IMPROVEMENTS IN DYEING LOOSE COTTON BLACK
Year: 1883

page_text: LETTERS PATENT to Gerard Wenzeslaus von Nawrocki Proprietor of the
firm of J Brandt & G. W v Nawrocki, Patent Solicitor and Civil Engineer of
124 Leipzigerstrasse Berlin Germany for an Invention of "IMPROVEMENTS IN
DYEING LOOSE COTTON BLACK A communication from Gustav Jagenburg
of Rydboholm in the Kingdom of Sweden
دو
PROVISIONAL SPECIFICATION left by the said Gerard Wenzeslaus von
Nawrocki at the Office of the Commissioners of Patents on the 7th March
1883.
"
GERARD WENZESLAUS VON NAWROCKI, Proprietor of the firm of J. Brandt &
G. Wv Nawrocki, Patent Solicitor and Civil Engineer of 124 Leipzigerstrasse
Berlin Germany. " IMPROVEMENTS IN DYEING LOOSE COTTON BLACK (A
Communication from Gustav Jagenburg of Rydboholm in the Kingdom of
Sweden)
In dyeing on a large scale loose cotton black according to the process patented
by me the 12th July 1882 N° 3308 with the aid of a vacuum it has been found
that in consequence of the steaming the cotton to some extent loses its elasticity,
this being probably caused by the incrustation in the cells of the cotton fibre of
the resinous matter contained in the dye, so that for the purpose of enabling the
cotton to be spun it has, when dyed to be saturated with fatty oil. This is no
disadvantage in the manufacture of Vicuna or of Shoddy as in these, oil must in
any case be used because of the stiff wool, but it causes almost insuperable
difficulties where the dyed cotton is to be worked up in ordinary cotton spinneries.
By further experiments it has now become apparent that under certain
conditions, steaming can be altogether dispensed with, by carrying out the black-
dyeing process in the following manner.
A solution is prepared from log-wood, log-wood extract, or of Haematine of,
from 2 to 3 degrees Beaumé, the quantity of "shading" matter is added (a solution
Quercitron fustic "French or Avignon" berries, catechu or aniline dies) and
per litre of this dye-bath 2 to 3 grammes of carbonate of potassa.
"

page_text: The cotton to be dyed is impregnated with this solution, it, is then freed from
the excess of moisture either by pressure or by a centrifugal machine and thoroughly
dried in a ventilated drying chamber (a temperature of from 40 to 60 degrees
Celsius being advisable) and the black colour is then developed immediately after
the drying by treatment with a cold solution of a metallic salt, for instance
3 grammes of bichromate of potassa and 1 gramme of sulphate of copper per litre
of water in perfect or partial vacuum
After the cotton has remained for some hours in the bath of metallic salt the
black-dyeing is effected and the cotton is then washed and dried in the usual
manner.
Cotton treated in this manner does not lose its elasticity and is easily worked
up in the ordinary cotton spinneries and by means of the ordinary machinery. It
is moreover not necessary, as hitherto done, to form it into slivers before dyeing
but is without any preparation brought from the balling to the dyeing.
The great advantages of this process are obvious to all experts.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Gerard Wenzeslaus von Nawrocki in the Great Seal Patent Office
on the 6th September 1883.
"
GERARD WENZESLAUS VON NAWROCKI Proprietor of the firm of J. Brandt &
G. W. v Nawrocki Patent Solicitor and Civil Engineer of 124 Leipzigerstrasse,
Berlin, Germany. "IMPROVEMENTS IN DYEING LOOSE COTTON BLACK
Communication from Gustav Jagenburg of Rydboholm in the Kingdom of
Sweden.
A
In dyeing on a large scale loose cotton black according to the process patented
by me the 12th July 1882 N° 3308 with the aid of a vacuum, it has been found
that in consequence of the steaming the cotton to some extent loses its elasticity
this being probably caused by the incrustation in the cells of the cotton fibre of
the resinous matter contained in the dye, so that for the purpose of enabling the
cotton to be spun it has when dyed to be saturated with fatty oil This is no
disadvantage in the manufacture of Vicuna Vigogne or of shoddy as in these, oil
must in any case be used because of the stiff wool, but it causes almost insuperable
difficulties where the dyed cotton is to be worked up in ordinary cotton spinneries.
By further experiments it has now become apparent that under certain con-
ditions steaming can be altogether dispensed with by carrying out the black dyeing
process in the following manner.
A solution is prepared from logwood, logwood extract, or of Haematine of, from
2 to 3 degrees Baumé, the quantity of "shading" matter is added (a solution
quercitron fustic, "French or "Avignon" berries, catechu or aniline dyes) and per
litre of this dyebath 2 to 3 grammes of carbonate of potassa (2 to 3 ounces per
3 gallons).
The cotton to be dyed is impregnated with this solution, it is then freed from
the excess of moisture either by pressure or by a centrifugal machine and thoroughly
dried in a ventilated drying chamber (a temperature of from 40 to 60 degrees
Celcius (104 to 140° F) being advisable) and the black colour is then developed
immediately after the drying, by treatment with a cold solution of a metallic salt,
for instance 3 grammes of bichromate of Potassa and 1 gramme of sulphate of
copper per litre of water (3 ounces bichromate and 1 ounce sulphate per 3 gallons
water in a perfect or partial vacuum.
After the cotton has remained for some hours in the bath of metallic salt the
black dyeing is effected and the cotton is then washed and dried in the usual
manner.
Cotton treated in this manner does not lose its elasticity and is easily worked
up in the ordinary cotton spinneries and by means of the ordinary machinery. It
is moreover not necessary, as hitherto done, to form it into slivers before dyeing
but is without any preparation brought from the balling to the dyeing.
The great advantages of this process are obvious to all experts.
The degrees of concentration and the proportions of the ingredients named in
the above described process for dyeing loose cotton black will be varied according
to requirements
In witness whereof I the said Gerard Wenzeslaus von Nawrocki have hereunto
set my hand and seal this First day of September in the year of Our Lord One
thousand eight hundred and eighty three.
GERARD WENZESLAUS VON NAWROCKI
(LS.)