EP1951936A1

EP1951936A1 - Method and device for melt spinning and cooling a multifilament thread comprising a measurement of the cooling air temperature inside the filament bundle

Info

Publication number: EP1951936A1
Application number: EP06829081A
Authority: EP
Inventors: Detlev Schulz
Original assignee: Oerlikon Textile GmbH and Co KG
Current assignee: Oerlikon Textile GmbH and Co KG
Priority date: 2005-11-24
Filing date: 2006-11-21
Publication date: 2008-08-06
Anticipated expiration: 2026-11-21
Also published as: DE502006003037D1; CN101313090B; CN101313090A; EP1951936B1; WO2007059914A1

Abstract

The invention relates to a method for melt spinning and cooling a multifilament thread and to a device for carrying out said method. According to said method, a plurality of filaments is extruded from a polymer melt, said filaments being guided in a filament bundle and cooled by a cooling air stream that passes transversally across the filament bundle, the temperature of the cooling air that is evacuated during the cooling of the filaments being measured and monitored. To detect the cooled state of the filaments and the characteristics of the thread derived from said state, the temperature of the cooling air is measured at least at one measuring point inside the filament bundle. To achieve this, a temperature sensor is located inside the filament bundle between the spinneret and a thread guide that is allocated to the latter.

Description

METHOD AND DEVICE FOR MELTING AND COOLING A MULTIFILΞN THREAD WITH COOLING AIR TEMPERATURE MEASUREMENT WITHIN THE FILAMENT BUNDLE

The invention relates to a method for melt spinning and cooling of a multifilen yarn according to the preamble of claim 1 and an apparatus for performing the method according to claim 11.

In the manufacture of synthetic filaments from a polymer melt, the filament is formed from a multiplicity of fine filamentary filaments. For this purpose, each of the filaments is extruded from the polymer melt through a nozzle bore of a spinneret. After extrusion, the filaments guided at a distance from one another within a bundle are cooled and then brought together after solidification to the thread. During the transition of the filament

From the molten state to the solidified state, certain physical properties of the subsequent filament can be determined by certain cooling conditions. In that regard, compliance with the uniformity of the cooling conditions for the production of high-quality threads is of particular importance.

20

For example, DE 100 31 106 A1 discloses a method and a device in which the temperature of a cooling air occurring during the cooling of the filaments is measured and monitored. Here, the cooling air is measured when entering a cooling shaft and exiting a cooling shaft.

25 sen, in order to always obtain a constant increase in temperature of the exhaust air during the cooling of the filament. However, the known method does not allow any conclusion on the cooling processes occurring on the individual filaments. In particular, it remains unclear to what extent a uniform cooling of all filaments with each other is present.

30

From DE 44 04 258 Al a method for melt spinning a plurality of filaments is known, in which on the solidified filaments continuously measured a physical or textile size, compared with a target value and used to control a process parameter, in particular the cooling. However, such physical variables as, for example, the filament titer, strength or birefringence can scarcely be detected on a running yarn with sufficiently high accuracy of measurement, so that sufficient measurement and monitoring for the quality determination of a yarn is not achieved.

It is an object of the invention to provide a method for melt spinning and cooling a multi-filament of the genus in contemporary art and to provide a device for carrying out the method in which the cooling of the thread can be adapted to the cooling behavior of the filaments substantially.

It is also an object of the invention to develop the generic method and the generic device such that from the cooling of the thread directly conclusions about the properties of the thread are possible.

Another object of the invention is to provide a method and an apparatus for melt-spinning and cooling a thread with which threads with predetermined and uniform cooling history can be wound into coils.

This object is achieved by a method with the features of claim 1 and by a device having the features of claim 15.

Advantageous developments of the invention are defined by the features and feature combinations of the respective subclaims.

The invention is based on the finding that, depending on the number of filaments and the leadership of the filaments, in particular the distances the filaments to each other during cooling, the cooling results are significantly influenced by the thread. Thus, in particular in the case of filamentary filaments, the problem arises of uniformly guiding the cooling air through the filter bundle. Thus, temperature measurements of the cooling air at various measuring points within the cooling zone revealed large differences. Thus, depending on the measuring point, the cooling history assigned to the individual filaments must be evaluated differently. The invention now represents a solution in which approximately the effective cooling effect on the thread can be detected by simple temperature measurements of the cooling air. For this purpose, the temperature of the cooling air is measured in at least one measuring point within the filament bundle. It has been found that the temperatures of the cooling air within the filament bundle are well above the temperatures measured outside the filament bundle. In that regard, the measurement of the temperature of the cooling air within the filament bundle gives a good measure to determine the instantaneous solidification state in the filaments. In addition, the uniformity of the cooling of the individual filaments within the filament bundle can be predetermined and specifically altered by intervention in the cooling process. In addition, in particular the external influences of the cooling, such as soiling on the blowing wall, spinneret errors, etc., can be detected and stopped at an early stage.

