Improved Process for Extracting India-rubber or Gutta-percha from Vegetables which contain them.
Year: 1899

page_text: Date of Application (in United Kingdom), 15th June, 1809
Complete Specification Left, 15th June, 1899-Accepted, 26th Aug., 1899
COMPLETE SPECIFICATION.
Improved Process for Extracting India-rubber or Gutta-percha from
Vegetables which contain them.
I, JEAN GEORGES DEISS, Manufacturer, of Salon, Bouches-du-Rhone, in the
Republic of France, do hereby declare the nature of this invention and in what
imanner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
It is known that india-rubber is contained in the milky sap of certain equatorial
plants, from which it is extracted by a very crude process, consisting in tapping
the tree and collecting the sap. Now, when the same tree has been subjected to
this operation a certain number of times, it becomes exhausted and dies. The
dead tree however still contains a very large proportion of india-rubber which,
hitherto, has been entirely lost to the india-rubber industry through inability to
obtain it with the existing process. The industry is thus deprived of an enormous
quantity of raw material which remains un-used.
The same may be said in regard to the gutta-percha industry, in which the tree
is cut down, the milky sap collected and evaporated in the open air, in order to
obtain the gum.
This invention has for its object to provide an improved process for the extrac-
tion of india-rubber or gutta-percha, which process is very simple and conse-
quently capable of being put into practice in countries remote from any industrial
centre and will enable the whole of the india-rubber or gutta-percha contained in
the plants referred to, to be collected. The improved process is not only suitable
for the treatment of fresh vegetables, from which it enables the whole of the india-
rubber or gum to be extracted by a single operation, but further, and especially
the treating of the immense quantities of plants which have become dead or
exhausted by one or more tappings, and hitherto, have remained unused and from
which by the process hereinafter described it is possible to collect the enormous
reserve stock of india-rubber or gutta-percha contained in them.
The improved process is described in connection with its application to the
obtaining of india-rubber. It is applied in the same manner for gutta-percha.
After having more or less bruised the bark by some suitable mechanism, (in
order to accelerate the operation) and which bark contains about 5% of its
weight of india-rubber, it is treated with a suitable acid, preferably sulphuric
acid, capable of decomposing the ligneous part of the raw material without affect-

page_text: ing or altering the india-rubber. The acid is used at 50 degrees Baume, the
proportion of acid used being such that the bark or other raw material employed
may be completely covered with acid in the receptacle which is used for the opera-
tion. The material is left from 5 to 6 days in the acid in order that the ligneous
part may be sufficiently decomposed so as to separated easily from the pure india-
rubber. This operation may be effected in a vat or any other suitable vessel
(leaded, if sulphuric acid should be used) constructed and arranged in any manner
with a view to render the operation as easy as possible. After the raw material
has remained in the acid during the necessary time for effecting sufficient
decomposition of the ligneous part, it only remains to separate by some suitable
means, this ligneous part from the pure india-rubber with which it is mixed. The
means employed preferentially for this purpose consists after allowing the acid
to drain off, and washing the material in water, in passing it between the rollers
of a rolling mill on which a continuous stream of hot water runs, diluting the
ligneous part and forming a pulp thereof, which is carried off with the water.
The india-rubber on the contrary, unites and agglomerates under the pressure of
the cylinders, and after passing it a few times through the rolling mill, the whole
or the natural india-rubber is collected in slabs and in an absolutely pure
condition.
The acid employed for a first operation is recollected and regenerated by decant-
ing and concentration in suitable apparatus. This acid thus serves indefinitely
seeing that, in the process, it forms no chemical combination, but, after being
concentrated recovers all its properties.
As mentioned above, the process described for obtaining india-rubber, can be
also applied in connection with gutta-percha, which is obtained by treating the
plants containing it by the same process as that described in relation to india-
rubber.
1
It is of course understood that the process is not confined to the particular
details of carrying it out as given by way of example, but that slight modifications
or variations may be introduced therein without departing from the spirit of the
invention.
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 process for extracting india-rubber or gutta-percha from the vegetables
in which they are contained, consisting in treating them with a suitable acid
capable of decomposing the ligneous part thereof without affecting the india-
rubber or the gutta-percha, and then separating the pure india-rubber or gutta-
perche from the decomposed ligneous matter.
1000
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.