An Improved Composition applicable for Electrical Insulating and other purposes, and the Process for Manufacturing the said Composition.
Year: 1890

page_text: Date of Application, 4th Feb., 1890
Complete Specification Left, 24th Oct., 1890-Accepted, 31st Jan., 1891
PROVISIONAL SPECIFICATION.
An Improved Composition applicable for Electrical Insulating and
other purposes, and the Process for Manufacturing the said
Composition.
I, ERNST FAHRIG, of 24 Listria Park, Stamford Hill, in the County of
Middlesex, Electrical Engineer, do hereby declare the nature of this invention to
be as follows
This invention relates to a composition which is applicable for electrical insulating
purposes, for high speed bearings, for acid proof and water proof containers and
battery cells, and for various other useful purposes, and to the process of manu-
facturing the said composition.
The composition I prepare in the following manner:-I first prepare celluloid,
cellulose or cellulin by subjecting silk, linen, cotton, or other fibres to the action of
combined acids in closed vessels so arranged that the washing and neutralizing can
be carried out without disturbing the celluloid raw material, for neutralizing I
prefer to use ammonia in a gaseous state. When the celluloid so treated is perfectly
neutral to all chemical tests and thoroughly washed, I form it into a pulp by sub-
jecting it to boiling for 20 minutes at a pressure of three atmospheres or at a
temperature of 273° F. with 100 to 150 per cent. of distilled water with the addition
of from 10 to 25 per cent. of sodium bi-carbonate and from 5 to 15 per cent. of silicate
of soda or potash, soda preferred. The pulping stuff' so prepared, I place in an
ordinary pulping engine and to ensure great strength I add from 5 to 15 per cent. of
manilla which has previously been beaten in the engine. When the pulp and
manilla are thoroughly mixed I add a soap solution, mix thoroughly and add alum
in finely divided powder, with 5 per cent. borax until precipitation shows itself in
the whole mass. If the usual test for finish shows the pulp to be ready, it can now
be run on to the engine. I now arrange a large cutter or trough over the engine
with a gauze sieve bottom, to which a rocking motion is imparted. In this cutter
or trough I place suitable insulating materials such as mica, talc, heavy calcined
magnesium, carbonate, flint glass, or other suitable material in a finely divided
state. This is sifted on to the surface of the sheets of pulpy material beneath, to which
it freely adheres.
The pulp may also be made into sheets in an ordinary hand millboard mould,
and the sifting of the insulating material may be done by hand, or machine power
arranged over the said moulds.
The sheets can be built up in this way to any suitable thickness, or pressed in the
wet state into any suitable shape or mould to form cylinders, cones, square battery
cells, or containers etc. The material however made, is subjected to pressure and
then dried in a steam heated oven at a temperature of from 150° to 200° F.
A solution is now prepared by dissolving various raw materials in their respective
solvents, such as gutta-percha, rubber, guaiacum, gum vita, ozokerit, paraffin-wax,
resin, amber gum, shellac, etc., and heated by means of a steam jacketed pan or
other protective means, such as a sand heated bath (steam preferred), until the
whole mass, being well stirred during the heating process, forms a thoroughly mixed
and incorporated juicy liquid.
The sheets are now taken from the drying room or oven and in the heated
condition are plunged into baths containing water and acid proofing solution.
They are then drained, returned to the heating room and calendered, trimmed,
and pressed at the highest possible hydraulic pressure to which the material can be
subjected.
A material prepared in accordance with this invention can be treated like wood,

page_text: brass etc. and can be filed, sawn, bored, turned and otherwise treated, finished and
coloured or enamelled according to the purpose for which it is required. It can
be made flexible by adding a small percentage of non-drying material, such as
glycerine, boiled oil etc., when the composition is in the pulping engine.
Dated this 4th day of February 1890.
CASTLE SMITH,
Per F. W. Golby,
"Invention" Office, 54, Fleet Street, London, E.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
An Improved Composition applicable for Electrical insulating and
other purposes, and the Process for Manufacturing the said
Composition.
I, ERNST FAHRIG, of 24 Listria Park, Stamford Hill, in the County of
Middlesex, Electrical Engineer, 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:-
This invention relates to a composition which is applicable for electrical insulating
purposes, for high-speed bearings, for acid proof and water proof containers and
battery cells, for electric light lead coverings, for underground cable channels or
conduits, and for various other useful purposes in electrical and other industries;
and to the process for manufacturing the said composition.
The stock composition I prepare in the following manner :-
I first prepare and treat the celluloid, cellulose or cellulin, contained in silk,
cotton, linen, or other fibres by subjecting the same to the action of combined acids
in closed vessels so arranged that the washing and neutralising can be carried on
without disturbing the cellulose. For neutralising I prefer to use ammonia in a
gaseous state, but other alkalies may be used. When the cellulose is perfectly
neutral to all chemical tests, and thoroughly washed I form it into a pulp by sub-
jecting it to boiling for twenty minutes under a pressure of three atmospheres or at
a temperature of 273° F., and during such boiling or pressure I add a solution of
from 10 to 25 per cent. of sodium bicarbonate and 5 to 15 per cent. of silicate of soda
or potash (soda preferred) in from 100 to 150 per cent. of distilled water.
In place
of this stock composition however I may use ordinary linen pulp although it is not.
likely to give such good results on account of the impurities which it usually
contains.
The pulping stuff so prepared or taken I place in an ordinary pulping engine,
and, to ensure great strength, I add from 5 to 15 per cent. of manilla or other strong
fibres which have previously been boiled and beaten in the engine. When the
pulp and fibres are thoroughly mixed and beaten, which should be carefully con-
tinued for from 4 to 6 hours I add the colouring matter, if such is desired, giving
preference to aniline colours fixed with vegetable acid. Next I add a soap solution
inade by dissolving 56 lbs. of soap in 23 gallons of water per ton of pulp, and mix
this thoroughly with the pulp; then a mixture of about 90 per cent. alum, 5 per
cent. borax, and 5 per cent. acetate of soda, or phosphate of ammonia in a finely-
divided state, supplying the said mixture to the pulp in the engine by degrees until
precipitation shows itself in the whole mass. If the usual tests for consistency
show the pulp to be ready, it may be pumped up into a reservoir and run on to an
ordinary paper or board making machine, or other machine, which will work up
materials in a similar or analogous manner. Arranged in line with and over the
cylinder of the machine, is a large gutter or trough, with a sieve bottom of a very
fine meshed gauze, to which a rocking motion is imparted.
In this gutter or trough place suitable electrical insulating material in finely
divided condition (not under 100 mesh) such as mica, tale, heavy calcined magnesia,

