METHOD FOR MELT SPINNING, DRAWING AND RELAXING SYNTHETIC YARN AND APPARATUS FOR CARRYING OUT THE METHOD - Patent application

Abstract

The present invention relates to a method and an apparatus for melt spinning, drawing and relaxing a synthetic yarn, in which after melt spinning the yarn is guided through a number of godets with driven and partially heated godet walls, each with one turn. The godet walls of the godets are controllable in their peripheral speed and surface temperature. To scale up production, the godet walls of the godets are held in a stationary configuration relative to the yarn run so that the yarn can be selectively drawn and relaxed in a dry or oiled state.

Description

[Technical field]

[0001] The present invention relates to a method for melt spinning, drawing and relaxing synthetic yarns and to an apparatus for carrying out the method for melt spinning, drawing and relaxing synthetic yarns according to the preamble of claim 10. [Background technology]

[0002] A method of the type mentioned at the outset for melt spinning, drawing and relaxing synthetic yarns and an apparatus of the type mentioned at the outset are known from WO 2013 / 020866.

[0003] In the production of synthetic yarns, the properties required for the use of the yarn, such as strength and ductility, are essentially produced by drawing, stretching and relaxing the multifilament yarn after melt spinning. For this purpose, a godet device is used with a number of godets, each having a driven godet wall. The godet walls are partly heated by heating means to a predefined surface temperature, which can thermally influence the yarn material of the yarn. The configuration of the godets with heated and unheated godet walls is therefore of great importance in order to produce the desired physical properties for each yarn type. Furthermore, the physical properties resulting from the godet configuration in the yarn can be influenced by subjecting the multifilament yarn to a pretreatment, for example by wetting.

[0004] Thus, from WO 2013 / 020866, it is known to wet the multifilament yarn with a fluid before drawing. However, the application of such a liquid to the multifilament yarn requires intensive heat treatment of the yarn in order to obtain the desired drawing temperature in the yarn. A significant proportion of the heat energy is therefore used just for heating the fluid contained in the yarn. Therefore, the number of turns around the godet circumference usually influences the contact length between the yarn and the godet.

[0005] In contrast, when the multifilament yarn is drawn and drawn in a dry state after melt spinning, the yarn material is heated in direct contact with the surface of the godet jacket. The contact length between the yarn and the godet jacket of the godet, which is required to reach a predefined drawing temperature, is therefore shorter. Depending on the properties of the multifilament yarn, in known methods and known devices, correspondingly adapted godet arrangements are used, which differ mainly by the number of godets with heated godet jackets and therefore require significant retooling operations. Summary of the Invention [Problem to be solved by the invention]

[0006] It is therefore an object of the present invention to provide a method for melt spinning, drawing and relaxing synthetic yarns of the type mentioned at the beginning, which allows a wide variety of synthetic yarns to be produced without costly reconfiguration operations, as well as an apparatus for carrying out this method of the type mentioned at the beginning. [Means for solving the problem]

[0007] This problem is solved by a method having the features of claim 1 and by a device having the features of claim 10.

[0008] Advantageous further configurations of the invention are defined by the features and feature combinations of the respective dependent claims.

[0009] The invention has the advantage that a stationary godet arrangement with a driven and partially heated godet wall can be used, which allows various processes for producing synthetic threads to be carried out. By varying the peripheral speed and the surface temperature at the godet wall of the godet arrangement as desired, synthetic threads can be produced in various pretreatment states with the desired physical properties. This allows the thread to be selectively stretched and relaxed in a dry or oiled state by means of the stationary godet arrangement. No reconfiguration of the godet arrangement is required.

[0010] A further embodiment of the invention, in which the peripheral speed and surface temperature of only one of the godet jackets is changed during the process change so that the yarn is drawn at the inlet of the godet jacket or at the outlet of the godet jacket, is particularly advantageous for minimizing the control effort. Furthermore, the contact length of the yarn can be changed by simple means in order to reach the drawing temperature. In the dry state of the yarn, the yarn can already be drawn at the inlet of the godet jacket. In contrast, when drawing the yarn at the outlet of the godet jacket, the godet jacket is used for the heat treatment of the yarn and for reaching the drawing temperature, whereby the moistened yarn is preferably guided along the godet jacket with a relatively long contact length until it is drawn.