On the one hand to be able to perform a substantially contactless temperature measurement of the cooling air within the filament bundle and on the other hand to increase the homogenization of the cooling of the filaments within the filament bundle, the method variant is particularly advantageous in which the filaments spread during cooling by an outer leading edge of a shaped body and out become. This makes it possible to produce larger filament spacings, in which a temperature measurement of the cooling air emerging in the back of the filament bundle is advantageously possible. In the event that the filaments get wetted before the convergence point, the shaped body is preferably used for preparing the filaments. In this case, the leading edge is wetted with a spin finish. A high uniformity of the cooling is achieved by an annular or disc-shaped molded body, on which the filaments of the filament bundle are guided.

In order to capture the cooling behavior of the filaments as accurately as possible under the predetermined cooling conditions, the method variant is preferably used in which the temperature of the cooling air are measured simultaneously at several measuring points within the filament bundle or outside the filament bundle or preferably within and simultaneously outside the filament bundle. Thus, temperature gradients can be detected over the cross-sections of a filament bundle, so that an even greater uniformity to the solidification of the single filament can be adjusted and so that the Abkühlhistorie the FIIa ^• elements with even greater accuracy detected and monitored is.

The measurements of the temperatures of the cooling air can be carried out both at vertical or horizontal side by side aligned measuring points. In particular, the vertical orientation of the measurement points allows the transition from the molten state of the filament material to the solidified material within the cooling zone zμ detect.

It has been found that the measured temperature of the cooling air is particularly suitable for performing quality monitoring on the thread. Maintaining the most uniform possible cooling conditions on the thread essentially requires predetermined physical properties of the thread. In that regard, the method variant is particularly advantageous, in which at least one temperature measurement or a plurality of time-sequential temperature measured values of the cooling air are stored and compared with a desired value or a limit value range. From this it is possible to conclude directly on the constancy of the yarn quality produced. The production process can be monitored particularly advantageously by the variant of the method in which the chronologically successive temperature measured values of the cooling air are converted to a statistical average or a plurality of statistical mean values and the mean value or mean values of the temperature measured values are compared with a desired value or a limit value range. The setpoint values and also the limit value ranges for the mean value of the cooling air temperature can be determined, for example, by empirical tests in which the physical properties ascertained on the thread were related to the cooling of the filaments. Thus, for example, by monitoring the mean temperature measured value of the cooling air temperature within a tolerance band with an upper limit value and a lower limit value, the course of the process for producing the thread can be monitored. The limit value overshoots that occur can represent additional monitoring and evaluation parameters that are important for documentation of ^• thread quality or for intervention in the process.

In that regard, it is possible to derive a quality value of the thread from the deviations of the measured temperature measured values or the average temperature measured values from the setpoint value or the limit value range of the cooling air temperature. The quality value can be directly related to a predetermined product parameter, so that, for example, the thread can receive a quality mark after production.

The method variant, in which the quality value is used to determine a product parameter, has the particular advantage that a product parameter determined by the cooling can be directly assigned to the yarn produced. This allows defining a product parameter that represents a measure of the internal uniformity of the thread. In particular, with a high uniform crystallinity of the yarn, a uniform ink absorption is made possible, so that an assessment, for example of the dyeing ability, is already given immediately upon production of the yarn. The case by the Quality value derived product parameters could thus be characterized in terms of their probable dyeability.

Since it is customary in the production of synthetic threads to extrude, cool, treat and coil a plurality of threads parallel to one another, the method variant in which a plurality of threads are used by the cooling air flow or by a plurality of separate ones is particularly preferred Cooling air streams are cooled and that for each thread a temperature reading of the cooling air is detected and used to monitor the quality of the respective thread. This makes it possible to compare the qualities of the threads already during production with each other in order to then make the following quality classifications. Thus, the coils produced on a winding spindle could already have threads of different quality levels, so that sorting based on the quality values would be possible in good time.

For the process control as well as for product production, the method variant is particularly advantageous, in which at least one momentary measured value of the temperature of the cooling air is adjusted to a desired value of the temperature and a difference signal is generated and converted to a control signal for intervention in the manufacturing process. Thus, external disturbances of the process are detected early on and quickly eliminated.

On the one hand, the control signal can be used to change a process parameter or a process sequence that determines the production of the thread. Thus, for example, the process parameters for changing the cooling of the filaments can be influenced such that a previously determined difference between the measured cooling air temperature and the predetermined setpoint temperature is as small as possible and compensated. In the event that the detected difference exceeds a predetermined limit range, so that the cooling conditions lead to a qualitatively inferior thread, the process sequence for producing the thread could be influenced so that, for example, a premature bobbin change during winding of the thread is performed. The inventive method thus allows early intervention in the manufacturing process of a synthetic thread, in particular to analyze the orientation and crystallinity of the filament material by cooling targeted and influence or to eliminate quickly eliminate external influences on the cooling disturbances, so that the setting of predetermined tex- tylphysikalischen properties or certain staining behavior or behavior are possible. The process according to the invention can be carried out independently of the further treatment of the melt-spun yarn. In this case, textile threads can be partially stretched or fully stretched and technical yarns, carpet yarns or staple fibers produced.

To carry out the method according to the invention, the device according to the invention has at least one temperature sensor within the filament bundle arranged between a spinneret and one of the spinning nozzles. Thus, a measuring point within the filament bundle can be realized in the area of cooling.

