IMPROVED PROCESSES AND MACHINERY FOR THE MANUFACTURE OF PULP FOR PAPER FROM A CERTAIN PLANT, AND OBTAINING A USEFUL PRODUCT THEREFROM
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at
.
the Office of the Commissioners of Patents, with his Petition, on
the 10th November 1874.-A communication from abroad by Jules
Edmond Chamas, Louis Delphin Prosper Bouju, and Marcelin
René Bouju, forming the Firm of Chamas and Bouju Brothers, of
Paris, France.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVED PROCESSES AND MACHINERY FOR THE
MANUFACTURE OF PULP FOR PAPER FROM A CERTAIN PLANT, AND OBTAINING A
USEFUL PRODUCT THEREFROM," to be as follows:-
-
This Invention relates to the production of pulp for paper or
cardboard, and is based upon four principal operations, consisting,-
1st. In the rapid and perfect disintegration of a particular plant
herein-after specified by means of specially constructed machinery.
2nd. In an economic and systematic boiling in lye by which the
disintegrated material is softened and prepared for being quickly and
completely reduced to pulp.

page_text: 3rd. In a particularly economic process of bleaching without
alteration of the material by avoiding the use of chlorine gas and by
the systematic employment of a reduced quantity of other chemical
agents.
4th. In sizing the pulp naturally yet perfectly by the retention
therein, when it is not required to be bleached, of a gummy resinous
substance or property contained in the plant (which is that known as
the hibiscus esculentum); said substance designated scientifically by
the name of "gombine," being retained in greater or less quantity
according to the kind of paper or cardboard to be made. This substance
may however be entirely eliminated if the pulp is to be bleached; but
in that case it is reserved separately for ulterior use in sizing white
paper or cardboard.
The plant employed specially for the purposes of this Invention, that
is to say, the hibiscus esculentum, is of, the mallow tribe. It is known
in the East by the name of bamich, and in Europe and the United
States by that of "gombo," and by its constitutive elements is admirably
adapted to undergo the operations herein specified for its conversion into
paper pulp, and has the further advantage of a very fine natural sizing
unattainable by the means at present in use.
I would remark that hitherto this plant has never been practically
utilized in the manufacture of paper or pasteboard, it is, only by
scientific research and chemical experiments that all the difficulties
incidental to the conversion of the raw plant into 'paper have been
overcome, and a simple and economical process arrived at, whereby an
article is produced as fine as can be obtained from new hemp rags, and
at a much lower cost.
The following is a description of the processes employed to convert
the entire plant, roots, stem, and branches, either into unbleached pulp
containing size, or into bleached pulp unsized, also of the means
whereby the resinous gum, gombine, may be preserved for sizing
bleached pulp.
I will first describe the process of producing pulp unbleached but
sized.
In tlie first place. When the plant has attained maturity it is
pulled and cut up into pieces about four inches in length. by means

page_text: of the cutter now employed for cutting up rags in most paper
manufactories.
Secondly. By means of the improved machinery of this Invention,
1st. the pieces are passed lengthwise between a pair of crushing rolls
and then submitted to the action of a rag engine cylinder by which
they are sufficiently disintegrated to receive the action of the lye, the
material during these two operations being washed to free it, more or
less, of the gombine which it contains.
Thirdly. The material thus disintegrated and drained is placed in lye
in a common rotary boiler, where by the aid of steam only it is subjected
to a temperature not exceeding 212 degrees, and lasting only 6 or 7
hours. Notwithstanding its low temperature and short duration this
is sufficient to soften the material and render it fit for conversion into
pulp.
Fourthly. The stuff is then replaced in the engine above referred to,
in which the cylinder is now lowered near to the block.
Fifthly. When the stuff is sufficiently reduced by this apparatus it is
subjected to the action of an ordinary beating engine or finisher, when
it soon acquires all the qualities of the best natural (that is to say, gray
or unbleached) pulp, containing moreover the size required. when it- is
manufactured into paper. In this operation a beating cylinder may be
substituted for the cylinder first mentioned, the pulp being thus obtained
in one and the same machine.
Finally. The pulp is dried by the ordinary means, and in such form
as may be most convenient for transport and use.
I will now describe the process by which a bleached but unsized
pulp is obtained. For this kind of pulp the cutting, crushing, and
disintegrating operations are the same as before described for the
unbleached pulp, and the washing is continued until the whole or nearly
the whole of the resinous gum or substance designated as gombine
is eliminated, as it is prejudicial to the bleaching operation, as it is
almost impossible to entirely eliminate this substance by simply washing
for no matter what length of time. I propose to use the following
means of wholly freeing the disintegrated material from all matters
foreign to the cellulose, and in which no time is consumed by a'
prolonged and useless washing. To this end I employ quicklime instead

