IMPROVEMENTS IN THE MANUFACTURE OF THREADS
Year: 1884

page_text: I, ALEXANDER MITSCHERLICH 6 Leopold Street, Friburg, Grand-Duchy of Baden,
German Empire, Professor of Chemistry and Doctor of Philosophy do hereby
declare the nature of my invention for "IMPROVEMENTS IN THE MANUFACTURE OF
THREADS" to be as follows:-
My invention has for its object to enable fibres even such as cannot be spun on
account of their small length, to be capable of being utilised in the formation of
thread.
The fibres are for this purpose stirred up in water by means of any suitable
known appliances and if requisite for the subsequent felting, they are subject to a
splitting process, but they are on no account broken up as in the manufacture of
paper material. They are then mixed with more water, and if desired, with some
cementitious substance respectively if necessary with some material for impregnating
the fibres. From the fibre pap thus produced, felted sheets may be produced in
various ways for the production of threads.
1. The fibre pap is caused to flow on the travelling sieves for removal of the
water, and the felt thus produced is cut into strips of any desired width by suitable
cutting appliances. The quantity of fibre pap allowed to flow on to the sieves is
regulated according to the desired thickness of the felt.
2. The fibre pap is caused to flow through special discharge appliances on to the
travelling sieves so as to be at once divided into separate strips of felt.
3. Through the fibre pap, while continuously stirred up, an endless band, is
caused to travel, having on its surface rows of small projecting pins or the like,
situated successively and close together, to which the fibres adhere, the arrangement
being by preference such as to admit of continuous working. By means of a
doffing arrangement, the band of felt thus formed on the pins is subsequently
removed.
By the last named arrangement it is possible to produce felt in which the fibres
have mostly a parallel position. The threads formed of such felt consequently are
of comparatively greater strength.
If it be desired to impart such parallel position to the fibres in the felt strips
produced according to the first and second methods, and thus also render those of
greater strength, this may be effected by lateral rolling up the felt while still wet
and subjecting them to gradually increasing pressure while wet. The rolled felts
are thus stretched and the fibre receives a more parallel position by the consequent

page_text: displacement relative to each other. These felt strips, which generally tear with
the slightest strain, are now as single strips separately strongly twisted either after
such pressure or without the same and thus converted into threads or several strips
are spun together at once. By such operation, the fibres, which of themsolves have
no strength, such for instance as the fibres of sulphite cellulose of pine-wood,
receive a comparatively great strength in the thread produced, in particular if a
considerable twist is imparted to the same.
The spinning is often performed with advantage while the fibre is wet.
When dried, the threads mostly remain in the strongly twisted form and retain
their strength.
If the fibres are spun when dry the thread produced may be moistened and then
dried again. If this be not done, the thread may under certain circumstances
easily untwist again, thereby considerably prejudicing its strength.
Threads prepared from felt not impregnated as above described, only absorb a
very small quantity of liquids, when the twist is maintained.
Curiously enough their strength is hardly diminished hereby, whereas by the
application of liquids to non impregnated felts, their strength is considerably
decreased.
-
The threads produced have, when certain materials, as for instance sulphite.
cellulose are employed, the advantage in their production and further use, that
they possess great elasticity. They can be utilised in any known manner for the
production of textile fabrics. The fabrics, when prepared from cellulose, may be
treated with sulphuric acid or other chemicals having similar properties, and can
thus be rendered-similar-to-parchment, but-no-great-advantage-has-been-derived_
The felts may be gilt, silvered or otherwise treated with metals or colors before
spinning and fabrics of great beauty may thus be prepared from them.
The before described process can be carried out in various ways.
I will describe arrangements which are the easiest to carry out because they
involve the use of mechanical devices already known¯ and consequently drawings
are not required for their explanation...
.