The development of the device according to the invention, in which the temperature sensor is associated with a guide means by which the filament strands are spread in the yarn path between the spinneret and the yarn guide, is a preferred embodiment to place the temperature sensor within the filament bundle. The danger of unwanted contacts between the temperature sensors and the filaments can thus be avoided.

The spreading of the filaments can be preferably carried out by a shaped body with an outer leading edge, which is held substantially concentric to the spinneret and the filaments leads to the leading edge. The temperature sensor is preferably held centric to the shaped body within the filament bundle. In the case of wetting of the filaments, the development of the device according to the invention is preferably used, in which the shaped body is formed by a preparation device, in which the peripheral leading edge carries a wetting agent.

The formation of the shaped body by a circular disk or a circular ring allows guidance of the filament bundle, in which a cooling air directed from the outside onto the filament bundle can penetrate the filament bundle as uniformly as possible.

To optimize the method according to the invention, the device according to the invention can also be developed in such a way that the sensor means is formed by a plurality of temperature sensors which are arranged horizontally or vertically next to one another inside or outside or inside and outside the filament bundle. Thus, a device variant is provided in which temperature profiles in relation to the cross section of the filament bundle or at which temperature profiles along the thread run could be detected. Each temperature sensor represents a measuring point in which the temperature of the cooling air is detected.

The sensor means is advantageously coupled to a control device which has electronic means for measuring value evaluation, means for data storage and means for signal generation. With the aid of the control device, a measured value evaluation in the sense of the method according to the invention and a targeted control intervention in the production process can be made possible.

To change a process parameter or a process sequence, the control device is coupled to at least one or more control devices that influence individual process units or process sequences.

To comply with predetermined and predetermined cooling conditions, at least one of the control units is connected to a cooling air source of the cooling device, then in that a blowing wall connected to the cooling air source can generate a predetermined cooling air flow for cooling the filament bundle.

However, it is also possible to couple the control device to an output device, so that the measured value analysis or the quality values of the thread resulting from the measured value analysis can be directly observed and documented. During the measured value analysis, the arithmetic operations known for the statistical evaluation can be carried out. As a means of measured value analysis are therefore preferably used by microprocessors with appropriate software equipment.

To determine the cooling behavior of the filaments, the design of the device is preferably used, in which at least one of the temperature sensors is arranged in an upper third of the cooling section extending between the spinneret and the yarn guide. Thus, temperature measurements are already possible immediately after extrusion of the filament in a relatively hot region of the cooling zone.

For process adaptation when producing different types of thread, the device variant provides a particular advantage, in which at least one of the temperature sensors is held by a height-adjustable holding carrier. Thus, the measuring point within the filament bundle can be realized at different heights and thus different temperature levels.

The device according to the invention extends essentially to all known cooling devices which generate a cooling air flow for cooling the filaments. Especially in the production of textile filaments, which are known to be produced at several side by side at the same time, the cooling device can preferably be formed by a side blowing wall, which is connected via the blow chamber with the cooling air source. This produces a one-sided directed to the filament bundle cooling air. With reference to some embodiments of the device according to the invention, the invention is described below with reference to the accompanying figures.

They show:

Fig. 1 and

Fig. 2 shows schematically different views of a first embodiment of the device according to the invention for carrying out the method according to the invention

Fig. 3 shows schematically a cross-sectional view of another embodiment of the device according to the invention

Fig. 4 shows schematically a further embodiment of the device according to the invention

Fig. 5 shows schematically a further embodiment of the device according to the invention

FIGS. 1 and 2 show a first embodiment of the device according to the invention for carrying out the method according to the invention for melt-spinning and cooling a multifilament yarn. 1 shows the device schematically in a cross-sectional view and FIG. 2 in a side view. Unless an explicit reference is made to one of the figures, the following description applies to both figures.

The spinneret 2 has on the underside of the spinner 1 a plurality of nozzle bores (not shown here) which are connected to a melt feed 4. Via the melt feed 4, the spinning head 1 is connected to a melt source, for example to an extruder. Within the spinning head 1 2 further facilities for distribution and management of the given over the melt supply 4 polymer melt to the spinneret 2 such as spinning pumps and distribution lines may be arranged. The spinning head 1 is formed heated.

Below the spinning head 1, a cooling device 6 is arranged. The cooling device 6 is designed as a cross-flow blowing for generating a cooling air flow. For this purpose, the cooling device 6 has a blowing wall 7, which extends below the spinning head 1 via a cooling path laterally adjacent to the spinneret 2, so that the extruded through the spinneret 2 filaments 3 are guided directly adjacent to the blowing wall 7. The blowing wall 7 is coupled via a blow chamber 8 with a blower 9. The blowing wall 7 is gas-permeable, so that a cooling air generated by the blower 9 exits the blow chamber 8 through the blowing wall 7 as a cooling air flow and acts substantially transversely from the outside on the extruded through the spinneret 2 filaments 3.

