Fabrics to Remove Vegetable Matters therefrom.
Year: 1886

page_text: Fabrics to Remove Vegetable Matters therefrom.
I OCTAVE CHEMIN of 95 Boulevard Beaumarchais, Paris in the Republic of
France, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
This invention consists in a novel mode of treating raw wool, silk, and other
animal fibres, to separate therefrom any vegetable matters that may be mixed
therewith or adhere thereto, and also in treating mixed textile fibres made from
animal and vegetable fibres, to obtain the separation or removal of the vegetable
fibres.
In carrying out my invention, I employ hydrofluoric acid, either in the form of
gas or liquid. This acid, which has a strong affinity for water, acts very rapidly
on the vegetable matters, but has no effect on animal fibres, if used suitably
diluted.
When treating the fibres or materials with the gas, they are first saturated with
water, and then placed in a suitable chamber or vessel constructed of or lined
with some material which is unaffected by this acid, such as lead.
The gaseous acid is produced by any of the known methods based on the
decomposition of natural fluorides, and in particular, of cryolite (which gives, as
bye products, alum,—with sulphuric acid), and is forced into the chamber of vessel
containing the saturated fibres or material.
In this vessel, the gas mixes with the water contained in the materials, and
carbonises the vegetable matters.
One hour suffices, in general, for the first operation. The fibres are then with-
drawn from the vessel, thoroughly washed with a large quantity of water, and dried
by artificial means.
When dry, the fibres are subjected to a beating operation. All the vegetable
matters, even of the hardest nature, fall into powder during the beating, and the
animal fibres are thus cleared of all vegetable matters.
When employing this acid in a liquid form, I produce the acid by placing.
in a suitable vessel a certain quantity of water, and I decompose therein a fluoride,
D
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page_text: preferably cryolite, by the aid of sulphuric acid, the proportion of which is
calculated in such a manner as to neutralize the bases, and to set at liberty the
acid, which is absorbed in the water as it is produced.
Into the bath thus formed, the temperature of which is maintained at about 70° 0,
I plunge the fibre or fabric to be treated, and allow it to remain for from one to
two hours. The fibre is then withdrawn and washed with plenty of water, and
hung out to dry.
The fibres are next passed through a stove, and finally are beaten, as before
explained.
It is unnecessary to disacidify, because the hydrofluoric acid is of such a volatile
nature, that any traces that may be left after the washing, will be driven off by
the stoving.

page_text: Improvements in the Treatment of Animal Fibres or Mixed
Fabrics to Remove Vegetable Matters therefrom.
:
' 1 OCTAVE CHEMIN of 95 Boulevard Beaumarchais, Paris, in the Republic of
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:―
The separation of vegetable matters which may be mixed with wool, is usually
effected, either by burring machinery, or by carbonization with the aid of heat,
or by the use of either sulphuric or hydrochloric acid.
The cleaning, or the recovery of wool fibre by carbonization, or the use of the
above acids, cannot however be accomplished without affecting, in some degree,
the animal fibres, either by reason of the high temperature necessary for carboni-
zation, or by the numerous operations entailed by the chemical process, and in any
case the recovery by these processes of silk, from fabrics in which it is mixed with
cotton or other vegetable fibre, is impracticable.
I have, however, discovered a new process, by means of which the clearing of
vegetable matters from raw, washed, or woven wool, or the recovery of silk or
wool fibres from stuffs or rags in which silk or wool is mixed with vegetable
fibres, may be readily effected without any of the disadvantages above mentioned.
The agent which I employ to attack the said fibres, or vegetable matters, is hydro-
fluoric acid, either in a liquid or gaseous form.-This acid has a strong affinity for
water, and acts rapidly upon vegetable matters, so that when submitted to a beating
operation, they will be reduced to powder, whilst if used suitably diluted, the
animal fibres remain unaffected.
When employing this acid in a gaseous state, I first soak the material to be
treated in water, and place it in a chamber suitably constructed of, or lined with,
some material which resists the action of this acid in a diluted state, such, for
instance, as lead.
The gaseous acid which may be produced in any well known manner, preferably
by the action of sulphuric acid upon cryolite (which furnishes me with an alum
as a bye product), is admitted into the chamber, where it is rapidly absorbed by
the water, contained in the material under treatment, and carbonizes the vegetable
without attacking the animal matters,
After about an hour, more or less, the materials are withdrawn from the
chamber, washed copiously, and rapidly dried in a suitable stove. They are then
submitted to a beating operation, when all vegetable matter, even the hardest,
such as the burrs commonly found in Australian and South American wools, will
be reduced to powder, and may readily be separated from the other material.
When using the acid in a liquid state, I employ a vessel of wood lined with
lead, if necessary, which I fill with water, and I introduce therein a suitable
fluoride, preferably cryolite. I then add just as much sulphuric acid as is sufficient
to take up the base, and set free the hydrofluoric acid, which will be absorbed by
the water as fast as it is liberated. Into the bath thus formed, which I may raise to

page_text: 2
and maintain at a temperature of about 70° centigrade (or, if thought desirable, the
bath may be used cold), I plunge the materials to be treated.
After remaining in the bath for from one to two hours, the material is withdrawn,
washed, stoved, and beaten, as described with reference to the preceding case.
As hydrofluoric acid is exceedingly volatile, any trace of acid which may remain
after the washing will be dissipated by the stoving operation, and there will
therefore be no necessity for any neutralizing process.
This treatment is applicable to furs and felts, and generally to all textile
products in which animal hairs or fibres are mixed with vegetable matters.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is:-
The use of hydrofluoric acid, either in a gaseous or in a liquid form, for the
elimination of vegetable fibres and other vegetable matters from animal fibres,
especially for burring wools, and for the recovery of wool or silk fibres, as above
set forth and explained.