Title of Invention

METHOD AND DEVICE FOR MELT SPINNING AND COOLING A MULTIFILAMENT THREAD COMPRISING A MEASUREMENT OF THE COOLING AIR TEMPERATURE INSIDE FILAMENT BUNDLE

Abstract Abstract A process for melt spinning and cooling a multifil yarn and apparatus for performing the process is described. From a polymer melt a multiplicity of extruded filaments are guided in the form of a filament bundle and cooled by a cooling air stream directed onto the filament bundle, a temperature of a cooling air arising in the cooling of the filaments being measured and monitored. To capture the cooling state of the filaments and, derived therefrom, the property of the yarn, the invention is that the temperature of the cooling air is measured at one or more points inside the filament bundle. To this end a temperature sensor is disposed inside the filament bundle between the spinneret die and a yarn guide assigned to the spinneret die.
Full Text

METHOD AND DEVICE FOR MELT SPINNING AND COOLING A
MULTIFILAMENT THREAD COMPRISING A MEASUREMENT OF THE
COOLING AIR TEMPERATURE INSIDE THE FILAMENT BUNDLE
This invention relates to a process for melt spinning and cooling a multifil yarn as classified in the preamble of claim 1 and also to apparatus for performing the process according to claim 11.
A synthetic yarn produced from a polymer melt is formed from a multiplicity of fine strand-shaped filaments. Each of the filaments is extruded from the polymer melt through a die hole in a spinneret die. After extrusion, the filaments, which are guided spaced apart within a bundle, are cooled and then, after solidification, converged to form the yarn. As the filament material transitions from the liquid state of a melt to a solidified state, fundamental physical properties of the later yarn can be determined via certain cooling conditions. So observing uniform cooling conditions is of particular importance if high-quality yarns are to be obtained.
For instance, DE 100 31 106 Al discloses a process and apparatus where the temperature of a cooling air arising in the cooling of filaments is measured and monitored. The cooling air is measured on entry into a cooling shaft and on exit from the cooling shaft in order that ideally a constant temperature increase of the exit air during cooling of the filament may be obtained at all times. However, this known process does not permit any inference with regard to the cooling processes occurring at the individual filaments. More particularly, it remains unclear to what degree uniform cooling of all the filaments with regard to each other is present.
DE 44 04 258 Al discloses a process for melt spinning a multiplicity of filaments where a physical or textile-

engineering variable is continually measured on the solidified filaments, compared with a target value and utilized to control a process parameter, in particular the cooling. However, such physical variables as for example the yarn linear density, strength or birefringence can scarcely be captured with sufficiently high measuring accuracy from a moving yarn, so that no measurement and monitoring sufficient to determine yarn quality is achieved.
The present invention has for its object to provide a process for melt spinning and cooling a multifil thread as classified and also apparatus for performing the process wherein the cooling of the thread can essentially be conformed to the cooling behavior of the filaments.
The present invention also has for its object to develop the type of process and apparatus in question such that the cooling of the yarn permits direct inferences about the properties of the yarn.
The present invention further has for its object to provide a process and apparatus for melt spinning and cooling a yarn whereby yarns of predetermined and uniform cooling history can be wound to packages.
We have found that this object is achieved in accordance with the present invention by a process having the features according to claim 1 and also by apparatus having the features according to claim 15.
Advantageous developments of the present invention are defined by the features and feature combinations of the respective subclaims.
The present invention is based on the discovery that the cooling outcomes at the yarn are crucially influenced by the number of filaments and also the

manner of guiding the filaments, in particular by the spacings between the filaments during cooling. Especially filaments guided in bundle form make it a problem to guide the cooling air uniformly through the filament bundle. Temperature measurements of the cooling air at various points inside the cooling zone found large differences. Thus, the cooling history associated with the individual filaments must be regarded as differing with the point of measurement. The present invention, then, provides a solution whereby, approximately, the cooling effects active on the yarn can be captured by simple temperature measurements of the cooling air. For this, the temperature of the cooling air is measured at one or more points inside the filament bundle. It has emerged that the temperatures of the cooling air inside the filament bundle are distinctly above the temperatures which are measured outside the filament bundle. To this extent, the measurement of the temperature of the cooling air inside the filament bundle provides a good measure for determining the instantaneous state of solidification in the filaments. In addition, the uniformity of cooling of the individual filaments inside the filament bundle can be predetermined and specifically altered by intervention in the cooling operation. In addition, early detection and counteraction is possible in particular for the disruptive influences acting on the cooling operation from the outside, examples being soiling/fouling of the quenching wall, spinneret die defects and so on.
To be able, on the one hand, to perform an essentially contactless temperature measurement of the cooling air inside the filament bundle and, on the other hand, to enhance the uniformization of the cooling of the filaments inside the filament bundle, the version of the process is particularly advantageous wherein the filaments in the cooling process are spread apart and guided by an outer guiding edge of a shaped body. This

