Improvements in or relating to the Manufacture of Insulating Material for Electric Cables and the like.
Year: 1899

page_text: Improvements in or relating to the Manufacture of Insulating
Material for Electric Cables and the like.
I, GEORGE EDWARD HEYL-DIA, of 55, Market Street, Manchester, in the County
of Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows:
This invention has for its object a process for making an insulation for cables,
and is an improvement upon my Specification No. 2610 of 1899. In that specifi-
cation I gave a description of the ingredients from which the paper can be
rolled by the ordinary machinery..
Now by my present invention, I may do without the rolling of the paper
altogether and use the material in a pulpy state for clothing the wires by
squirting it in a similar manner to lead under hydraulic pressure. The plan,
however, which I still prefer is to make paper out of the material and then
clothe the wire with it in any of the ordinary manners.
For the purposes of my invention I take any form of paper pulp or wood pulp,
such as straw pulp, esparto grass, bamboo fibre, wood, linen, cotton, hemp, flax
or silk pulp worked up into a semi-liquid state by being broken up with water,
oil, benzine, spirits or the like.
In case water be added for this purpose, the insulating material consists of
oils or resins or mixtures of the two, oxydized or unoxydized, added in a saponi-
fied state to the fibrous mass. Then after the paper has been formed in the
paper machine in the ordinary way, the oils or resin soaps are destroyed by
passing the paper sheets or web through a bath of acid or acid salt, thus
neutralizing the alkali contained in the soap and leaving the pores of the fibrous
material filled with oils or resins or mixtures thereof. Preferably the web or
sheet is now passed between rollers in clean water so as to wash out the salts,
and then all moisture is removed by exposing the sheets or webs to any desired
temperature, preferably above 2120 F. but not sufficient to char the fibre or
volatilize or decompose the oleaginous or resinous matter. By this means the
oily resinous matter is melted or liquified in and among the fibres of the pulp,
and if in this condition the web or sheet be passed between rollers a paper
impervious to moisture is obtained.
Where spirits, benzole or the like has been used instead of water, no saponifi-
cation and treating with acid is required. The material is preferably passed
through a bath of the solution of oils and resins and then through squeezing
rollers while the material is still heated and then between hot plates where the
solvent is evaporated and can be collected. While it is still hot it can be rolled
or not as desired. Where a very hard tough paper is required it is best to roll it:
where a soft paper is preferred the rolling can be done away with. In some
cases, however, I may simply add volatile materials, such as spirits, benzine,
oil of turpentine or the like to the oils or resins or mixtures thereof, and

page_text: thoroughly impregnate the pulp with this material and then work it into paper
in the ordinary manner. This method leaves the oils and resins in the fibrous
sheet in a very finely divided state and has the advantage of quick manufacture,
as the solvent or liquid evaporates rapidly. In some cases a little water may be
added to prevent the evaporation taking place so quickly. In all cases the sheets
are preferably exposed afterwards to heat to obtain a similar result to that
mentioned in the first described method.
Where the material has to be squirted, the pulp and oils are kept well mixed
in the cylinder and with a sufficient amount of solvent to act as a semi-liquid in
the heated state, and the die through which it is pressed is artificially cooled so
that the material on the wire shall be sufficiently solid to undergo no change
of shape as it escapes from the nozzle, and the material is again preferably
compressed after the solvent has been- allowed to evaporate.
That this 8th day of V 1808
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
Improvements in or relating to the Manufacture of Insulating
Material for Electric Cables and the like.
I, GEORGE EDWARD HEYL-DIA, of 55, Market Street, Manchester, in the County
of Lancaster, 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 has for its object a process for making an insulation for cables,
and is an improvement upon my Specification No. 2610 of 1899. In that specifi-
cation I gave a description of the ingredients from which the paper can be
rolled by the ordinary machinery.
Now by my present invention, I may do without the rolling of the paper
altogether and use the material in a pulpy state for clothing the wires by
squirting it in a similar manner to lead under hydraulic pressure. The plan,
however, which I still prefer is to make paper out of the material and then
clothe the wire with it in any of the ordinary manners.
For the purposes of my invention I take any form of paper pulp or wood pulp,
such as straw pulp, esparto grass, bamboo fibre, wood, linen, cotton, hemp, flax
or silk pulp worked up into a semi-liquid state by being broken up with water,
oil, benzine, spirits or the like.
In case water be added for this purpose, the insulating material consists of
oils or resins or mixtures of the two, oxydized or unoxydized, added in a saponi-
fied state to the fibrous mass. Then after the paper has been formed in the
paper machine in the ordinary way, the oils or resin soaps are destroyed by
passing the paper sheets or web through a bath of acid or acid salt, thus
neutralizing the alkali contained in the soap and leaving the pores of the fibrous
material filled with oils or resins or mixtures thereof. Preferably the web or
sheet is now passed between rollers in clean water so as to wash out the salts.
and then all moisture is removed by exposing the sheets or webs to any desired
temperature, preferably above 212° F. but not sufficient to char the fibre or
volatilize or decompose the oleaginous or resinous matter. By this means the
oily resinous matter is melted or liquefied in and among the fibres of the pulp,

