Processes for Dyeing Textile Materials of all kinds in the Hypo- sulphite Vat.
Year: 1890

page_text: Date of Application, 29th Oct., 1890
Complete Specification Left, 20th July, 1891-Accepted, 22nd Aug., 1891
PROVISIONAL SPECIFICATION.
Communicated from abroad by MARC MAURICE ROTTEN, of Schiffbauerdamm 29*,
Berlin, Germany, Engineer.]
Processes for Dyeing Textile Materials of all kinds in the Hypo-
sulphite Vat.
1, CHARLES DENTON ABEL of 28 Southampton Buildings, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention to be as
follows:-
-:
This invention relates to a process for dyeing textile materials of all kinds in the
hyposulphite vat, and it consists primarily in exposing the textile materials (yarns
&c.), after leaving the bath, to the action of a liquid containing oxygen, such as
water, to which ammonia may be added, instead of exposing them to the air as
heretofore, for the purpose of producing a more uniform tint.
Secondly the invention relates to a special process for the preparation of such
a dye-vat which shall contain no more alkali than is requisite for dissolving the
indigo-white.
It is a fact that in the hyposulphite vat, as heretofore employed, there was
always an excess of alkali, which was increased with every fresh addition of the dye
solution to the exhausted vat, and which prevented the attainment of dark colors,
and, in addition, acted injuriously upon the wool fibre.
By means of the above described process these disadvantages are obviated.
It is well known that on exposing the yarn &c. coming from the dye vat to the
air, the oxygen of the latter does not act uniformly upon the yarn, but in the first
instance only oxidizes the indigo white on the surface, while the indigo contained
in the interior of the separate threads or situated on the surfaces that are in close
contact, is either not oxidized at all or only partially. The yarn consequently
receives in this way alternate lighter and darker parts, in particular with the
more delicate shades, so that such yarns become useless for the intended
purpose.
This
In order to obviate this disadvantage it is requisite to effect the oxidisation of the
indigo white adhering to the yarn or other textile material coming from the dye
vat in such a manner, that the oxygen will penetrate uniformly to all the fibres,
and thus effect a simultaneous and uniform oxidation of all such fibres.
is effected according to the present invention by conveying the yarn &c. coming
from the dye vat, under the most perfect possible exclusion of the atmosphere,
directly into a vat filled with an oxidising liquid. The liquid containing oxygen,
for example water, then penetrates into the yarn &c. so that the latter swells, the
innermost fibres thereof being acted upon by the oxygen of the water to the same
degree as the outer fibres.
The oxidation of the indigo white is completed in from 10 to 15 minutes,
and the yarn is at the end of this time introduced, for rinsing purposes, into a
second, and, if necessary, into a third vat, through which fresh water is made to
circulate.
If delicate tints have to be produced, it is advisable to add ammonia thereto,
which keeps the indigo white in solution, and in a favorable condition for uniform
oxidation, thereby enabling uniform light blue tints to be obtained, which are
otherwise obtained with great difficulty.
In the same way the water employed. for oxidising purposes may have other
liquid or solid soluble ingredients, mixed with it which increase or decrease the
solvent action of the water with regard to oxygen, so that by this means, by

page_text: suitably preparing the solvent liquid, it is possible to obtain liquids having an
accurately determined percentage of oxygen, and which will consequently act more
or less rapidly upon the yarn, according to such greater or less percentage.
This invention relates in the second place to the production of a hyposulphite
bath of a very weak alkaline nature, which shall contain only such a small
quantity of alkali as will suffice for the solution of the indigo white.
Practical experiments have shewn that the bath prepared in the usual manner by
the reaction of zinc upon sodium bisulphite and addition of the necessary alkali and
indigo, becomes strongly alkaline already after it has been used for only a short
time, because at every addition of concentrated solution of reduced indigo, fresh
quantities of alkali are added to the dye vat.
In consequence hereof the indigo is only deposited to a small extent upon the
fibres, and after oxidation it washes off to a considerable extent, whereby the
production of dark blue is impossible.
The yarn is in addition deteriorated by the action of the alkali, and the
uniformity of the tint produced also suffers therefrom. In order to prevent this,
according to the present invention there is added to the hyposulphite vat at
intervals a certain quantity of the original acid solution produced by the action of
sodium bisulphite upon zinc.
The vat loses by this means its strongly alkaline properties and becomes
suitable for the production of uniform colors, both of the lightest and the
darkest shades.
For practically carrying out this invention the proceeding is as follows:-
.