The plurality of filaments extruded through the spinneret 2 are guided as a filament bundle 5 through the cooling path extending parallel to the blast wall 7. Below the blowing wall 7, a yarn guide 11 is provided to bring together the filaments 3 of the filament bundle 5, so that a multifilament yarn 16 is formed. The yarn guide 11 thus represents the convergence point associated with the spinneret 2, in which all the filaments 3 are bundled together to form the yarn 16. Usually, the yarn guide 16 is coupled to a preparation device (not shown here) in order to improve the cohesion of the filament strands 3 by a spin finish.

Within the cooling section between the spinneret 2 and the yarn guide 11, a sensor means 10 is provided. The sensor means 10 has a temperature sensor 12, which is arranged within the filament bundle 5. The temperature sensor 12 is coupled via a signal line with a control device 17 arranged outside.

For guiding the filaments 3 and for placing the temperature sensor 12, the sensor means 10 is associated with a guide means 13, which is characterized by a concentra- is formed trically to the spinneret 2 held molding 14. The molded body 14 is upstream of the yarn guide 11 in the yarn path, wherein the shaped body 14 has a circumferential leading edge 15 which causes a deflection to the natural convergence of the filaments, so that the filament bundle 5 is spread by the molding 14 after deduction of the spinneret 2. For this purpose, the leading edge 15 of the molded body 14 preferably has an envelope diameter which is equal to or greater than the enveloping contour formed by the nozzle bores of the spinneret 2. As a result, immediately above the shaped body, a free space formed essentially centrally with respect to the filament bundle is formed, in which the temperature sensor 12 is held. For this purpose, the temperature sensor 12 is held at the free end of a rod-shaped sensor carrier 26, which is connected to its opposite end with the shaped body 14. Thus, a temperature measuring point within the filament bundle 5 can advantageously be realized with which a temperature of a cooling air flowing through the filament bundle 5 can be measured.

In addition to the creation of a free space within the filament bundle 5, the spreading of the filament bundle 5 through the shaped body 14 has the particular advantage that the distances between the filaments 3 change as the movement of the filaments progresses depending on the size of the shaped body 14. Thus, for example, the outer filaments 3 can be largely parallel to each other with substantially the same size between the shaped body 14 and the spinneret 2. In the event that the shaped body 14 for spreading the filament bundle 5 is larger than the arrangement of the nozzle bores in the spinneret 2, can be in the outer filaments with continuous guidance, the distances between the filaments even increase. These changes in the distance of the filaments 3, in particular of the outer region of the filament bundle 5 guided filaments 3 causes the cooling air flow generated by the blowing wall 7 can penetrate unhindered into the filament bundle 5 and thus to a uniform cooling of the inner and facing away from the blowing wall 7 filaments third leads. For carrying out the method according to the invention, the device according to the invention has a control device 17 coupled to the sensor means. To receive the measurement signals provided by the temperature sensor 12, the control device 17 has electrical and electronic means which carry out signal evaluation, signal and data storage and signal generation allow for control. In the exemplary embodiment illustrated in FIG. 1, the control device 17 is coupled to a control unit 18.1, which is assigned directly to the blower 9 acting as a cooling air source.

In operation, a plurality of filaments 3 are continuously extruded from a pressurized polymer melt via the spinneret 2. The filaments 3 are guided together as a filament bundle 5 along the cooling path laterally to the blast wall 7 and deflected at the leading edge 15 of the shaped body 14 to be merged by den- yarn guide 11 to a thread 16. In order for the filament material in the filaments 3 to solidify in a predetermined manner, the cooling device 6 generates a cooling air flow oriented essentially transversely to the direction of yarn travel from the outside and blows it through the blowing wall 7 against the filament bundle 5. The cooling air of the cooling air flow penetrates the filament bundle 5 and causes the molten filament material after extrusion to solidify as the agitation progresses to obtain a crystalline structure of the filamentary material as defined by the deduction of the filaments 3 and cooling air condition. In order, for example, to produce a predetermined textile property on the thread which could, for example, include the internal uniformity of the crystallinity of the filaments for realizing a defined dyeing behavior, the method according to the invention starts by measuring the cooling air occurring inside the filament bundle 5 with respect to its temperature. The temperature value of the cooling air detected by the temperature sensor 12 in the measuring point within the filament bundle 5 is supplied to the control device 17 via a signal line. The current temperature reading of the cooling air could for example be _st Ti. In the control device 17 can advantageously be specified for compliance predetermined target temperature of the cooling air as Ts _o ii deposit so in that a nominal / actual comparison of the cooling air temperatures indicates compliance or deviation of the predetermined cooling by the means contained in the control device 17. In the case of an impermissible difference between T _inst and Ts _o ii, a control signal S is generated in the control _device 17 from the difference signal, which is used directly to the control unit 18.1 for controlling the cooling air source in this case of the blower 9. Thus, for example, by intensifying the cooling air flow and thus increasing the blower output of the blower, a higher cooling air flow rate can be generated so that, for example, an internal air temperature that is too high Ti _{st is} lowered and thus improved cooling is achieved. Thus, important textile properties, such as the dyeing behavior, which are decisive for further processing, can be specifically influenced during the production process. The change in the cooling of the filaments that occurs as a result of an external disturbance, for example a soiled blowing wall, is detected directly by the change in the temperature measured values Ti _st and the subsequent actual / nominal comparison and immediately compensated for by appropriate control of the blower 9. Thus, the filaments can be cooled with substantially constant cooling conditions.

