1. Cleaning the cotton by boiling it for four hours in a weak alkaline
bath, cooling and rinsing.
2. Working it thoroughly four times over in a steep, consisting of 300
pounds of water, 15 pounds of potash, 1 pailful of sheep’s dung, and
12-1/2 pounds of olive oil, in which it should remain during the night.
Next day it is drained for an hour, wrung out and dried. This treatment
with the dung steep, and drying, is repeated 3 times.
3. It is now worked in a bath containing 120 quarts of water, 18 pounds
of potash, and 6 quarts of olive oil; then wrung out and dried. This
steep is also repeated 4 times.
4. Steeping for a night in the river is the next process; a slight
rinsing without wringing, and drying in the air.
5. Bath made of a warm decoction (100° F.) of sumach and nut-galls, in
which the goods remain during the night; they are then strongly wrung,
and dried in the air.
6. Aluming with addition of potash and chalk; wringing; working it well
through this bath, where it is left during the night.
7. Draining, and strong rinsing the following day; piling up in a water
cistern.
8. Rinsing repeated next day, and steeping in water to remove any excess
of alum from the fibres; the goods continue in the water till they are
taken to the dyeing-bath.
9. The maddering is made with the addition of blood, sumach, and
nut-galls; the bath is brought to the boil in 1 hour and 3/4, and kept
boiling for half an hour.
10. The yarn is rinsed, dried, boiled from 24 to 36 hours in a covered
copper, with an oily alkaline liquid; then rinsed twice, laid for two
days in clear water, and dried.
11. Finally, the greatest brightness is obtained by boiling for three or
four hours in a soap bath, containing muriate of tin; after which the
yarn is rinsed twice over, steeped in water, and dried.
_Process of Haussmann._--He treats cotton twice or 4 times in a solution
of aluminated potash, mixed with one thirty-eighth part of linseed oil.
The solution is made by adding caustic potash to alum. He dries and
rinses each time, and dries after the last operation. He then rinses and
proceeds to the madder bath. For the rose colour, he takes one pound of
madder for one pound of cotton; for carmine red, he takes from 2 to 3
pounds; and for the deepest red, no less than 4 pounds. It is said that
the colour thus obtained surpasses Turkey red.
_The French process, by Vitalis of Rouen._--First operation. Scouring
with a soda lye, of 1° Baumé, to which there is usually added the
remainder of the _white_ preparation bath, which consists of oil and
soda with water. It is then washed, wrung out, and dried.
In the second operation, he states that from 25 to 30 pounds of sheep’s
dung are commonly used for 100 pounds of cotton yarn. The dung is first
steeped for some days in a lye of soda, of 8° to 10° B. This is
afterwards diluted with about 500 pints of a weaker ley, and at the same
time bruised with the hand in a copper basin whose bottom is pierced
with small holes. The liquor is then poured into a vat containing 5 or 6
pounds of fat oil (Gallipoli), and the whole are well mixed. The cotton
is washed in this, and the hanks of yarn are then stretched on perches
in the open air, and turned from time to time, so as to make it dry
equably. After receiving thus a certain degree of desiccation, it is
carried into the drying house, which is heated to 50° Reaumur (144°
Fahrenheit), where it loses the remainder of its moisture, which would
have prevented it from combining with the other mordants which it is
afterwards to receive. What is left of the bath is called _avances_, and
is added to the following bath. Two, or even three dung baths are given
to the cotton, when it is wished to have very rich colours. When the
cotton has received the dung baths, care must be taken not to leave it
lying in heaps for any length of time, lest it should take fire; an
accident which has occasionally happened.
The white bath is prepared by pouring 6 pounds of fat oil, into 50 pints
of soda water, at 1° or sometimes less, according as, by a preliminary
trial, the oil requires. This bath ought to be repeated two, three, or
even a greater number of times, as more or less body is to be given to
the colour.
To what remains of the white bath, and which is also styled _avances_,
about 100 pints of soda lye of two or three degrees are added. Through
this the cotton is passed as usual. Formerly it was the practice to give
two, or three, or even four oils. Now, two are found to be sufficient.
The cotton is steeped for five or six hours in a tepid solution of soda,
of 1° at most; it is set to drain, is then sprinkled with water, and at
the end of an hour is washed, hank by hank, to purge it entirely from
the oil. What remains of the water of degraissage, serves for the
scouring or first operation.