makes it possible to produce larger filament spacings in which a temperature measurement of the cooling air exiting in the interior of the filament bundle is advantageously possible. When the filaments are given a wetting upstream of the convergence site, the shaped body is preferably used for spin finishing the filaments. In this case, a spin finish wets the guiding edge.
High uniformity of cooling is provided by a ring-shaped or disk-shaped body along which the filaments of the filament bundle are guided.
To ensure very accurate capture of the cooling behavior of the filaments under the given cooling conditions, preference is given to that version of the process wherein the temperature of the cooling air is measured simultaneously at a plurality of points inside the filament bundle or outside the filament bundle, or preferably inside and simultaneously outside the filament bundle. This makes it possible to capture temperature courses across the cross sections of a filament bundle, so that an even greater uniformity for solidifying the individual filaments is establishable, or so that the cooling history of the filaments is even more accurately detectable and monitorable.
The measurements of the temperatures of the cooling air can be effected on measuring points aligned not only vertically or horizontally side by side. The vertical alignment of the measuring points in particular makes it possible to capture the transition from the liquid-state melt of the filament material to the solidified material inside the cooling zone.
It has emerged that the temperature measured for the cooling air is particularly useful to perform quality monitoring on the yarn. Maintaining very uniform cooling conditions on the yarn occasions essentially

predetermined physical properties for the yarn. A version of the process is particularly advantageous in this regard wherein at least one measured temperature value or a plurality of successive measured temperature values of the cooling air are stored and compared with a target value or a limiting value range. The consistency of the yarn quality produced can be directly inferred therefrom.
The manufacturing operation is particularly advantageously monitored by the version of the process wherein the successive measured temperature values of the cooling air are transformed into one or more statistical mean values and in that the mean value or values of the measured temperature values are compared with a target value or a limiting value range. The target values and also the limiting value ranges for the mean value of the cooling air temperature can have been determined for example by empirical tests in which the physical properties ascertained on the yarn were correlated with the cooling of the filaments. For instance, the yarn production process can be monitored by observing the mean measured temperature value for the cooling air temperature within a tolerance band having an upper limiting value and a lower limiting value. The limiting value exceedances which occur can represent further crucial monitoring and evaluation parameters for a documentation of yarn quality or for an intervention in the process.
So the deviations of the measured temperature values or the mean measured temperature values relative to the target value or the limiting value range of the cooling air temperature can advantageously be used to derive a quality value for the yarn. The quality value can correlate directly with a predetermined product parameter, so that the yarn after production can receive a quality characterization for example.

The process variant wherein the quality value is utilized to determine a product parameter has the particular advantage that the yarn produced can be directly accorded a product parameter determined by the cooling. It is thus possible to define a product parameter which constitutes a measure of the inner uniformities of the yarn. Especially a high uniform crystallinity of the yarn makes uniform color uptake possible, so that an assessment of dyeability for example is directly obtained in the course of the production of the yarn. The product parameter derived by the quality value could thus be characterized with regard to the likely dyeability.
Since in the production of synthetic yarns it is customary to extrude, cool, treat and wind up a plurality of yarns all at once side by side and concurrently, particular preference is given to using that version of the process wherein a plurality of yarns are cooled by the cooling air stream or by a plurality of separate cooling air streams and in that a measured temperature value of the cooling air is captured for each yarn and utilized for quality monitoring with regard to the respective yarn. This makes it possible to compare the qualities of the yarns with one another even as they are being produced in order then to make subsequent classifications as to quality. Thus, the packages produced on one winding spindle could hold yarns differing in quality level, so that sorting with regard to the quality values would be possible early on.
In a version of the process which is particularly advantageous for process control and also for product manufacture at least one instantaneous measured temperature value of the cooling air is compared with a target value for the temperature and a difference signal is generated and transformed into a control signal for intervention in the manufacturing operation.

External disruptions of the operation are hence identified early and quickly eliminated.
The control signal can be utilized on the one hand for changing a process parameter or a process sequence determining the production of the yarn. For instance, the process parameters for changing the cooling of the filaments can be influenced such that a previously detected difference between measured cooling air temperature and the predetermined target value temperature becomes as small as possible and is made to disappear. In the event that the detected difference exceeds a predetermined limiting value range, so that the cooling conditions lead to a qualitatively inferior yarn, the process sequence for producing the yarn could be influenced such that, for example, an early package change is performed when the yarn is being wound up.
The process of the present invention thus permits an early intervention in the manufacturing operation of a synthetic yarn in order that, in particular, the orientation and the crystallinity of the filament material due to the cooling may be specifically analyzed and influenced or external disruptive influences acting on the cooling operation may be rapidly eliminated, making it possible to set predetermined textile-physical properties or certain dyeing behaviors or service behaviors. The process of the present invention can be performed irrespectively I of the further treatment of the melt-spun yarn. It is thus possible to produce textile yarns partly drawn or fully drawn and also industrial yarns, carpet yarns or staple fibers.
To perform the process of the present invention, the apparatus according to the present invention has inside the filament bundle at least one temperature sensor disposed between a spinneret die and a yarn guide assigned to the spinneret die. This makes it possible

to realize a measuring point inside the filament bundle in the region of the cooling operation.
The development of the present invention's apparatus wherein the temperature sensor is assigned a guide meana whereby the filament strands are spread apart in the yarn path between the spinneret die and the yarn guide constitutes a preferred configuration to place the temperature sensor inside the filament bundle. This eliminates the risk of unintentional contacts between the temperature sensors and the filaments.
The spreading of the filaments may preferably be effected by means of a shaped body having an outer guiding edge and being held essentially concentrically to the spinneret die and guides the filaments along the guiding edge. The temperature sensor is preferably held essentially centrically relative to the shaped body.
When the filaments are subjected to wetting, preference is given to using the development of the present invention's apparatus wherein the shaped body is formed by a spin-finishing apparatus where the circumferential guiding edge bears a wetting agent.
Configuring the shaped body as a circle-shaped disk or as a circle-shaped ring enables the filament bundle to be guided in a way where a cooling air directed at the filament bundle from the outside is able to penetrate the filament bundle very uniformly.
To optimize the process of the present invention, the apparatus according to the present invention can also be further developed such that the sensor means is formed by a plurality of temperature sensors disposed horizontally or vertically side by side inside or outside or inside and outside the filament bundle. This provides a version of the apparatus where temperature profiles could be captured in relation to the cross