The sodium bisulphite dissolved in water is in the first instance made to act upon
zinc, and a portion of the so-called acid solution resulting from this reducing
process is poured off, and, after adding a certain quantity of caustic soda and
indigo blue, it is introduced into the dye vat, while the other part of the acid
solution is stored for subsequent use. The yarn is then hung upon wooden bars
which are laid upon an iron frame extending across the vat, and which are held
down upon the same by suitable means, such as by iron bars laid across the
wooden bars. The frame carrying the yarn is then lowered uniformly by suit-
able means until the yarn is completely immersed in the vat, whereupon by a
lateral to and fro motion of the bars a uniform saturation of the yarn will be
effected.
When the latter has taken up a sufficient quantity of the dye, the bars with the
yarn are withdrawn as rapidly as possible, and are at once plunged into oxygenated
water, which may have ammonia added to it, and which in order to increase
the percentage of oxygen may also be mixed with a suitable body that will
not injure either the dye or the yarn, such as alcohol, ethyl-ether &c. The
separate threads then swell and the water penetrating uniformly to the interior
thereof converts by means of its oxygen, the indigo white into indigo blue. This
process being completed, the yarn may be advantageously passed through a second
and even a third vat through which water is made to flow so as to wash off all salts
still adhering to the yarn.
In consequence of the perfectly uniform oxidation of the indigo white by means
of the oxygenated liquid, very large quantities of yarn &c. can be introduced at
the same time into the vat in order to be simultaneously acted upon, which is
not possible with the ordinary process of blue coloration by contact with the
atmosphere.
If large quantities of yarn or other textile material have been consecutively
treated in one and the same vat, the vat will have become alkaline to such a degree
that in the further use thereof the material would suffer, and no uniform, useful
dyeing could be any longer carried out. There is consequently added to the
vat as much of the acid solution (consisting mainly of sodium hyposulphite)
which was retained on preparing the vat, as will cause the strongly alkaline
reaction of the vat to disappear and will therefore render the latter again suitable
for the production of uniform tints.

page_text: The above described process is applicable to all textile materials in any form
with appropriate manipulation.
1000
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Processes for Dyeing Textile Materials of all kinds in the Hypo-
sulphite Vat.
1, CHARLES DENTON ABEL, of 28, Southampton Buildings, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:—
This invention relates to a process for dyeing textile materials of all kinds in the
hyposulphite vat, and it consists primarily in exposing the textile materials (yarns
&c.), after leaving the bath to the action of a liquid containing oxygen, such as
water, to which ammonia may be added, instead of exposing them to the air as
heretofore, for the purpose of producing a more uniform tint.
Secondly the invention relates to a special process for the preparation of such a
dye-vat which shall contain no more alkali than is requisite for dissolving the
indigo white.
It is a fact that in the hyposulphite vat as heretofore employed, there was
always an excess of alkali, which was increased with every fresh addition of the dye
solution to the exhausted vat, and which prevented the attainment of dark colors,
and, in addition, acted injuriously upon the wool fibre.
By means of the above described process these disadvantages are obviated.
It is well known that, on exposing the yarn &c. coming from the dye vat to the
air, the oxygen of the latter does not act uniformly upon the yarn, but in the first
instance only oxidizes the indigo white on the surface, while the indigo contained in
the interior of the separate threads or situated on the surfaces that are in close
contact, either not oxidised at all or only partially. The yarn consequently
receives in this way alternate lighter and darker parts in particular with the
more delicate shades, so that such yarns become useless for the intended
purpose.
In order to obviate this disadvantage it is requisite to effect the oxidisation of
the indigo white adhering to the yarn or other textile material coming from the
dye vat in such a manner that the oxygen will penetrate uniformly to all the fibres
and thus effect a simultaneous and uniform oxidation of all such fibres. This is
effected, according to the present invention, by conveying the yarn &c. coming
from the dye vat, under the most perfect possible exclusion of the atmosphere,
directly into a vat filled with an oxidising liquid. The liquid containing oxygen,
for example water, then penetrates into the yarn &c., so that the innermost fibres
thereof are swelled and acted upon by the oxygen of the water to the same degree
as the outer fibres.
The oxidation of the indigo white is completed in from 10 to 15 minutes and the
yarn is at the end of this time introduced for rinsing purposes, into a second, and if
necessary into a third vat through which fresh water is made to circulate.
If delicate tints have to be produced it is advisable to add ammonia to the bath,
which keeps the indigo white in solution and in a favorable condition for uniform
oxidation thereby enabling uniform light blues to be obtained which are otherwise
obtained with great difficulty.
