IMPROVEMENTS IN THE MANUFACTURE OR TREATMENT OF INDIA RUBBER AND GUTTA PERCHA, AND IN THE APPLICATIONS THEREOF
Year: 1852

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EMERY
RIDER, of Bradford, in the County of Wilts, Manufacturer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twentieth day of July,
in the sixteenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Emery Rider, Her especial license, full
power, sole privilege and authority, that I, the said Emery Rider, my exors,
adñiors, and assigns, and such others as I, the said Emery Rider, my exors,
adiiors, or assigns, should at any time agree with, and no others, from time
to time and at all times during the term of years therein mentioned, should and
lawfully might make, use, exercise, and vend, within England, Wales, and
the Town of Berwick-upon-Tweed, and also within the Islands of Jersey,
Guernsey, Alderney, Sark, and Man, and in all Her Majesty's Colonies and
Plantations abroad, an Invention of "IMPROVEMENTS IN THE MANUFACTURE OR
TREATMENT OF INDIA RUBBER AND GUTTA PERCHA, AND IN THE APPLICATIONS
THEREOF," being in part a communication to me from abroad; in which said
Letters Patent is contained a proviso obliging me, the said Emery Rider, by
an instrument in writing under my hand and seal, particularly to describe
and ascertain the nature of the said Invention, and in what manner the
same is to be performed, and to cause the same to be inrolled in Her

page_text: Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Emery Rider, do hereby declare the nature of the said Invention, and in
what manner the same is to be performed, to be particularly described and
ascertained in and by this present Instrument in writing as follows, that is
to say:
This Invention relates to a new process or processes of treatment for gutta
percha, whereby that gum is greatly improved in quality, and is rendered
much more suitable for practical application to a greater variety of uses than
heretofore. The process involves a novel system of preparatory treatment of
the raw material, in order to prepare it for effectually undergoing the
process
technically known as vulcanization, or treatment with sulphur or compounds
thereof. It is believed that the insuperable difficulties hitherto met with in
the attempts to cure or vulcanize gutta purcha and to convert it into a service-
able material for the many practical purposes to which it is deemed applicable,
have arisen, in a great measure, from erroneously considering the material to
be identical or nearly so in constitution, chemical properties and composition,
and general character, with ordinary caoutchouc, and that the same routine
of processes is applicable in the conversion of both substances; whereas the
two gums are obtained from trees belonging botanically to different orders,
and their mechanical properties and chemical composition are widely different.
Foremost amongst the peculiarities in which the two materials are really
found to be essentially different is that of their behaviour under the influence
of heat. In its original raw state gutta percha, in addition to its frequent
admixture with fibrous impurities and other foreign matter, is by no means
fitted to be at once mixed or treated with sulphur or sulphuric compounds, by
reason of its possessing within its substance certain volatilizable ingredients of
such a nature as to interfere materially with the after effect of vulcanization.
It is primarily essential to the success of the vulcanization process to get rid
of the solid impurities which break the continuity of the mass, and it is addi-
tionally necessary to expel the volatilizable ingredients, whether these consist of
water, the elements of water, volatile oils, or acids. According to this process
it is immaterial whether the volatile impurities are expelled from the mass
before or after the removal therefrom of the solid impurities, but generally
it is preferred to remove the solid matters first. After such preparatory
cleansing, which is necessary under all circumstances of treatment, the gum
undergoes the first stage of the improved processes, by being heated alone to
such a temperature as may suffice to reduce it to a soft pasty consistence, or

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a thin dough or batter, which result is usually attained by the agency of a
temperature of from four hundred degrees to four hundred and fifty degrees of
Fahrenheit. But the necessary tenperature varies considerably with different
samples of gutta percha, some qualities demanding a temperature no higher
than three hundred degrees. The time occupied in this heating process mate-
rially depends upon the actual heat employed therein, as well as on the mass,
and the state of aggregation of the material at the time. It must, however,
be so managed that a uniform temperature is given throughout the entire
mass. From two to four hours are usually found sufficient for the purpose,
the, heat being applied by means of hot metal rollers, or by any other easy
mode of applying a regular temperature, such as in a stove heated by steam
or hot air. This heating process, besidés driving off the purely volatile matters
in gutta percha, causes a viscid oleaginous fluid to come away, leaving the
gum in a comparatively pure state. The gutta percha then, after having been
subjected to this treatment, is, either alone or in combination with caoutchouc,
mixed with the well-known ingredients, and by the agencies and in similar
or nearly similar proportions as are used in curing or vulcanizing caoutchouc.
But I prefer hyposulphite of lead or zinc. It is, however, found more advan-
tageous in, the manufacture of the gutta percha alone to employ rather a less
degree of heat in the grinding process, and a higher degree of heat in
the vulcanizing process, than is ordinarily employed in the manufacture of
caoutchouc, certain minor modifications being introduced where peculiar
and special uses are involved. For example, when a hard inelastic or com-
paratively inelastic compound is wanted, more mixture and a higher degree of
heat is used than in the manufacture of a very elastic gum. But such modes
of treatment are capable of various modifications, as is well understood by the
practical worker in gums of this nature.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I may observe, in conclusion, that I do not confine or restrict
myself to the precise details which I have had occasion to describe or refer to,
as many variations may be made therefrom without deviating from the
principles or main features of the Invention; but what I consider to be novel
and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent, is,―
First, the preparation of gutta percha by preliminary heating to such a
degree that the volatile and oleaginous fluids or ingredients contained therein
in its raw state are expelled, whereby I am enabled to subject it to the same

page_text: treatment that caoutchouc receives when being cured or vulcanized, and of
producing the same valuable results.
Second, the production from gutta percha of a new material permanently
elastic, not liable to be affected by any change or degree of temperature, and
applicable to all the important purposes for which caoutchouc alone has been
heretofore used, as well as being much more valuable for the many purposes to
which gutta percha is at present applied.
In witness whereof, I have hereunto set my hand and seal, this Twentieth
day of January, in the year of our Lord One thousand eight hundred
and fifty-three.