Improvements in the Manufacture of Manilla Paper.
Year: 1890

page_text: Date of Application, 15th July, 1890
Complete Specification Left, 22nd Nov., 1890-Accepted, 6th Dec., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Manilla Paper.
A communication from abroad by LOUIS DEBOICE BECK, of 58, Cedar Street, New
York City, United States of America, Contractor.
I, JAMES BASSNET ATHERTON of Mayfield, Huyton, in the County of Lancaster,
Cable Manufacturer, do hereby declare the nature of this invention to be as
follows:-
--
This invention relates to certain improvements in the manufacture of manilla paper,
the said paper being designed more especially for use as an insulating material for
electric wires and the like. The object is mainly to produce a very thin and tough
paper of pure manilla fibre which may be applied to the wire in its unchanged fibrous
condition. The paper is not, however, limited to the above application.
In manufacturing the paper, the stock of raw material is first carefully selected so
that no rotten or mouldy fibres shall be mixed with the paper stock. The stock is then
cut into lengths, preferably not exceeding 24 inches. The fibres are then thoroughly
opened and picked by a suitable machine, such, for instance, as that known as an
"oakum devil."-
The fibre, having been thoroughly picked, is placed in a large open vessel, preferably
of wood, called a "kier," having a false bottom covered with some suitable substance
such as coarse gunny bagging. The picked fibre is placed in this kier, being packed
perfectly tight therein, so that, when covered with the liquids in which it is to be
treated, no movement of the fibre can occur. It is an important point to keep the
fibres perfectly still in the kier, as, when the fibres are agitated, they felt and form
knots, and this materially deteriorates the strength of the paper subsequently made
from said fibre. To keep the fibres stationary within the kier, they may be wedged
down by planks or boards laid over the top of the fibres.
In preparing the liquor with which the fibres are to be treated, a quantity of lime is
taken, say about 20 pounds to the hundredweight of fibre. This is dissolved in water
and the lime is allowed to settle. A quantity of commercial soda ash, say about
10 pounds to each 100 pounds of fibre, is now dissolved in water, in a separate vessel
from that in which the lime was dissolved.
The lime water and the water containing the disolved soda ash are then drawn off
into the kier, the latter being filled sufficiently to submerge the fibres to a depth of,
say, from 4 to 6 inches, and at no point during the treatment of the fibres in the kier
should they be allowed to become uncovered by evaporation.
The kier is heated, and the liquor therein boiled by a steam coil or other suitable
arrangement, placed beneath the aforesaid false bottom. Or, it may be heated in the
old fashioned way employed in the regular "puffing" kier.
The manilla fibre being a vegetable fibre which is difficult to subdue, a great deal of
care is necessary in examining the fibres during maceration. The first examination
may be made after they have been macerated, say, from 15 to 20 hours. An
examination of the fibres can be readily made by taking a hook and drawing from the
tank a small portion of the fibre, and by then taking it between the finger and thumb
to ascertain whether all the gums and silex of the fibre are thoroughly dissolved. If
one fibre readily slips from another, one may conclude that the mass is capable of
being thoroughly disintegrated. If they will not slip one from the other aз above
described, the maceration must be continued until they will do so, even if it takes from
40 to 50 hours to accomplish the result. If the fibres be not sufficiently macerated,
hard fibrous portions will occur in the paper made from it, and such portions will cut
the paper when subjected to the pressure of the calenders, and thus the paper will be
rendered, unfit for the purpose of insulation, as before mentioned.

page_text: After the paper has been thoroughly boiled, the liquid is drawn off and the fibre
washed down with water (preferably cold) either in the kier or in separate vats
constructed for the purpose.
The fibre, being thoroughly washed in the kier or in vats, is then placed in the
beating engines, but these are preferably so adjusted that the rolls will merely brush
the fibre, as it is very important to retain the ultimate fibre of as great a length as
possible. The beating process in these engines will occupy say from 5 to 7 hours,
care being meanwhile taken that no acids of any kind come in contact with the fibres
to neutralise the alkalies therein, nor should any bleaching powder or chloride of
lime be used in the process, but the alkalies must be thoroughly removed by washing
alone.