For 100 pounds of cotton, from 20 to 25 pounds of galls in sorts must be
taken, which are bruised and boiled in about 100 pints of water, till
they crumble easily between the fingers. The galling may be done at two
operations, dividing the above quantity of galls between them, which is
thought to give a richer and more uniform colour.
The aluming of 100 pounds of cotton requires from twenty-five to thirty
pounds of pure alum, that is, alum entirely free from ferruginous salts.
The alum should be dissolved without boiling, in about 100 pints of
river or rain water. When the alum is dissolved, there is to be poured
in a solution of soda, made with the sixteenth part of the weight of the
alum. A second portion of the alkaline solution must not be poured in
till the effervescence caused by the first portion has entirely
ceased,--and so in succession. The bath of saturated alum, being merely
tepid, the cotton is passed through it, as in the gall bath, so as to
impregnate it well, and it is dried with the precautions recommended
above. The dyers who gall at two times, alum also twice, for like
reasons.
For 25 pounds of cotton, 25 pints of blood are prescribed, and 400 pints
of water. Whenever the bath begins to warm, 50 pounds of madder are
diffused through the bath; though sometimes the maddering is given at
two operations, by dividing the madder into two portions.
The brightening bath is prepared always for 100 pounds of cotton, with
from four to five pounds of rich oil, six pounds of Marseilles white
soap, and 600 litres of soda water of 2° B.
The rosing is given with solution of tin, mixed with soap water.
The Turkey-red dye of Messrs. Monteith and Co., of Glasgow, is
celebrated all over the world, and merits a brief description here.
The calico is taken as it comes from the loom without bleaching, for the
natural colour of the cotton wool harmonizes well with the dye about to
be given; it is subjected to a fermentative steep for 24 hours, like
that preliminary to bleaching, after which it is washed at the dash
wheel. It is then boiled in a lye, containing about 1 pound of soda
crystals for 12 pounds of cloth. The oiling process now begins. A bath
is made with 10 gallons of Gallipoli oil, 15 gallon measures of sheep’s
dung not indurated; 40 gallons of solution of soda crystals, of 1·06
specific gravity; 10 gallons of solution of pearl-ash of spec. grav.
1·04; and 140 gallons of water; constituting a milk-white, soapy
solution of about spec. grav. 1·022. This liquor is put into a large
cylindrical vat, and constantly agitated by the rotation of wooden
vanes, which are best constructed on the plan of the mashing apparatus
of a brewery, but far slighter. This saponaceous compound is let off as
wanted by a stopcock into the trough of a padding machine, in order to
imbue every fibre of the cloth in its passage. This impregnation is
still more fully ensured by laying the padded cloth aside in wooden
troughs during 16 or 18 days. The sheep’s dung has been of late years
disused by many Turkey-red dyers both in England and France, but it is
found to be advantageous in producing the very superior colour of the
Glasgow establishment. It is supposed, also, to promote the subsequent
bleaching during the exposure on the green; which is the next process in
favourable weather, but in bad weather the goods are dried over a
hot-flue.
The cloth is padded again with the saponaceous liquor; and again spread
on the grass, or dried hard in the stove. This alternation is repeated a
third time, and occasionally, even a fourth.
The cloth by this time is varnished as it were with oil, and must be
cleansed in a certain degree by being passed through a weak solution of
pearl-ash, at the temperature of about 122° F. It is then squeezed by
the rollers and dried.
A second system of oiling now commences, with the following liquor:--10
gallons of Gallipoli oil; 30 gallons of soda crystals lye, of sp. grav.
1·06; and 10 gallons of caustic potash lye, of specific gravity 1·04,
thoroughly diffused through 170 gallons of water. With this saponaceous
liquor the cloth is padded as before, and then passed between
squeezing-rollers, which return the superfluous liquor into the
padding-trough. The cloth may be now laid on the grass if convenient;
but at any rate it must be hard dried in the stove.
These saponifying, grassing, and drying processes, are repeated three
times; whereby the cloth becomes once more very oleaginous, and must be
cleansed again by steeping in a compound lye of soda crystals and
pearl-ash of the spec. grav. 1·012, at the temperature of 122°. The
cloth is taken out, squeezed between rollers to save the liquor, and
washed. A considerable portion of the mingled alkalis disappear in this
operation, as if they entered into combination with the oil in the
interior of the cotton filaments. The cloth is now hard dried.