section of the filament bundle or where temperature courses along the yarn path could be captured. Each temperature sensor represents a measurement point in which the temperature of the cooling air is captured.
Advantageously, the sensor means is coupled to a control facility comprising electronic means for measured value evaluation, means for data storage and means for signal generation. The control facility provides a measured value evaluation within the meaning of the process of the present invention and a targeted control intervention in the manufacturing operation.
To change a process parameter or a process sequence, the control facility is coupled to one or more control instruments influencing individual process assemblies or process sequences.
To maintain predetermined and given cooling conditions, at least one of the control instruments is assigned within the cooling facility to a cooling air source, and so a quenching wall connected to the cooling air source can produce a predetermined cooling air stream to cool the filament bundle.
However, it is also possible to couple the control facility to an output instrument, so that the measured value analysis or the yarn quality values obtained from the measured value analysis can be directly observed and documented. The measured value analysis can be performed using the arithmetic operations known for statistical evaluation. Therefore, it is preferable to use microprocessors equipped with appropriate software as measured value analysis means.
To determine the cooling behavior of the filaments, preference is given to using the configuration of the apparatus wherein at least one of the temperature sensors is disposed in an upper third of the cooling

sector extending between the spinneret die and the yarn guide. This makes temperature measurements possible immediately after extrusion of the filaments in a relatively hot region of the cooling zone.
For process adjustment in the case where different yarn types are produced, the version of the apparatus is of particular advantage wherein at least one of the temperature sensors is held by a height-adjustable holding carrier. This makes it possible to realize the measuring point inside the filament bundle at different heights and hence different temperature levels.
The apparatus according to the present invention extends essentially to all known cooling facilities that produce a cooling air stream to cool the filaments. Particularly in the case of the production of textile filaments, which as will be known are produced in plural numbers simultaneously side by side, the cooling facility may preferably be formed by a lateral quenching wall which is connected to the cooling air source via the quenching chamber. This provides a cooling air directed one-sidedly onto the filament bundle.
Some illustrative embodiments of the apparatus according to the present invention will now be used to more particularly describe the invention with reference to the accompanying figures, where )
Fig. 1 and
Fig. 2 depict schematically different views of a first
illustrative embodiment of the present
invention's apparatus for performing the
process of the present invention, Fig. 3 depicts schematically a cross-sectional view of a further illustrative embodiment of the present invention's apparatus,

Fig. 4 depicts schematically a further illustrative
embodiment of the present invention's
apparatus, and
Fig. 5 depicts schematically a further illustrative
embodiment of the present invention's
apparatus.
Figures 1 and 2 depict a first illustrative embodiment of the present invention's apparatus for performing the present invention's process for melt spinning and cooling a multifil yarn. Fig. 1 shows the apparatus schematically in a cross-sectional view and Fig. 2 shows the apparatus in a side view. Unless express reference is made to one of the figures, the description which follows holds for both figures.
The first illustrative embodiment shows a spinneret head 1 for receiving a spinneret die 2. The spinneret die 2 is equipped on the underside of the spinneret head 1 with a multiplicity of die holes (not depicted here), which are connected to a melt supply line 4. The melt supply line 4 connects the spinneret head 1 to a melt source, for example an extruder. Within the spinneret head 1, further facilities such as for example spinning pumps and distributor lines can be disposed to distribute and guide the polymer melt supplied via the melt supply line 4, to the spinneret die 2. The spinneret head has a heated construction.
A cooling facility 6 is disposed underneath the spinneret head 1. The cooling facility 6 is constructed as a cross stream quench for producing a cooling air stream. To this end, the cooling facility 6 has a quenching wall 7 which underneath the spinneret head 1
extends over a cooling sector laterally next to the spinneret die 2, so that the filaments 3 extruded through the spinneret die 2 are guided directly next to the quenching wall 7. The quenching wall 7 is coupled to a blower 9 via a quenching chamber 8. The quenching

wall 7 has a gas-permeable construction, so that a cooling air produced by the blower 9 exits from the quenching chamber 8 through the quenching wall 7 as a cooling air stream and acts essentially transversely from the outside on the filaments 3 extruded by the spinneret die 2.
The multiplicity of filaments extruded by the spinneret die 2 is guided as a filament bundle 5 through the cooling sector extending parallel to the quenching wall 7. A yarn guide 11 is provided underneath the quenching wall 7 to converge the filaments 3 of the filament bundle 5 to form a multifil yarn 16. The yarn guide 11 thus constitutes the convergence site assigned to the spinneret die 2, in which all the filaments 3 are converged in bundled form to form the yarn 16. Customarily, the yarn guide 16 is coupled to a spin-finishing facility (not depicted here) in order that the coherency of the filament strands 3 may be improved by means of a spin finish.
A sensor means 10 is provided inside the cooling sector between the spinneret die 2 and the yarn guide 11. The sensor means 10 comprises a temperature sensor 12 which is disposed inside the filament bundle 5. The temperature sensor 12 is coupled via a signal line to a control facility 17 disposed on the outside.
To guide the filaments 3 and to place the temperature sensor 12, the sensor means 10 is assigned a guide means 13 which is formed by a shaped body 14 held concentrically with regard to the spinneret die 2. The shaped body 14 is disposed in the yarn path upstream of the yarn guide 11, and the shaped body 14 has a peripheral guiding edge 15 which effectuates a deflection relative to the natural convergence course of the filaments, so that the filament bundle 5 is spread open by the shaped body 14 after withdrawal from the spinneret die 2. The guiding edge 15 of the shaped