In the same way the water employed for oxidising purposes may have other
liquid or solid soluble ingredients mixed with it which increase or decrease the
solvent action of the water with regard to oxygen, so that by this means by
suitably preparing the solvent liquid it is possible to obtain liquids having an

page_text: accurately determined percentage of oxygen, and which will consequently act mor
or less rapidly upon the yarn, according to such greater or less percentage.
This invention relates in the second place to the production of a hyposulphit
bath of a very weak alkaline nature which shall contain only such a small quantity
of alkali as will suffice for the solution of the indigo white.
Practical experiments have shewn that the bath prepared in the usual manner by
the reaction of zinc upon sodium bisulphite and addition of the necessary alkali and
indigo becomes strongly alkaline after it has been used for only a short time, because
at every addition of concentrated solution of reduced indigo, fresh quantities o
alkali are added to the dye vat.
In consequence hereof the indigo is only deposited to a small extent upon the
fibres, and after oxidation it washes off to a considerable extent, whereby the
production of dark blue is impossible.
The yarn is in addition deteriorated by the action of the alkali and the uniformity
of the tint produced also suffers therefrom. In order to prevent this, according to
the present invention, there is added to the hyposulphite vat at intervals a certain
quantity of the original acid solution produced by the action of sodium bisulphite
upon zinc.
The vat loses by this means its strongly alkaline properties and becomes
suitable for the production of uniform colors, both of the lightest and the darkest
shades.
For practically carrying out this invention the proceeding is as follows:
The sodium bisulphite dissolved in water is in the first instance made to act upon
zinc and a portion of the so called acid solution resulting from this reducing process
is poured off, and, after adding a certain quantity of caustic soda and indigo blue, it
is introduced into the dye vat, while the other part of the acid solution is stored for
subsequent use. The yarn is then hung upon wooden bars which are laid upon an
iron frame extending across the vat, and which are held down upon the same by
suitable means, such as by iron bars laid across the wooden bars. The frame
carrying the yarn is thien lowered uniformly by suitable means inntil the yarn is
completely immersed in the vat, whereupon by a lateral to and fro motion of the
bars a uniform saturation of the yarn will be effected.
When the latter has taken up a sufficient quantity of the dye, the bars with the
yarn are withdrawn as rapidly as possible, and are at once plunged into oxygenated
water, which may have ammonia added to it, and which, in order to increase the
percentage of oxygen, may also be mixed with a suitable body that will not injure
either the dye or the yarn, such as alcohol, ethyl ether &c. The separate threads
then swell and the water penetrating uniformly to the interior thereof converts by
means of its oxgen, the indigo white into indigo blue. This process being completed,
the yarn may be advantageously passed through a second and even a third vat
through which water is made to flow so as to wash off all salts still adhering to
the yarn.
In consequence of the perfectly uniform oxidation of the indigo white by means
of the oxygenated liquid, very large quantities of yarn &e. can be introduced at the
same time into the vat in order to be simultaneously acted upon, which is not
possible with the ordinary process of blue coloration by contact with the
atmosphere.
If large quantities of yarn or other textile material have been consecutively
treated in one and the same vat, the vat will have become alkaline to such a degree
that in the further use thereof the material would suffer, and no uniform, useful
dyeing could be any longer carried out. There is consequently added to the vat
as much of the acid solution (consisting mainly of sodium hyposulphite) which was
retained on preparing the vat; as will cause the strongly, alkaline reaction of the
vat to disappear, and will therefore render the latter again suitable for the
production of uniform tints.
The above described process is applicable to all textile materials in any. form
with appropriate manipulation.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in. what manner the same is to be performed, I declare that what I
claim is:-
1. A process for effecting the blue coloration of textile materials taken from the
hyposulphite vat, consisting in passing such materials directly from the said vat,
under exclusion, as much as possible, of the atmosphere, into a liquid containing
oxygen, where it is left until complete blue coloration is attained, in order, by the
uniformly commencing and uniformly proceeding oxidation at all parts of the
materials, even when large quantities are simultaneously under treatment, to obtain
a perfectly uniform coloration.
2. In the process referred to in the preceding claim, the addition of ammonia to
the oxydising liquid employed for the blue coloration, for the purpose of maintaining
the indigo white, in a uniform solution suitable for oxidation, for the production of
light tints.
3. The preparation of the slightly alkaline dye vat serving for the process
referred to in the preceding claim, by adding thereto at intervals of time during
use a quantity of acid solution produced by the reaction of zinc upon sodium
bisulphite, for the purpose of obtaining uniform tints, and of obviating any
deterioration of the yarn by the presence of alkali in excess.
Dated this 15th day of July 1891.
ABEL & IMRAY,
Agents for the Applicant.