However, there is also the possibility that, if the difference between the temperature measured value and the temperature setpoint value is too great, the difference signal is additionally or alternatively converted into an alarm signal that leads to a visual or acoustic display or is directed to a higher-order control unit.

Li Fig. 3 is a further embodiment of the device according to the invention is shown schematically in a cross-sectional view. The design and arrangement of the device parts is substantially identical to previously described exemplary embodiment according to FIGS. 1 and 2, so that only the differences are explained at this point and otherwise reference is made to the aforementioned description. In the embodiment of the device according to the invention shown in FIG. 3, the sensor means 10 is formed by a plurality of temperature sensors 12.1 and 12.4 for realizing a plurality of measuring points within the filament bundle and outside the filament bundle. The temperature sensors 12.1 and 12.2 are held at a distance from each other on a rod-shaped sensor carrier 26.1, which is coupled to a conical shaped body 14. In this case, a first measuring point within the filament bundle 5 is defined by the temperature sensor 12. 1 at the free end of the sensor carrier 26. 1, which is preferably located directly below the spinneret 2 in the first third of the cooling section. The measuring point realized by the temperature sensor 12.2 in the same plane is located in the middle region of the cooling section, so that a temperature gradient detected on the cooling air within the cooling section can be detected. The temperature sensors 12.3 and 12.4 represent two further measuring points outside the filament bundle, which are formed in particular on the side of the filament bundle 5 facing away from the blowing wall 7. In this case, the inner and outer measuring points for detecting the cooling air temperature are each at the same height of the cooling section. The temperature sensors 12.3 and 12.4 are held on a second sensor carrier 26.2, which is fixed directly to a support rod 23. The support rod 23 protrudes with a free end into the filament bundle 5 and carries the molded body 14. The molded body 14 is formed conically, wherein the pointed cone end of the spinneret 12 faces and the sensor carrier 26.1 holds. At the blunt cone end, a leading edge 15 is formed, on which the extruded from the nozzle bores of the spinneret 2 filament 3 are guided.

To adjust the height of the temperature sensors 12.1 to 12.4 and the molded body 14, the free end of the support rod 23 is externally coupled to a cross member 24, which is guided in a vertical guide 25. The cross member 24 is adjustable in the guide 25, so that the position of the molded body 14 and thus the degree of spreading within the cooling section and the measurement points formed by the temperature sensors 12.1 to 12.4 are selectable and changeable. The temperature sensors 12.1 to 12.4 are coupled to the control device 17 via signal lines. The control device 17 is connected to the control unit 18.1 for influencing a process parameter and to an output device 19 for displaying and outputting a quality value. The connection of an output device 19 makes it possible to directly display a quality value derived by the temperature measurement, so that the manufacturing quality of the thread 13 can be monitored continuously at the output device 19. Thus, the output device 19 can be formed by a monitor 20 and a printer 21. Advantageously, the output device 19 is linked to the control device 17 via a microprocessor.

In the exemplary embodiment illustrated in FIG. 3, a temperature gradient within the cooling section can be detected directly in relation to the cooling of the filaments 3 for carrying out the method according to the invention by the temperature sensors 12.1 to 12.4. Furthermore, by means of the measuring points arranged at a height of the cooling section, temperature measurements over the profile of the filament bundle 5 are possible, which allow immediate information about the uniformity of the cooling. In this way, very precise measurements can be made of the actual cooling behavior of the filaments 3, so that orientations and crystallinities of the filament material during cooling can be influenced in a targeted manner. The production of threads with predetermined textilphysikalsichen properties or certain staining behavior or specific behavior is thus possible. By directly engaging in the cooling process, the highest thread qualities can be produced.

In order to monitor the production process, the measured value analyzes, which are contained in the control device 17 for evaluating the temperature measured values, the means for data storage and the means for signal generation, depending on the given software configuration, can be carried out in different ways. In the simplest version, for example, a temperature measured by the temperature sensor 12.1 temperature measured value with a target value of Cooling air temperature compared. The deviation between the target value and the temperature measurement value is detected as a difference value and can be immediately displayed as a quality value on the monitor 20. In this case, in addition, the temperature measured value curves with regard to a setpoint value overshoot can be displayed so that the course of the process and thus the yarn quality, in particular the uniformity of the yarn quality, becomes visible.

However, there is also the possibility that measured value fluctuations and blurring of the measurements are first compensated for by converting the temporally consecutive temperature values of the cooling air to a statistical mean value. Preferably, the mean values are formed in specific time segments, so that a course of the mean value also sets over time. The mean value curve of the measured cooling air temperature can be assigned directly to a desired value or to a limit value range, preferably with an upper limit value and a lower limit value. The difference values determined between the mean of the temperature measured values and the desired value or the limit value range likewise represent a measure of the quality of the thread or a measure of the uniformity of the cooling of the filaments. The difference values thus obtained can advantageously be displayed directly as a quality value.

