U.S. patent application number 14/421316 was filed with the patent office on 2015-08-20 for melt-spinning method and melt-spinning apparatus for producing a crimped yarn.
The applicant listed for this patent is Oerlikon Textile GmbH & Co. KG. Invention is credited to Mathias Stundl.
Application Number | 20150233020 14/421316 |
Document ID | / |
Family ID | 48949144 |
Filed Date | 2015-08-20 |
United States Patent
Application |
20150233020 |
Kind Code |
A1 |
Stundl; Mathias |
August 20, 2015 |
MELT-SPINNING METHOD AND MELT-SPINNING APPARATUS FOR PRODUCING A
CRIMPED YARN
Abstract
A melt-spinning method and a melt-spinning apparatus produce a
crimped yarn. In this case, by spinning of a plurality of
filaments, at least one filament bundle is generated from a
thermoplastic polymer, is cooled and drawn and is compressed by
means of an air stream in a stuffing chamber into a yarn plug, the
yarn plug being opened up into a crimped yarn and being wound into
a bobbin. So that the tendency to shrinkage and the crimp
resistance on the crimped yarn can be set independently of one
another, before compression, the drawn filament bundle is heated,
in a first heat treatment for expansion, to a relaxation
temperature and, in a second heat treatment for preliminary thermo
control, to a crimping temperature. For this purpose, at least one
further treatment means for the heat treatment of at least one
filament bundle before entry into the stuffing chamber is provided
between a drawing device a texturing device.
Inventors: |
Stundl; Mathias; (Wedel,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Oerlikon Textile GmbH & Co. KG |
Remscheid |
|
DE |
|
|
Family ID: |
48949144 |
Appl. No.: |
14/421316 |
Filed: |
August 8, 2013 |
PCT Filed: |
August 8, 2013 |
PCT NO: |
PCT/EP2013/066608 |
371 Date: |
February 12, 2015 |
Current U.S.
Class: |
264/168 ;
425/72.2 |
Current CPC
Class: |
D10B 2503/04 20130101;
D01D 5/22 20130101; D10B 2331/04 20130101; D02J 13/001 20130101;
D01D 10/02 20130101; D01D 5/08 20130101 |
International
Class: |
D01D 5/22 20060101
D01D005/22; D01D 10/02 20060101 D01D010/02; D01D 5/08 20060101
D01D005/08 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 23, 2012 |
DE |
10 2012 016 799.7 |
Claims
1. A melt-spinning method for producing a crimped yarn, in which at
least one filament bundle is generated from a thermoplastic polymer
by the spinning of a plurality of filaments, in which, after
cooling, the filament bundle is drawn and is compressed by means of
a thermally controlled air stream in a stuffing chamber into a yarn
plug, and in which the yarn plug is opened up into a crimped yarn
and wound into a bobbin, wherein, before compression, the drawn
filament bundle is heated, in a first heat treatment of expansion,
to a relaxation temperature and, in a second heat treatment for
preliminary thermo control, to a crimping temperature.
2. The method as claimed in claim 1, wherein, for the second heat
treatment, the filament bundle is guided in a plurality of loopings
on a hot godet pair with heated godets.
3. The method as claimed in claim 1, wherein, for the first heat
treatment, the filament bundle is guided in a plurality of loopings
on a drawing godet pair with heated godets.
4. The method as claimed in claim 1, wherein the relaxation
temperature for the expansion of the filament bundle is identical
to the crimping temperature for the preliminary thermo control of
the filament bundle.
5. The method as claimed in claim 1, wherein the relaxation
temperature for the expansion of the filament bundle lies above the
crimping temperature for the preliminary thermo control of the
filament bundle.
6. The method as claimed in claim 1, wherein the relaxation
temperature for the expansion of the filament bundle lies above the
crimping temperature for the preliminary thermo control of the
filament bundle, and in that the filament bundle is slightly drawn
between expansion and preliminary thermo control.
7. A melt-spinning apparatus for producing a crimped yarn, with a
melt-spinning device, with a cooling device, with a drawing device,
with a texturing device which has a conveying nozzle and a stuffing
chamber, and with a winding device, the drawing device having a
take-off godet pair and a drawing godet pair with heated godets,
wherein at least one further treatment means for the heat treatment
of at least one filament bundle before entry into the texturing
device is provided between the drawing device and the texturing
device.
