AN IMPROVED MODE OF MANUFACTURING PAPER PULP FROM WOOD AND OTHER FIBROUS MATERIALS.
Year: 1868

page_text: LETTERS PATENT to David Adam Fyfe, of Edinburgh, North
Britain, for the Invention of "AN IMPROVED MODE OF MANUFACTURING
PAPER PULP FROM WOOD AND OTHER FIBROUS MATERIALS.".
Sealed the 14th July 1868, and dated the 17th January 1868.
PROVISIONAL SPECIFICATION left by the said David Adam Fyfe at
the Office of the Commissioners of Patents, with his Petition, on
the 17th January 1868.
I, DAVID ADAM FYFE, of Edinburgh, North Britain, do hereby
declare the nature of the said Invention for "AN IMPROVED MODE OF
MANUFACTURING PAPER PULP FROM WOOD AND OTHER FIBROUS MATERIALS," to
be as follows:-
The object of this Invention is to effect an economy in the manu-
facture of pulp, whether the material under treatment be raw (or
unmanufactured) fibres or linen and other rags, by ensuring a larger
yield than heretofore from a given weight of fibrous material.
I will describe my Invention in connection with the conversion of
wood or wood shavings into pulp, but the same will apply in most
particulars to the treatment of other matters as a source for obtaining

page_text: the fibres for conversion. The wood or wood shavings I first cut into
a suitable length, using for the purpose an ordinary straw or chaff
cutter or other suitable machine; I then place them in a steam boiler
provided with a false bottom on which the wood rests, and I boil the
same in a solution of caustic soda. After a time I run off this soda
solution and apply a weak solution of sulphuric acid and boil again,
but for a shorter time. After this boiling I remove the macerated wood
from the boiler and submit it to the pressure of callender rollers for
the purpose of softening the wood and reducing it to fine fibres.
The next process is to subject the fibres to the action of a washing
engine, the water supplied to which is made acid by the addition of
sulphuric acid thereto. By this process the fibre is again further
reduced and softened. After this washing the fibre is submitted to a
beating engine containing a solution of chloride of lime or bleaching
powder, with the addition of sulphuric acid. After revolving in the
beating engine a suitable time the fibre is run off from the beating
engine along with the bleaching liquor into a large vat or cistern fitted
with a false bottom. An upright central spindle carrying cross rakes is
mounted in this vat, and by its rotation continuous agitation is kept up
in the vat for several hours. After this the bleaching liquor is drained
off by a false bottom, and a weak solution of sulphuric acid is run into
the vat, and the agitation is continued until the fibre is ready to be
received into the ordinary beating engine preparatory to its being
made into paper in the ordinary course of manufacture.
When operating with sawdust or esparto fibre these substances are
put through a pair of heavy calenders for the purpose of crushing and
softening any hard or refractory part of the fibre previous to being
boiled, but they undergo the same process after boiling, as herein-before
described. The rags go through the same process as the wood or wood
shavings.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Seventeenth day of January, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said David Adam Fyfe, Her special licence
that I, the said David Adam Fyfe, my executors, administrators, and
assigns, or such others as I, the said David Adam Fyfe, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time, and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED MODE
OF MANUFACTURING PAPER PULP FROM WOOD AND OTHER FIBROUS MATERIALS,'
upon the condition (amongst others) that I, the said David Adam
Fyfe, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said David Adam Fyfe, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawings here-
unto annexed, and to the letters and figures marked thereon (that is
to say) :-
The object of this Invention is to effect an economy in the manu-
facture of paper pulp by ensuring a larger yield than heretofore from
a given weight of fibrous material and expediting the operation of
converting the same into pulp.
The Invention consists in submitting wood, wood shavings, sawdust,
esparto, and other fibrous material to certain mechanical and chemical
treatment, whereby they are converted into pulp suitable for the manu-
facture of paper. To enable others skilled in the art to use this process
I will proceed to describe it minutely and in detail.
When ordinary logs of wood are to be operated upon they are first
reduced to thin shavings by means of a planing or other suitable
machine. The wood shavings are next cut into suitable lengths by an

