Improvements in Bleaching Vegetable Textile Materials.
Year: 1899

page_text: Date of Application, 18th Dec., 1899
Complete Specification Left, 10th Aug., 1900-Accepted, 3rd Nov., 1900
PROVISIONAL SPECIFICATION.
Improvements in Bleaching Vegetable Textile Materials.
We, CHARLES FREDERICK CROSs, of 4, New Court, Carey Street, in the County
of London, Analytical Chemist, and GEORGE ALFRED PARKES, of Muckmore,
County Antrim, Ireland, Technical Chemist, do hereby declare the nature of this
invention to be as follows:
Our invention relates to the bleaching of vegetable textile materials, chiefly
those made of cotton and flax, and to those steps of the entire bleaching process
in which the materials are treated with alkaline reagents at more or less elevated
temperatures. The immediate object of the present invention is to provide means
for safely carrying out a drastic alkaline treatment under the condition of reduc-
ing to a minimum the proportion of alkaline lye to the material treated.
It is well known that in ordinary boiling in vomitive kiers the proportion of
liquor to goods is from 7 to 10 to 1: in kiers with forced circulation it has been
possible to reduce this to about one half the above proportion. In our improved
method the proportion is so far reduced that the process becomes one of steam-
ing (in contact with the action solution) rather than boiling, and the circulation
of liquor is consequently dispensed with. At the same time we associate with
the more active alkali, such as caustic soda, other reagents having specific effects,
(a) upon the physical properties of the active solution, (b) upon the constituents
of the fibres which it is required to attack and remove.
Thus, for treating linen webs we prepare an aqueous solution of 1 to 2% caustic
soda, to which we add silicate of soda to increase its viscosity and a mineral or
other suitable oil emulsified with a soda or potash soap solution. This mixture
which at 30°-40° C. is of a gelatinous character, is placed in the box of a starch
mangle and the webs of linen are run through it at the width, and, after passing
through the squeezing rollers, are run into a roll or batch. Cotton piece goods
are similarly treated. In the roll or batch they are exposed to the action of
"dry" steam at about 4 lbs. pressure for 1 to 2 hours. By this treatment the
non cellulose constituents are powerfully attacked. The goods are afterwards
subjected to an ordinary open boil to clear away the constituents thus attacked.
This operation may be carried out in many cases upon the "brown or gray
goods in other cases, it is necessary to prepare them by a preliminary lime boil
or other souring process.
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By the treatment above set forth the linen webs are brought at once to the
condition suitable for the dipping" and first course of bleaching operations.
Cotton fabrics are so far advanced that they may be completely bleached by a
treatment with bleaching powder solution, souring and washing.
In the treatment of yarns, the condition of impregnation and arrangement for
steaming are suitably modified, the essential condition of the treatment remain-
ing the same.
Dated this 18th day of December 1899
ABEL & IMRAY,
Agents for the Applicants.

page_text: Improvements in Bleaching Vegetable Textile Materials.
We, CHARLES FREDERICK CROSs, of 4, New Court, Carey Street, in the County
of London, Analytical Chemist, and GEORGE ALFRED PARKES, of Muckmore,
County Antrim, Ireland, Technical Chemist, 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:-
Our invention relates to the bleaching of vegetable textile materials, chiefly
those made of cotton and flax, and to those steps of the entire bleaching process
in which the materials are treated with alkaline reagents at more or less elevated
temperature. The immediate object of the present invention is to provide means
for safely carrying out a drastic alkaline treatment under the condition of reduc-
ing to a minimum the proportion of alkaline lye to the material treated.
It is well known that in ordinary boiling in vomiting kiers the proportion of
liquor to goods is from 7 to 10 to 1; in kiers with forced circulation it has been
possible to reduce this to about one half the above proportion. In our improved
method the proportion is so far reduced that the process becomes one of steam-
ing (in contact with the active solution) rather than boiling, and the circulation
of the solution is consequently dispensed with. At the same time we associate with
the more active alkali, such as caustic soda, other reagents having specific effects,
() upon the physical properties of the active solution, (b) upon those constituents
of the fibres which it is required to attack and remove.
Thus for treating linen webs we prepare an aqueous solution of 1 to 2 per cent.
caustic soda, to which we add silicate of soda to increase its viscosity and a mineral
or other suitable oil emulsified with a soda or potash soap solution. The propor-
tion of the ingredients of the mixture may be varied. We find the following
mixture suitable for linen webs:-
1.75 lbs. soap, e.g. potash-fish oil or soft soap.
14.0 lbs. silicate of soda, with a silicate ratio Na0.3SiО. and containing by
weight 30 per cent. SiO..
1.5 lbs. caustic soda, NaOH,
1.75 lbs. oil-generally mineral or petroleum oil of high boiling point, but in
some cases it may be a fatty oil or a mixture of fatty with mineral oil, and its
quantity may be varied.
10 gallons of water.
For treating flax goods of open texture such as cambrics or damasks, we increase
the water to 15 gallons retaining the above proportions of the other ingredients.
This mixture at 30°-40° C. is of a gelatinous character, so that it does not
run to form uneven patches. The webs of linen or cotton are run through it at
the width, becoming equally saturated by squeezing rollers and then formed into
a roll or batch, in the following manner. The fabric at its full width is led into
a chamber containing steam at atmospheric pressure and then it is wound into
a roll. It is essential that before the web is rolled it should be exposed at its
full width to steam so that both the web and the agents with which it is impreg-
nated become uniformly heated together, thus ensuring equal action on all the
layers of the roll.
On the outside of the roll a few folds of fabric which may be remnants or fents,
also saturated with the solution, should be wound to form a protective covering
and prevent unequal action on the fabric. When the rolling is completed, the
opening into the chamber is closed and the roll is exposed to the action of " dry"
steam at pressure usually not exceeding 4 lbs. per square inch, for 1 to 4 hours.
By this treatment with steam the special alkaline mixture described is made to
saturate uniformly the whole mass of fabric and to attack powerfully its non-
cellulose constituents so that they are brought to a soluble condition. The goods,