8. The apparatus as claimed in claim 7, wherein the treatment means
is designed as a hot godet pair with heated godets.
9. The apparatus as claimed in claim 7, wherein the drawing godet
pair and the hot godet pair have in each case a heating control
appliance, by means of which a plurality of godet heating means can
be controlled.
10. The apparatus as claimed in claim 9, wherein the heating
control appliances are connected to a process control unit.
11. The apparatus as claimed in claim 7, wherein the texturing
device has a cooling drum for cooling a yarn plug guided out of the
stuffing chamber.
Description
[0001] The invention relates to a melt-spinning method for
producing a crimped yarn, according to the preamble of claim 1, and
to a melt-spinning apparatus for producing a crimped yarn,
according to the preamble of claim 7.
[0002] A generic method and a generic apparatus are known from WO
2011/138 302 A1.
[0003] When crimped yarns, which are preferably used for production
of carpets, are being produced in a melt-spinning process, all the
treatment steps for generating the desired physical properties of
the yarn usually take place in succession. First, a multiplicity of
filaments are extruded from a polymer melt and, after cooling, are
brought together as a filament bundle, prepared and drawn. After
the drawing of the filament bundle, compression of the filament
bundle takes place inside a stuffing chamber, in which the filament
bundle is conveyed by means of a preferably heated air stream.
Inside the stuffing chamber, the filaments are deposited in curves
and loops to form the yarn plug, subsequent cooling of the yarn
plug bringing about a fixing of the loops and curves of the
filaments which causes crimping.
[0004] In the method known in the prior art and in the known
apparatus, the godet pairs used for drawing the filament bundle are
designed to be heated. Thus, the filament bundle is taken off from
the spinning device by means of a take-off godet pair and is heated
to a temperature necessary for drawing. The drawing of the filament
bundle takes place between the take-off godet pair and a following
drawing godet pair. The drawing godet pair is likewise designed
with heated godets, so that thermally controlled expansion takes
effect on the filament bundle. Subsequently, the drawn and expanded
filament bundle is immediately compressed into the yarn plug by
means of a hot air stream. The bends, loops and curves of the
filaments within the yarn plug cause crimping. Depending on the
process settings, different crimping intensities are obtained, the
temperature of the yarn material having a decisive influence as a
setting parameter. Thus, in general, the higher the yarn
temperature is before compression, the more ductile the filaments
are and the more easily crimping can be imparted.
[0005] In the prior art, there is, however, the problem that the
yarn temperature of the filament bundle before compression depends
essentially upon the expansion of the filament bundle at the heated
drawing godet pair. Moreover, on top of this, the conveying medium,
for example hot air, also gives rise to thermal effects on the
filament bundle.
[0006] The object of the invention, therefore, is to develop a
melt-spinning method and a melt-spinning apparatus of the generic
type, in such a way as to ensure that crimping can be set in a
stipulated way via the yarn temperature of the filament bundle.
[0007] A further aim of the invention is to make available a
melt-spinning method and a melt-spinning apparatus in which the
physical properties of the yarn can be set individually in terms of
shrinkage and crimping.
[0008] This object is achieved, according to the invention, for the
melt-spinning method in that, before compression, the drawn
filament bundle is heated, in a first heat treatment of expansion,
to a relaxation temperature and, in a second heat treatment for
preliminary thermo control, to a crimping temperature.
[0009] The melt-spinning apparatus according to the invention
offers the solution in that at least one further treatment means
for the heat treatment of a filament bundle before entry into the
stuffing chamber is provided between the drawing device and the
texturing device.
[0010] Advantageous developments of the invention are defined by
the features and feature combinations of the respective sub
claims.
[0011] The invention is distinguished in that, before compression,
two separate heat treatments are provided on the drawn filament
bundle and are coordinated with those respective physical
properties of the yarn material and of the filaments which are to
be influenced. Thus, the first heat treatment provided immediately
after drawing can be utilized in order to carry out desired
expansion on the filament bundle in order to obtain a specific
shrinkage on the yarn. Shrinkage in this case characterizes the
ability of the yarn to reduce the yarn length under thermal load.
