Improvements in the Manufacture of Artificial Silk and Mixed Threads, and in Apparatus therefor.
Year: 1891

page_text: The decision of the Comptroller-General, of the 30th day of March 1893, allowed
under Section 18 of the Patents, &c., Act, 1883, an Amendment of tliis
Specification.
Date of Application, 11th July, 1891.
Complete Specification Left, 11th Apr., 1892-Accepted, 25th June, 1892.
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Artificial Silk and Mixed
Threads, and in Apparatus therefor.
I, FRIEDRICH LEHNER, of Augsburg, in the Empire of Germany, Chemist, do
hereby declare the nature of this invention to be as follows :-
This invention consists of a method and apparatus for the manufacture of artificial
and mixed silk of or from collodium mixed with ether alcohol and vegetable acid
which substance is pressed through a narrow opening and afterwards passes through
turpentine, juniper oil, 'benzoin benzole, petroleum hydro-carbons in general and
sulphuret of carbon and is drawn into fine threads.
It is known that a solution of collodium exposed to the air is drawn into threads
of a silky nature during which action the ether alcohol, by means of which the
pyroxiline is dissolved, evaporates and that the same result is obtained by heavily
compressing the collodium under water.
According to this invention, the collodium passes through a thin glass tube and
the required thickness of the threads is obtained by drawing them out by means of
a spindle which is placed at a short distance from the narrow opening. The thread
becomes more solid if it is kept for some time in turpentine, juniper oil, benzoin etc.,
these substances destroying the effect of the ether alcohol, vegetable acid etc. The
ether alcohol and the vegetable acid is recoverable from the other fluids by
means of distillation. A thread of silk, cotton or wool is twisted with the
collodium thread and the thread thus obtained is the so-called mixed thread.
The collodium is pressed through a tube which connects the receiver or tank (at
one side of which is a gauge glass) with another tube and from the latter it passes
through several narrow tubes provided with taps or cocks for the purpose of closing
the same.
Each of these narrow tubes is connected by means of an indiarubber tube or joint
with a curved glass tube leading into a second receiver and made tapering towards
its point of emergence therein. This receiver is filled with oil of turpentine and
petroleum and the level of these fluids must be somewhat less than that of the
collodium in the first receiver.
When the collodium leaves the curved tube and enters the receiver in which are
the other fluids it assumes the shape of a thick thread. The pressure which causes
the collodium to leave the basin in which it is contained must be very slight. The
ether alcohol and vegetable acid which is in the collodium are dissolved in the
fluids contained in the second receiver and the remaining collodium is drawn into a
silky thread.
The fluid containing the dissolved ether alcohol vegetable acid and other fluids
pass constantly through a tube connected out of the second receiver or basin which
is supplied with fresh fluid in such a manner that a uniform level is maintained.
A certain number of the threads meet and pass through or over an eye or gatherer
and when a mixed thread is to be made they are here mixed with other threads

page_text: coming from bobbins and entering at the bottom of the compartment through a
narrow opening therein. The gathered threads are twisted by a flyer or the like
as in spinning and thereafter wound upon drums.
A directing bar which moves to and fro winds the threads evenly round the
drums in spiral form.
The compartment containing the drums and the threads must be hermetically
closed making it possible however to easily remove the drum if necessary. These
compartments are closed with glass plates or covers (a separate one for each spindle)
and are provided with and can be opened by means of a rope and weight running
over pulleys. The bottom of the compartment prevents the ether alcohol and
vegetable acid gases from escaping and is provided with taps or cocks which
can be opened should the air inside become too hot and by means of which the
condensation can be facilitated.
A large part of the bottom of the compartment is kept cold by water by means
of supply and discharge pipes.
The condensed ether and alcohol constantly passes through the tube leading to
the first receiver.
Situated near the drums is a tubo which leads into the apparatus and is filled with
hot water for the purpose of facilitating the evaporation of the ether alcohol and
vegetable acid remaining in the threads wound on the drums.
The motion of the drums is transmitted to the flyers by means of conical wheel
arrangements, and by means of a lever it is possible to stop the motion of one or
more drums.
The silk thus manufactured of collodium is of a highly combustible nature owing
to the quantity of nitre contained in the threads and in order to remove the nitre it.
is necessary to wash the threads in dilute sulphuric acid or solution of an alkaline
sulphate (sulphate of potash) of specific weight of 1.205 and afterwards in water.
Dated this 11th day of T... 1001
Improvements in the Manufacture of Artificial Silk and Mixed
Threads, and in Apparatus therefor.
I, FRIEDRICH LESHNER, of Augsburg, in the Empire of Germany, Chemist, 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
The object of this invention is to manufacture threads resembling silk from
collodion or in other words nitrated cellulose or a mixture containing this and also
to form mixed threads by the addition of other fibrous matters thereto in the course
of manufacture as hereinafter described.
The material of which the threads are composed consists preferably of a mixture
of resin, such as copal, sandarach, dammar etc., linseed oil, nitrated cellulose and if
desired also any inorganic salt suitable to render the thread fireproof. These
materials are first made up in three solutions; viz. (a) 500 parts of resin dissolved
in 2400 parts of ether and 100 parts of linseed oil added and the whole solution
filtered (b) Any kind of cellulose, tissue paper, cotton, cotton waste boiled
or warmed in a five per cent. solution of caustic potash or caustic soda or the copper
oxyde of ammonia for about a quarter of an hour. This destroys the fibres and
allows them to be more easily nitrated. The mass is washed in warm water and
dried at a temperature of about 110° centigrade. It is then steeped in a fine state
of subdivision, in a mixture of four parts sulphuric acid of 1-84 specific gravity and
three parts of nitric acid of 14 gravity, at a temperature of 75° C. until it is
converted into nitro-cellulose which is then well washed and dried and afterwards