page_text: while still in the chamber are then thoroughly boiled under pressure with weak
alkaline solution, which may be soda or sodium silicate. After the boiling the
goods are cleaned by thorough washing which is also conducted under pressure
if necessary.
The successive operations of winding the webs into a roll or batch, steaming
the roll, boiling it in a clearing solution circulated through the roll,
and finally washing the roll are to be carried on without exposure to
the air until all the non-cellulose ingredients are cleared away, which result could
not be attained if the operations were interfered with by lowering of the tempera-
ture or exposure to the atmosphere. In order that this may be done the opera-
tions may be most advantageously effected in apparatus described in the Patent
Specification of William Mather, No. 16730 of 1899.
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This operation may be carried out in many cases upon the "brown" or "gray"
goods; in other cases it is necessary to prepare the goods by a preliminary lime
boil or other scouring process.
By the treatment above set forth, linen webs are brought at once to the condi-
tion suitable for the "dipping" and first course of bleaching operations. Cotton
fabrics are so far advanced that they may be completely bleached by the ordinary
treatment with bleaching powder solution, scouring and washing.
The mechanical arrangements for treating yarns require to be modified. Warps
or chains may be saturated with the active solution in continuous length as in
the case of fabric; but for impregnating yarns in the hank, it is convenient to
operate as in a dyeing process by immersing them in the solution and applying
the usual manipulation for evenly distributing the solution, then laying them
up to drain and freeing them from excess of solution by squeezing rollers or
centrifugal action. The yarns may then be placed in a cage, to be steamed, this
cage being preferably lined with remnants or fents (which had been also impreg-
nated with the alkaline solution) to protect the outside portions of the yarn.
For goods of comparatively slight make, whether fabric or yarn, the propor-
tions of the chemical agents in the active solution are reduced, especially the
caustic soda, the proportion of which may be from a 05 to a 15 per cent. solu-
tion; and the same applies in producing limited bleaching effects such as half
bleaches and scoured shades.
We are aware that textile fabrics have been saturated with alkaline solutions
and steamed: but the fabrics have not been so treated at the width, nor with
solutions having the particular physical character herein specified, and conse-
quently there has been great unevenness in the treatment, accompanied by tender-
ing, due to local concentration of the active solution, and excessive chemical
action.
We therefore make no general claim for a process of steaming with alkaline
solutions, but having now particularly described and ascertained the nature of
our said invention and in what manner the same is to be performed, we declare
that what we claim is;-
1. The herein described bleaching treatment of vegetable textile fabrics by
saturating them with alkaline solutions and mixtures of the kind specified, ex-
posing them at full width to the action of steam in a chamber in which they are
wound into a roll, then subjecting them to the action of steam at higher pressure,
boiling and washing them without exposing them to the atmosphere during the
whole treatment.
2. The bleaching treatment of yarns, as herein described by saturating them
with the alkaline solutions or mixtures of the kind specified, and exposing them
thus saturated to the action of steam.
Dated this 10th day of August 1900.
ABEL & IMRAY.
Agents for the Applicants.