The second heat treatment is independent of the first heat
treatment and may advantageously be utilized in order to obtain on
the filament bundle a crimping temperature which is desired for
compression and therefore for crimping. Crimping is the capacity
for resilience of the filaments after mechanical load.
[0012] In order, within the filament bundle, to heat each of the
stringily guided filaments to a desired crimping temperature, the
method variant is preferably used in which, for the second heat
treatment, the filament bundle is guided in a plurality of loopings
on a hot godet pair with heated godets. Owing to the number of
loopings of the filament bundle on the hot godet pair, relatively
long dwell times can be achieved, even at higher thread running
speeds, and ensure uniform full heating of the entire filament
bundle. The godet casings of the heated godets are in this case
heated to the desired crimping temperature.
[0013] The first heat treatment is advantageously carried out
directly on a drawing godet pair of heated godets, so that there is
no need for any additional treatment means for expansion of the
filament bundle.
[0014] Since the properties of the filaments extruded from a
thermoplastic polymer can be influenced vary greatly by the
subsequent heat treatments, the melt-spinning method according to
the invention offers high flexibility in the setting of various
combinations of crimping and shrinkage. Thus, it is generally known
that a low treatment temperature leads during expansion to
increased shrinkage and during compression to low crimping.
[0015] Conversely, at relatively high treatment temperatures the
filaments undergo low shrinkage during expansion and higher
crimping during compression. In order to obtain a crimped yarn
having balanced properties, the method variant is preferably used
in which the relaxation temperature for the expansion of the
thermal bundle is identical to the crimping temperature for the
preliminary thermo control of the filament bundle.
[0016] Consequently, crimped yarns with low shrinkage and intensive
crimping or crimped yarns with low crimping and increased shrinkage
can be generated.
[0017] The method variant in which the relaxation temperature for
the expansion of the filament bundle lies above the crimping
temperature for the preliminary thermo control of the filament
bundle is especially suitable for producing a crimped yarn with low
shrinkage and low crimping. Since crimping not only determines the
bulkiness of the yarn, but also has an appreciable influence upon
the appearance of the yarn in the carpet, special color apparitions
can consequently be generated in the carpet.
[0018] To produce crimped yarns with relatively high shrinkage and
high crimping, the method variant is provided in which the
relaxation temperature for the expansion of the filament bundle
lies above the crimping temperature for the preliminary thermo
control of the filament bundle, and in which the filament bundle is
slightly drawn between expansion and preliminary thermo control. To
that extent, the method according to the invention is especially
suitable for implementing special effects both in the yarn and in
the subsequent carpet end product.
[0019] The melt-spinning apparatus according to the invention, in
principle, affords the possibility that the treatment means for the
second heat treatment could be formed by conventional heating means
known in the fiber industry. At the transition of the filament
bundle from the drawing device to the texturing device, for
example, a radiant heater or a steam nozzle can be used for heating
the filament bundle to a crimping temperature.
[0020] However, the variant is especially advantageous in which the
treatment means is designed as a hot godet pair with heated godets.
Consequently, depending on the yarn titer, the dwell time for heat
treatment can be varied in a simple way by the choice of the number
of loopings. The melt-spinning apparatus is thus suitable for
crimped yarns of any type.
[0021] The high flexibility in carrying out the heat treatments is
also improved in that, according to an advantageous development,
the drawing godet pair and the hot godet pair have in each case a
heating control, by means of which a plurality of godet heating
means can be controlled. Thus, the separate heat treatments by the
drawing godet pair and by the hot godet pair can be controlled and
regulated independently of one another.
[0022] For stipulating the desired relaxation temperature and the
desired crimping temperature, the heating controls are preferably
connected to a process control unit which stipulates the process
parameters.
[0023] To fix the material variations triggered as a result of the
heat treatments, the apparatus is preferably used with a texturing
device which has a cooling drum for cooling a yarn plug lead out of
the stuffing chamber. Only after all the compressed filaments
within the yarn plug are thermally controlled to a desired cold
temperature is the yarn plug opened up into the crimped yarn.
