Process for Chemically Cleansing Wool and Woollen Fabrics and Rags.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
A Process for Chemically Cleansing Wool and Woollen Fabrics
and Rags.
1, EMILIEN LASBORDES, of Castres, (Taru) France, Manufacturer, do hereby
declare the nature of this invention to be as follows:-
My invention has for object to clean wool and woollen fabrics by chemical meaus.
in order to get rid of the thistles, teasels, straw and other vegetable fibres which,
they may contain by placing them in an acid bath at a low temperature.
In carrying out the invention the wool is first passed into a bath consisting, for
every 100 kilogrammes of wool to be treated, of about a thousand litres of water
and 1500; kilogrammes of panama or other similar wood such, for example as
hawthorn. This wood, previously heated and broken into small fragments, is
soaked in water for about two hours.
The wool should remain at least four hours in the bath and when removed from
the same it is drained and dried. The wool is thus scoured, cleansed, caused to
swell and prepared for being subjected to the action of the acid in the cleansing
bath. It is in one step bleached and covered with a layer to protect it against
the further action of the acid. Furthermore this action is facilitated, for
experience has shown that the panama or other similar wood considerably aids
carbonization.
The acid bath is prepared in two steps; first 450 litres of water are poured into
a wooden cask and to this water a sufficient quantity of sulphuric acid is added to
obtain a density of from 13° to 15° Benumé, about 1-200 kilogrammes of grey plaster
of Paris are then added to this. The addition of the plaster rids the sulphuric
acid of nitric acid which is always present and which colours the wool yellow. At
the end of about two hours a deposit is formed at the bottom of the cask and the
liquid is relatively clear; it is then decanted. About 950 litres of cold water are
then added, to this first bath so that the density is reduced to about 25 degrees
Beaumé or more according to the nature of the wool to be treated and the kind of
straw particles that it contains.
In order to destroy the large thistles of the back wool it is preferable to prepare
a bath having a density of 4° to 5°. For small particles of straw in wools or those
in fabrics a bath at a density of 3° is sufficient.
With these baths carbonization is brought about at a temperature of 50° C.
The baths could be weakened if it were desired to raise the temperature or to keep
them longer in the heating apparatus or to prolong the time taken in the cleansing
operation.
To the acid bath prepared as hereinbefore described and of 1400 litres capacity,
about 8 kilogrammes of a solution of sulphurous acid and 1800 grammes of bisulphite
of soda are added.
The wool which has been subjected to the first operation of scouring is introduced
into this acid bath composed as above described of sulphuric acid, sulphurous acid
and bisulphite of soda. It is allowed to soak in this bath generally for about two
hours, but half an hour is sufficient for wools or fabrics containing only small
particles of straw,
.
The wool is then allowed to drain for a, sufficient length. of time, (an operation
which is very, useful) and thoroughly dried.
The
next step is the carbonization. To effect this the wool is placed in the

page_text: heating apparatus and kept at a temperature rising from 35° C. to 50° C. for three
hours until the vegetable material is carbonized it being only necessary to shake up
the wool three or four times.
In this desiccating operation the sulphurous acid completes the action of the
sulphuric acid by becoming transformed by oxidization into sulphuric acid. The
acid in a nascent state is more active than ordinarily. The employment of
bisulphite of soda produces the same effect.
The acid is removed from the wool by soaking the latter in a bath of panama
aided by immersing the wool in a cold or preferably tepid bath of carbonate of
soda. It is then rinsed.
The panama wood employed in the last operation renders
the wool brilliant.
This method is adopted in the treatment of wools, fabrics, rags, and the like which
are required to remain white and which contain vegetable threads. This process
does not alter the nature of the animal fibre as can be easily proved by examination
under the microscope. Moreover the temperature is not raised above 50° C. in the
course of the process and the wool after carbonization is at least as white as it was
before the commencement of its treatment.
The acid bath is weak and the panama has protected the animal fibre.
