IMPROVEMENTS IN THE MANU- FACTURE OF VULCANITE OR HARD RUBBER
Year: 1878

page_text: LETTERS PATENT to William Lloyd Wise, of Chandos Chambers, Adelphi, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF VULCANITE OR HARD RUBBER." A communication from abroad
by the Harburger Gummi-Kamm Company, of Harburg, in the Kingdom of
Prussia, German Empire.
Sealed the 9th May 1879, and dated the 3rd December 1878.
PROVISIONAL SPECIFICATION left by the said William Lloyd Wise at the
Office of the Commissioners of Patents on the 3rd December 1878.
WILLIAM LLOYD WISE, of Chandos Chambers, Adelphi, in the County of Mid-
dlesex. "IMPROVEMENTS IN THE MANUFACTURE OF VULCANITE OR HARD RUBBER."
(A communication from abroad by the Harburger Gummi-Kamm Company, of
Harburg, in the Kingdom of Prussia, German Empire.)
As is well known vulcanite or hard rubber is manufactured by subjecting certain
soft compounds, mixed according to certain proportions, to a certain degree of heat
in the vulcanizing apparatus, whereby the intimate chemical combination of the
different ingredients, the consistency, the blackness, and the elasticity peculiar to
vulcanite or hard rubber are finally attained. During the process of vulcanisation
the rubber must however be protected against the destructive effect of the water,
steam, or gases contained in the heater or vulcanizing apparatus, otherwise the
blackness will suffer, and the surface of the vulcanite will be materially injured and
roughened.
Now this Invention consists in the application and use of glass for the protection
of the surface of soft rubber compounds during the process of vulcanisation. To

page_text: produce vulcanite or hard rubber sheets with lustrous and level surfaces the vul-
canizing is effected on plate glass. By this process the vulcanite or hard rubber
sheets leave the vulcanizing apparatus (heater) with a jet black polish on their
surfaces, superior in finish to those attained by existing polishing manipulations, and
resembling in fineness a plate glass surface.
By vulcanizing in cut glass moulds similar results are obtained with articles of
various shapes. By using opaque cut glass a corresponding or similar surface is
obtained on the vulcanite sheets, and by the use of glass plates or moulds cut,
corroded, or blown, or ornamented in other ways, similar surfaces are reproduced on
the vulcanite without further finish.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Lloyd Wise in the Great Seal Patent Office on the 31st May
1879.
WILLIAM LLOYD WISE, late of Chandos Chambers, Adelphi, in the County of
Middlesex, now of 7, Whitehall. Place, in the City of Westminster. "IMPROVEMENTS
IN THE MANUFACTURE OF VULCANITE OR HARD RUBBER." (A communication from
abroad by the Harburger Gummi Kamm Company, of Harburg, in the Kingdom of
Prussia, German Empire.)
The present extended use of hard rubber or vulcanite is due to its many valuable
qualities, more particularly to its jet black colour, and to the brilliant black polish
which it retains after certain manipulations.
Hitherto these manipulations of polishing "hard rubber" have been very
laborious and costly, not infrequently doubling the cost of production. In cases of
articles of complicated form the cost of labour in polishing would often be such as
to preclude their sale.
The present Invention is designed to enable superior polish to be produced,
whether on flat sheets or on articles moulded in various shapes; also to produce an
even surface without extra labour by using a certain material for the plates and
moulds used for vulcanising "hard rubber" or " vulcanite."
As is well known vulcanite or "hard rubber" is manufactured by subjecting
certain soft compounds, mixed according to certain proportions, to a certain degree
of heat in the vulcanising apparatus, whereby the intimate chemical combination of
the different ingredients, the consistency, the blackness, and the elasticity peculiar
to vulcanite or hard rubber are finally attained.
During the process of vulcanisation the rubber must however be protected against
the destructive effect of the water, steam, or gases contained in the heater or vul-
canizing apparatus, otherwise the blackness will suffer, and the surface of the
vulcanite will be materially injured and roughened.
Talc has been used to protect the material, but the surface thus attained on
articles of hard rubber, although the blackness is somewhat protected, is by no
means smooth, and the manipulation of polishing remains very expensive.
In 1854, L. Otto P. Meyer, Engineer, discovered tin-foil to be a superior envelope
for the protection of the surface of hard rubber during the process of vulcanisation.
He consequently applied for and was granted a Patent for the United States, dated
April 4th, 1854, extended May 5, 1868, for seven years.
The use of tin foil in the manufacture of hard rubber or vulcanite has since
proved of the utmost importance.
Up to the present date tin-foil or its alloys are almost exclusively employed by
all hard rubber manufacturers for the protection of the surface of soft rubber com-
pounds during the process of vulcanisation.
Now although by the aid of tin-foil a tolerably black and smooth surface is
obtained, and the manipulation of polishing is thereby made considerably more
easy, yet serious obstacles remain. On large sheets the surface frequently appears
undulated, and takes from the tin-foil a glossy metallic appearance, which greatly
impedes the polishing.
Now my foreign correspondents have discovered that glass constitutes a medium
far superior to tin moulds or tin-foil (when used as a substitute for them) for pre-
serving and protecting vulcanite during the process of vulcanisation against the
destructive influence of steam, et cætera, as herein above set forth.
According to this Invention, in order to produce vulcanite or hard rubber sheets
with lustrous and level surfaces, the vulcanising is effected on plate glass. By this
process the vulcanite or hard rubber sheets leave the vulcanising apparatus (heater)
with a jet black polish on their surfaces, superior in finish to those attained by
existing polishing manipulations, and resembling in fineness a plate glass surface.

page_text: To produce articles of various shapes, the vulcanising is effected in cut glass
moulds of appropriate forms. Opaque cut glass is employed to produce a corre-
sponding or similar surface to that of such glass on vulcanite sheets, and glass
plates or moulds cut, corroded, or blown, or ornamented in other ways, are employed
to produce similar surfaces to their own on the vulcanite, which effect is obtained
without further finishing being requisite..
Having described the nature of the said Invention, and explained the manner of
carrying it into practical effect, I would have it understood that in carrying out
this Invention glass in all its different compositions, qualities, and shapes may be
used for the vulcanisation of vulcanite without departure from the essential charac-
teristic of the Invention, as respects which, what I consider to be novel and original,
and therefore claim as secured to me under the Letters Patent hereinbefore in part
recited is, the use of glass in the manufacture of vulcanite or hard-rubber; substan-
tially as hereinbefore described.
In witness whereof, I, the said William Lloyd Wise, have hereunto set my
hand and seal, this Thirtieth day of May, in the year of our Lord One
thousand eight hundred and seventy nine.