However, there is also the possibility that the aforementioned measurement value evaluation is carried out in parallel to each of the temperature sensors 12.1 to 12.4. However, it is also possible for the measured temperatures within the filament bundle 3 to be combined into an average value and the temperatures outside of the filament bundle 3 to form an average value in each case. Basically, a variety of evaluation options are executable that allow an immediate quality assessment of the thread produced.

It has been found, in particular, that the uniformity of the cooling of the filaments has a positive effect on uniform crystallinity and thus uniform dyeability of the filament. In that regard, the possibility exists ability to use the quality value directly to determine the quality of a product parameter. For example, the staining behavior of the thread can be defined by the quality values. In this case, value ranges of the quality value can be defined which determine a permissible uniformity or an unacceptable uniformity of the dyeability of the thread. In this case, quality ratings can be made already during the production of the thread. Thus, for example, the threads produced with a high quality value can be classified as A quality and, moreover, lower qualities can be classified as B or C qualities. From this it is possible, in particular for the further processing of the threads, to make advantageous classifications of the wound coils.

In the exemplary embodiment according to FIG. 3 of the method according to the invention, in order to detect and determine the cooling history of the thread as precisely as possible, a measuring point is directly assigned to the spinning head, through which, for example, the polymer melt temperature control or else directly the Melting temperature of the polymer melt is detected. For this purpose, a temperature sensor 12.5 is shown in dashed lines on the spinning head 1. The temperature sensor 12.5 is likewise coupled to the control device 17 via a signal line. This makes it possible to perform additional evaluations and analyzes to determine the cooling behavior of the filaments 3.

4, a further embodiment of the device according to the invention for carrying out the method according to the invention is shown, which is formed substantially identical to the embodiment of FIGS. 1 and 2. In so far, reference is made to the above description and explained at this point only the differences.

In the embodiment illustrated in FIG. 4, in addition to the devices required for spinning and cooling, the devices used for further treatment of the melt-spun thread are also shown by way of example. Thus, below the cooling device 6 of the spinneret 2 directly associated with a treatment device 27 with one or more exhaust members. The Discharge members are formed by godets or godet units that pull the thread 16 from the cooling section and from the spinneret 2. The structure of the treatment device 27 is dependent on the thread type to be produced. Thus, fully drawn or partially drawn threads can be produced. In addition, additional units such as turbulators, or tempering or KLräuseleinrichtungen may be provided to perform individual treatment steps on the thread can.

At the end of the thread 16 is wound into a coil 28. For this purpose, a winding device 29 is provided. The winding device 29 is preferably formed by a Spulrevolver having two held on a turntable spindles, which are used alternately for winding the thread. In that regard, a continuous process for the production of ^• yarn 16 is possible. The winding device 29 is assigned a control device 18. 2, which is coupled to the control device 17.

With the arrangement shown in Fig. 4, another method variant of the invention can be carried out, in which the monitoring of the cooling air temperature inside the filament bundle is used to control the process. In the event that the difference between the measured cooling air temperature T ^ and the required cooling air _temperature Ts _{0U is} too large and thus an impermissible limit value is exceeded in an actual-target comparison between a temperature _reading and a target value within the control _{device 17} , there is the possibility to generate from the difference signal, a further control signal for controlling the winding device 29. Thus, for example, the controller 18.1 for controlling the blower 9 and the control unit 18.2 to control the take-up device 29 can be controlled via the control device 17. First, the control of the blower 9 causes a correction of the cooling of the filaments 3 in the required manner, so that an approximation is achieved between the measured cooling air temperature and the required cooling air temperature. As soon as the required limit values are met, the takeup device 29 is controlled via the control device 18. 2 in such a way that a coil Change is performed. Thus, the qualitatively now perfectly produced thread is wound directly onto a new spool. The thread produced with a non-optimized cooling can be classified in a targeted manner by means of defined winding processes, so that during the further processing process the original bobbins can be provided in a defined manner according to specific criteria. The embodiment shown in Fig. 4 is particularly suitable for the production of textile threads.

FIG. 5 shows a further exemplary embodiment of the device according to the invention for carrying out the method according to the invention. The embodiment is substantially identical to the embodiment of FIG. 3, wherein the embodiment shown in Fig. 5 is shown in a side view. With reference to the description of FIG. 3, only the differences to the embodiment of FIG. 5 are explained. The components of the same function have been given identical reference numerals.

In the exemplary embodiment illustrated in FIG. 5, a plurality of multifilament threads 16 spun parallel to one another are produced at the same time. As is apparent from Fig. 5, the apparatus has a total of four spinning stations 33.1 to 33.4. The spinning stations 33.1 to 33.4 is associated with a beam-shaped spinning head 1, which is connected via a melt feed 4 with a melt source, not shown here. The spinning head 1 has a spinneret 2 for each spinning station 33.1 to 33.4. In that regard, a total of four spinnerets 2 are held side by side on the spinner 1.