page_text: ordinary straw cutting or other suitable machine. They are next placed
in a steam boiler provided with a false bottom on which the wood rests,
and are there boiled for about six hours under a pressure of, say, ten
pounds to the inch in a solution of caustic soda. When sufficiently
boiled the soda solution is drained off. A weak solution of sulphuric
acid, say one part of the acid to thirty parts of water is next applied,
and the wood is again boiled but for a shorter time, say for two hours,
at about the same pressure, after which the macerated wood is removed
from the boiler.
The wood is next submitted to a crushing and opening-out process,
which may be conveniently effected by the use of a novel construction
of machine containing callendering rollers for breaking down and
crushing the fibres, and a carding or combing cylinder which serves to
open out the matted fibres and prepare them for the washing and beating
engine.
This improved callendering, and opening machine is shewn in Sheet I.
of the accompanying Drawings, Fig. 1 being a side elevation of the
same, and Fig. 2 a longitudinal sectional elevation of the opening portion
of the machine.
A, A, and A', A', are two pairs of callendering or compressing rollers
mounted in suitable standards B, B', of cast iron. The lower rollers are
driven by suitable gearing indicated by the dotted circles C, C¹, and the
upper rollers are held down to their work by coiled springs a, a', the
tension of which is adjusted by regulating screws b, b'; D, D', are
endless cloths or aprons for feeding the macerated fibres up to the bite
of the rollers. These cloths move up between fixed guides, and they
are driven by friction of contact with their respective rollers E, E¹,
which receive motion through a strap c from a pulley on the axle of the
lower or driven callendering rollers, the endless cloths being kept taut
by adjustable tension rollers d. The fibres as they leave the first cloth
or apron D fall on to an inclined board e which guides them on to
the lower roller A. The rotation of this roller in the direction of the
arrow carries the fibres into the bite of the rollers. In passing between
these rollers the liquor absorbed by the fibres is squeezed out, and the
fibres are delivered in a comparatively dry state to the second apron.
To prevent the fibres adhering to the rollers scrapers fare applied to
both the top and bottom rollers. These scrapers are held to their work
by weighted arms keyed to the spindles on which the scrapers are fixed.

page_text: The fibres as they leave the first pair of rollers A are received upon
the apron D and passed to the second pair of rollers A', which are
fitted with guide board and scrapers like the first pair. Between these
rollers the fibres are further crushed and reduced to something like a
matted sheet, and it is to open out this sheet and separate the fibres
from each other that I employ the carding or combing mechanism, the
construction of which I will now proceed to explain. F is an endless
apron supported and operated by rollers having their bearings in the
framing H shaped somewhat like that of an ordinary carding engine.
This apron receives the fibres as they leave the rollers A', and delivers
it to a pair of retaining rollers G, which present it to the action of a
cylinder I furnished with porcupine teeth or it may be wire cards.
This cylinder is inclosed in a case, the upper half of which is hinged
to permit of ready access to the cylinder. Working in contact with
this cylinder at the opposite side to that at which the retaining rollers
are situate is a rotary brush K, which works within an extension of
the case containing the cylinder. This brush serves to disengage the
fibres from the teeth of the cylinder, and deliver it on to an endless
apron L, by which it is discharged from the machine into a suitable
receptacle M.
The gearing for giving the requisite rotary motion to the parts
described above will be clearly traced by reference to Fig. 1, where i is
a belt from any prime mover passing over a pulley on the axle of the
cylinder I and giving motion thereto. A pinion on this axle gears
into and drives a spur wheel k which carries a ring of bevil teeth on its
boss. This ring of teeth gears into a bevil pinion which slides on a
feather on a longitudinal shaft . The pinion is thrown into and out
of gear by the action of a weighted crank lever pivotted on the side
of the machine and furnished with a handle at its upper end. The
crank lever is connected by a rod with a rock lever which embraces
a reduced diameter of the boss of the pinion 1. The weighted crank
lever will thus serve to keep the pinion in gear, but the thrusting
forward of the lever against the action of the weight will cause its
disengagement and consequently (as will be presently explained) the
suspension of the action of the mechanism. The shaft is fitted at
both ends with bevil pinions. That at the right hand gears with a
bevil wheel m which carries on its boss a spur pinion in gear with an
intermediate pinion which drives a spur wheel keyed to the axle of the