page_text: dissolved in wood-spirit or ethylic-alcohol (ono part in nino parts). The third
solution consists of 100 parts of acetate of soda or of any salt of ammonia dissolved
in 1000 parts of spirits of wine containing water.
The three solutions are mixed in such proportions that to each 1000 parta
of nitro cellulose, about 200 parts of resin, 50 parts linseed oil and 100 parts of
acetate of soda, or ammonia salts are added, and the resulting mixture forms
a substance from which shining threads may be made by simply allowing the
mixture to flow out of an opening into the air-and-winding-the-thread-so-formed-on
a--rotating warmed-cylinder or suitable-moving surface, so that the solvents are
evaporated and the solids remain behind as a firm filament.
In-place-of-allowing The material to-flow-out-into-the-air, -it-may-be is allowed to
flow out of an opening for instance a small but not too narrow pipe with an opening
of about a millimeter, under a pressure of a few centimeters into turpentine oil,
juniper oil, benzine, benzole, petroleum or other liquid hydrocarbon or bisulphide
of carbon, but not into water. The filament so forming in the liquid may be
drawn finer therein and by remaining a length of time in the liquid may attain the
desired degree of solidity.
A further mixture suitable for the manufacture of thread may be made as.
follows:-
Silk refuse of all kinds such as that unsuitable even for the manufacturo of floss silk
is well washed and steeped for about 24 hours in concentrated solution of potash or
soda, or in copper oxyde of ammonia, whereby the silk substance is dissolved. The
solution is filtered, diluted with water and neutralized with an acid so that the
silky substance, a mixture of fibroine and serisino separates as fine threads. This
is then well washed in water and dissolved in acetic acid (concentrated).
The cellulose, silk paper, cotton etc. before mentioned is also propared with
alkali and nitrated, and the nitrocellulose is dissolved in a mixture of wood spirit
and ether to which a little sulphuric ether has been added. This solution is mixed
with that of the silk in such proportions that 5 parts of nitrocellulose are used to
one part of silk, and the resulting material is converted into a thread exactly as
before described by allowing it to issue into-the-open-air or under a slight pressure
into the liquids before mentioned.
Also without the addition of the resin or of the silk, nitrocellulose dissolved in
wood spirit, ethylic-alcohol, and sulphuric ether may be used alone to form a thread.
Reference being made to the annexed drawing, the thread may be formed in the -
liquid as follows:-
The mixture issues from the opening e either as a thick thread or as a drop-
which is taken by a wire and drawn slowly out the fineness of the resulting filament
being according to the speed of the drawing. The mixture issues quite soft but
being drawn much thinnor rapidly solidifies and attains its ultimate form within
about one third of its course. If the thread were drawn in water this would not
occur and the thread would be dull in appearance. The thread made by simply
allowing the mixture to flow into the liquid and drawing it thorein to the desired
fineness obviates heavy pressure to expel the mixture or fine openings therefor
which are liable to become choked.
As the thread is drawn it may be wound with or mixed with a fibrous thread
such as one of silk, cotton, wool or other desired material drawn from a reel or
otherwise supplied along with the thread drawn.
Fig. 1 is a longitudinal section of the machine.
Fig. 2 is a plan thereof.
t
A is the reservoir for the liquid mixture with gauge a to show the height of level
of the mixture therein which should be kept so far as possible at a uniform level.
The mixture flows through pipe B to the cross pipe B¹ with a number of outlet
pipes c closed each by a cook 1. Each pipe c is connected by a piece of rubber
tube d with a bont glass pipe e drawn to a point and entering the vessel G which is
supplied with the petroleum, turpentine oil, or other liquid before mentioned,
through a pipe H, the overflow being taken off through pipe h. The level of