Below the spinning head 1, the cooling device 6 is arranged with a blowing wall 7, which extends over the entire width of the spinning stations 33.1 to 33.4, so that the extruded in the spinning stations 33.1 to 33.4 filament strands 3 are guided at a distance to the blowing wall 7. The blowing wall 7 is connected to a blower via a blowing chamber (see FIG. 3). As shown in FIG. 5, each spinneret 2 in the spinning stations 33.1 to 33.4 is assigned one of the preparation device 30 in each case. The preparation device 30 has within the spinning stations 33.1 to 33.4 each have a conical shaped body 14. At the blunt end of the conical shaped body 14, a guide edge 15 wetted by a spin finish is formed, on which the filament strands 3 extruded from the nozzle bores of the spinneret 2 are guided. The molded body 14 has for this purpose in the back distribution lines and liquid chambers, which are connected via a supply line 31 with a preparation pump 32. As a result, a continuous supply of a lubricant to the moldings 14 for wetting the leading edge 15 is ensured. The fluid at the periphery of the leading edge 15 of the molded body 14 is continuously absorbed by the filament strands 3, so that a uniform preparation takes place.

Temperature sensors are respectively arranged at the pointed cone end of the molded body 14, wherein the temperature sensor 12.1 of the spinning station 33.1, the temperature sensor 12.2 of the spinning station 33.2, etc. are assigned. The temperature sensors 12.1 to 12.4 are coupled to the control device 17 via signal lines.

The spinning units 33.1 to 33.4 associated with the preparation device 30 is held together with the moldings 14 and the temperature sensors 12.1 to 12.4 on a height-adjustable cross member 24. The cross member 24 is formed height adjustable via a guide 25. The position of the molded bodies 14 and thus the degree of spreading within the cooling section and the height position of the temperature sensors 12.1 to 12.4 can thereby be selected and changed.

Below the cooling device 6 each thread guide 11 are provided in the spinning stations 33.1 to 33.4, which merge the filament strands 3 to a respective thread 16. The control device 17, which is connected via parallel signal lines with the temperature sensors 12.1 to 12.4 in the spinning units 33.1 to 33.4, essentially has one or more means for evaluating the measured values by statistical methods, which are brought to an output device 9 for display and output. In addition, the control device 17 is connected via a control line with a control device or a higher-level control device (not shown here).

In the embodiment of the device according to the invention shown in FIG. 5, several threads are extruded and cooled simultaneously. In order to detect the cooling history of the filaments 3 independently of each other, a temperature reading is detected within each of the Fialmentbündel 3 via the temperature sensors 12.1 and 12.4 and the control device 17 abandoned. For each spinning station 33.1 to 33.4 within the control device 17 is a measured value. evaluation carried out. In this case, an actual / desired comparison is preferably formed between a setpoint value or a limit value range with a temperature measurement value or an average value obtained from the temperature measurement values. The difference values found can be compared directly with the difference values of neighboring spinning stations. Thus, a comparison between see the filament bundles made in the individual spinning stations possible. Each of the filament bundles 3 and thus each of the threads 16 in the spinning units 33.1 to 33.4 can thus be assigned a quality value which can be determined and displayed continuously over the course of the process.

In addition, there is the possibility that in the case of impermissible deviations between the temperature setpoints and the temperature measured values within the control device 17, control signals are generated which bring about a change in the process setting. In addition, alarm signals can also be generated if impermissible limit value excesses are detected, so that appropriate measures by operators for correction in the devices can be carried out. In the exemplary embodiments according to FIGS. 1 to 5, the cooling air flow for cooling the filaments is formed by a cooling device which, as cross-flow blowing, generates a cooling air flow directed unidirectionally transversely. In principle, however, it is also possible to use a radially outwardly inwardly directed cooling air generation in order to cool the filament bundle. In addition, it is also advantageously possible to realize a plurality of measuring points at one height within the filament bundle. Likewise, the shaping of the guide means for spreading the filament bundles is exemplary, preferably circular or annular shaped bodies are used. However, oval or oblong forms are also possible for spreading filament bundles. In this case, both round, annular or rectangular arrangements of nozzle bores in a spinneret can be used. When using annular spinnerets, the sensor means are also advantageous to place without additional guide means within the filament bundle

The apparatus and method of the present invention are suitable for making any multifilament yarns of synthetic materials with high uniformity in physical properties. This can be used to create textile, technical or carpet yarns. In particular, the invention extends to the methods and apparatus in which a plurality of frusto-fibrous fiber strands are cooled from a polymeric material after being extruded by a cooling air or gas stream. In that regard, the invention is also suitable for monitoring a staple fiber melt spinning process.

LIST OF REFERENCE NUMBERS

1 spinning head

2 spinneret

3 filament

4 melt feed

5 filament bundles

6 cooling device

7 blowing wall

8 blow chamber

9 blowers

10 sensor means

11 thread guides

12, 12.1 ..-. 12.4 Temperature sensor

13 guiding means

14 moldings

15 leading edge

16 threads

17 control device

18.1, 18.2 Control unit

19 output device

20 monitor

21 printers

23 handrail

24 cross members

25 leadership

26, 26.1, 26.2 sensor carrier

27 treatment device

28 coil

29 winding device

30 preparation device

31 supply line 32 preparation pump

33.1 ... 33.4 spinning station

Claims

claims

A process for melt spinning and cooling a multifilament yarn wherein the yarn is made from a polymer melt wherein a plurality of extruded filaments are cooled as a bundle of filaments through a stream of cooling air directed to the filament bundle and subsequently gathered into the yarn and at a temperature of Cooling air occurring during the cooling of the filaments is measured and monitored, characterized in that the temperature of the cooling air is measured in at least one measuring point within the filament bundle.

