Purposes to which it is Applicable.
Year: 1884

page_text: Purposes to which it is Applicable.
We, FRANK WYNNE of 4, Carteret Street, Westminster, Civil Engineer and
LEGH SYLVESTER POWELL of 56 St James' Square, Notting Hill, Chemist both in
the County of Middlesex do hereby declare the nature of our invention for
IMPROVEMENTS IN THE PRODUCTION OF A CABONIZABLE MATERIAL SUITABLE FOR
THE MANUFACTURE OF CARBONS FOR ELECTRIC LAMPS AND IN THE MANUFACTURE
OF THIS MATERIAL FOR THIS AND OTHER PURPOSES TO WHICH IT IS APPLICABLE,
to be as follows :-
--
We have discovered that under certain conditions, solutions of Zinc Chloride,
Zinc Iodide, Zinc Bromide, Chloride of Bismuth Iodide of Bismuth, Bromide of
Bismuth and others and certain mixtures of the above, with each other will
dissolve cellulose in the form of cotton or other vegetable fibre or fabric or
material, so as to form a more or less transparent solution and we find that as regards
Zinc Chloride that a specific gravity of 18 and a temperature of 80-90° C is
suitable for obtaining the proper action of the Zinc Chloride on the cellulose. The
more or less transparent solution can be re-precipitated by Alcohol, Ether, Sulphuric
Ether, Acetic Acid, Hydrochloric Acid etc and our improvements consist in the
manufacture of such solution and in the obtaining of it, pure & free from
oxychlorides and in the employment of such solutions or each or any of them for
the production of a transparent. horny substance, which is also a carbonizable
material and suitable for the manufacture of carbons for electric lamps and other
purposes, such as insulating wires, imitation parchment, artificial ivory etc.
Our Improvements further consist in the means & methods we employ to obtain
such solutions free from air and of uniform quality, which consists essentially
in treating such solutions "in vacuo and filtering it and by the application of
warmth.
"

page_text: Our improvements further consist in the method, which we employ, for precipi-
tating the cellulose from the said solutions, by the use of the hereinbefore
mentioned precipitating liquids or any of them. This method consists in an
arrangement by which the solution is freed from air, as before mentioned, and
then is closed in a vessel provided with a suitably sized orifice or orifices, through
which the solution is pressed or forced, preferably by mercury, at a high pressure,
underneath it, but other pressure may be used. Sometimes we suck it through
these orifices. In passing out of the orifices, before mentioned, it comes in contact
with the precipitating liquid, which causes it to retain the shape which its passage
through the orifices has given it & this shape may be changed or modified while it
is still in a soft condition and while still in the setting liquid or afterwards, when
removed from the setting liquid & washed & dried; this shaping consisting in
drawing it through dies of the required form or in rolling it between cylinders,
like callendering drums & subsequently cutting & punching it to the required
form.

page_text: improvements In the Production of a Carbonizable Material
Suitable for the Manufacture of Carbons for Electric Lamps;
and in the Manufacture of this Material for this and other
Purposes to which it is Applicable.
We, FRANK WYNNE of 4, Carteret Street, Westminster, Civil Engineer & LEGH
SYLVESTER POWELL of 50, St James' Square, Notting Hill, Chemist both in the
County of Middlesex do hereby declare the nature of our invention for IMPROVE-
MENTS IN THE PRODUCTION OF A CARBONIZABLE MATERIAL SUITABLE FOR THE
MANUFACTURE OF CARBONS FOR ELECTRIC LAMPS AND IN THE MANUFACTURE OF
THIS MATERIAL FOR THIS AND OTHER PURPOSES TO WHICH IT IS APPLICABLE, and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
We have discovered that under certain conditions a solution of Chloride of Zinc.
is capable of dissolving Cellulose. The principal conditions to be observed in the
practical manufacture of the resulting solution, which we prefer to refer to herein-
after as a solution of cellulose, and which are desireable are the following.
The temperature should be about 100° C; the specific gravity of the solution of
Chloride of Zinc should be about 18; it should be practically neutral, should be
free from Zinc Oxychloride: the cellulose employed should be in a loose form
such as cotton wool and during the process of manufacture, continual stirring
should be kept up.
The proportions of materials used may be considerably varied In addition to.
Chloride of Zinc we also find that this property of dissolving cellulose is also
possessed by the respective solutions of Zinc Iodide, Zinc Bromide, Bismuth.
Chloride & Bismuth Bromide. Certain other solutions of salts such as Chlorides
of Calcium, Aluminium & Iron etc which by themselves do not possess the power of
dissolving cellulose may be added to one or more of the active solutions named to
produce modifications in the process, which, for some purposes are advantageous:
We have also discovered that the cellulose may be reprecipitated from these
solutions by placing in contact with certain liquids; among these we may mention,
Alcohol, Ether, Acetic Ether, Acetic Acid, Ammonia, Glycerine. Certain vapours
have also the property of setting the cellulose from these solutions notably alcohol
& Ether. In some cases it is desireable to render the precipitating liquid acid & in
others alkaline. By suitably varying the salts employed to produce the solution
of cellulose and also the precipitating liquids according to well known chemical
methods, it is possible to obtain homogeneous mixtures of cellulose with certain
metallic oxides & other substances. Thus, if the Chloride of Zinc solution be
mixed with Chloride of Calcium or of Aluminium or of Iron, and if the Cellulose
solution produced therewith be placed in contact with a mixture of alcohol &
ammonia, the hydrates of the metallic salts employed, will be precipitated, the