For splitting fibres crushing machines are very suitable, the various constructions
of-which-are-well-known-Such-a-construction will be found in "Hofmann's;
Handbuch der Papierfabrikation Berlin 1875 page 422 and 423." The construction
here given is, it is true, intended for other purposes, but could be rendered
applicable with modifications. When using these crushing machines, the precaution
must be taken that the pressure be not so great as to crush the fibre.
For mixing the material, any known arrangement of stirring apparatus may be
used, as much water being added as will produce a thin fibre pap. For the pro-
duction of felt from such fibre pap an arrangement similar to a board machine
producing continuous endless board may be used such as are described in various
works as for instance, in "Hofmann's Handbuch der Papierfabrikation."
In order to cut the felt into narrow strips an arrangement is employed, such by
instance as is described in Hofmann's work ahove mentioned p 309 and following,
which arrangement is provided with the necessary modifications especially with an
apparatus for cutting into very narrow strips.
For supplying the fibre pap to the travelling sieve so as at once to produce
narrow strips, apparatus known to the paper manufacturers under the name of
"Apron" may be employed, such as described in Hofmann's work p 229 and
following, but with the modification that channels are arranged in the same closely
side by side, from which the fibre pap flows in thin streams on to a draining
screen travelling slowly underneath the same. In order to prevent the strips from
running together there may be provided in the screen longitudinal partitions
corresponding to the strips. The arrangement for producing the strips by an endless
band passing through the fibre pap has already been described.
In order to produce parallelism of the fibres in the strips by lateral rolling, plates
are employed that are caused to pass to and fro over the same at right angles

page_text: thereto, at first almost without pressure, and afterwards with gradually increasing
pressure.
For spinning the strips, machines may be used such as are well known and
described in various works, with such modifications as will be obvious, and with
due consideration of the fact that the strips must not be subjected at first to any
strain and that this spinning is frequently limited to imparting a considerable twist
to each strip separately. Machinery suitable to this purpose will be found described
amongst others in "Karmarsch & Heeren's technisches Wörterbuch" 3rd Edition,
Prague.
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.
COMPLETE SPECIFICATION.
I, ALEXANDER MITSCHERLICH, of No 6 Leopold Street, Friburg, Grand-Duchy of
Baden, German Empire, Professor of Chemistry and Doctor of Philosophy do
hereby declare the nature of my invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF THREADS" 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 the manufacture of threads from very short fibres and
to a method of treating the said short fibres, whereby they are readily spun into
threads.
The invention consists in mixing the fibres with water so as to form a pulp, in
which condition they may be further split and the pulp be formed into strips of
felt either directly, or by cutting sheets of folt into strips of the required width
and thickness, which strips of felt, either in a wet or dry condition, are then spun
into threads. In order to ensure a good quality of the threads, in particular as to
strength, it is very essential that the separate fibres should have a parallel position
in the felt strips.
For the preparation of the threads, the fibres are mixed with water and then, if
required, split by suitable means but so as not to have their length reduced. They
are then mixed with more water and, if desired, with any substances with which it
is desired to impregnate them. For splitting the fibres, edge runners may be used
but so arranged that fibres are not subjected to too great a pressure; the runners
are, for this purpose, slightly raised. For effecting the mixture of the fibres with
the further quantities of water, incorporating apparatus may be used, in which
so much water is added to the fibres as to produce a thin pulp. From this pulp
-

page_text: a felt material is manufactured which may be produced in various ways as herein
described, and which is then employed for the manufacture of threads.
1, The pulp is allowed to flow upon a continuous travelling, endless, web, about
three feet wide, through which the water passes away with a minimum loss of
fibre. The thickness of the layer of felt is regulated according to the size of
thread to be produced. For converting the felt into narrow strips, apparatus is
used such as is shewn in Fig. 1 of the accompanying drawings, in plan and
elevation. A is a cast iron cylinder which may be suitably covered with a wool
felt. Over this passes, in the direction of the arrows, the continuous sheet of felt
to be divided, as it comes from the travelling web before mentioned, and in passing
over the cylinder it is cut into strips by the circular cutters c, on the cylinder b,
which is made to rotate at a much greater speed than, and in the contrary direction
to, the cylinder a. The width of the felt strips is determined by the distance
apart of the circular cutters. From this apparatus, the felt strips are led to the
roller a, Figs. 6 and 7, from which they are afterwards removed for the purpose of
spinning.