page_text: '
of steam only, which suffices in the case of the unbleached pulp, and
before being converted into pulp it is washed freely in an ordinary
washer and then placed in an hydraulic press to expel the lime. The
material is then reduced, as in the case of the unbleached pulp, and
during this operation the bleaching is effected in the same apparatus by
adding a small quantity of chloride of lime or hypochlorite from which
the chlorine is afterwards disengaged by the addition of a small quantity
of sulphate of alumina. The pulp having been reduced to the desired
degree of fineness, I may now add the quantity of gombine required for
sizing the pulp after bleaching, which is quickly effected, and the
operation is continued as in the case of the unbleached pulp.
The process by which the gombine is obtained in a free state for use
in the sizing of bleached paper or pasteboard is as follows:-The gombine
is eliminated as already described by washing, the water being received
in suitable receptacles, in which by adding a small quantity of pulverized
alum stirred quickly therein all the gum contained in the water is
rapidly precipitated. When the precipitation is complete the water is
draw off by means of a syphon or by decantation, and the gum is then
dried in a stove in order to preserve it for sizing the pulp. The gombine
thus obtained is perfectly white, and may be employed without any
further preparation.
I would here remark that by these processes and by means of the
plant employed a great economy in manipulation and in motive power
is effected. The caustic soda and potash is economized in the boiling,
and also the acids, and a great portion of the other chemical agents in
the bleaching, together with the whole of the chlorine gas, which is so
costly and so injurious. Moreover the artificial sizing is dispensed with
and replaced by a natural size of the finest quality, and which costs
nothing.
In order that the Invention may be more readily understood I have
illustrated in the accompanying Drawing by way of example the
improved machinery.
Figure 1 is a vertical longitudinal section of the apparatus on the line
1-2, Figure 2.
Figure 2 is a top plan, and Figure 3 shows on a larger scale a
transverse section of a portion of the cylinder.

page_text: .
e
a, vat or cistern containing water, which may be made in brickwork,
or of wood or metal, and having a longitudinal central partition to
produce a circulation of the stuff therein; c, c, are distributing cylinders
turning in contrary directions, and provided on their peripheries with
arms or teeth. These cylinders receive from hoppers or otherwise the
cut roots, stems," and branches of the plant, and feed the same to the
crushing rolls d, d. These rolls are of cast iron, and also revolve in con--
trary directions, their journals turning in bearings fixed in the sides of
the vat and on the partition b. They are kept close together by means
of levers e and weights f in such manner that they will adjust theirselves
automatically to the thickness of the pieces passing through them. 9. is
a washing drum whose circumference is composed of wire cloth of
proper gauge. This drum is keyed on a shaft h carried in pillow
blocks i, i, bolted to the sides and partitions of the vat. k is the cylinder
keyed on shaft and rotated rapidly in the direction of the arrow,
Figure 1, thereby imparting a gyratory movement to the water and other
material contained in the engine, as indicated by the arrows. This shaft
has its bearings in the levers m, m, at either side of the machine,
fulcrumed at n, n, and adjustable as regards height by means of the
hand wheel and screws o, o. p, bed block disposed beneath cylinder k.
This cylinder and block are of novel construction. Instead of employing
straight blades fixed parallel to the axis of the cylinder and bevelled, the
blades are inclined or placed obliquely, and are not bevelled, as clearly
seen in Figures 2 and 3: The advantage of this arrangement is that the
substances acted on are only bruised or torn, instead of being cut or
triturated, whereby the entire length of the fibre is preserved.
.
During the first period of the treatment; that is to say, before the
boiling in lye, the cylinder k is raised slightly from its bed p, so as merely
to disintegrate the material. After the boiling and when the material
is again placed in the engine the cylinder is lowered towards its bed p,
seen in the Drawings.
A syphon is used to draw off the gombine in solution in the water
after the washing. q is a continuously revolving wheel keyed on shaft r
provided with a suitable number of buckets or scoops & which dip into
the material contained in the vat and elevate and discharge it on to the
inclined shoot t, by which it is conducted again to the distributers c, c,
from whence it falls on the crushing rolls d, d, and is again passed-

page_text: through the engine, and so on. to is a hole provided with a plug to empty
the vat of its contents.
The transmission of motion to the different working parts shown in
the Drawing is merely given by way of example as it may be effected
by toothed gearing, belts and pulleys, endless chains, or in any con-
venient manner. n is the main shaft and mounted in bearing v and
provided with fast and loose pulleys x, y. Motion is given, to the
crushing rolls d by means of a small pinion ≈ keyed on main shaft and
meshing with toothed wheels 1 keyed on the shaft of one of the crushing
rolls, which communicates motion to the other in an opposite direction
by toothed wheels 2, 2, keyed on the shafts of the rolls.
- 1
Motion is transmitted from main from the main shaft 7 of the washing
drum by means of a band and pulleys 3, 4, shaft 7 of the cylinder k is
driven from the motor itself by a band on pulley 5 keyed. to the shaft;
said shaft ? communicates motion to shaft r of the bucket wheel by.
band and pulleys 6, 7, and a shaft is adjustable, as before mentioned,
the band is provided with a tension pulley.
The distributing rollers may receive motion from any of the shafts, for
example, from h, as shown, by pulleys 9, 10, 11, with bands or cords.
All the shafts may be provided with fast and loose pulleys so that the
motion of any one of the parts may be arrested without interfering with
the action of the other parts of the machine.