page_text: hydrate of Zinc dissolves.in excess of ammonia but the other or others remain
evenly precipitated throughout the cellulose, which when dried remains trans-
parent & colorless should the oxide be white or transparent amber colour in case of
Iron.
For the manufacture of filaments we use a solution of Chloride of Zinc. This
is prepared by dissolving metallic Zinc in Hydrochloric Acid until effervescence
practically ceases. When the solution is quite cooled it is shaken up and digested
with carbonate of Zinc, whereby it becomes practically neutral. After filtering so
as to get a clear solution it may be evaporated out of contact with the air in a
vessel such as a retort till it reaches a specific gravity of 1.8.
During the manufacture, that is in the process of solution of the Cotton in the
Chloride of Zinc solution, it becomes filled with a mass of bubbles of air which
owing to the consistency of the liquid is unable to escape. In order to extract
this air the solution is introduced, preferably by sucking it through a filter, into a
vessel which is arranged so that it can be both heated & exhausted. Cotton
fabric nitrated cellulose & glass wool form suitable material for filters. When the
solution has filtered in, the vessel is surrounded with a water bath & slowly heated
up to about 90° C, a vacuum being maintained the whole time. As the tempera-
ture rises innumerable small bubbles rise up and burst and as soon as the air has
been extracted, large heaving bubbles appear which show the operation to be
complete. The solution is then ready for precipitating the cellulose in suitable
form for the manufacture of filaments or for other industries. For the manufacture
of filaments we prefer to squirt the solution through a small orifice by applying
mercury pressure & thus forcing it out, the squirt being introduced into a vessel
containing the precipitating liquid. A continuous thread of cellulose is thus
produced. If the material required be thick it is led over a train of wheels in
such a manner that it forms a series of loops, each loop being introduced into a
vessel containing the precipitating liquid, the last vessel containing a drum on
which the thread is collected. The precipitating liquid preferred is alcohol, which
is slightly acidulated to prevent the formation of Zinc Hydrate The drums are
then subjected to further washing in alcohol to free the threads entirely from salts.
In some cases it is necessary to wash it finally in water as otherwise it may dry
white instead of transparent owing to air getting into the centre of the material.
We can also produce threads or bands of cellulose by rolling the solution
between grooved rollers into the precipitating liquid. For this purpose we employ
two rollers. placed close to one another in a horizontal position. One or more
grooves are turned in each roller so as to be exactly opposite one another: two
side pieces placed between the axles of the rollers press against the ends. There is
thus formed a sort of four sided compartment, the two rollers forming two sides &
the two end pieces the other two sides.
The lower half of the rollers is placed in the precipitating liquid while in the
upper compartment is introduced the solution of cellulose. On rotating the rollers,
towards each other, the solution issues into the liquid through the grooves and
becoming set, forms a continuous thread as with the apparatus previously described..
The washed & dried material previous to being 'carbonised may be drawn
through, dies, rolled or otherwise treated to render to it a higher polish.
Having now particularly described and ascertained the nature of our said
Invention & in what manner the same is to be performed, we declare that what
we claim is
1. The production of a solution of cellulose in Chloride of Zinc solution.
2. The process as hereinbefore described for obtaining a solution of cellulose in
Chloride of Zinc solution.
3. The production of a solution of cellulose in a solution of Iodide of Zine,
Bromide of Zinc, Chloride of Bismuth or Bromide of. Bismuth or mixtures of one
or more of these.

page_text: 4. The employment of liquids or vapours substantially as described, to precipi-
tate the cellulose in a suitable form from the above solution.
"
5. The process substantially as described for the obtaining the precipitated
cellulose in the form of threads or bands by pressing the solution through squirts,
or by rolling it between grooved rollers, into a setting liquid such as alcohol.
6. The process, substantially as described, for the production of a homogeneous
mixture of cellulose & certain other substances such as lime, oxide of iron etc
effected by adding a salt of such metals to the Zinc Chloride solution used for the
manufacture of Cellulose solution & then adding to the setting liquid a chemical
such as Ammonia which precipitates the hydrate of calcium, Iron etc evenly
throughout the cellulose.
7. The process, substantially as described of freeing the solution of cellulose from
air by enclosing it in a chamber which is in connection with an exhaust pump
which keep a more or less perfect vacuum above it, when the solution is exposed
to heat.
8. The employment of the threads, bands, rods or pipes of precipitated cellulose,
with or without admixture of other suitable bodies, obtained substantially as
described for the manufacture of carbon filaments for electric lamps.
-
9. The employment of the threads, bands, rods or pipes of precipitated cellulose
with or without admixture of other suitable bodies, obtained substantially as
described for the manufacture of a material for electrical insulation and also for
making woven articles.