When the paper is designed for insulating purposes, it will be found that the
machine best adapted for the purpose of making the paper is a cylinder machine, as
the paper is only required to have a maximum strength in the direction of its length.
It is preferable, however, not to use the old fashioned cylinder machine, but the double
cylinder machine fitted with a screen to prevent, as far as possible, any abnormally
large fibres from becoming incorporated in the sheet of paper. Also it is preferable
that the paper be not dried too quickly, but that there should be plenty of drying surface
in the machine, and that lower heats than those usually employed should be used, as a
stronger and firmer paper will result. All sizing of the paper should be, in particular,
avoided, as the paper should be wholly free from anything of the kind.
The paper is then cut into suitable lengths and widths, depending upon the purpose
to which it is ultimately to be put.
The paper may be calendered by simple plain calenders. Friction calenders are not
desirable, as a glossy surface is not required upon the paper. When designed for
insulating purposes, special care should be taken that the thickness of the paper is
equal throughout the entire sheet, as, if there is variation in the thickness of the paper,
it would be very difficult to keep the insulating coating, for which it is to be used, of
a uniform thickness throughout. In making the manilla paper for insulating purposes,
the lighter paper may conveniently be about 25 pounds to the ream (sheet 24 × 36;
488 sheets to the ream).
For a paper of intermediate weight, 45 pounds to the ream will be found
suitable.
For the heaviest paper, 90 pounds to the ream may be taken.
The proportions and the details of the process above set forth are adapted more
especially for a paper intended to be used for insulating purposes. It will be obvious
that such proportions and details may, however, be varied considerably, especially
when the paper is required for purposes other than insulating.
Dated this 14th day of July 1890.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Manilla Paper.
A communication from abroad by LOUIS DEBOICE BECK, of 58, Cedar Street, New
York City, United States of America, Contractor.
I, JAMES BASSNET ATHERTON of Mayfield, Huyton in the County of Lancaster,
Cable Manufacturer, 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 certain improvements in the manufacture of manilla paper,
the said paper being designed more especially for use as an insulating material for
electric wires and the like. The object is mainly to produce a very thin and tough
paper of pure manilla fibre, which, when applied to the wire in its unchanged fibrous
condition, forms an insulating coating having very little induction and enormous

page_text: insulating properties. The paper is not however limited, in its application, to
above purpose.
ՆԱԵ
Up to the present time, various kinds of woven felted and paper fabrics have been
used for insulating wires. All of these, however, have one or more of the following
defects, either they are comparatively poor non-conductors and have large induction
owing to gum, silex or other mineral matter in their composition, or they are too
porous, or have not sufficient tensile strength.
Now my invention is designed to give a purely organic covering not liable to
decompose, having considerable density, and one having little or no inductive property.
I form my material out of manilla fibre. This fibre has been long used for paper
making, but the paper at present made from manilla fibre is comparatively useless for
insulating purposes, as there is a large amount of gum and silex in it, and it also
requires some adhesive material or weighting in order to form a good strong paper, the
fibres of ordinary manilla not having much felting power.
In order to extract the silex and gummy matter, and also to give the fibres a
thoroughly good felting power, while, at the same time, to form the paper with a
strong tensile strength longitudinally, I carry out the process of manufacture in the
following manner, reference being had to the accompanying drawing, which illustrates
the only novel apparatus used in the process :-
Figure 1 is a vertical section through the vat in which the stock is cooked in a special
solution, and
Figure 2 is a similar view showing a tank in which the fibre is washed after being
removed from the first vat.
I select the manilla stock with care, seeing that no rotten or mouldy fibres are mixed
therein. It is then cut into lengths, preferably not to exceed two and a half inches.
This fibre is then thoroughly opened and picked by any suitable ordinary apparatus
commonly used for such a purpose. After the picking operation has been completed
the fibre is placed in a vat A, such as an ordinary kier, having a false perforated
bottom B that may be covered with coarse cloth or gunny bagging. The vat is
arranged to be heated by a steam coil C placed in its bottom. The picked fibre is
tightly packed in the vat or kier, to prevent any movement of the fibre when being
treated with the solutions or liquids, as hereinafter described. 1 therefore cover them
with planks or a heavy grating D, that is wedged down by means of posts E and
wedges E held in place by cross-beams F arranged over the top of the vat. The
holding of the fibre perfectly still is an important feature of my invention, as 1 have
discovered that, if the fibre is permitted any motion while being treated with the
alkaline solutions and heat, it is liable to felt, or form knots, that materially impair the
quality and strength of the paper.