Hydrochloric acid may be substituted for the sulphuric acid; in this case it is
not necessary to use bisulphite of soda the employment of which is not so
advantageous.
In treating wools which are to be dyed or are already dyed, tannic acid may be
added to the sulphuric or hydrochloric acid or to salts such as chloride of
magnesium, sulphate of aluminium, etc. employed for cleansing by chemical means.
Tannic acid then acts as a powerful oxidizing agent and increases the action of the
acids or of the salts. Green bark of oak would have the same effect. For
materials which are required to remain white I advise the use or the addition of
hawthorn in the same way and with the same object as the herein before specified
addition of tannic acid or of green bark of oak and also for obtaining, as regards
the white colour, a result as good as that obtained with panana wood.
following gives approximately the proportions which may be advantageously used
when employing tannin.
The
Water 200 litres, hydrochloric acid 4 kilogrammes, tannic acid 150 grammes.
The density of the bath is then about 10 Beaume. The soaking lasts from 30
to 45 minutes and the carbonization takes place at about 50° C. This process may
be used with evaporation if so desired. Grey plaster of Paris may also be added
to the hydrochloric acid with the same object of cleansing as in the case of its
addition to the sulphuric acid as hereinbefore described.
Dated the 19th of February 1895.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
A Process for Chemically Cleansing Wool and Woollen Fabrics
and Rags.
I, EMILIEN LAS BORDES, of Castres, (Tarn) France, Manufacturer, 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:-
My invention has for object to treat wool and woollen fabrics by chemical means
in order to get rid of the thistles, teasels, straw and other vegetable fibres which
they may contain by placing them in an acid bath at a low temperature.
In carrying out the invention the wool is first passed into bath consisting, for

page_text: every 100 kilogrammes of wool to be treated, of about a thousand litres of water
and 1-500 kilogrammes of panama or other similar wood such for example as
hawthorn. This wood, previously heated and broken into small fragments, is
soaked in water for about two hours.
The wool should remain at least four hours in the bath and when removed from
the same it is drained and dried. The wool is thus scoured, cleansed, caused to
swell and prepared for being subjected to the action of the acid in the burring bath.
It is in oue step bleached and covered with a layer to protect it against the further
action of the acid. Furthermore, this action is facilitated, for my experience has
shewn that the panama or other similar wood considerably aids carbonization.
The acid bath is prepared in two steps; first 450 litres of water are poured into
a wooden cask and to this water a sufficient quantity of sulphuric acid is added to
obtain a density of from 13° to 15° Beaumé, about 1-200 kilogrammes of grey
plaster of Paris are then added to this. The addition of the plaster rids the
sulphuric acid of nitric acid which always discolours it and colours the wool yellow.
At the end of about two hours a deposit is formed at the bottom of the cask and
the liquid is relatively clear; it is then decanted. About 950 litres of cold water
are then added to this first bath so that the density is reduced to about 25 degrees
Beaumé or more according to the nature of the wool to be treated and the kind of
straw particles that it contains.
In order to destroy the large thistles of the back wool it is preferable to prepare
a bath having a density of 4° to 5°. For small particles of straw in wools or those
in fabrics a bath at a density of 3° is sufficient.
With these baths carbonization is brought about at a température of 50° C.
The baths could be weakened if it were desired to raise the temperature or to keep
them longer in the heating apparatus or to prolong the time taken in the burring
operation.
To the acid bath prepared as hereinbefore described and of 1400 litres capacity,
about 8 kilogrammes of a solution of sulphurous acid and 1800 grammes of
bisulphite of soda are added.
The wool which has been subjected to the first operation of scouring is intro-
duced into this acid bath composed as above described of sulphuric acid, sulphurous
acid and bisulphite of soda. It is allowed to soak in this bath generally for about
two hours, but half an hour is sufficient for wools or fabrics containing only small
particles of straw.
The wool is then allowed to drain for a sufficient length of time (an operation
which is very useful) and thoroughly dried.