[0024] The melt-spinning method according to the invention and the
melt-spinning apparatus according to the invention are suitable, in
principle, for all thermoplastic polymers which are used for fiber
production. Thus, crimped yarns can be produced from polyolefins,
polyamides, polyesters or other polymers, such as, for example,
PTT, PLA.
[0025] The melt-spinning method according to the invention and the
melt-spinning apparatus according to the invention are explained in
more detail below by means of some exemplary embodiments, with
reference to the accompanying figures in which:
[0026] FIG. 1 illustrates diagrammatically a view of a first
exemplary embodiment of the melt-spinning apparatus according to
the invention, and
[0027] FIG. 2 illustrates diagrammatically a view of a further
exemplary embodiment of the melt-spinning apparatus according to
the invention.
[0028] FIG. 1 illustrates diagrammatically a view of a first
exemplary embodiment of the melt-spinning apparatus according to
the invention for producing a crimped yarn from a thermoplastic
polymer. The exemplary embodiment of the melt-spinning apparatus
according to the invention is shown by the example of one yarn run,
although melt-spinning apparatuses of this type are also used for
the production of a plurality of yarns next to one another in
parallel.
[0029] The exemplary embodiment, shown in FIG. 1, of the
melt-spinning apparatus according to the invention has a spinning
device 1, a cooling device 5, a drawing device 11, a texturing
device 15, a posttreatment device 20 and a winding device 24, which
are arranged one behind the other to form a yarn run. In this
exemplary embodiment, the spinning device 1 is illustrated by a
spinning head 2. The spinning head 2 is designed to be heated, in
order to control thermally the assemblies and lines used for
guiding and distributing a polymer melt. Thus, the spinning head 2
has at its underside a spinneret 3 which is coupled to a spinning
pump, not illustrated here. The spinneret 3 carries on its
underside a nozzle plate with a multiplicity of nozzle bores,
through which a multiplicity of filaments are extruded. Such
spinnerets are sufficiently known and in that respect are not
described in any more detail here. The polymer melt supplied by an
extruder, not illustrated here, is supplied to the spinning head 2
via a melt inflow 4.
[0030] When a plurality of yarns are being produced next to one
another in parallel, the spinning head 2, which is also designated
by specialists as a spinning beam, carries a plurality of
spinnerets next to one another.
[0031] Underneath the spinning device 1, a cooling device 5 is
provided, which forms a cooling shaft 6 for the reception of
freshly extruded filaments, the cooling shaft 6 being assigned a
blowing means 7 for generating a cooling air stream. The cooling
air may in this case occur from the outside inward by means of
cross flow blowing or radial blowing. In principle, however, there
is also the possibility of conducting a cooling air stream through
the filament bundle radially from the inside outward.
[0032] After cooling, the filaments 8 generated by the spinnerets 3
are brought together into a filament bundle 10. For this purpose, a
preparation device 9 is provided underneath the cooling device 5.
The preparation device 9 conventionally has a collective yarn guide
and a wetting means. The wetting means used may be preparation pins
or preparation rollers.
[0033] The preparation device 9 is followed in the yarn run by a
drawing device 11 which is formed in this exemplary embodiment by a
take-off godet pair 12 with two heated godets 12.1 and 12.2 and by
a drawing godet pair 14 with the heated godets 14.1 and 14.2. The
godet heating means used for heating the godets 12.1 and 12.2 of
the take-off godet pair and the godets 14.1 and 14.2 of the drawing
godet pair 14 are illustrated symbolically and are characterized by
the reference symbols 12.3 and 14.3. The heated godets 12.1 and
12.2 and also 14.1 and 14.2 are arranged in each case in a godet
box 13. There is in this case, in principle, the possibility that
the godet pairs 12 and 14 are arranged in separate godet boxes or
in one common godet box.
[0034] So that the respective surface temperatures of the heated
godet casings of the godets 12.1 and 12.2 can be set, the godet
heating means 12.3 are coupled to a heating control appliance 27.1.
The godet heating means 14.3 of the drawing godet pair 14 are
likewise coupled to a separate heating control appliance 27.2. The
heating control appliances 27.1 and 27.2 are connected to a process
control unit 31.