body 14 preferably has an envelope diameter which is equal to or greater than the envelope contour formed by the die holes in the spinneret die 2. This creates, immediately above the shaped body, a free space formed essentially centrically relative to the filament bundle and holding the temperature sensor 12 on the inside. To this end, the temperature sensor 12 is held at the free end of a rod-shaped sensor carrier 26 which at its opposite end is connected to the shaped body 14. This makes for an advantageous realization of a temperature-measuring point inside the filament bundle 5 whereby a temperature of a cooling air flowing through the filament bundle 5 can be measured.
As well as creating a free space inside the filament bundle 5, the spreading open of the filament bundle 5 by the shaped body 14 has the particular advantage that the spacings between the filaments 3 change as a function of the size of the shaped body 14 as the movement of the filaments progresses. For instance, if the size is essentially the same, the outer filaments 3 can be guided predominantly in a parallel side by side arrangement between the shaped body 14 and the spinneret die 2. When the shaped body 14 for spreading the filament bundle 5 is greater than the arrangement of the die holes in the spinneret die 2, the spacings between the filaments can be even increased for the outer filaments as their travel continues. These spacing changes for the filaments 3 in particular of
) the outer region of the filament bundle 5 guided filaments 3 has the effect that the cooling air stream produced by the quenching wall 7 can penetrate without hindrance into the filament bundle 5 and thus leads to uniform cooling of the inner filaments 3 and of the
3 filaments 3 away from the quenching wall 7.
To perform the process of the present invention, the apparatus according to the present invention has a control facility 17 coupled to the sensor means 10. To

record the measurea signaxs supplied by the temperation sensor 12, the control facility 17 has electric and electronic means for signal evaluation, signal and data storage and also signal generation for control. In the illustrative embodiment depicted in Fig. 1, the control facility 17 is coupled to a control instrument 18.1 which is directly assigned to the blower 9 acting as cooling air source.
In operation, the spinneret die 2 continuously extrudes a multiplicity of filaments 3 from a pressure-supplied polymer melt. The filaments 3 are guided conjointly as a filament bundle 5 along the cooling section and laterally relative to the quenching wall 7 and are deflected at the guiding edge 15 of the shaped body 14 to be converged by the yarn guide 11 to form a yarn 16. To ensure that the filament material in the filaments 3 solidifies in a predetermined manner, the cooling facility 5 generates a.cooling air stream directed from the outside essentially transversely to the yarn path direction, and this stream is blown through the quenching wall 7 against the filament bundle 5. The cooling air of the cooling air stream penetrates through the filament bundle 5 and causes the extruded molten liquid filament material to solidify as it continues to move to obtain for the filament material a crystalline construction defined as a function of the withdrawal of the filaments 3 and of the cooling air condition. To create for example a predetermined textile property in the yarn, for example the inner uniformity of the crystallinity of the filaments to realize a defined dyeing behavior, the process of the present invention proceeds by measuring the cooling air arising in the interior of the filament bundle 5 with regard to its temperature. The cooling air measured temperature value captured in the measuring point inside the filament bundle 5 by the temperature sensor 12 is supplied by a signal line to the control facility 17. The instantaneous measured temperature value of the

cooling air could be Tactual for example. A cooling air target temperature may advantageously be deposited in the control facility 17 as Ttarget SO that through the means contained in the control facility 17 a target-actual comparison of the cooling air temperatures indicates compliance with or deviation from the predetermined cooling operation. In the event of an impermissible difference between Tactual and Ttarget, the control facility 17 uses the difference signal to create a control signal S which is directly supplied to the control instrument 18.1 to control the cooling air source in this case the blower 9. For example, by intensifying the cooling air stream and hence enhancing the blower's power output, a higher throughput of cooling air can be generated, so that for example an excessively high internal cooling air temperature Tactual is lowered and hence improved cooling is achieved. Thus, important textile properties crucial for further treatment such as dyeability for example can be specifically influenced even as the yarn is being produced. Any change in the cooling of the filaments due to an external disruption, for example a soiled/fouled quenching wall, is immediately captured through the change in the measured temperature values Tactual and the subsequent actual-target comparison and immediately compensated through appropriate control of the blower 9. It is thus possible for the filaments to be cooled with essentially constant cooling conditions.
However, it is also possible in the event of an excessively large deviation between the measured temperature value and the target temperature value for the difference signal to be additionally or alternatively converted into an alarm signal which leads to a visual or acoustical indication or is routed to a superordinate control unit.
Fig. 3 depicts a further illustrative embodiment of the present invention's apparatus schematically in a cross-