The next step is the carbonization. To effect this the wool is placed in the beating
apparatus and kept at a temperature rising from 35° C. to 50° C. for three hours
until the vegetable material is carbonized, it being only necessary to shake up the
wool three or four times.
In this desiccating operation the sulphurous acid completes the action of the
sulphuric acid by becoming transformed by oxidization into sulphuric acid. The
acid in a nascent state is more active than ordinarily. The employment of bisulphite
of soda produces the same effect.
The acid is removed from the wool by soaking the latter in a bath of panama
aided by immersing the wool in a cold or preferably tepid bath of carbonate of
soda. It is then rinsed. The panama wood employed in the last operation renders
the wool brilliant.
This method is adopted in the treatment of wools, fabrics, rags, and the like
which are required to remain white and which contain vegetable threads. This
process does not alter the nature of the animal fibre as can be easily proved by
examination under the microscope. Moreover, the temperature is not raised above
50° C. in the course of the process and the wool after carbonization is at least as
white as it was before the commencement of its treatment.
The acid bath is weak and the panama has protected the animal fibre.
Hydrochloric acid may be substituted for the sulphuric acid; in this case it is

page_text: not necessary to use bisulphite of soda the employment of which is not so
advantageous.
In treating wools which are to be dyed or are already dyed, tannic acid may be
added to the sulphuric or hydrochloric acid or to salts such as chloride of magnesium,
sulphate of aluminium, etc. employed for burring by chemical means. Tannic acid
then acts as a powerful oxidizing agent and increases the action of the acids or of
the salts. Green bark of oak would have the same effect. For materials which
are required to remain white I advise the use or the addition of hawthorn in the
same way and with the same object as the herein before specified addition of tannic
acid or of green bark of oak and also for obtaining, as regards the white colour, a
result as good as that obtained with panama wood. The following gives
approximately the proportions which may be advantageously used when employing
tannin.
Water 200 litres, hydrochloric acid 4 kilogrammes, tannic acid 150 grammes.
The density of the bath is then about 14° Beaumé. The soaking lasts from 30 to
45 minutes and the carbonization takes place at about 50° C. This process may be
used with evaporation if so desired. Grey plaster of Paris may also be added to
the hydrochloric acid with the same object of purifying as in the case of its addition
to the sulphuric acid as herein before described.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. The herein described process of treating wool and woollen fabrics and rags
for chemically burring them by means of a weak acid bath at a low temperature,
the said process consisting
(a) In treating the wool, fabrics or white rags in a decoction of panama or other
similar wood such as, for example, hawthorn, for the purpose of scouring
the wool, causing it to swell, cleansing it and hastening the carbonization,
this treatment facilitating the subsequent action of the acid on the straw
and thistle and at the same time protecting the fibre of the wool against the
action of the acid.
(b) In adding at the commencement of the preparation of the acid bath grey
plaster of Paris to sulphuric or bydrochloric acid for the purpose of purifying
this acid.
(c) In the employment of a weak acid bath consisting of sulphuric, hydro-
chloric or a similar acid and a solution of sulphurous acid and bisulphite of
soda, the sulphurous acid possessing the power of penetrating the vegetable
matter and becoming oxidized there and of forming sulphuric acid in a
nascent condition.
(d) In the employment of tannin, tannic acid, green oak bark, hawthorn and
like materials for the purpose of increasing the oxidizing action of the acids
or salts employed for the carbonization of wools already dyed or that are to
be dyed.
(e) In the use of a bath of panama after the carbonization to remove the acid
from the wool and to render the latter brilliant.
2. The employment for the chemical burring of wool and woollen fabrics and
rags of panama wood and sulphurous acid with the aid of sulphuric acid, tannin,
and various chlorides, which allow of carbonizing at a low temperature without
affecting the animal fibre, and of obtaining a brilliant white, open wool, substantially
as herein before described.
Dated the 15th day of November 1895.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.