[0035] Further along the yarn run, a further godet pair, which in
this case is designated as a hot godet pair 26, is provided between
the drawing device 11 and the texturing device 15.
[0036] The hot godet pair 26 has two heated godets 26.1 and 26.2
with the assigned godet heating means 26.3. In this exemplary
embodiment, the godets 26.1 and 26.2 are likewise arranged in a
godet box 13. To set the respective surface temperatures of the
heated godet casings of the godets 26.1 and 26.2, the godet heating
means 26.3 are connected to a further heating control appliance
27.3. The heating control appliance 27.3 is coupled to the process
control unit 31.
[0037] In this exemplary embodiment, the texturing device 15 is
formed by a conveying nozzle 16 and a stuffing chamber 17 which is
arranged on the outlet side of the conveying nozzle 16 and which
cooperates with a following cooling drum 19. The conveying nozzle
16 is coupled to a compressed air source in order to convey the
filament bundle 10 into the stuffing chamber 17 by means of an air
stream and to compress it into a yarn plug. The air stream for
conveying the filament bundle is preferably heated. The yarn plug
18 is cooled on the circumference of the cooling drum 19 by cooling
air.
[0038] The texturing device 15 is followed by a posttreatment
device 20 which, on the one hand, opens up the yarn plug 18 by
taking off a crimped yarn on the circumference of the cooling drum
19 and, on the other hand, performs intermingling of the yarn to
increase the yarn strength. For this purpose, an intermingling
nozzle 22 is arranged between two guide godet units 23.1 and 23.2.
Each of the guide godet units 23.1 and 23.2 has a godet and an
auxiliary roller.
[0039] At the end, the crimped yarn 21 is wound into a bobbin 25 by
means of the winding device 24. For this purpose, the winding
device 24 has a reeling turret 28 with two projecting reeling
spindles 29.1 and 29.2. The reeling spindles are guided
successively into a winding region and a changing region in order
to wind the crimped yarn continuously into bobbins. Such winding
devices are generally known, and therefore there will be no further
description in this respect at this juncture.
[0040] In the exemplary embodiment, illustrated in FIG. 1, of the
melt-spinning apparatus, for example via an extruder, a granulate
of a thermoplastic polymer material, for example a polyester, is
melted down and is supplied to the spinning head 2 via the melte
flow 4. Inside the spinning head 2, the melt is conveyed under
pressure to the spinneret 3 by means of a spinning pump, so that a
multiplicity of filaments 8 emerge on the underside of the
spinneret 3 from the nozzle orifices of the nozzle plate. The
freshly extruded filaments 8 are cooled inside the cooling device 5
by means of a cooling air stream and are brought together at the
end into a filament bundle 10. For this purpose, the filaments 8
are wetted with a preparation fluid, preferably an oil/water
emulsion.
[0041] The filament bundle 10 is taken off from the spinning device
by means of the take-off godet pair 12. The godet heating means
12.3 are set via the assigned heating control appliance in such a
way that the godets 12.1 and 12.2 have on their godet casings a
surface temperature in the range of 90.degree. C. to 100.degree. C.
In this case, the filament bundle 10 is guided with preferably 7 to
15 loopings on the take-off godet pair 12. The yarn material of the
filaments is thereby heated to a temperature suitable for
drawing.
[0042] For drawing the filament bundle 10, the drawing godet pair
14 is driven at a higher speed than that of the take-off godet pair
12, so that the filament bundle 10 is drawn in the yarn section
between the take-off godet pair 12 and the drawing godet pair
13.
[0043] After drawing and before compression, the drawn filament
bundle 10 is heated to a relaxation temperature in a first heat
treatment for expansion. The first heat treatment after drawing is
carried out directly by the drawing godet pair 14. For this
purpose, the godet heating means 14.3 are set via the heating
control appliance 27.2 at a relaxation temperature suitable for the
yarn material. Depending on the type of polymer, the godet casings
of the godets 14.1 and 14.2 have a surface temperature in the range
of 120 to 240.degree. C., preferably of 170 to 210.degree. C. The
surface temperature of the godet casings of the godets 14.1 and
14.2 constitutes at the same time the relaxation temperature at
which the yarn material of the filaments within the filament bundle
10 is heated. For this purpose, the filament bundle 10 is
preferably guided with overall 8 to 12 loopings on the godet pair
14. The number of loopings on the godet pair 14 in this case
determines the dwell time for the expansion of the filaments.