The fibres having been tightly packed in the vat, and firmly wedged down by means
of the planks or grating so that they are incapable of motion, the liquid that I employ
is then drawn into the vat until the entire mass of fibre is submerged several inches.
This liquid is a combined solution of lime and soda-ash in water, of a strength
preferably as follows:-
I take sufficient water to submerge the fibre in the vat to the depth of about
4 inches, and divide this water into two parts. To one of these, I add about 20 pounds
of lime to each one hundredweight of fibre operated upon, thoroughly stir, and then
allow all surplus coarse lime to settle, using only the milk of lime. 10 pounds of
commercial soda-ash to each 100 pounds of fibre are similarly dissolved in the other
portion of the water in a separate vessel. Both solutions are then drawn off into the
vat until the Sbres are covered to a depth of from four to six inches. At no time in
the progress of the operation should the fibres be allowed to become uncovered, and, if
necessary, water should be supplied from time to time to compensate for evaporation.
The particular proportions above given I find to be specially adapted to produce the
result sought, though, of course, they might be varied more or less.
The object of using soda-ash and lime instead of caustic soda or caustic potash
is this
I have found that, if I use caustic alkali, the fibre becomes brittle and weak, unless

page_text: the solution be extremely weak, while if, on the contrary, I use an extremely weak
solution, a very long time is taken up and a frequent renewing of the solution is
required before the operation is accomplished and a partial decay (or rotting) of the
fibres takes place. Now, by using carbonate of soda and milk of lime in this way, I
form a very strong solution, which, at first, contains no caustic alkali, but the lime
immediately begins attacking the carbonate of soda and taking the carbonic acid from
it, thus liberating the required amount of caustic alkali to do the work, the silex and
gums of the fibre taking up the caustic alkali as it is formed without the solution
ever becoming sufficiently powerfully caustic to affect the strength and toughness of
the fibre.
The vat and its contents are now heated by the steam coil. As manilla fibre is one
of the most difficult vegetable fibres to subdue, considerable care should be taken in
examining the fibre from time to time after it has been allowed to boil in the above
mentioned solution for from fifteen to twenty hours. This examination is easily made
by withdrawing from the vat a small portion of the fibre and testing it between the
finger and thumb nail. An expert can tell when all the gums or silex are thoroughly
dissolved, and the material capable of separating into its ultimate fibres. If the fibres
slip readily one upon the other, it may be concluded that the mass is capable of being
thoroughly disintegrated, and has, therefore, been sufficiently treated in the boiling
solution. At all events, the operation must be continued until the fibre is brought into
the proper condition; otherwise, there will be hard spots in the paper that will tend to
cut it, and render it totally unfit for slitting into narrow ribbons, as hereinafter
described, its tensile strength will be impaired, and its inductive capacity will be
correspondingly increased.
After the fibre has been thoroughly treated or reduced in the vat, the lime and
soda-ash solution is drawn off, and pure warm water is run in, to, in a measure, cleanse
the fibre from the solution. The warm water is then followed by one or more baths
of cold water, which further cleanse the fibres and thoroughly cool them. The fibres
having been thoroughly treated with the solution described, and cleansed with pure
warm water, and finally with cold water, there is no danger of knotting or felting
during the subsequent steps of the process. The fibres are now released from pressure
and removed from the vat, and are placed in an open vessel G having a false bottom of
wire grating G' covered with gunny bagging g, as usual. The fibres being in a
perfectly loose and free state, cold water is then turned into the vat and allowed to run
through and over the fibres, which will settle at the bottom, until they have become
thoroughly freed from all traces of the lime and soda-ash, as well as the gummy and
silex matters, which it is the purpose of this treatment to thoroughly remove. It will
be observed that I employ no acids to neutralise the alkaline solution. The fibres are
then placed in an ordinary beating engine, but are not ground or cut therein, being
merely brushed and further thoroughly washed. That is to say, the knives of the
revolving cylinder are adjusted so as not to come in contact with, or extremely close
to, the knives in the bottom of the box, so that the fibre is not ground or cut between
the knives, but is brushed or washed by the passage under the roll and over the bottom
knives, being kept in circulation in this apparatus for any desired length of time, say
from 5 to 7 hours in ordinary cases. After treatment in such a beating or brushing
engine, the fibres will be ready for manufacture into paper.
