IMPROVEMENTS IN DECOLORIZING TEXTILE AND OTHER MATERIALS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the Office
of the Commissioners of Patents on the 25th August 1877. A communication
from abroad by Joseph Marie Clément, of Paris, France.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN DECOLORIZING TEXTILE AND OTHER MATERIALS."
[A communication from abroad by Joseph Marie Clément, of Paris, France.]
This Invention relates to improvements in decolorizing textile and other materials
of vegetable or animal origin.
The processes of this Invention, although similar to a certain extent to those
ordinarily employed, yet differ essentially therefrom, both as regards the manipulation
and the inatters employed, whereby a very rapid decolorization is effected..
The first operation in all bleaching processes is to remove the weavers' dressing
from the material by steeping in warm water and lyes.
According to the improvement of this Invention the operations are carried on
without the aid of heat, the fabric being placed in water, to which yeast is added to
induce a fermentation of the size or dressing without injuring the fibre. After
fermentation for 12 hours the fabric is well rinsed, and passed into an oxidizing bath
composed of water 1,000 litres, a new oxidizing salt (hereafter mentioned)
500 grammes, the proportion of salt being however variable, according to the
degree to which the bleaching is to be carried, and the rapidity desired. After
remaining in the bath for an hour, the material is well rinsed and placed in bath
No 2 composed of

page_text: remaining in the bath for two hours the fabric is rinsed, and placed in a bath of
hypochlorite of soda or potash of the following composition:
Water
Hypochlorite of soda or potash
Carbonate of soda
:.
-
1,000 litres.
330
"
2,500 grammes.
Cotton is bleached in this manner in from 8 to 10 hours, and it need then only
be rinsed, and passed into a second bath for about an hour, when it is again rinsed.
and prepared as in ordinary. For linen materials these several operations should be
repeated in the above order until they are perfectly bleached. Three operations will
ordinarily suffice.
The decolorization of wool differs from that of vegetable textiles in the preliminary
preparation (substituted for the fermentation with yeast), as an example of which
I will give the method of bleaching raw wool:-Wool is usually deprived of its yoke
or grease, either by the aid of the yolk or grease of a bath which has already been
used or by putrid urine.
The process of this Invention differs essentially from the ordinary method, the
raw wool being first steeped in oleic acid or sour olive oil, for from one to two
hours or longer, and then washed in a bath of pure water, either tepid or cold,
which is renewed until it becomes colorless. This immersion in water has no
effect on the fibre, and the wool being impregnated with oil can neither swell nor
tear, and felting is rendered impossible. All the earthy and other impurities which
soil the wool are removed by this first washing, and the wool is then drained and
washed afresh in a bath of the following composition:-
Water
•Prepared liquid
Liquid ammonia
Benzoline
This liquid is composed of,-
1,000 litres.
15 "
66 parts (by volume)
33 "
"
"
the mixture being well stirred before being poured into the vat. Any other hydro-
carbon would produce the same result, but benzoline is preferred as being more
uniform in its action. The mixture should be well stirred before dipping the wool,
which is then washed either by hand or by mechanical means in the ordinary way.
In this manner the grease is entirely removed from the wool in the space of a few
minutes, and a first bleaching is effected, which has been hitherto, unattainable at
this stage; the wool also acquires great softness.
To obtain a lustrous white wool it is treated the same as for cotton, except that
the baths of hypochlorite are omitted; one passage through the baths is sufficient to
produce a wool of snowy whiteness.
The decolorization of sponges is obtained by the use of oxidising baths and
sulphite baths, only in preparing the latter the sulphuric and other acids are replaced
by a vegetable acid, preferably oxalic acid. The same system is applicable for
bleaching old woollen goods and flannels, which latter after they have been worn
and become discolored by age and use, may be made to present the appearance of
new in a single operation.
H
The chief features of Invention are as follows:-
1st. The production and use of two new oxidizing salts not hitherto defined, and
composed of a mixture of permanganate of potash or of soda, acid chromate of potash;
and sulphate of soda in the following proportions
First Salt
Permanganate of potash or soda
Acid chromate of potash
Permanganate of potash or soda
Second Salt Acid chromate of potash
Sulphate of soda
-
-
-
670 grammes.
»
-
330
450 grammes.
160
"
1 390 "
The solution being made is concentrated in order to completely crystallize or evaporate
the matter. These salts are highly stable, readily crystallize, and are quite unaffected
by evaporation. The oxidation produced by them is very powerful and uniform, and

page_text: the baths may be used at the time of mixing, the quantity of water employed in the
solution being in that case taken into account.
2nd. The employment of a bath evolving sulphurous acid in a nascent state, and
rendered permanently alkaline by the use of sulphites, hyposulphites, bisulphites of
soda, potash, ammonia, or lime, according to circumstances, and allowing the
evolution in a nascent state to take place in a regular manner. The acidulation is
effected in these baths, not only with sulphuric or hydrochloric acid, but also
according to the fineness of the fabric or substance to be bleached with vegetable
acids, such as oxalic or tartaric acids. The formation of this bath, which although
it has a very powerful action does not injure the fibres, whether animal or vegetable,
forms an especial feature of the Invention. The same is the case with the bath
of hypochlorite of soda or potash. Sulphurous acid gas may also be employed
according to circumstances, more particularly for decolorizing straw and straw
plait.
3rd. The preliminary application to the wool of "yolk" to prevent the felting,
swelling, and tearing of the fibre in the first operation, and to obtain wool of great
softness and whiteness from this first treatinent.
Sponges bleached in the above manner may be used for toilet and other purposes,
either pure white or dyed with aniline or other colors.
The Invention is also applicable for bleaching pulp for paper, feathers, and alpha.