[0044] In order to obtain thermo controls of the filament bundle
which are especially suitable for the texturing operation, in a
second heat treatment the filament bundle is heated to a crimping
temperature. For this purpose, the godets 26.1 and 26.2 of the hot
godet pair are heated by the godet heating means 26.3 to a
predetermined surface temperature of the godet casings. The surface
temperature of the godet casings of the godets 26.1 and 26.2
corresponds to the crimping temperature to which the yarn material
of the filaments is heated. The instructions and settings take
place in this case via the process control unit 31 which is coupled
to the godet control appliance 26.3.
[0045] The setting of the crimping temperature in the second heat
treatment on the drawn filament bundle is dependent upon the in
each case desired yarn effect which is to be achieved on the
crimped yarn. In this case, in principle, the following setting
variants are possible.
[0046] In a first variant, the relaxation temperatures in the first
heat treatment for expansion and the crimping temperature in the
second heat treatment for preliminary thermo control of the
filament bundle are set at an identical level. Depending on the
absolute height of the temperature, different yarn types can be
generated according to the yarn material. Thus, it is generally
known that, at very high relaxation temperatures and crimping
temperatures in the range of above 190.degree. C., expansion leads
to a very low shrinkage behavior. Shrinkage is the ability of the
fibers to become shorter under thermal load.
[0047] The result of setting relatively high crimping temperatures
on the filament bundle is that the ductility of the filaments
increases and therefore intensive bending and loop and curve
formation occur during the compression of the filaments into the
yarn plug. The outcome of this is relatively high crimping and
crimp resistance of the crimped yarn.
[0048] Crimping can in this case be defined as resilience of the
fiber after mechanical load. The higher is the degree of resilience
of the fiber, the more crimp-resistant is the yarn.
[0049] In the first variant, with the relaxation temperature and
the crimping temperature being identical, crimped yarns which are
characterized by relatively high shrinkage and low crimping can
also be produced by setting the temperature level. Thus, sufficient
expansions of the filaments are not generated when the relaxation
temperature of the first heat treatment is very low. The residual
stresses remaining in the filaments then lead to a high tendency of
the crimped yarn to shrinkage. During preliminary thermo control,
low crimping temperatures have the effect of a lack of ductility of
the filaments and lead to low crimping and crimp resistance of the
yarn.
[0050] When the temperature level between the relaxation
temperature and crimping temperature is different, a distinction
can be made between two further variants for the production of
crimped yarns. In a further variant, the heat treatment for
expansion is carried out at a relaxation temperature which is
substantially higher than the crimping temperature in the second
heat treatment for preliminary thermo control of the filament
bundle. A crimped yarn is consequently generated which is
characterized by low shrinkage and low crimping.
[0051] In the variant in which the relaxation temperature in the
heat treatment for expanding the filament bundle is higher than the
crimping temperature in the second heat treatment for the
preliminary thermo control of the filament bundle and in which the
filament bundle is slightly drawn between expansion and preliminary
thermo control, opposite effects occur, so that a yarn with high
shrinkage and high crimping is generated. The amount of post
drawing decisively influences the shrinkage of the yarn which could
lie in the range of -1% to +5%.
[0052] It was shown that, by virtue of the method according to the
invention, crimped yams can be produced which generate special
effects, particularly in carpet production. Thus, it is generally
known that crimping has an appreciable influence not only on the
bulkiness of the yarn, but also on the appearance of the fibers in
the carpet. Thus, color apparition is determined by the crimping. A
highly crimped filaments tends in a carpet to produce duller, less
high-contrast colors, since the eyes are drawn to an increased
extent to more bent side faces of the filaments. However, increased
shrinkage is undesirable, since otherwise, with a thermal load, the
fiber contracts to too great an extent and therefore the pile
height in the carpet is reduced. Carpets with high-contrast colors
therefore tend to be produced with crimped yarns which are
characterized by low crimping and low shrinkage.