page_text: liquid in C is lower than that in A, so that owing to the difference of pressure the
mixture passes from A into G and collects in drops on the ends of the pipes e.
The drops are taken by wires and drawn out of the vessel (and the endless
threads i hanging to them are drawn over the guide k, through the twisters O and
guido R to be wound on the drums or frames L, which are revolved to draw the
threads out of the reservoir G, by means of gear from shaft C (each having a
separate clutch 7), the speed of revolution governing the fineness of the drawing.
The filaments or slivers drawn out and made thinner as aforesaid gathered by the
guides are spun into a thread at o. The most part of the solvents used for the
materials of the mixture in A are separated in the vessel G and pass away with
the overflow from said vessel G through the pipe h. They may be separated by
distillation for use again. But a certain part of the contents of the thread.
vaporises (under heat from pipe 4) during the further travel of the thread and
condenses on floor Z of the chamber K which is provided above with hinged
doors xy, for access to the interior. The condensed spirit etc. in Z is cooled by
the water jacket q under the lowest part of the chamber, 1 boing the cold water
inlet 2 the outlet. The condensed liquid is further cooled in the worm 3 and falls
into a reservoir at the base of the latter.
The thread to be added to that produced as described is passed from a bobbin M
through a hole m to the gatherer and spun with the thread by the spinner o which
consists of a small tube n through which the thread passes leaving through a side
hole. The tube n forms part of the disk revolved by strap from the pulley p and
gives a slight twist to the thread which is wound on the frame L by the guide R
which travels endwise to regulate the winding.
The thread may pass only once round the drum L and be thence forwarded to a
spinning machine such as an ordinary bobbin and fly-frame, but in any case at
least one turn of the thread around the drum L is necessary to regulate the
drawing and allow for the perfect drying of the thread.
The threads made are very inflammable. To correct this if desired they may be
steeped in dilute sulphuric acid, then well washed and steeped in a dilute alkaline
solution or finally washed therein. Or they may be steeped in a solution of sulphate
of potash in water of about 1.26 specific gravity. This removes the nitro-groups
without hurting the thread.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1) The method-of-producing threads alone or in combination with other threads
as-heroin-set-forth.
2) The method of producing threads by drawing out a mixture of resin dis-
solved in ether, a cellulose nitrated as described and dissolved in wood spirit and
ether-alcohol, with addition of acetate of soda or salts of ammonia.
3) The--method of producing artificial-silk-by-dissolving-natural--silk--or--by
specially prepared nitrocellulose-dissolved-in-wood-spirit, other and sulphurie
other.
4) The method of producing threads by allowing a mixture as described to flow
out-of-a-small-opening-under-very-slight-pressure.
5)2 The method of producing threads by allowing a mixture as described to issuo
into a liquid hydrocarbon or other liquid herein described.
6) 3 The method of producing threads by drawing a mixture as described, in a
liquid hydrocarbon or other liquid as set forth.
7) In the method herein described the recovery of the solvents from the bydro-
carbon-or-other-liquid-as-described.
8) The formation of a thread-as-set-forth-by-twisting threads-made as described
with-a-thread-of-silk, cotton-weel-or-other desired material.
9) The apparatus herein described consisting of reservoir A with pipes--B B-c
in-combination with vessel G-with-pipes-e-for-the-purpose-described.

page_text: 10) The arrangement of the thread drawing mechanism in a closed chamber K
for the purpose set forth.
H)4 The arrangement of drawing mechanism within a closed chamber in com-
bination with a spinning machine outside the said chamber.
12 The twister herein described consisting a tubo n with disk thereon.
13 In the process herein described the combination of the frames L with the
heating tube 4.
14. The arrangements in the chamber K for condensation of the solvents
volatilized from the threads substantially as set forth.
15) The combination of several drums L with one motive shaft C and a separate
clutch notion for each drum:
16) The methods of denitrifying the threads herein described.
Dated this 11th day of April 1892.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.