sectional view. The configuration and the arrangement of the apparatus parts is essentially identical to the above-described illustrative embodiment according to Figures 1 and 2, so that only the differences need be explained here and reference is made to the aforementioned description for the rest.
In the illustrative embodiment of the present invention's apparatus depicted in Fig. 3, the sensor means 10 is formed by a plurality of temperature sensors 12.1 and 12.4 to realize a plurality of measurement points inside the filament bundle and outside the filament bundle. The temperature sensors 12.1 and 12.2 are held spaced apart on a bar-shaped sensor carrier 26.1 which is coupled to a cone-shaped body 14. The temperature sensor 12.1 at the free end of the sensor carrier 26.1 defines a first measurement point inside the filament bundle 5, preferably situated in the first third of the cooling sector directly underneath the spinneret die 2. The measuring point realized by the temperature sensor 12.2 in the same plane is situated in the middle region of the cooling sector, so that a temperature gradient found for the cooling air within the cooling sector is capturable. The temperature sensors 12.3 and 12.4 constitute two further points of measurement outside the filament bundle which are formed in particular on that side of the filament bundle 5 which is remote from the quenching wall 7. The inner and outer points of measurement for capturing the cooling air temperature are each situated at an identical height of the cooling sector. The temperature sensors 12.3 and 12.4 are held on a second sensor carrier 26.2 which is directly fixed to a holding bar 23. The holding bar 23 projects with a free end into the filament bundle 5 and carries the shaped body 14. The shaped body 14 has a conical construction, the pointy end of the cone pointing toward the spinneret die 12 and holding the sensor carrier 2 6.1. The blunt end of the cone is configured

into a guiding edge 15 along which the filaments 3 extruded from the die holes in the spinneret die 2 are guided.
For height adjustment of the temperature sensors 12.1 to 12.4 and also of the shaped body 14, the free end of the holding bar 23 is coupled on the outside to a transverse carrier 24 which is guided in a vertical guide 25. The transverse carrier 24 is adjustable in the guide 25, so that the position of the shaped body 14 and hence the degree of spreading inside the cooling sector and also the points of measurement formed by the temperature sensors 12.1 to 12.4 are choosable and alterable.
The temperature sensors 12.1 to 12.4 are coupled via signal lines to the control facility 17. The control facility 17 is connected to the control instrument 18.1 for influencing a process parameter and also to an output instrument 19 for displaying and outputting a quality value. The attachment ,of an output instrument 19 makes it possible for a quality value derived by the temperature measurement to be immediately displayed, so that the as-produced quality of the yarn 13 can be continually monitored on the output instrument 19. The output instrument 19 may thus be formed by a monitor 20 and a printer 21. Advantageously, the output instrument 19 is linked via a microprocessor to the control facility 17.
In the illustrative embodiment depicted in Fig. 3, the process of the present invention may be performed by having the temperature sensors 12.1 to 12.4 capturing a temperature gradient inside the cooling sector directly in relation to the cooling of the filaments 3. Furthermore, the points of measurement disposed at one height of the cooling sector provide temperature measurements across the profile of the filament bundle 5 which immediately permit a statement about the


uniformity of cooling. This makes it possible to establish very precise measurements in relation to the actual cooling behavior of the filaments 3, so that orientations and crystallinities in the filament material can be specifically influenced during cooling. The production of yarns having predetermined textile-physical properties or certain dyeing behaviors or certain service behaviors is possible as a result. Very high yarn qualities can be produced by direct intervention in the cooling operation.
To monitor the manufacturing operation, the means in the control facility 17 for evaluating the measured temperature values, the means for data storage and the means for signal generation can each be used, depending on the predetermined software configuration, to carry out various kinds of measured value analyses. In the simplest version, for example, a measured temperature value signalized by the temperature sensor 12.1 is compared with a target value for the cooling air temperature. The deviation between the target value and the measured temperature value is captured as difference value and can be directly displayed as a quality value on the monitor 20. In addition, the measured temperature value courses can be displayed with regard to a target value exceedance, so that the process course and hence the yarn quality, in particular the uniformity of yarn quality, becomes visible.
However, it is also possible for measured value fluctuations and uncertainties in the measurements to be initially compensated by converting the consecutive measured temperature values for the cooling air into a statistical mean value. Preferably, the mean values are formed within certain time sections, so that a course of the mean value over time is likewise obtained. The mean value course of the measured cooling air temperature can be directly assigned to a target value

or a limiting value range preferably with an upper limiting value and a lower limiting value. The difference values found between the mean value of the measured temperature values and the target value or the limiting value range likewise constitute a measure of the quality of the yarn or to be more precise a measure of the uniformity of the cooling of the filaments. The difference values obtained as a result can advantageously be displayed directly as a quality value.
However, it is also possible for the aforementioned measured value evaluation to be performed concurrently to every one of the temperature sensors 12.1 to 12.4. However, it is also possible for the measured temperatures inside the filament bundle 3 to be combined into a mean value and for the temperatures outside the filament bundle 3 to be combined into a mean value. In principle a multiplicity of possible evaluations can be performed to obtain a direct quality assessment of the yarn produced.
It has emerged in particular that uniform cooling of the filaments shows up positively in a uniform crystallinity and hence uniform dyeability for the yarn. It is accordingly also possible to utilize the quality value directly for quality determination of a product parameter. For instance, the dyeing behavior of the yarn can be defined through the quality values. Value ranges can be defined for the quality value that determine a permissible uniformity or an impermissible uniformity of yarn dyeability. Quality classifications can be done even as the yarn is being produced. For instance, yarns produced with a high quality value can be classified as A quality and inferior qualities can be classified as B or C qualities. On that basis it is possible in particular to do classifications of the wound packages which are advantageous for further processing of the yarns.

