, grass,
and other vegetable fibres.
I claim as my Invention the immersion of colored rags and vegetable fibres
in a solution of muriatic acid and water as above described, and retaining
therein a portion of such solution before steeping the same in bleaching liquor,
and thereby preserving the fibres uninjured.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Gray in the Great Seal Patent Office on the
17th December 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
GRAY, of No. 19, Hill's Cottages, Union Road, Wandsworth, in the County
of Surrey, Manufacturer of Materials for Making Paper, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of June, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas Gray, Her special licence that I, the said Thomas Gray,
my executors, administrators, and assigns, or such others as I, the said
Thomas Gray, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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 "AN IMPROVED
METHOD OF BLEACHING COLORED RAGS AND VEGETABLE FIBRES," upon the condition
(amongst others) that I, the said Thomas Gray, my executors or adminis-
trators, 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 Thomas Gray, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-

page_text: formed, to be particularly described and ascertained in and by the tonowing
statement, that is to say:-
For bleaching rags, whether linen or cotton of all colours, including those
colours denominated fast, colours, I take any required quantity of such colored
rags and thoroughly cleanse and boil them according to the usual method of
cleansing rags for paper-making. I then immerse them in a vat or other
vessel containing a solution of muriatic acid and water in either a cold or
lukewarm state (but I prefer the latter), which solution is to consist of about
the following proportions, namely, one part by measure of muriatic acid
to thirty-two parts of water. The rags are to remain immersed in this
solution for a period of about two hours, so that they may become saturated
with the solution, which in a large bulk will occupy about this time for the
acid to loosen the colors. The rags are then to be taken out and drained
but not dried, and for this purpose I recommend a slanting board to be fixed
to one side of the vat, so that the solution that drains from the rags may
return to the vat, by which means by far the greatest portion of the liquor will
be recovered and it will be fit for use again. The object and effect of steeping
the rags in the above solution is to loosen the colors in them previously to
steeping them in chlorine bleaching liquor. After the rags have undergone
the processes above described they are to be placed in a sufficient quantity
of ordinary chlorine bleaching liquor, the proportions of which are well known,
and after the rags have remained immersed therein for the space of about
fifteen minutes, it will be found that the colors have been completely dis-
charged, and that the rags are then fit for pulping and undergoing the ordinary
remaining processes of paper-making, and that the fibres of the linen or
cotton will remain uninjured and will be as strong as they were before
undergoing the process of bleaching.
It will also, be found that by adopting my Invention white paper can be
male entirely from colored rags, and of as good quality as paper could be made
from white rags of a like quality, and further that a great saving of time
and expence is attained over the ordinary processes of bleaching now in use,
which are also great advantages.
My Invention is also applicable to bleaching all kinds of vegetable fibres,
either dried or in a green state and thereby obtaining from them a white fibrous
substance fit for making paper with a less amount of loss in weight than is
attained by the ordinary processes now in use; I recommend for this purpose
clover, grass, flax, hemp, straw, and all other fibrous vegetable substances of a
like nature.
I claim as my Invention the steeping and immersion of the substances

page_text: to be bleached in a solution of muriatic acid and water in the manner
herein-before described previously to their being submitted to the action of
bleaching liquor.
In witness whereof, I, the said Thomas Gray, have hereunto set my
hand and seal, the Seventeenth day of December, One thousand eight
hundred and sixty-one.
THOMAS GRAY. (L.S.)