[0011] In a further configuration of the invention, in which the godet jacket of the godet is selectively driven at a peripheral speed in the range of 1800-2200 m / min or at a peripheral speed in the range of 4800-5200 m / min, it is envisaged that drawing can take place at the inlet or outlet of the godet jacket, depending on the assignment to the godet in question. A relatively high peripheral speed thus allows drawing at the inlet of the godet jacket, whereas a relatively low peripheral speed allows drawing of the yarn at the outlet of the godet jacket.

[0012] If the yarn is already drawn at the inlet of the godet jacket, a method embodiment is particularly advantageous in which the godet jacket of the godet is selectively heated to a surface temperature in the range from 60 to 110° C. or to a surface temperature in the range from 130 to 160° C. This allows a higher surface temperature at the godet jacket to be used in order to bring about relaxation of the yarn.

[0013] In order to be able to produce all current yarn types of fiber yarns, a method embodiment has been proven to be effective in which the yarn is stretched and relaxed by a total of five godets with five heated godet sleeves, the godet sleeve of the middle godet being changed in peripheral speed and surface temperature for process changes. This allows a compact godet arrangement to be realized despite one winding around the godet sleeve. Thus, depending on the yarn condition, selectively two or three heated godet sleeves can be used for preheating the yarn. Thus, selectively two or three heated godet sleeves can be used to relax the yarn.

[0014] In order to be able to generate the highest possible tensile stresses inside the drawing zone, the surface properties of the godet jacket, in particular the surface roughness, are important. It is therefore furthermore assumed that, if necessary, the godet jacket of the middle godet is replaced in the event of a process change, and thus is designed to be replaceable.

[0015] In order to achieve preheating of the oiled yarn to the predetermined drawing temperature despite the limited peripheral contact length at the godet circumference, a method embodiment is furthermore particularly advantageous in which the oiled condition of the yarn is achieved by oiling the yarn with an emulsion with an oil content of more than 90% before drawing. The water content in the emulsion during wetting of the yarn is thus reduced to a minimum. So-called boiling of the water for heating the yarn is not necessary.

[0016] Regardless of whether the yarn is drawn and relaxed in oiled or dry state, a certain degree of wetting must prevail in the yarn for further processing of the yarn in the subsequent process. For this purpose, a method embodiment is particularly advantageous in which the yarn is oiled after drawing and relaxation, selectively with an emulsion with an oil content of 15-50% or with an emulsion with an oil content of 0.5-2%. Overall, this results in an adapted wetting in the yarn at the end of the process.

[0017] For this purpose, the oil supply device of the device according to the invention has a number of switchable stations, whereby by means of at least one of the stations the yarn can be selectively wetted either with an emulsion with an oil content of 15-50% or with an emulsion with an oil content of 0.5-2%.

[0018] Due to the multifilament nature of the yarn, which is formed from a large number of fine filaments, a method embodiment is preferably configured in which the yarn is entangled with compressed air in the range of 0.05-0.4 bar before drawing, thereby allowing a uniform entanglement to be produced in the multifilament yarn, substantially without the formation of so-called entanglement nodes, in which case filament bundles can be produced both in the dry and in the cooled state.

[0019] The device according to the invention has for this purpose an interlacing device between the melt spinning device and the godet device, by means of which the yarns can be interlaced by means of compressed air.

[0020] A further configuration of the device according to the invention is particularly advantageous in that the godet jacket of the middle godet is held thermally insulated from the adjacent godet jackets so that a change in the surface temperature can be made without influence, as a result of which the surface temperature required for yarn preheating or for yarn relaxation can be adjusted and maintained without influence.

[0021] The method according to the invention and the device according to the invention for melt spinning, drawing and relaxing synthetic yarns significantly expand the flexibility and production range with which synthetic yarns, especially for textile applications, can be produced.

