IMPROVEMENTS IN PRINTING FABRICS. OR IN PRODUCING PATTERNS THEREON."
Year: 1867

page_text: LETTERS PATENT to William Whitehead, of Dartford Print Works,
Dartford, in the County of Kent, for the Invention of "IMPROVEMENTS
IN PRINTING FABRICS. OR IN PRODUCING PATTERNS THEREON."
PROVISIONAL SPECIFICATION left by the said William Whitehead at the
Office of the Commissioners of Patents, with his Petition, on the 13th
September 1867.
I, WILLIAM WHITEHEAD, of Dartford Print Works, Dartford, in the County
of Kent, do hereby declare the nature of the said Invention for "IMPROVE-
.MENTS IN PRINTING FABRICS, OR IN PRODUCING PATTERNS THEREON," to be as
follows:-
This Invention has for its object improvements in printing fabrics or in
producing patterns thereon. I prepare the fabric, which I prefer should be of
silk or wool, by dyeing it with an aniline color, it may be magenta, or purple,
or other dye, such as is prepared from aniline, and I then print upon the
dyed the pattern desired, using for this purpose an alkali (I prefer
potash) thickened with gum and sulphate of lead, or it may be other powder,
which will prevent the pattern spreading; I then place the piece in a steam
box together with red prussiate of potash and oxalic or other acid, and .the
steam being turned on a gas is generated which acting with the material
which has been printed on to the fabric discharges the aniline dye in the parts

page_text: on to which the alkali has been printed, and so a white figure is obtained.
If it be desired that the figure should be colored a suitable dye may be mixed
with the preparation with which the fabric is printed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Whitehead in the Great Seal Patent Office on the
13th March 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
WHITEHEAD, of Dartford Print Works, Dartford, in the County of Kent,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of September, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Whitehead, Her special licence that I, the said. William
Whitehead, my executors, administrators, and assigns, or such others as I,
the said William Whitehead, 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 "IMPROVE-
MENTS IN PRINTING FABRICS, OR IN PRODUCING PATTERNS THEREON," upon the
condition (amongst others) that I, the said William Whitehead, 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 William Whitehead, 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:-
This Invention has for its object improvements in printing fabrics or in
producing patterns thereon.. I prepare the fabric, which I prefer should be of
silk or:wool, by dyeing it with an aniline color, it may be magenta, or purple,
or other dye, such as is prepared from aniline, and I then print upon the

page_text: fabric so dyed the pattern desired, using for this purpose an alkali (I prefer
potash) thickened with gum and sulphate of lead, or it may be other powder,
which will prevent the pattern spreading; I then place the piece in a steam
box together with red prussiate of potash and oxalic or other acid, and the
steam being turned on a gas is generated, which acting with the material
which has been printed on to the fabric discharges the aniline dye in the parts
on to which the alkali has been printed, and so a white figure is obtained.
If it be desired that the figure should be colored a suitable dye may be mixed
with the preparation with which the fabric is printed.
And in order that my said Invention may be most fully understood and
readily carried into effect I will proceed to describe the manner in which I
prefer to conduct the process.
The fabric, whether it be of silk or of wool, is dyed in the ordinary way with
aniline dye; it may be purple, or red, or other color according to the effect
required. I prefer however that it should not be with aniline yellow, both because
the effect produced with a yellow ground dye is indifferent and because the
yellow aniline dye is less readily acted upon. On to the fabric thus dyed I.
print the pattern usually with hand printing blocks worked in the ordinary
manner. In this printing I use an alkaline discharge composition, which I prefer
to prepare as follows:-Of a solution of American potash of a specific gravity
of 62 degrees Twaddle (made, say, with 4 lbs. of potash to the gallon of water)
I take one pint, and with it I mix four parts of gum senegal liquor, prepared
by dissolving the gum in water, in the proportion of four pounds of the gum
to the gallon of water; half a pound of flake white or sulphate of lead I also
add, and thoroughly rub the whole together. This is the discharge which I
employ when I desire that the figure, which is printed on to the fabric, should
appear white in the finished goods; ordinarily however I. prefer to obtain a
yellow figure, and for this purpose I add to the discharge prepared in the
manner above set forth half a pint of aniline yellow, consisting of one ounce
of dry color dissolved in spirit. Other colors may if desired be given to the
figure by substituting for the aniline yellow other dyes (not aniline dyes)
which are fast under the action of alkali and steam heat. The fabric
having been printed with the discharge and dried is hung up in a steam
closet in the same way as fabrics are now commonly steamed, and in such
manner that the steam can penetrate freely to every part of the fabric.
I prefer to admit the steam at the bottom of the closet, and underneath a
screen or horizontal partition of a coarsely and loosely woven fabric which
forms as it were a false bottom to the closet. On to this cloth I sprinkle a
powder consisting of a mixture of six ounces of red prussiate of potash and

page_text: four ounces of oxalic acid; this quantity is sufficient for sixteen pieces of
medium substance, and each seven yards long and one yard wide; the size
of the closet being as I assume adapted to take this quantity of fabric, but if
the closet should hold more or less fabric than the above-mentioned quantity,
the quantity of the powder will be varied in proportion. The steam is now
turned on and the closet filled with it, the air escaping at a small vent at the
top of the closet. The powder under the influence of the steam liberates
hydrocyanic acid vapour, which with the alkali acts to discharge the dye at
the places where the discharge has been printed.
In place of using the mixture of red prussiate of potash and acid hydro-
cyanic acid itself may, but less conveniently, be supplied to the closet during
the steaming operation, or in other ways the presence of the hydrocyanic acid
vapour may be ensured. After ten minutes steaming the pieces are taken
out and well washed in cold water, they are then dried and finished. The
escape from the steam closet should be directed into the external air so that
any vapour escaping from it may not act injuriously on the workpeople.
The color of yellow aniline dye can be discharged in a similar manner, but
it requires considerably stronger alkali and a more prolonged steaming with
hydrocyanic acid vapour; in practice the discharge of the yellow dye will
hardly ever be required.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that what I claim is,-
The improvements in printing fabrics or in producing patterns thereon, sub-
stantially as herein described.
I also claim the printing or producing a pattern, on a fabric dyed with
aniline dye by the combined action of an alkaline discharge and of hydro-
cyanic acid vapour.
In witness whereof, I, the said William Whitehead, have hereunto set my
hand and seal, this Eleventh day of March, in the year of our Lord
One thousand eight hundred and sixty-eight.
WILLIAM WHITEHEAD. (L.S.)