The fibre is now passed to an ordinary cylinder machine, such as is well known and
used in the paper trade. This cylinder machine must be so arranged and geared, in a
manner well understood in the trade, as to lay the fibres in a direction parallel to the
length of the paper. I prefer to employ, for this purpose, double cylinder machines
with a screen to hinder, as far as possible, any large fibres from becoming incorporated
with the paper web. In making the paper, I use no sizing, china clay, baryta filling
or other material in the machine, the sole materials being water and the prepared
manilla fibre.
The paper, as it comes-out of the cylinder machine, is slowly dried at a low heat, as
I find such an operation produces a stronger and firmer paper and better adapted to
the special use for which this paper is designed.

page_text: The paper may be dried and pressed by simple plain calenders, but, when required for
insulating purposes, friction calenders are not desirable, as a glossy surface is not
required upon the paper. When designed for insulating purposes, special care should
be taken that the thickness of the paper is equal throughout the entire sheet, as, if
there is variation in the thickness of the paper, it would be very difficult to keep the
insulating coating, for which it is to be used, of a uniform thickness throughout.
The paper, after being thoroughly dried (if intended for insulating purposes) is cut
into long narrow ribbons, say to of an inch wide. These ribbons are wound upon
bobbins into rolls, and then, by means of suitable well known machinery, they are
wound spirally in superimposed layers upon an electrical conductor which traverses
through the machine. Unless these ribbons are very strong, they are liable to break
in this machine, causing a stoppage, hence it is very desirable that the fibre should be
as strong as possible.
In making the manilla paper for insulating purposes, the lighter papers may
conveniently be about 25 pounds to the ream (sheet 24 x 36; 488 sheets to the
ream).
For a paper of intermediate weight, 45 pounds to the ream will be found suitable.
For the heaviest paper, 90 pounds to the ream may be taken.
The proportions and the details of the process above set forth are adapted more
especially for a paper intended to be used for insulating purposes. It will be obvious
that such proportions and details may, however, be varied to a certain extent,
especially when the paper is required for purposes other than for insulating.
Having now particularly described and ascertained the nature of the said invention,
and in what manner the same is to be performed, as communicated to me by my
foreign correspondent, I declare that what I claim is
1. The herein described process for manufacturing paper from manilla fibre, which
consists in taking the fibre, cut into suitable lengths and properly picked or separated,
cooking it, while held firmly under pressure to prevent movement of the fibres, in a
combined solution of carbonate of soda and lime, then drawing off such solution and
subjecting the mass of fibre while still confined under pressure to a bath of warm
water, then to a bath of cold water, then relieving the mass of fibre from pressure and
finally thoroughly washing it while in a loose state in water, passing it through the
cylinder machine in such manner that the fibres shall for the most part lie in the
longitudinal direction, forming it into paper without sizing or weighting material and
slowly drying.
2. In the manufacture of paper from manilla fibre, the following operations taken
separately: :―
(a) Treating the fibre (cut into short lengths) under pressure with a combined
solution of carbonate of soda and lime, added separately after the fibre has been
placed in position, and of about the strength described, until the gums and silex
are properly softened or dissolved.
(b) Holding the fibre, by pressure, against movement whilst treating it with a hot
alkaline solution and during the subsequent first washing, whereby knotting or
felting of the fibres is prevented.
(c) Washing the fibre, after treatment with the hot solution as described and
whilst still held under pressure, with hot water, then with cold water, and
afterwards relieving the fibre from pressure and thoroughly washing it with
water while in a loose state.
3. Manilla paper for insulating purposes manufactured substantially in the manner
herein described.
ribed.
this zist day of November 1890.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham & London, Patent Agents.