[0022] In order to illustrate the method according to the invention for melt spinning, drawing and relaxing synthetic yarns, several embodiments of the apparatus according to the invention for carrying out the method are illustrated and described below. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 shows a schematic diagram of a first embodiment of an apparatus according to the invention for carrying out a method according to the invention for melt spinning, drawing and relaxing a synthetic yarn. [Diagram 2] FIG. 2 shows a schematic diagram of the embodiment of FIG. 1 after a process modification. [Diagram 3] FIG. 2 is a schematic cross-sectional view of one of the godets with a heated godet peripheral wall. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In FIG. 1, an embodiment of the device according to the invention for carrying out the method according to the invention for melt spinning, drawing and relaxing synthetic yarns is shown. For melt spinning of multifilament yarns, a melt spinning device 1 is provided with a heated elongated spinning beam 1.1, which supports on its underside a number of spinning nozzles 1.3, each with a number of nozzle openings. On the upper side of the spinning beam 1.1, a melt supply 1.2 is shown, which is usually connected to the spinning nozzles 1.3 via a multi-spinning pump and a melt distribution system inside the spinning beam 1.1. The melt supply 1.2 is connected to a melt source, which is not shown here, for example an extruder. Since the spinning beam 1.1 is oriented transversely to the drawing plane, only one of the spinning nozzles 1.3 is visible in FIG. 1. The subsequent devices and units will therefore be described in more detail only on the basis of the yarn run of one of the multiple yarns. Basically, each of the yarns formed parallel to one another is treated in the same way.

[0025] A cooling device 3 is provided below the melt spinning device 1, which comprises a cooling duct 3.1 and a blow wall 3.2. The cooling duct 3 is arranged below the spinning nozzle 1.3 so that the multiple filament strands extruded from the spinning nozzle 1.3 pass through the cooling duct 3.1. The blow wall 3.2 cooperates with a blow chamber 3.3 which is connected to a cooling air source. Through the blow wall 3.2, a cooling air flow is introduced into the cooling duct 3.1, so that the filament strands extruded from the spinning nozzle 1.3 are uniformly cooled by the cooling air flow.

[0026] The cooling device 3 shown here is an example. Basically, the cooling duct 3.1 can also be formed by several cooling cylinders through which the filament strand of the spinning nozzle 1.3 is guided. The cooling cylinders have air-permeable walls and are arranged in the blow chamber so that a radially directed cooling air flow from the outside to the inside impinges on the filament strand. The cooling device 3 shown in FIG. 1 is usually called a transverse flow blowing. This cooling device can therefore also be replaced by a so-called radial blowing.

[0027] Below the cooling duct 3.1 there are arranged a yarn guide 4 and an oil supply device 5. The yarn guide 4 is arranged centrally below the spinning nozzle 1.3 and forms a so-called focusing point, which brings the filament strands together into a yarn 2. Adjacent yarn guides 4 of adjacent spinning nozzles 1.3 lie in a plane extending transversely to the drawing plane.

[0028] The oil supply device 5 comprises a first oil supply station 5.1 below the cooling duct 3.1 and a second oil supply station 5.2 below the godet device 6. The oil supply station 5.1 comprises wetting means 5.4 which can be guided back and forth between an operating position and a rest position via an adjustment means 5.6. The wetting means 5.4 is connected to a fluid container 5.5 below a metering pump 5.3. The fluid container is filled with an emulsion with an oil content of more than 90%. The water content of the emulsion is therefore arranged to be less than 10%.

[0029] The second oil supply station 5.2 below the godet arrangement 6 has wetting means 5.4 which are constantly held in contact with the yarn 2. The wetting means 5.4 are connected to a metering pump 5.3. Via an adjustment means, the metering pump 5.3 can be selectively connected to a fluid container 5.5 and 5.5'. The fluid container 5.5 contains an emulsion with an oil content in the range of 15-50%. In contrast, the fluid container 5.5' contains a highly aqueous emulsion with a very low oil content of only 0.5-2%. By means of an adjustment means 5.6, the metering pump 5.3 can be selectively connected to one of the fluid containers 5.5 or 5.5'.