[0053] In the exemplary embodiment of the melt-spin apparatus
according to the invention, as shown in FIG. 1, the first and the
second heat treatment on the drawn yarn are carried out in each
case by means of godet pairs. Such a heat treatment proved
appropriate particularly at high process speeds in the region of
4000 m/min, such as are customary in the production of crimped
yarns. Longer dwell times can also be implemented by the choice of
the loopings of the filament bundle. In principle, however, heat
treatment by a godet pair is not absolutely necessary. Thus, other
treatment means customary for the heating of fibers may also be
used in order to carry out expansion on the filament bundle or
preliminary thermo control of the filament bundle. Thus, it is
possible that the thermo control of the filament bundle takes place
by means of radiant heaters or hot steam.
[0054] For compression, the filament bundle 10 is conveyed through
the conveying nozzle 16 into the stuffing chamber 17 and built up
into a yarn plug. The conveyance of the filament bundle may in this
case take place by means of a hot air stream or a cold air stream.
In this case, the preliminary thermo control of the filament bundle
to the crimping temperature must be taken into account. The yarn
plug 18 formed by the compressed filaments of the filament bundle
10 is conveyed out of the stuffing chamber 17 and cooled on the
circumference of the cooling drum 19. The opening up of the yarn
plug 18 into the crimped yarn 21 takes place by means of the
posttreatment device 20 which has a first guide godet unit 23.1.
Further along the run, the crimped yarn 21 is intermingled in the
intermingling nozzle 22 and is subsequently guided via the second
guide godet unit 23.2 to the winding device 24. In the winding
device 24, the crimped yarn 21 is wound into the bobbin 25.
[0055] In the exemplary embodiment according to FIG. 1, the
melt-spinning method according to the invention and the
melt-spinning apparatus according to the invention are illustrated
by the example of the yarn run of a crimped yarn which is generated
from a filament bundle. Crimped yarns of this type are preferably
produced as single-color yarns. To generate multicolor yarns which
are preferably used for the production of carpets, the crimped yarn
is generated from a plurality of colored filament bundles. An
exemplary embodiment of this kind is illustrated diagrammatically
in FIG. 2.
[0056] In the exemplary embodiment, as shown in FIG. 2, of the
melt-spinning apparatus according to the invention, the spinning
device 1 has a spinning head 2, on the underside of which three
spinnerets are held next to one another. Each of the spinnerets
3.1, 3.2 and 3.3 is connected to a separate spinning pump, which
spinning pumps are coupled in each case to separate extruders via
the melt inflows 4.1, 4.2 and 4.3. Thus, differently colored
polymer melts can be extruded from each spinneret 3.1, 3.2 and 3.3
to form a group of filaments. The filaments 8 are guided jointly
through a cooling shaft 6 of the cooling device 5 and are cooled by
means of a cooling air stream. The cooling air stream is in this
case generated by a blowing means 7, preferably by cross flow
blowing. Underneath the cooling device 5, a preparation device 9 is
provided, which has in each case a wetting means 9.1 to 9.3 for
each spinneret 3.1 to 3.2, in order to bring together the filaments
8 extruded through one of the spinnerets into a filament bundle.
The group of filaments 8 is brought together into overall three
filament bundles 10.1, 10.2 and 10.3. The filament bundles 10.1,
10.2 and 10.3 are taken off from the spinning device 1 by separate
spinning godet units 30.1, 30.2 and 30.3 and are guided to a
following drawing device 11. The spinning godet units 30.1, 30.2
and 30.3 have in each case a godet and an auxiliary roller.
[0057] In the drawing device 11, the filament bundles 10.1, 10.2
and 10.3 are guided next to one another in parallel and jointly
drawn. For this purpose, the drawing device 11 has a take-off godet
pair 12 and a drawing godet pair 14. The take-off godet pair 12 is
formed in this case by a heated godet 12.1 and an auxiliary roller
12.4. The heated godet 12.1 has a godet heating means 12.3 which
can be controlled via a heating control appliance 27.1. The drawing
godet pair 14 has the heated godets 14.1 and 14.2, the godet
casings of which are heated by the godet heating means 14.3. The
godet heating means 14.3 are coupled to a heating control appliance
27.2. The drawing godet pair 14 is to that extent identical to the
abovementioned exemplary embodiment according to FIG. 1 and is
arranged inside a godet box 13.