2. The method according to claim 1, characterized in that the temperature of the cooling air in the center of the filament bundle is measured, wherein the filaments are spread and guided by an outer leading edge of a shaped body.

3. The method according to claim 2, characterized in that the filaments of the filament bundle are passed through an annular shaped body.

4. The method according to any one of claims 1 to 3, characterized in that the temperature of the cooling air are measured simultaneously in several measuring points within and / or outside of the filament bundle.

5. The method according to claim 4, characterized in that the measurement of the temperatures of the cooling air inside and / or outside of the filament bundle in vertically or horizontally juxtaposed measuring points.

6. The method according to any one of claims 1 to 5, characterized in that at least one temperature measurement or more sequentially in time stored temperature readings of the cooling air are stored and compared with a setpoint or a threshold range.

7. Method according to claim 6, characterized in that the temporally successive temperature measured values of the cooling air are converted to a statistical mean value or a plurality of statistical mean values and that the mean value or the mean values of the temperature measured values are compared with a nominal value or a limit value range.

8. The method according to claim 6 or 7, characterized in that the deviations are detected to the target value or the limit value range as a difference value or as a plurality of difference values and converted to a quality value of the thread.

9. The method according to claim 8, characterized in that the quality value is used to determine the quality of a product parameter.

10. The method according to claim 9, characterized in that the product parameter determines a color absorption capacity of the thread for further processing.

11. The method according to any one of claims 1 to 10, characterized in that a plurality of threads are cooled by the cooling air flow or by a plurality of separate cooling air streams and that detected for each thread a temperature reading of the cooling air and quality control of the respective

Thread is used.

12. The method according to any one of claims 1 to 11, characterized in that at least one instantaneous temperature measured value of the cooling air is compared with a stored nominal value of the temperature and that a

Difference signal is generated and converted into a control signal.

13. The method according to claim 12, characterized in that the control signal is used to change a process parameter or a process sequence determining the production of the thread.

14. The method according to claim 13, characterized in that the process parameter influences the cooling of the filaments in such a way that a temperature of the cooling air corresponding to the predetermined desired value is established.

15. An apparatus for carrying out the method according to any one of claims 1 to 14, comprising a spinneret (2) for extruding a plurality of filaments (3), with a cooling device (6) for producing a filaments guided transversely to the filament bundle (5) (3) directed cooling air flow, with one of the spinneret (2) associated yarn guide (11) for forming a convergence of the filaments (3) causing convergence 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 between the spinneret (2) and the yarn guide (11) within the filament bundle (5) arranged temperature sensor (12).

16. The apparatus according to claim 15, characterized in that the temperature sensor (12) is associated with a guide means (13) through which the filament strands (3) in the yarn path between the spinneret (2) and the thread guide (11) are spread.

17. The device according to claim 16, characterized in that the guide means (13) by a shaped body (14) having an outer guide edge (15) is formed, which is held substantially concentric with the spinning nozzle (2) and the filaments ( 3) at the leading edge (15) leads and that the temperature sensor (12) is held substantially centrally to the shaped body (14).

18. The device according to claim 17, characterized in that the shaped body (14) is formed by a circular disc or a circular ring, wherein the guide edge (15) is arranged on the circumference of the disc or of the ring.

19. The device according to claim 17, characterized in that the shaped body (14) by a preparation device (30) is formed, in which the peripheral leading edge (15) carries a wetting agent.

20. Device according to one of claims 15 to 19, characterized in that the sensor means (10) by a plurality of temperature sensors (12.1, 12.2) is formed, which are arranged horizontally or vertically next to each other within and / or outside of the filament bundle (5).

21. Device according to one of claims 15 to 20, characterized in that the sensor means (10) with a control device (17) is coupled, which has electronic means for measuring value evaluation, means for data storage and means for signal generation.

22. The device according to claim 21, characterized in that the control device (17) is connected to a control device (18.1) for changing a process parameter or a process sequence.

23. The device according to claim 22, characterized in that the control device (18.1) is associated with a cooling air source (9) of the cooling device (6) which is connected to produce a cooling air with a blowing wall (7).

24. Device according to one of claims 21 to 24, characterized in that the control device (17) is connected to an output device (19) for outputting a quality value.

25. Device according to one of claims 15 to 24, characterized in that at least one of the temperature sensors (12.1, 12.2) in an upper third of the between the spinneret (2) and the yarn guide (11) extending cooling path is arranged.

26. Device according to one of claims 15 to 25, characterized in that at least one of the temperature sensors (12.1, 12.2) by a height-adjustable support rod (23) is held.

27. Device according to one of claims 15 to 26, characterized in that the blowing wall (7) arranged laterally to the spinneret (2) and via a blowing chamber (8) with the cooling air source (9) is connected.