[0030] Below the cooling device 3, a godet arrangement is arranged with a number of godets 6.1-6.8 for a predefined yarn runway. The godets 6.1-6.8 are arranged on the godet support 8 in such a way that the driven godet jackets 7.1-7.8 protrude in front of the godet support 8. The drives of the godets 6.1-6.8, not shown, are arranged on the rear side of the godet support 8. In order to guide the yarns in a single turn around the godet jackets 7.1-7.8 with a comparatively narrow yarn spacing relative to one another, a run-in device 11 is provided in front of the first godet 6.1. The run-in device 11 usually includes a comb yarn guide in order to guide the yarns with a predefined yarn spacing. Furthermore, a cutting device and a suction device, not shown, are integrated in order to collectively guide the yarns coming from the melt spinning device 1 in the event of a yarn break.

[0031] For stretching and relaxing the yarn 2, the godet arrangement 6 has a total of five godets, each with one heated godet wall. Thus, godets 6.2 to 6.6 are formed, each with one heated godet wall 7.2 to 7.6. The other godets 6.1 as well as 6.7 and 6.8 are formed with a significantly smaller diameter and with non-heated godet walls 7.1, 7.7 and 7.8.

[0032] The godets 6.1-6.8 are in a stationary configuration and form a defined yarn path for the yarn 2. The peripheral speeds of the godet jackets 7.1-7.8 can be controlled individually depending on the process by the associated drives. Similarly, the heating means for heating the godet jackets 7.2-7.6, which are provided in the godets 6.2-6.6, can be controlled individually in order to obtain predefined surface temperatures for the heat treatment of the yarn 2. The heated godet jackets 7.2-7.6 of the godets 6.2-6.6 are arranged separated from one another by a partially insulating wall 9, so that mutual influences on the surface temperatures due to the small distances between the godet jackets 7.2-7.6 can be prevented. In particular, the godet jacket 7.4 of the middle godet 6.4 is thermally insulated from the adjacent godet jackets 7.2 and 7.3 as well as 7.5 and 7.6. For drawing and relaxing the yarn 2, the godet arrangement 6 has a total of five godets each with one heated godet wall. Depending on the state of the yarn 2, the drawing zone can be selectively formed between the godet walls 7.3 and 7.4 or between the godet walls 7.4 and 7.5, as will be explained in more detail below.

[0033] For the pre-treatment of the yarn 2, a pre-entangling device 10 is arranged between the oil supply station 5.1 and the godet device 6. The pre-entangling device 10 usually has a separate yarn treatment channel for each yarn, through which the yarns are guided separately. A compressed air channel is assigned to each treatment channel, through which compressed air is introduced into the treatment channel in order to entangle the multifilament yarn 2. Since such pre-entangling devices 10 are generally known, further illustration of this device is omitted.

[0034] A post-entanglement device 12 is arranged in the area below the godet device 6, by means of which the splice in the yarn 2 can be stabilized by means of so-called interlacing nodes before the yarn is wound up. Such a post-entanglement device 12 is based on a similar principle as the pre-entanglement device 10, but is operated with a higher compressed air pressure in order to generate the interlacing nodes.

[0035] At the end of the process, a winding machine 13 is arranged to wind the yarn 2 into a package 14. The winding machine 13 has two protruding winding spindles 13.1, which are held in a rotatable winding revolver 13.3. This allows the winding spindles 13.1 to be guided alternately between a working area for winding the package 14 and a replacement area for replacing the fully wound package 14. To wind the yarn 2, it is guided back and forth between the winding points by a traverse device 13.5 and is wound over the surface of the package 14 by means of a pressure roller 13.4. Above the traverse device 13.5, a deflection roller 13.2 is provided for each winding point, by means of which the yarn 2 guided as a yarn bundle at the godet jackets 7.1-7.8 can be separated. The yarn 2 is therefore guided from an approximately horizontal distribution plane to the winding point of the winder 13 after emerging from the last godet jacket 7.8 of the godet arrangement 6.

