Improvements in, and in the Manufacture of, India Rubber and Gutta Percha."
Year: 1897

page_text: Date of Application, 10th Nov., 1897-Accepted, 11th Dec., 1897
66
COMPLETE SPECIFICATION.
Improvements in, and in the Manufacture of, India Rubber and
Gutta Percha."
We HARRIS MARKUS of 69 Lever Street, Manchester, in the County of Lancaster,
Waterproof Garment Manufacturer, and GEORGE BENJAMIN BEIIRENS of the firmi
of Daniel Lee and Company, of 55 Fountain Street, Manchester, aforesaid, Mer-
chant and Calico Printer, 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 that is to say.
Our said Invention relates to improvements in and in the manufacture of,
india rubber and gutta percha.
India rubber in the course of manufacture is largely mixed with various sub-
stances or compounds such as chalk, and zinc in order to increase its bulk.
These substances are added to the caoutchouc or pure rubber before vulcaniza-
tion, and intimately incorporated therewith by pressure, the proportion of such
substance or substances varying according to the quality of rubber desired.
Our invention consists in the use of ground cork in the form of impalpable
powder as a substitute for the substances previously employed. The cork powder
is incorporated or intimately mixed with the pure rubber in the usual and well
known manner of mixing compounds with rubber and such cork powder possesses
many distinct valuable properties and advantages over the usual substances
employed.
In the first place it is comparatively light in weight.
Compared therefore with previously used substances it is possible with equal
weight to produce a larger bulk or mass of rubber, a very important advantage in
the economical manufacture of rubber.
The cork powder has no injurious effects upon the nature of the rubber, the
rubber thus produced possessing therefore more durable and lasting properties.
In its natural state the cork powder corresponds in colour very accurately with
the colour of the rubber.
The colour of the finished article retains to a great degree therefore, the char-
acteristic colour and appearance of pure rubber.
Moreover if desired the cork powder may be readily dyed or artificially coloured
to any desired shade or tint, thus enabling us when the same is mixed with the
rubber, to produce rubber in a variety of colours if such should be required for
various ornamental or other purposes. The elasticity of the rubber too is not so
much impaired with the use of cork powder as with the ingredients now in
use.
The proportions of cork powder and pure rubber would of course vary as in the
present practice, with the quality of rubber desired, and the purpose for which
the finished product was required. For instance when using a very large pro-
portion of cork dust with the rubber it would be possible to produce a very tough,
pliable and durable material such as artificial leather the rubber serving as a
cement to bind the fine particles of cork together.

page_text: It will of course be understood that the mixture of rubber and cork dust is
afterwards vulcanized by any suitable process.
As in the case of india rubber, the cork dust may also be similarly used in the
manufacture and treatment of gutta percha, as a substitute for the substances
usually incorporated therewith.
The improved india rubber and gutta percha may be utilised for many useful
and ornamental purposes.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:
1) In the manufacture of india rubber and gutta percha the use or employment
of cork, finely ground or in the form of impalpable powder, either in its natural
colour, or artificially dyed or coloured, such cork dust being intimately mixed
with the rubber or gutta percha for the purposes and substantially as described.
2) The improved india rubber. and gutta percha, consisting of a mixture of
pare rul ber or gutta percha with cork in the form of impalpable powder either
plain or coloured substantially as described.
י