page_text: magnesite, carbonates, sulphur, gums, ozokerit, stearine, shellac, paraffin wax, horu,
ivory, bone dust, flint, glass, silicate-cotton, or mineral wool, mineral asbestos, or
any other suitable materials or mixture of materials.
These insulating powders are sifted on to the surface of the composition as the
sheets roll round the drum of the machine, which said drum is kept in continuous
motion. Thus the powdered insulating materials are evenly and equally distributed
between the thin sheets made at each revolution of the drum, and the process
proceeds until the required thickness is attained.
If preferred however, the insulating materials may be mixed with the pulp in the
pulping engine, but for economical reasons the sifting method is preferable as the
water required to run on the pulping engine separates and carries away a large
percentage of the heavier insulating powders. I have found in practice that it is
most difficult to pulverise silicate cotton or mineral wool, and mineral asbestos,
and therefore when using these ingredients I beat them up with the pulp in the
pulping engines.
The composition may also be formed into sheets of various thicknesses in an
ordinary hand millboard mould and the insulating powders sifted on by hand or
power arranged over the moulds, or mixed with the pulp, which latter method I
prefer in this case.
In this way the sheets can be built up into any desired thickness, or any shape
or mould, or to form any design, or may be made into blocks, cylinders, cones,
square battery cells, containers etc. etc. The material thus prepared and formed is
subjected to 100 tons pressure and slowly dried in a steam heated oven at a
temperature of 150 or 200° F.
An insulating solution is now. prepared by dissolving various electrical insulating
raw materials such as gutta-percha, rubber, gum, guaiacum, shellac, ozokerit,
paraffin wax, stearine, resin, amber, gum, etc. etc., and heating it or them in a steam
jacketed pan or other protective means, such as a sand heated bath, until the whole
mass, being well stirred during the heating process, becomes a perfectly mixed and
incorporated juicy liquid. If special colour is desired the colouring matter should
be added now.
The sheets blocks or forms of the insulating compound are now taken from the
drying room, and in the heated condition are plunged into baths containing the
above insulating liquid maintained nearly at the boiling point, and they are kept
immersed until bubbles cease to rise to the surface. To drive off air from the
blocks or forms of the insulating compound I may if desired place them in a vessel
from which the air is exhausted in the ordinary manner, and when sufficiently
exhausted I add the heated insulating liquid. The heating process first described
however is preferred as being the cheaper of the two. The said sheets, blocks, or
forms, are then taken from the bath and are pressed at the heaviest obtainable
pressure; the greater the pressure to which they are at this stage subjected, the
higher the resultant quality of the material. They are then trimmed, calendered,
or finished, according to requirements.
The herein described process may be summarised as follows:-
(1) Cellulose is formed;
Washed or neutralised;
Boiled;
Or ordinary linen pulp is taken, and,
Beaten in engine and mixed with fibres;
(5) Dyed:

page_text: solution added;
(14) Subjected to great prostic to incorporate the whole mass.
A material prepared in accordance with this invention is of extremely high
electrical insulative properties. It is also of great strength, very hard, and per-
fectly acid and water proof. It can be used in place of wood, vulcanite, or metal;
and sawn filed, bored, turned, polished and finished, or coloured and enamelled
according to the purpose for which it is required.
I do not confine myself to the details or chemical proportions given, as these may
be varied and added to according to the nature of the product required. As for
example, when a flexible product is required, I use only about one-third (3) of the
maximum pressure for incorporating the whole; or 1 add a small percentage of a
non-drying material such as boiled oil, glycerine, etc., when the composition is in
the pulping engine.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
(1) The process employed for manufacturing an improved composition sub-
stantially as described.
(2) The use in the manner and for the purposes mentioned of the various
ingredients or their equivalents in about the proportions stated substantially as
hereinbefore set forth.
(3) The improved composition herein described prepared substantially in the
manner set forth.
Dated this 21st day of October 1890.
<<
CASTLE SMITH,
Per F. W. Golby,
Invention" Office, 54, Fleet Street, London, E.C., Agent for the Applicant.