[0058] Underneath the drawing device 11, a hot godet pair 26 is
provided, which is likewise designed identically to the
abovementioned exemplary embodiment according to FIG. 1, and
therefore reference is made at this juncture to the abovementioned
description.
[0059] The following texturing device 15, the posttreatment device
20 and the winding device 24 are identical to the exemplary
embodiment according to FIG. 1 and therefore reference is also made
at this juncture to the abovementioned description.
[0060] In the exemplary embodiment illustrated in FIG. 2, of the
melt-spinning apparatus according to the invention, the filament
bundles 10.1, 10.2 and 10.3 are heated jointly by means of the
drawing godet pair 14 to a relaxation temperature for expansion.
For this purpose, the filament bundles 10.1 to 10.3 are guided next
to one another in parallel in a plurality of loopings around the
godets 14.1 and 14.2.
[0061] The preliminary thermo control of the filament bundles 10.1
to 10.2 to the crimping temperature takes place by means of the hot
godet pair 26, the filament bundles 10.1 to 10.3 likewise being
guided next to one another in parallel with a plurality of loopings
on the godets 26.1 and 26.2.
[0062] For texturing, the filament bundles 10.1 to 10.3 are jointly
compressed by a conveying nozzle 16 into a yarn plug 18. The yarn
plug 18 is thus generated from differently colored filament bundles
and, after cooling, is opened up into the crimped yarn. In
principle, however, there is also the possibility of compressing
the differently colored filament bundles 10.1 to 10.3 separately in
each case into a separate yarn plug and of opening up said yarn
plugs into a plurality of crimped yarns which are subsequently
combined in the posttreatment device 20 into a composite yarn with
the aid of the intermingling nozzle 22.
[0063] The melt-spinning method according to the invention and the
melt-spinning apparatus according to the invention thus extend to
crimped single-color yarns and to crimped multicolor yarns. There
may be yarns with different physical properties, such as individual
titer, cross section, color or else different types of polymer. It
is essential in this case that the heat treatments for the
relaxation of the filaments and the heat treatment for the
preliminary thermo control of texturing take place in separate
treatment steps. This ensures that the expansion of the filaments
and the crimping of the filaments can be set independently of one
another. The melt-spinning method according to the invention and
the melt-spinning apparatus according to the invention are
suitable, in principle, for all thermoplastic polymers which are
used for fiber production.
LIST OF REFERENCE SYMBOLS
[0064] 1 Spinning device [0065] 2 Spinning head [0066]
3,3.1,3.2,3.3 Spinneret [0067] 4,4.1,4.2,4.3 Melt inflow [0068] 5
Cooling device [0069] 6 Cooling shaft [0070] 7 Blowing means [0071]
8 Filament [0072] 9 Preparation device [0073] 10,10.1,10.2,10.3
Filament bundle [0074] 11 Drawing device [0075] 12 Take-off godet
pair [0076] 12.1,12.2 Heated godets [0077] 12.3 Godet heating means
[0078] 12.4 Auxiliary roller [0079] 13 Godet box [0080] 14 Drawing
godet pair [0081] 14.1,14.2 Heated godets [0082] 14.3 Godet heating
means [0083] 15 Texturing device [0084] 16 Conveying nozzle [0085]
17 Stuffing chamber [0086] 18 Yarn plug [0087] 19 Cooling drum
[0088] 20 Post treatment device [0089] 21 Crimped yarn [0090] 22
Intermingling nozzle [0091] 23.1,23.2 Guide godets [0092] 24
Winding device [0093] 25 Bobbin [0094] 26 Hot godet pair [0095]
26.1,26.2 Heated godets [0096] 26.3 Godet heating means [0097]
27.1,27.2,27.3 Heating control appliance [0098] 28 Reeling turret
[0099] 29.1,29.2 Reeling spindle [0100] 30.1,30.2,30.3 Spinning
godet unit [0101] 31 Process control unit
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