Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
In the textile industry, manufacture and finishing
of filaments and yarns are usually carried out separately
as individual process steps. The laying-on and insertion
of filaments does not offer any particular problem in a
'. discontinuous procedure of this kind. The insertion or
threading of filaments into closed systems is also known
i per se.
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, ~; The manufacture of textile filaments and yarns
,~ - becomes a rational process only when the individual steps
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~ ;~, of the process are combined with one another, i.e., when
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spinning, stretching and then texturing are carried out
in a single continuous, sequential operation (see, for
example, Swiss Patent Specification 546,284 and German Laid-
open Pending Patent Application 1,435,640~. In such pro-
cedure, a continuous filament flow is obtained from the
first step, but in subsequent steps of the process, this
; filament flow cannot be simply passed or introduced
through closed systems, such as a nozzle, without stopping
the apparatus.
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105Z990
German Laid-open Pending Patent Application
2,164,802 discloses a method of drawing or threading con-
tinuous yarn into a fixedly mounted texturing device main-
tained at operating temperature. The yarn is drawn or
threaded into the passage of the texturing device by means
of a wire loop which can be moved through the passage, the
yarn being cut practically simultaneously with the drawing
or threading operation by means of a pair of magnetic yarn
shears located between the wire loop and a lateral suction
gun which picks the continuous yarn up before it is dra~n
into the passage. The essential structural element of this
arrangement is a spring gun which serves to draw the yarn
into the passage. The spring gun consists of a guide sleeve,
-' a compression spring, a pin, a clamping sleeve screwed to-
gether with the pin for gripping the wire loop together
with the associated clamping piece, a sliding piece for
tensioning the compression spring, and an electromagnetic
device for releasing the tensioned compression spring.
, The end of the guide sleeve which is opposite the clamping
sleeve is closed by means of a threaded cap. A rubber ring
` softens the impact of the pin (see Fig. 1 of the said Laid-
open Pending Patent Application). Thus, the continuous
filament flow is threaded through the closed system of the
texturing apparatus by means of a wire loop and a rather
- 25 elaborate spring gun assembly. Moreover, the closed system
must be so designed that it automatically takes over the
further transport of the filament.
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A new method has now been found which enables a
s filament such as a polymer yarn like poly- -caprolactam
to be threaded with a minimum
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lOSZ990
of mechanical elaborateness and at full production rate into
a closed nozzle system as is usually represented by a tex- :
turing device. For best results, any such system or method
must consider 1) the temperature of the nozzle system in
question is above the melting point of the filament,
2) the closed nozzle system does not take over the transport
of the filament and 3) the system should neither scratch nor
damage the filament.
Thus, the present invention relates to a process and
apparatus for threading filaments or yarn into narrow
passages. The method of the invention comprises the steps .:
of picking up said filament or yarn with a suction gun,
.:.,
` employing an auxiliary filament having a looped end and a
free end; threading said free end through said narrow passage, ~:
moving said continuous filament or yarn through said looped ~;
end, engaging said free end in a suction gun and cutting the `
continuous filament or yarn as said looped end of the auxiliary --
`~ filament is drawn through said narrow passage thus drawing
said continuous filament or yarn through said narrow passage.
The apparatus of the invention comprises a movable
suction gun for picking up filaments or yarns, an auxiliary
. filament having a free end and a looped end, a guide frame,
a release device, a cutting device, and a stationary suction
gun, said release device, said cutting device, and said
stationary suction gun being mounted on said guide frame, said `~
looped end being affixed to said release device and said free ~ ~
. end being threaded through said narrow passage whereby said ~: -
. movable suction gun can pick up and carry said continuous
filament or yarn through said looped end and transfer said
30 filament or yarn to said stationary gun and further pick up
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105Z990
said free end of said auxiliary filament, draw said auxiliary
filament through said narrow passage; and cause the release
of said looped end, said looped end pulling said continuous
filament or yarn through the cutting means while it also
pulls said continuous filament or yarn through said narrow
passage.
The method according to this invention satisfies these
requirements and very generally allows filament flows to
.....
be threaded into any kind of passage of relatively small
10 diameter and transported further without stopping the ap- -
paratus concerned. Such passages need not be self-feeding
.
