IMPROVEMENTS IN PRINTING AND DYEING TEXTILE FABRICS AND YARNS
Year: 1879

page_text: LETTERS PATENT to James Harvey Rae, of Glasgow, in the County of Lanark,
North Britain, for the Invention of "IMPROVEMENTS IN PRINTING AND DYEING
TEXTILE FABRICS AND YARNS." A communication from abroad by Alexander
Schultz, of Paris, in the Republic of France, Chemist.
PROVISIONAL SPECIFICATION left by the said James Harvey Rao at the
Office of the Commissioners of Patents on the 16th December 1879.
JAMES HARVEY RAE, of Glasgow, in the County of Lanark, North Britain.
"IMPROVEMENTS IN PRINTING AND DYEING TEXTILE FABRICS AND YARNS." [A
communication from abroad by Alexander Schultz, of Paris, in the Republic of
France, Chemist.]
Since the discovery of aniline black chemists have made numerous researches to
produce it "ungreenable." Many means have been proposed. That which appeared
to fulfil best the conditions of unchangeability consists in printing a salt of aniline
on the cloth or fabric padded beforehand with a solution of bichromate of potash
and dried, but this process has been abandoned on account of the inconvenience it
presented.
The aniline blacks generally used in print-works are obtained by hanging up
the printed pieces in ageing rooms. The oxidation takes place also in a quicker
manner by passing the printed cloth through a machine known as the "ageing
machine," but the blacks thus obtained are "greenable" by exposure to the air or
by sulphurous acid. The blacks however have been rendered much less sensitive to
the "greening" action by passing them through boiling solutions of salt of iron,
acids, or other oxidising agents, but this process presents many inconveniences.
To avoid these inconveniences under the present Invention there is printed on
the cloth a colour composed of a salt of aniline, such as the chlorhydrate, the nitrate,
the sulphate, or other salt of aniline in the necessary proportions. The pieces of
cloth are padded with an engraved roller, either in spots or stripes, or of any other
pattern suitable for covering. The padding is effected with an engraved roller
with a thickened solution of bichromate of potash or other suitable oxidising agent,
TD-1

page_text: and by this means an "ungreenable" black is obtained cleanly printed, whilst the
white of the picces of cloth is not altered, as is the case by printing on the padded
cloth with bichromate of potash or other oxidising agents.
By this Invention the aniline salt covered over by the bichromate of potash forms
instantly "ungreenable" black by the drying of the pieces on the steam chests or
drums of the printing machines, which allows of the suppression of the oxidation
obtained hitherto by hot ageing, by steaming, by the ageing machine, or by
printing on cloth padded with bichromate of potash.
Immediately after padding the pieces with the engraved roller they are passed
through a hot solution of carbonate of soda, and after having washed them they
are soaped, as is usually practised for aniline blacks.
The substances and proportions used in carrying out the Invention are those
generally used, but they may be varied, as may also the thickenings
The process of printing cloth herein described may also be used for printing and
dyeing yarns, as well as for printing and dyeing with colours derived from
naphty lamine, such as puce, lilac, and others.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Harvey Rae in the Great Seal Patent Office on the 11th June
1880.
A
JAMES HARVEY RAE, of Glasgow, in the County of Lanark, North Britain.
"IMPROVEMENTS IN PRINTING AND DYEING TEXTILE FABRICS AND YARNS."
communication from abroad by Alexander Schultz, of Paris, in the Republic of
France, Chemist.
Since the discovery of aniline black chemists have made numerous researches
with a view to enable them to produce it "ungreenable," and many means have
been proposed for attaining the desired end. Of these means that which appeared
to fulfil best the conditions of unchangeability consisted in printing a salt of aniline
on the cloth or fabric padded beforehand with a solution of bichromate of potash
and dried, but this process has been abandoned on account of the inconvenience it
presented.
The aniline blacks generally used in print works are obtained by hanging up
the printed fabrics in ageing rooms after they have been printed. The oxidation
takes place in a quicker manner by passing the printed cloth through a machine
known as the "ageing machine," but the blacks thus obtained are "greenable" by
exposure to the air or by sulphurous acid. The blacks have however been rendered
much less sensitive to the "greening" action by passing them through boiling
solutions of salts of iron or other oxidizing agents, but this process also presents
many inconveniences.
To avoid these inconveniences there is, under the present Invention, printed on
the cloth, or the cloth otherwise covered with a colour composed of a salt of aniline,
such as the chlorhydrate, the nitrate, the sulphate, or other salt of aniline in the
necessary proportions, that is to say, one gallon of water is thickened with white
starch and boiled, and after it has become cold two lbs. salt of aniline are dissolved
in it. After being printed or otherwise covered with this colour the pieces of cloth
are dried. The pieces of cloth are afterwards padded with a roller or by blocks
engraved with a pattern, which will print upon the said cloth either in spots or
in stripes, or in any other pattern which may be desired, the padding being effected
with a thickened solution of bichromate of potash or other suitable oxidizing
agent, and by this means an "ungreenable" black is obtained clearly printed,
whilst the white of the pieces of cloth is not altered, as is the case by printing on
the cloth padded with bichromate of potash or other oxidizing agents.
The cloth thus prepared is passed over the steam chests or drums in the usual
way, and the aniline salt covered over by the bichromate of potash, according to
this Invention, as hereinbefore described, is instantly converted to "ungreenable"
black in the pattern desired by the drying of the cloth on the said chests or drums,
which allows oxidation, obtained hitherto by both ageing, by steaming, or the
ageing machine, or by printing on cloth padded by bichromate of potash, to be
dispensed with.
The pieces are passed then through a hot solution of carbonate of soda, and after
having washed them they are soaped, as is usually practised for aniline blacks.
The substances and proportions and thickenings used in carrying out the Inven-
tion are or may be those generally used, but they may be varied.
In producing an "ungreenable" black upon yarns the said yarns are treated in
the same manner as described with regard to cloth.
Having now described and particularly ascertained the nature of the said
Invention, and the system, mode, or manner in or under which the same is or may
be used or practically carried into effect, I would observe in conclusion that what

page_text: I consider to be novel and original, and therefore claim as the Invention secured to
me by the hereinbefore in part recited Letters Patent is,-
"
The hereinbefore described improvements in printing and dyeing textile fabrics
and yarns for the purpose of producing an ungreenable" black, that is to say,
first printing or otherwise covering the cloth or yarns with a colouring medium
composed of a salt of aniline, and afterwards padding the said cloth or yarns by
printing thereupon in the parts which are to be dyed with a thickened solution of
bichromate of potash or other suitable oxidizing agent, the cloth or yarns being
afterwards treated and finished in the ordinary or other suitable way.
In witness whereof, I, the said James Harvey Rae, have hereunto set my
hand and seal, this Fourth day of June, in the year of our Lord One thousand
eight hundred and eighty.
J. HARVEY KAE. (L.S.)