[0036] Depending on the adjustment of the oil supply device 5 and the godet device 6, the device according to the invention shown in FIG. 1 can carry out various production processes with substantially different pretreatment states of the yarn 2. The first oil supply station 5.1 below the cooling device 3 allows the yarn to be selectively drawn off in a wet or dry state. The operating state of the device according to the invention shown in FIG. 1 shows the adjustment for producing fully drawn yarns (FDY) in a dry pretreatment state. For this, a polymer melt, for example consisting of polyester or polyamide, is fed to the spinning beam 1.1. Inside the spinning nozzle 1.3, the polymer melt is pushed under pressure through a nozzle hole formed below the spinning nozzle 1.3, whereby a number of filaments are extruded. By means of the cooling device 3, the filaments are cooled by a cooling air flow to a temperature below the glass transition temperature of the thermoplastic material, so that hardening and preorientation of the filaments occurs. After cooling, the filament strands are each gathered into a single yarn 2.

[0037] In the oil supply station 5.1, the wetting means 5.4 is in a rest position, so that the yarn 2 is drawn off unwetted and therefore dry. Before the yarn runs into the godet device 6, the yarn 2 is entangled with compressed air by the pre-entanglement device 10. In this case, the compressed air is supplied at a low positive pressure in the range of 0.05-0.4 bar.

[0038] The run-in device 11 brings the yarns 2 together with a yarn spacing in the range of 2 mm to 4 mm so that they can be guided together as a yarn group at the godet jackets 7.1 to 7.8 of the godets 6.1 to 6.8. The first godet 6.1 with the cold godet jacket 7.1 serves to pull the yarns 2 out of the melt spinning device 1. To stretch and relax the yarns 2, they are first preheated at the godet jackets 7.2 and 7.3. In this case, the speed difference required to stretch the yarns is adjusted between the godet jackets 7.3 and 7.4. The yarns are thus stretched at the inlet of the godet jacket 7.4 of the middle godet 6.4. The godet jacket 7.4 of the middle godet 6.4 is driven for this purpose at a peripheral speed in the range of 4000 to 5200 m / min. Additionally, the godet jacket 7.4 of the middle godet 6.4 is heated to a surface temperature in the range of 120°C to 160°C, so that a relaxation and thus a stress reduction in the yarn 2 can be achieved. Between the godet jackets 7.4 to 7.6 of the godets 6.4 to 6.8, no or only a very small speed difference is adjusted, which results in a small yarn stress for reducing the stress in the yarn 2. The surface temperatures of the following godet jackets 7.5 and 7.6 are thus likewise in the range of 120°C to 160°C.

[0039] After drawing and relaxing the yarn 2, the yarn is moistened with an emulsion of water and oil in a second oil supply station 5.2. For this purpose, a metering pump 5.3 of the second oil supply station 5.2 is connected via an adjustment means 5.6 to a fluid container 5.5. An emulsion having an oil content of min. 15% to max. 50% is preliminarily stored in the fluid container 5.5.

[0040] After wetting of the yarns 2, they are entangled in a post-entanglement device 12 and then wound into a package 14 in a winder 13.

[0041] However, depending on the yarn type and polymer composition, the production of yarns in the dry state can inevitably lead to poor yarn quality or even process failures. Therefore, with the device according to the invention shown in Fig. 1, a process modification can be implemented in order to stretch and relax the yarn under oiling conditions. For this purpose, Fig. 2 shows a modified operating state of the embodiment shown in Fig. 1.

[0042] In the operating state shown in Fig. 2, the oiling station 5.1 is shown in the operating position. For this, the wetting means 5.4 is guided by the adjustment means 5.6 from the rest position into the operating position, so that the yarn 2 after cooling can be wetted with emulsion. For this, the metering pump 5.3 pumps a defined amount of the corresponding emulsion from the fluid container 5.5 for wetting the yarn 2. However, in this case the emulsion consists essentially of oil, in particular neat oil. The proportion of oil in the emulsion is therefore more than 90%. The state of the yarn is therefore referred to as oiled in this document.