2. The fibre pulp is caused to flow through a number of separate spouts on to
the above mentioned travelling web so as to form, upon this, corresponding felt
strips of the desired width and thickness. Figs. 2 and 3 show how this can be
conveniently effected; Fig. 3 shews a part plan to an enlarged scale. The fibro
pulp is caused to flow through channels tt, arranged closely side by side, in thin
streams, on to the travelling web, passing slowly along beneath the channels. In
order to prevent the felt strips from running one in to the other, the travelling
-web-may-be-divided longitudinally by means of caoutchouc bands kinto_corre-
“sponding separate compartments. From the opposite end of the travelling web, the
felt strips are led on to the roller a shewn at Figs. 6 and 7.
3, A number of bars or bands are caused to pass through the receptacle
containing the fibre pulp which, thereby becomes deposited upon the bars, these
being arranged, by preference, so that the deposit shall take_place_in_a_continuous_
manner. A suitable arrangement for this purpose consists of an endless leather
buud o, Fig. 4, in which are inserted short lengths of wire p, bent us shewn, and
situated close together. These wires or bars must, of course, be placed so close
-together-that-in-working, a continuous strip of felt is produced, and the arrange-
ment must be led through the pulp in such a manner that a continuous uniform
supply of fibres can pass on to the bars or wires, this being effected by suitably
stirring up the pulp. The strips of felt so formed, are then taken off the bands.
The following arrangement for taking them off may be employed. Before the
leather band, with its wires, passes into the pulp, it is covered with a web having
large interstices through which the bars or wires can project sufficiently. As soon
as the leather band passes out of the pulp, the web is made to move away from the
same, thereby lifting off the felt strips which can then be pressed and coiled upon
the roller, Figs. 6 and 7. The perforated web is also mado endless and passes in
contact with the leather bands again, before these pass into the pulp.
the last described means, the formation of felt strips in which the fibres
have a more or less parallel position to one another is particularly facilitated.
Threads formed of felt strips so prepared have almost double the strength
against tearing as compared with threads in which there is no parallel position
of the fibres. If it is desired to bring the fibres of the felt strips, prepared as
described under No 1 and 2, into a more parallel position relative to each
other, this may be effected by rolling the wet felt strips in the lateral direction
under gradually increasing pressure. For effecting this lateral rolling, plates may
be conveniently employed such as are shewn at a and b, Fig. 5. The felt strips
are caused to pass longitudinally over the stationary plate a, the longitudinal
motion being arrested when the plate b comes into action, this having a small
horizontal reciprocating motion in the direction at right angles to the felt strips,
and at the same time being pressed upon these with a gradually increasing
pressure. When this has been continued for a sufficient length of time, the plate b
By

page_text: is slightly raised and the felt strips are moved longitudinally to such an extent
that a new part thereof is presented to the action of the plates. Instead of
arranging the plate a to be stationary, it may be made to travel a certain distance
with the felt strips while, at the same time, the plate b, while participating in the
longitudinal, also has the transverse motion before described, imparted to it.
When the action of the plate b has been sufficiently continued, it is slightly raised,
and the two plates then move back longitudinally into their original position,
where they are made to act in a similar manner upon a fresh length of thread.
With this latter arrangement, the longitudinal motion of the felt strips can be
continuous. It is of advantage that, in these operations, the felt strips should be
supported by a travelling web, as they are still of a very fragile nature. After
treating the strips in the above described manner, they are led to the spinning
apparatus as above described. The rolling operation effects an elongation of the
felt strips, whereby a more or less parallel position is imparted to the fibres.