For the cooling history of the yarn to be very precisely captured and determined, the illustrative embodiment according to Fig. 3 of the process according to the present invention can be further improved by having the spinneret head directly assigned a point of measurement, whereby for example the polymer melt heating or else directly the melt temperature of the polymer melt is captured. A temperature sensor 12.5 is depicted for this as a dashed line on the spinneret head 1. The temperature sensor 12.5 is likewise coupled via a signal line to the control facility 17 . This makes it possible to perform additional evaluations and analyses for determining the cooling behavior of the filaments 3.
Fig. 4 shows a further illustrative embodiment of the present invention' s apparatus for performing the present invention's process, which is configured essentially identical to the illustrative embodiment according to Figures 1 and 2. So the aforementioned description is incorporated by reference and only the differences are elucidated here.
In the illustrative embodiment depicted in Fig. 4, the facilities used for further treating the melt-spun yarn are depicted by way of example as well as the facilities needed for spinning and cooling. Thus, a treating facility 27 comprising one or more withdrawal elements is disposed directly underneath the cooling facility 6 of the spinneret die 2. The withdrawal elements are formed by godets or godet units which withdraw the yarn 16 out of the cooling sector and from the spinneret die 2. The construction of the treating facility 27 is dependent on the yarn type to be produced. Fully drawn or partly drawn yarn can thus be produced. In addition, additional assemblies such as for example entangling facilities or heating facilities or crimping facilities can be provided in order that

individual treatment steps may be carried out on the yarn.
At the end, the yarn 16 is wound up as a package 28. A winding facility 29 is provided for this. The winding facility 29 is preferably formed by a winding revolver which comprises two winding spindles held on a turntable which are used alternately to wind up the yarn. A continuous process is possible in this regard to produce the yarn 16. The winding facility 29 is assigned a control instrument 18.2 which is coupled to the control facility 17.
The arrangement depicted in Fig. 4 can be used to carry out a further process variant of the present invention wherein the monitoring of the cooling air temperature in the interior of the filament bundle is utilized for controlling the operation. In the event that an actual-target comparison between a measured temperature value and a target value inside the control facility 17 shows the difference between the measured cooling air temperature Tactual and the required cooling air temperature Ttarget to be too large and that accordingly an impermissible, limiting value is being exceeded, it is possible to use the difference signal to generate a further control signal for controlling the winding facility. For instance, the control facility 17 makes it possible to control the control instrument 18.1 for controlling the blower 9 and the control instrument 18.2 for controlling the winding' facility 29. Initially, the controlling of the blower 9 effectuates a correction of the cooling of the filaments 3 in the required manner, so that an equalization is achieved between the measured cooling air temperature and the required cooling air temperature. As soon as the required limiting values are complied with, the winding facility 29 is controlled via the control instrument 18.2 such that a package change is performed. The yarn produced, which is then impeccable

in quality terms, is thus directly wound onto a new bobbin. The yarn produced with a non-optimized cooling can be specifically classified via defined winding operations, so that the feed packages provided to a further-processing operation can be defined according to certain criteria. The illustrative embodiment depicted in Fig. 4 is particularly useful for producing textile yarns.
Fig. 5 shows a further illustrative embodiment of the present invention' s apparatus for performing the present invention's process. The illustrative embodiment is essentially identical to the illustrative embodiment according to Fig. 3, bearing in mind that the illustrative embodiment shown in Fig. 5 is depicted in a side view. With reference to the description relating to Fig. 3, only the differences will be elucidated in relation to the illustrative embodiment according to Fig. 5. The structural components performing the same function bear identical reference signs.
In the illustrative embodiment depicted in Fig. 5, a plurality of multilfil threads 16 are produced simultaneously by spinning in a parallel, side by side arrangement. As is apparent from Fig. 5, the apparatus has altogether four spinning sites 33.1 to 33.4. The spinning sites 33.1 to 33.4 are assigned a beam-shaped spinneret head 1 which is connected via a melt supply line 4 to a melt source not depicted here. The spinneret head 1 has one spinneret die 2 for each of the spinning sites 33.1 to 33.4. So four spinneret dies 2 altogether are held side by side on the spinneret head 1.
Underneath the spinneret head 1 there is a cooling facility 6 comprising a quenching wall 7 which extends over the entire width of the spinning sites 33.1 to 33.4, so that the filament strands 3 extruded in the

spinning sites 33.1 to 33.4 are guided at a distance from the quenching wall 7 . The quenching wall 7 is connected via a quenching chamber to a blower (cf. Fig. 3).
As shown in Fig. 5, each spinneret die 2 in the spinning sites 33.1 to 33.4 is assigned one spin-finishing apparatus 30. The spin-finishing apparatus 30 has a cone-shaped body 14 inside each of the spinning sites 33.1 to 33.4. The blunt end of the cone-shaped body 14 is formed into a guiding edge 15 which is wetted by a spin finish and along which the filament strands 3 extruded from the die holes in the spinneret die are guided. For this, the shaped body 14 has in its interior distribution lines and liquid chambers which are connected via a supply line 31 to a spin-finish pump 32. This ensures a continuous feed of spin finish to the shaped body 14 for wetting the guiding edge 15. The fluid at the circumference of the guiding edge 15 of the shaped body 14 is continuously taken up by the filament strands 3, so that uniform spin finishing takes place.
Temperature sensors are each disposed on the pointy cone end of the shaped body 14, the temperature sensor 12.1 being assigned to the spinning site 33.1, the temperature sensor 12.2 being assigned to the spinning site 33.2, and so on. The temperature sensors 12.1 to 12.4 are coupled via signal lines to the control facility 17.
The spin-finishing apparatus 30 assigned to the spinning sites 33.1 to 33.4 is held conjointly with the shaped bodies 14 and the temperature sensors 12.1 to 12.4 on a height-adjustable transverse carrier 24. The transverse carrier 24 is constructed to be height adjustable via a guide 25. The position of the shaped bodies 14 and hence the degree of spreading inside the cooling sector and also the height position of the