page_text: and if in this condition the web or sheet be passed between rollers, a paper
impervious to moisture is obtained.
Where spirits, benzole, or the like has been used instead of water no saponifi-
cation and treating with acid is required. The material is preferably passed
through a bath of the solution of oils and resins and then through squeezing
rollers while the material is still heated and then between hot plates where the
solvent is evaporated and can be collected. While it is still hot it can be rolled
or not as desired. Where a very hard tough paper is required it is best to roll it:
where a soft paper is preferred the rolling can be done away with. In some
cases, however, I may simply add volatile materials, such as spirits, benzine,
oil of turpentine or the like to the oils or resins or mixtures thereof, and
thoroughly impregnate the pulp with this material and then work it into paper
in the ordinary manner. This method leaves the oils and resins in the fibrous
sheet in a very finely divided state and has the advantage of quick manufacture,
as the solvent or liquid evaporates rapidly. In some cases a little water may be
added to prevent the evaporation taking place so quickly. In all cases the sheets
are preferably exposed afterwards to heat to obtain a similar result to that
mentioned in the first described method.
Where the material has to be squirted, the pulp and oils are kept well mixed
in the cylinder and with a sufficient amount of solvent to act as a semi-liquid in
the heated state, and the die through which it is pressed is artificially cooled so
that the material on the wire shall be sufficiently solid to undergo no change
of shape as it escapes from the nozzle, and the material is again preferably
compressed after the solvent has been allowed to evaporate.
As a practical illustration in squirting or forcing materials into cables the
following makes an excellent covering 1 by weight of pulp 1 resin and one heavy
vegetable oil, heated to about 250° Fahr. With some heavy oils a little light
solvent such as spirits is added with advantage but for most it is not required.
For paper 50 parts I use for impregnation at present 50 parts resin 40 parts
heavy oils and ten parts solvent preferably spirits or benzole, then roll the paper
when if the oils have been previously saponified I neutralise with acids.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. The improved manufacture of insulating material for electric cables and
the like, which consists in working fibrous substances into a semi-liquid state
with water, adding insulating materials such as oils or resins or mixtures of oils
and resins in a saponified state, and running the mass through a paper machine
in the ordinary way, then treating the resulting fibrous sheets with acid to
neutralize the alkali in the soaps and leave the pores of the fibrous material
filled with oils resins or mixtures thereof, and finally heating the sheets to
remove all moisture and to melt or liquefy the insulating components so that
they are absorbed by the fibre, thereby rendering the sheets impervious to
moisture, substantially as described.
2. In the manufacture of insulating material of the kind described, the
method of quickening the working consisting in treating the insulating compo-
nents of the fibrous mass with suitable solvents and then running the mass
through the paper machine or squeezing rollers, and after evaporation of the
solvents exposing the resulting sheets to heat to cause the insulating components
to melt or liquefy and be absorbed by the fibrous portion, substantially as
described.
3. The improvement relating to the manufacture of insulating material for
electric cables and the like, which consists in preparing a pulp of insulating
properties with a sufficient amount of solvent to act as a semi-liquid in a heated
state, and squirting it on to the wires or the like in a similar manner to lead
under hydraulic pressure, the die through which it is pressed being cooled to

page_text: prevent the mass undergoing any change of shape on the wire or the like as it
leaves the nozzle, and the material being again preferably pressed after evapora-
tion of the solvent, substantially as herein before set forth.
4. An insulating material consisting of a fibrous mass incorporated or impreg
nated with insulating materials in substantially the manner set forth.
Dated this 8th day of February 1900.
WM. P. THOMPSON & Co.,
Patent Agents, of Liverpool, Manchester, Birmingham and London.