The felt strips prepared in either of the above described ways and which, mostly,
are very fragile still, are now spun into threads either before or after being
subjected to pressure. For spinning the threads, the following arrangement may
be advantageously employed:-
==
The felt strips c, prepared as above described, are drawn from the roller a,
between rollers g, and over an endless band b and through rings & and pass thence
to spindles f. The rollers g are then stopped and the spindles are rotated for
spinning the felt strip. When the felt strip has been slightly twisted, so as to
increase its strength, it contracts slightly and is put into slight tension by means
of the elastic band c. After the threads have been sufficiently spun, the spindles
are placed into position for coiling up the spun portion and the rollers g simul-
taneously commence to rotate again so as to draw a further quantity of felt strip
from the roller a. The coiling up of the spun thread is carried on very carefully in
order that no fracture of the unspun portion of felt may be produced.
whole of the spun portion has been coiled, the rollers 9 are again stopped, and the
spindles f, having been brought into their original position again, the spinning of a
further portion of felt is effected. Roller wis a guide roller and roller i servos to
prevent the band c from being drawn up too tightly by means of the cord e.
When the
Fig. 6 shews the commencement of the spinning and Fig. 7, the end of the same;
Fig. 8 shews the arrangement of the apparatus to a larger scale. The above
described spinning operation is preferably effected while the felt is wet, but it can
also be carried out with dry felt strips. If the felt strips are spun wet, the
finished threads, if they are not dried during the spinning, must be subsequently
dried. If the threads are dried in their strongly spun form, they retain their
strength. If the felt strips are spun in a dry condition, it is advantageous to
moisten them and then to dry them again. If the threads are neither spun wet
nor subsequently moistened, the twist may afterwards give way, whereby the
strength of the threads is so much reduced as to become very small.
The improved manufacture of thread, produced by the above described process,
can be made from any fibres that will admit of felting, the length of which may be
considerably shorter than 08 in, and the strength of which may be exceedingly
small. The threads have the following properties:-First, they have considerable
strength owing to the great amount of twist imparted to them; second, they have
a very high degree of elasticity which is of considerable importance for the textile
fabrics manufactured therefrom, and which is caused by the small particles of fibre
that are situated in a transverse direction in the thread; third, on account of the
above named feature of the threads, they are of a woolly and bulky nature, even
when they are not prepared from short wool fibres, and consequently they may be
substituted for woollen yarns in the manufacture of textile fabrics; fourth, threads
with a considerable twist, that are prepared from non impregnated felis do not
take up liquids in considerable quantity. In absorbing liquid their strength does
not decrease to any extent, whereas such threads with a small amount of twist
readily take up a large amount of liquid and thereby lose considerably in strength,

page_text: The threads can be employed for the manufacture of woven fabrics in any well
known manner; but it is to be observed that the twist of the threads must not be
loosened, they are, therefore, best employed after receiving double twist or after
having been plaited. Lastly it may be observed that the improved manufacture
can be produced at a comparatively low cost, particularly when using such raw 5
materials as sulphite cellulose.
.
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 use, as a substitute for woollen threads, in woven fabrics, of soft elastic 1
threads produced from short fibres that are first formed into felt by means of water,
and are then spun.
2, The method of producing threads from short fibres by spinning strips of felt
formed from fibre pulp, substantially as herein described.
3, In the manufacture of threads as set forth in the preceding claim, the 1
production of the felt strips by causing the fibre pulp to flow-upon a travelling
web, where the water is removed therefrom, the felt being either formed-at once
into strips or into sheets that are afterwards cut into strips, and subjecting the felt
strips so produced to a lateral rolling action while still wet.
--
4, In the manufacture of threads as set forth in the second claim, the production 2
of the felt strips by causing bands having comb like projections to pass through the
fibre pulp so as to take up a portion thereof.