temperarure sensors 12.1 to 12.4 are as a result choosable and alterable.
Beneath the cooling facility 6 are arranged in each of the spinning sites 33.1 to 33.4 yarn guides 11 which converge each of the filament strands 3 to one yarn 16.
The control facility 17, which is connected via parallel signal lines to the temperature sensors 12.1 to 12.4 in the spinning sites 33.1 to 33.4, has essentially one or more means for measured value evaluation according to statistical methods, which are brought to display and output via an output instrument 9. In addition, the control facility 17 is connected via a control line to a control instrument or a superordinate control facility (not depicted here).
In the illustrative embodiment depicted in Fig. 5 of the apparatus according to the present invention, a plurality of yarns are extruded and cooled simultaneously. To capture the cooling history of the filaments 3 independently of each other, a measured temperature value is captured inside each filament bundle 3 via the temperature sensors 12.1 to 12.4 and sent to the control facility 17. A measured value evaluation is performed inside the control facility 17 for each spinning site 33.1 to 33.4. Preferably, an actual/target comparison between a target value or a limiting value range with a measured temperature value or a mean value obtained from the measured temperature values is formed. The difference values found in the process can be compared directly with the difference values of adjacent spinning sites. Therefore, a comparison between the filament bundles produced in the individual spinning sites is possible. Each of the filament bundles 3 and hence each of the yarns 16 in the spinning sites 33.1 to 33.4 can therefore be assigned a quality value which can be continuously

determined and displayed throughout the course of the operation.
It is additionally possible, in the event of impermissible deviations between the target temperature values and the measured temperature values, for control signals to be generated inside the control facility 17 which effectuate a change in the process setting. In addition, it is also possible to generate alarm signals if impermissible limiting value exceedances are detected, so that operatives can take appropriate measures for correction in the facilities.
In the illustrative embodiments according to Fig. 1 to Fig. 5, the cooling air stream for cooling the filaments is formed by a cooling facility which by way of a cross flow quench generates a one-sidedly transversely directed cooling air stream. In principle, however, the present invention also provides the possibility of cooling the filament bundle by using a cooling air generation directed radially from out to in. In addition, a plurality of measuring points can also advantageously be realized at one height inside the filament bundle. Similarly, the shaping of the guiding means for spreading the filament bundles is illustrative, although it is preferable to use circle-shaped or ring-shaped bodies. Yet oval or elongated shapes for spreading filament bundles are also possible. Not only round, ring-shaped or rectangular arrangements of die holes in a spinneret die can be used. When ring-shaped spinneret dies are used, the sensor means can advantageously also be placed without additional guide means inside the filament bundle.
The apparatus of the present invention and the process of the present invention are useful for producing any kinds of multifilament yarns from synthetic materials with high uniformity in the physical properties. Textile, industrial or carpet yarns can be produced

therewith. The present invention extends in particular to the processes and apparatus wherein a multiplicity of fiber strands of a polymer material which are guided in bundle form are, after extrusion, cooled using a cooling air or a gas stream. So the present invention is also useful for monitoring a staple fiber melt-spinning operation.

List of reference signs
1 Spinneret head
2 Spinneret die
3 Filament
4 Melt supply line
5 Filament bundle
6 Cooling facility
7 Quenching wall
8 Quenching chamber
9 Blower
10 Sensor means
11 Yarn guide
12, 12.1... 12. 4 Temperature sensor
13 Guide means
14 Shaped body
15 Guiding edge
16 Yarn
17 Control facility
18 Control instrument
19 Output instrument
20 Monitor
21 Printer
23 Holding bar
24 Transverse carrier
2 5 Guide
26, 26.1, 26.2 Sensor carrier
27 Treating facility
28 Package
) 29 Winding facility
30 Spin-finishing apparatus
31 Supply line


We claim:-
A process for melt spinning and cooling a multifil yarn, said yarn being produced from a polymer melt and said process comprising a multiplicity of extruded filaments in the form of a filament bundle being cooled by a cooling air stream directed onto the filament bundle and subsequently being converged to the yarn and a temperature of a cooling air arising in the cooling of the filaments being measured and monitored, characterized in that the temperature of the cooling air is measured at one or more points inside the filament bundle.
The process according to claim 1, characterized in that the temperature of the cooling air is measured in the center of the filament bundle, the filaments being spread apart and guided by an outer guiding edge of a shaped body.
The process according to claim 2, characterized in that the filaments of the filament bundle are guided through a ring-shaped body.
The process according to any one of claims 1 to 3, characterized in that the temperature of the cooling air is measured simultaneously at a plurality of points inside and/or outside the filament bundle.
The process according to claim 4, characterized in that the measurement of the temperatures of the cooling air inside and/or outside the filament bundle is effected at points disposed vertically or horizontally side by side.
The process according to any one of claims 1 to 5, characterized in that at least one measured

temperature value or a plurality of successive measured temperature values of the cooling air are stored and compared with a target value or a limiting value range.
The process according to claim 6, characterized in that the successive measured temperature values of the cooling air are transformed into one or more statistical mean values and in that the mean value or values of the measured temperature values are compared with a target value or a limiting value range.
The process according to claim 6 or 7,
characterized in that the deviations from the
target value or the limiting value range are
captured as one or more difference values and are
transformed into a quality value for the yarn.
The process according to claim 8, characterized in that the quality value is utilized for quality determination with regard to a product parameter.
The process according to claim 9, characterized in that the product parameter determines a color uptake capacity of the yarn for a further treatment.
The process according to any one of claims 1 to
10, characterized in that a plurality of yarns are
cooled by the cooling air stream or by a plurality
of separate cooling air streams and in that a
measured temperature value of the cooling air is
captured for each yarn and utilized for quality
monitoring with regard to the respective yarn.
The process according to any one of claims 1 to
11, characterized in that at least one
instantaneous measured temperature value of the