- as suction and transport may be provided with a movable suction
' gun. Arriving at high speed, the main filament is held and
-~, carried away laterally by means of a suction system. At~ -
a speed which is at least as high, the main filament is
then pulled through the opening of the closed system by a
looped auxiliary filament. A suction device with a high
suction power is employed to pull the filament in a selected
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;', direction. The main filament is then cut at the instant of
20 the pulling movement to form a counter-loop. (The length
of the loop corresponds to the distance between the contact
-' point of the two filaments and the cutting point ). More-
over, an automatic release device frees the auxiliary filament
to allow the pulling movement.
For best results, the auxiliary filament may consist
s of a multifilament resistant to high temperatures
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such as an aramide (aromatic amide), which, at the instant
of maximum loading, exhibits favorable elongation behavior.
The elongation behavior should correspond basically to that
of the main filament.
Referring now to the drawings:
Fig. 1 is a diagramatic side view of the entire
threading system;
Figs. 2 through 5 sequentially depict the basic
steps of the threading method. - ~
Fig. 1 shows diagrammatically the entire threading
system with the closed system (6) into which the main fila-
ment is to be threaded, the main filament (8) the auxiliary
filament together with the loop (9) and a pair of suction
` guns (2,7).
The threading arrangement proper comprises the
release device (1) for the auxiliary filament, a suction
gun (2), a cutting device (3), which is preferably sharp
and V-shaped, and a guide frame (4). The suction gun (2),
the cutting device (3) and the filament guiding roller (5)
are advantageously located along a substantially straight
line above the closed system (6), the narrow opening of
which must be traversed by the main filament (8). This
arrangement can be constructed as an independent auxiliary
unit and then be brought up to the machine in question when ~-
needed.
Moreover, it should be pointed out that this in-
vention produces a low surface pressure at the point of
contact of the main and auxiliary filaments. Accordingly,
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the risk of breaking the main filament is slight and
reliability of operation is improved. In addition, only
a small investment is required for putting this method -
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into effect. Besides the suction units which are conventi-
; onally employed, the only other necessary elements are
a simple cutting device consisting of a pair of sharp
cutting blades arranged in the form of a V, a filament
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guiding roller, a filament guiding frame and a mechanically
operating rocking device, which merely has to be in the form
. of a lever with a counterweight (Release device 1). Highly
refined apparatus of the type previously used in the art i -
are completely dispensed with and it is also possible to
dispense with the filament guiding roller (5) where there
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is a constantly smooth supply of filament.
The threading arrangement employed can be used
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universally for introducing filaments into closed systems
having a small opening.
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Example
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-~, Referring to Figs. 2 through 5, nylon 6 fila-
ment is spun (lO) with a spinning size of denier 6000 and 136
fibrils per bundle. The bundle of fibrils is picked up with
a movable suction gun (13) and placed in conventional fashion
on the stretching system (11) (Fig. 2).
. ~ .
The gun is then moved into position to transfer
. the bundle of fibrils from the transportable suction gun (13)
to the stationary suction gun of the threading arrangement
(15). The threading arrangement is provided with an
auxiliary aramide filament (1~) consisting of Keflar 29 -~
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105'~990
(Registered Trademark of Du Pont, U.S.A.), which has first
been drawn through the texturing chamber (14). The auxiliary
filament, which extends out of the lower end of the chamber
housing (14) for about 30 cm, is now picked up with the
transportable suction gun (13) (Fig. 3).
On approach of the suction gun (13) to the lower
end of the chamber housing, the induced suction increases
to such an extent that the release device present in the
threading arrangement (15) is tripped. The auxiliary fila-
ment, which is sucked in and accelerated very powerfullyby the suction gun (13), drags the main filament through
a conventional closed texturing unit (14) which has been
preheated to 300C. As a result of the downward movement,
the main filament is cut through on the cutting device
(3 in Fig. 1) present in the threading arrangement (15).
~ This terminates the actual threading operation (Fig. 4).
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The yarn is now placed or laid on the winding
system (12) with the aid of the suction gun (13) (Fig. 5).
The speed at which the 2000 g/den main filament
may be conveyed through the texturing unit is 1800 m/min.
The diameter of the filament passage in this example is
preferably 2.1 mm.
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Many modifications of the invention described
above may occur to those skilled in the art. It is in-
tended to cover all such modifications which fall within
- the spirit and scope of the invention as defined in the
claims appended hereto.
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