of Plants of the Urtica Family and the like.
Year: 1885

page_text: of Plants of the Urtica Family and the like.
'I GEORGE FREDERICK REDFERN, of the General Patent Office, N° 4, South
Street, Finsbury, in the County of Middlesex, Patent Agent, do hereby declare
the nature of this invention (a communication from abroad by Professor Edmond
Frémy, member of the Institute of France and Victor Urbain, Engineer and
Chemist, both of Paris, in the republic of France) and in what.manner the same
is to be performed to be particularly described and ascertained in and by the
following statement :-
This invention relates to improvements in treating the bark or outer covering
or rind of various fibrous plants such as those of the urtica family so as to obtain
practically all the fibre contained therein in a condition ready for being carded,
combed, spun and dyed by any usual means.
By these improvements we obtain practically the whole of the fibre contained
in the bark or outer covering or rind of the plant at a less cost of fuel, labor and
chemical agents than in the processes hitherto usually employed. The fibre
produced by the improved process is not liable to the brittleness and absence of
gloss which is a frequent cause of depreciation in its value when obtained by the
processes hitherto in use, The new process ensures likewise the softness and
evenness of the fibre.
We have found that the reason why fibre of plants of the urtica family
and the like is sometimes hard and dull is that the bark or outer covering
or rind contains lime, frequently amounting to about three to eight per cent
and that this lime is the main cause of the defects of the prepared fibre
rendering the complete disintegration of the fibres almost impossible and preventing
the complete removal of the gum and extraction of the colouring matter.
According to this invention I eliminate from the bark outer covering or rind
the said lime by a preparatory bath as hereinafter described.

page_text: According to this invention moreover I free the fibre from all or much of the
colouring matter it contains without using Chlorine as hitherto and I thus preserve
the textile strength of the fibre.
In carrying out my invention I take the bark or outer covering or rind of the
said plants which have been stripped or detached from the wood by any known
process. I find that I can use with great advantage the process described in the
specification of Letters Patent N° 1609 of 1800 and known as Favier's process.
I immerse the fibre so prepared for about one day in a cold water bath containing
hydrochloric acid of a strength such that the solution shall mark about two
degrees Beaumé.
I then proceed to effect the disorganisation of the cuticle and also the cement
which binds together the fibres themselves.
For this purpose I take the bark or rind after treatment in the said acid bath as
above described and wash the same thoroughly and place it in a keir containing
water to which I add about ten grammes (or about one third of an ounce) of
caustic Soda for each litre (or about one and three quarters pint) of water so that
the bath shall make 1°.5 Beaumé and I boil the said bark or rind in the said bath
for about three hours under a pressure of about three atmospheres. In treating
the bark of certain plants of the family of Urtica of which the cuticle is very
thick it is necessary to repeat this last operation a second time the cost whereof is
only small as the alkali of the second bath can be used for the first bath of another
lot. The bark after being treated as above mentioned is well washed in cold
water and dipped during about a quarter of an hour in a bath of Hydrochloric
acid marking about two degrees Beaumé. The bark is then submitted to the
washing action of cold water; the cuticle will then be found to be wholly
removed and the fibre freed therefrom. Before removing the fibre from the water
I ascertain that there is no trace of acid left in the fibre and that incineration
shows that nearly all the lime has been eliminated.
The fibre being now nearly free from lime and detached from the cuticle is
heated during about three hours in the above mentioned keir with a liquid
composed of water, caustic soda and oleic acid in about the following proportions,
videlicet: one kilo (or about two one fifth pounds) of caustic soda and six
hundred grammes (or about twenty one ounces) of oleic acid to every hundred
litres (or about twenty two gallons) of water.
It will now be found that practically no trace of lime is left in the fibre.
The fibre is then removed from the bath and hung up to dry.
The fibres obtained and treated by the process above described will be found to
be sufficiently bleached to allow of their being utilized for ordinary purposes
without requiring to be submitted to the action of chlorine as has been hitherto
necessary and the doing away with the use of chlorine is a great advantage, as the
action of chlorine tends to diminish the strength of the fibre.
Having now particularly described and ascertained the nature of the invention
communicated to me and the means of performing the same I desire to state that
I am aware that hydro-chloric acid has been used as a final process for saturating
or neutralising the soda remaining after the soda process but it has never to my
knowledge been discovered that the presence of lime in the bark has the prejudicial
effects above named and that a preliminary bath as described will free the fibres
therefrom and thus prevent the depreciation of the raw material.
But what I claim is
1. The treatment of the barks of plants of the urtica family, and the like so as
to effect the extraction of the lime therefrom as and for the purposes herein before
described,
2. In the treatment of the barks of plants of the urtica family and the like the
freeing the fibre from the cuticle substantially as herein before described.

page_text: 3. The method herein described of extracting the colouring matter from fibres
obtained from the barks of plants of the urtica family and the like by subjecting
the same to the action of a bath composed of water, caustic soda, and oleic acid,
herein before described.
4. The manufacture of prepared fibres from the barks of plants of the urtica
family and the like by the series of operations substantially as hereinbefore
described.