cooling air is compared with a lodged target value for the temperature and in that a difference signal is generated and transformed into a control signal.
The process according to claim 12, characterized in that the control signal is utilized for changing a process parameter or a process sequence determining the production of the yarn.
The process according to claim 13, characterized in that the process parameter influences the cooling of the filaments such that a cooling air temperature corresponding to the predetermined target value becomes established.
Apparatus for performing the process according to any one of claims 1 to 14, with a spinneret die
(2) for extruding a multiplicity of filaments (3), with a cooling facility (6) for generating a cooling air stream directed transversely to the filaments (3) guided as filament bundle (5), with a yarn guide (11) assigned to the spinneret die
(2) and adapted to form a convergence site effecting the convergence of the filaments (3) , and with a sensor means (10) for measuring a temperature of the cooling air, characterized in that the sensor means (10) is formed by at least one temperature sensor (12) disposed between the spinneret die (2) and the yarn guide (11) inside the filament bundle (5) .
The apparatus according to claim 15, characterized in that the temperature sensor (12) is assigned a guide means (13) whereby the filament strands (3) are spread apart in the yarn path between the spinneret die (2) and the yarn guide (11).

The apparatus according to claim 16, characterized in that the guide means (13) is formed by a shaped body (14) having an outer guiding edge (15) and being held essentially concentrically to the spinneret die (2) and the filaments (3) are guided along the guiding edge (15), and in that the temperature sensor (12) is held essentially centrically relative to the shaped body (14).
The apparatus according to claim 17, characterized in that the shaped body (14) is formed by a circle-shaped disk or a circle-shaped ring, the guiding edge (15) being disposed at the circumference of the disk or ring.
The apparatus according to claim 17, characterized in that the shaped body (14) is formed by a spin-finishing apparatus (30) where the circumferential guiding edge (15) bears a wetting agent.
The apparatus according to any one of claims 15 to
19, characterized in that the sensor means (10) is
formed by a plurality of temperature sensors
(12.1, 12.2) disposed horizontally or vertically
side by side inside and/or outside the filament
bundle (5).
The apparatus according to any one of claims 15 to
20, characterized in that the sensor means (10) is
coupled to a control facility (17) comprising
electronic means for measured value evaluation,
means for data storage and means for signal
generation.
The apparatus according to claim 21, characterized in that the control facility (17) is connected to a control instrument (18.1) for changing a process parameter or process sequence.

The apparatus according to claim 22, characterized in that the control instrument (18.1) is assigned within the cooling facility (6) to a cooling air source (9) connected to a quenching wall (7) to produce a cooling air.
The apparatus according to any one of claims 21 to 24, characterized in that the control facility (17) is connected to an output instrument (19) for outputting a quality value.
The apparatus according to any one of claims 15 to
24, characterized in that at least one of the
temperature sensors (12.1, 12.2) is disposed in an
upper third of the cooling sector extending
between the spinneret die (2) and the yarn guide
(11) .
The apparatus according to any one of claims 15 to
25, characterized in that at least one of the
temperature sensors (12.1, 12.2) is held by a
height-adjustable holding bar (23) .
The apparatus according to any one of claims 15 to
26, characterized in that the quenching wall (7)
is disposed laterally with regard to the spinneret
die (2) and is connected to the cooling air source
(9) via a quenching chamber (8).


Documents:

2457-CHENP-2009 EXAMINATION REPORT REPLY RECEIVED 06-06-2013.pdf

3246-CHENP-2008 AMENDED CLAIMS 06-06-2013.pdf

3246-CHENP-2008 CORRESPONDENCE OTHERS 06-03-2013.pdf

3246-CHENP-2008 EXAMINATION REPORT REPLY RECEIVED 06-06-2013.pdf

3246-CHENP-2008 FORM-3 06-06-2013.pdf

3246-CHENP-2008 POWER OF ATTORNEY 06-06-2013.pdf

3246-chenp-2008 abstract.pdf

3246-chenp-2008 claims.pdf

3246-chenp-2008 correspondence-others.pdf

3246-chenp-2008 description (complete).pdf

3246-chenp-2008 drawings.pdf

3246-chenp-2008 form-1.pdf

3246-chenp-2008 form-18.pdf

3246-chenp-2008 form-3.pdf

3246-chenp-2008 form-5.pdf

3246-chenp-2008 pct.pdf


Patent Number 256739
Indian Patent Application Number 3246/CHENP/2008
PG Journal Number 30/2013
Publication Date 26-Jul-2013
Grant Date 23-Jul-2013
Date of Filing 24-Jun-2008
Name of Patentee OERLIKON TEXTILE GMBH & CO., KG
Applicant Address 45, 41069, MONCHENGLADBACH,
Inventors:
# Inventor's Name Inventor's Address
1 SCHULZ,DETLEV, HASENBERGER WEG 2ND, 42897 REMSCHEID,
PCT International Classification Number D01D 5/088
PCT International Application Number PCT/EP06/11130
PCT International Filing date 2006-11-21
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 102005056041.5 2005-11-24 Germany