page_text: top retaining roller. A pinion on the axle of this roller gears into a
pinion on the axle of the inner roller carrying the apron F, and thus
the requisite traverse motion is imparted thereto. The bevil pinion on
the rear end of the shaft gears into a bevil wheel n mounted on a stud
.axle and carrying a spur pinion. This spur pinion drives an inter-
mediate pinion n' which gears into and drives a spur wheel o keyed on
:the axle of the upper roller carrying the apron L. On the axle of this
roller is also keyed a band pulley, a crossed band o' from which passes
over a pulley o' on the axle of the brush K and imparts rotary motion
thereto. It will now be understood that when the bevil pinion is
thrown out of gear the action of the feed apron, retaining rollers, rotary
brush, and delivery apron are at once suspended. As the compressed
sheet of fibres is presented by the retaining rollers to the cylinder the
porcupine teeth will tear up the sheet separating the fibres from each
other. This being done the brush K will brush out the fibres from the
teeth and deliver them on to the apron L in a proper state for the next
succeeding stage of the process.
The fibre is now to be submitted to the action of a washing and
beating engine. The water used in this engine is made acid by the
addition of, say, one part of sulphuric acid to thirty parts of water;
and in order to preserve the fibre of sufficient length I prefer to use
the construction of engine shewn in Sheet II. of the Drawings.
Fig. 3 is a plan view of the washing and beating engine; Fig. 4
is a longitudinal section of the same taken in the line 1, 2, of Fig. 3,
and Fig. 5 is a longitudinal section taken in the line 3, 4, of Fig. 3.
A, A, is a tank formed with semicircular ends and a longitudinal
central partition B as usual. On one side of this partition is mounted
the rotary beater C, and on the other side the tank is fitted with a
perforated floor D. Below this floor is a chamber E with which a
water-supply pipe F and an air pipe G communicate. The beater C
is ribbed longitudinally and the edges of the ribs are rounded
to prevent the fibres being cut. With the like object I substitute for
the ordinary knives or plates below the beater a corrugated plate H,
which is fitted in the race as shewn in Fig. 5. The engine being set in
motion and the fibre floating in the acidulated water being thereby
caused to circulate in the race, air under pressure is discharged into the
chamber E. In rising to the surface of the water it will meet with the
perforated floor D, and in passing through the perforations will be

page_text: distributed over a large surface. Thus as the fibres pass over the per-
forated plate ascending streams of air will pass between the fibres,
thereby separating or dispersing them and facilitating the action of the
water upon them. This operation I continue for about one hour. By
the use of the washing engine above described I not only obtain this
important advantage, but I avoid the cutting or shortening of the fibre,
the action of the engine being to rub or beat out the fibre into fine
filaments. The washed fibre while still saturated with acidulated water.
is next. put into a bleaching engine (of the same construction as that
just described) charged with a solution of chloride of lime or bleaching
powder. Air being forced by means of a fan or air pump into the
liquor will pass up through the fibre while it continuously moves round
the race of the bleaching engine, and will greatly facilitate the bleaching
process. After being subjected to the action of the engine for about an
hour the fibre is run off along with the bleaching liquor into a large
vat or chest having a false bottom.
I would here remark that an essential feature in this process is
immersing the fibre in the bleaching liquor while it is thoroughly
saturated with the dilute sulphuric acid. The presence of this acid in
the fibre causes the chlorine to be set free the instant it comes in contact
with the fibre under treatment, whereas by other processes in which no
acids have been previously used, the chloride of lime is required to
remain in contact with the fibres several hours, thereby weakening and
even destroying the fibre. The acid used in my processes is so dilute
that it tends to strengthen the fibre which remains in contact with the
bleaching liquor so short a time that it comes out of the process as
strong as it went in. The vat or chest into which the fibres are run
with the bleaching liquor is fitted with an upright central spindle
carrying radial rakes. By the rotation of this spindle continuous
agitation is kept up for about four hours, by which time the fibre becomes
bleached to the required degree of color or whiteness. The bleaching
liquor is next drained from this vat or chest, and a weak solution of
sulphuric acid (say one part of acid to thirty parts of water is applied,
and agitation is then continued for about one hour. This has the effect
of still further improving the color of the fibre, and entirely setting
free the chlorine, should any remain in the fibre, after it has been
removed from the bleaching liquor. The fibre is now ready to be
received into the ordinary beating engine preparatory to its being

page_text: converted into paper in the ordinary course of manufacture. This process
of preparing paper pulp effects a considerable economy of time, as the
fibre is converted into pulp in sixteen hours instead of twenty-four
hours which are ordinarily required for its conversion.
When operating with sawdust or esparto fibres they are first put
through a set of heavy callender rollers to reduce or soften any hard or
refractory part of the fibre previous to boiling; but they undergo the
same processes after boiling as herein-before described.
Having now set forth the nature of my Invention of "An Improved
Mode of Manufacturing Paper Pulp from Wood and other Fibrous
Materials, and explained the manner of carrying the same into effect,
I wish it to be understood that I am well aware of certain of the stages
of the process above described being familiar to paper makers, I do not
therefore claim such steps in the process apart from my improved mode
of treating fibres for the reduction of the same to pulp, the novelty of
which consists in subjecting the macerated fibres to the crushing and
opening-out process above described, and subsequently submitting the
washed fibres while still saturated with the acid solution in which they
have been immersed to the action of the bleaching liquor, as described,
for the purposes above set forth.
In witness whereof, I, the said David Adam Fyfe, have hereunto
set my hand and seal, the Fourteenth day of July, in the year of
our Lord One thousand eight hundred and sixty-eight.
DAVID ADAM FYFE. (L.S.)