_Galling_ is the next great step in the Turkey-red preparation; and for
its success all the oil should have been perfectly saponified.
From 18 to 20 pounds of Aleppo galls (for each 100 libs of cloth) are to
be bruised and boiled for 3 or 4 hours, in 25 gallons of water, till 5
gallons be evaporated; and the decoction is to be then passed through a
searce. Two pounds of sumach may be substituted for every pound of
galls. The goods must be well padded with this decoction, kept at 90°
F., passed through squeezing-rollers, and dried. They are then passed
through a solution of alum of the sp. gr. 1·04, to which a certain
portion of chalk is added to saturate the acid excess of that supersalt;
and in this cretaceous mixture, heated to 110°, the cloth is winced and
steeped for 12 hours. It is then passed between squeezing-rollers, and
dried in the stove.
The _maddering_ comes next.
From two to three pounds of madder, ground to powder in a proper mill,
are taken for every pound of cloth. The cloth, as usual in maddering, is
entered into the cold bath, and winced by the automatic reel during one
hour that the bath takes to boil, and during an ebullition of two hours
afterwards. One gallon of bullock’s blood is added to the cold bath for
every 25 pounds of cloth; being the quantity operated upon in one bath.
The utility of the blood in improving the colour has been ascribed to
its colouring particles; but it is more probably owing to its albuminous
matter combining with the margarates of soda and potash condensed in the
fibres.
As madder contains a dingy brown colouring matter associated with the
fine red, the goods must be subjected to a clearing process to remove
the former tinge, which is more fugitive than the latter. Every hundred
pounds of cloth are therefore boiled during 12 hours at least, with
water containing 5 pounds of soda crystals, 8 pounds of soap, and 16
gallons of the residual pearl-ash and soda-lye of the last cleansing
operation. By this powerful means the dun matter is well nigh removed;
but it is completely so by a second boil, at a heat of 250° F., in a
tight globular copper, along with 5 pounds of soap, and 1 pound of
muriate of tin crystals, dissolved in a sufficient body of water for 100
pounds of cloth. The muriate of tin serves to raise the madder red to a
scarlet hue. A margarate of tin is probably fixed upon the cloth in this
operation.
When the weather permits, the goods should be now laid out for a few
days on the grass. Some manufacturers give them a final brightening with
a weak bath of a chloride of lime; but it is apt to impoverish the
colour.
According to the latest improvements of the French dyers, each of the
four processes of oiling, mordanting, dyeing, and brightening differs,
in some respects, from the above.
1. Their first step is boiling the cloth for four hours, in water
containing one pound of soap for every four pieces. Their saponaceous
bath of a creamy aspect is used at a temperature of 75° F.; and it is
applied by the padding machine 6 times, with the grassing and drying
alternations. In winter, when the goods cannot be exposed on the grass,
no less than 12 alternations of the saponaceous or white bath are
employed, and 8 in spring. They consider the action of the sun-beam to
aid greatly in brightening this dye; but at Midsummer, if it be
continued more than 4 hours, the scarlet colour produced begins to be
impaired.
They conceive that the oiling operation impregnates the fibres with
super-margarate of potash or soda, insoluble salts which attract and
condense the alumina, and the red colouring particles of the madder, so
firmly that they can resist the clearing boil.
2. Their second step, the mordanting, consists first in padding the
pieces through a decoction of galls mixed with a solution of an equal
weight of alum; and after drying in the hot-flue, &c., again padding
them in a solution of an acetate of alumina, made by decomposing a
solution of 16 libs. of alum with 16 libs of acetate of lead, for 6
pieces of cloth, each 32 _aunes_ long.
3. The maddering is given at two successive operations; with 4 pounds of
Avignon madder per piece at each time.
4. The _brightening_ is performed by a 12 hours’ boil in water with soda
crystals, soap, and salt of tin; and the _rosing_ by a 10 hours’ boil
with soap and salt of tin. Occasionally, the goods are passed through a
weak solution of chloride of potash. When the red has too much of a
crimson cast, the pieces are exposed for two days on the grass, which
gives them a bright scarlet tint.