[0043] The subsequent interlacing of the yarns in the pre-interlacing device 10 takes place as already described above with reference to FIG.

[0044] In order to stretch and relax the yarn 2 by means of the godet arrangement 6, the peripheral speed of the godet jacket 7.4 and the surface temperature of the godet jacket 7.4 are changed at the middle godet 6.4 in such a way that the yarn stretching takes place in the yarn path between the godet jacket 7.4 and the godet jacket 7.5. The preheating of the yarn 2 for stretching is now additionally sensed by the godet jacket 7.4 of the middle godet 6.4. The surface temperature of the godet jacket 7.4 is thereby adjusted to a value in the range of 60°C to 110°C, so that the contact length for preheating the yarn is enlarged by the winding area at the godet jacket 7.4. In this case, the adjustments at the godet jackets 7.2 and 7.3 are maintained. To transfer the drawing zone to the outflow of the godet jacket 7.4 of the middle godet 6.4, the peripheral speed of the godet jacket 7.4 of the middle godet 6.4 is reduced and adjusted in the range of 1800-3500 m / min. This causes all the yarns 2 to be drawn at the outflow of the godet jacket 7.4 of the middle godet 6.4. The relaxation of the yarns 2 is then carried out by the godet jackets 7.5 and 7.6 of the godets 6.5 and 6.6, whose adjustment remains unchanged with respect to the preceding process. A process change in the godet arrangement 6 therefore requires only an adaptation of the speed and surface temperature of the middle godet 6.4.

[0045] In order to be able to form a sufficient number of interlacing nodes during interlacing in the post-interlacing device 12, the yarn 2 is moistened again after relaxation in a second oil supply station 5.2. In this case, however, the wetting takes place with an emulsion which consists mainly of water. The metering pump 5.3 is therefore connected by means of a regulating means 5.6 to a fluid container 5.5'. The fluid container 5.5' contains an emulsion with a slight oil content which may be in the range of 0.5-2%. Finally, the yarn 2 is wound by a winder 13 into a package 14.

[0046] The method according to the invention for melt spinning, drawing and relaxing synthetic yarns and the device according to the invention for carrying out the method according to the invention significantly expand the production range for producing fully drawn yarns (FDY). No extensive reconfiguration is required to produce yarns in dry or oiled conditions. Only by controlling the actuators of the oil supply device 5 and the drive and heating control of the middle godet 6.4 a high degree of flexibility is available for carrying out various processes.

[0047] A jacket exchange, which may be performed at the middle godet 6.4, can further expand the process versatility. Thus, in FIG. 3, the structure of the middle godet 6.4 is shown diagrammatically in cross section. The godet 6.4 is held on the godet support 8 via a flange housing 21. The godet jacket 7.4 of the godet 6.4 is guided so as to protrude on the front side of the support 8. The godet jacket 7.4 is formed for this purpose in the shape of a hollow cylinder and is connected internally to a drive shaft 20. The drive shaft 20 is connected to a drive 15. The godet jacket 7.4 is covered by a heating means 16. The heating means 16, which may be formed, for example, by an induction coil, is held on a heating support 17 and is electrically connected to an external heating control device 18. Via the heating control device 18, the respective desired surface temperature is set at the godet jacket 7.4. Sensors provided for closed-loop control and monitoring of the surface temperature are not shown in this exemplary embodiment. A drive control 19 is assigned to the drive 15, by means of which the peripheral speed of the godet jacket 7.4 can be controlled.

[0048] The godet jacket 7.4 is removably connected to the drive shaft 20. It can therefore be easily replaced from the front side of the support 8. To transfer the yarn stretching from the inlet to the outlet, it can be advantageous to replace the godet jacket 7.4 in order to change the surface roughness. It is generally known that a low surface roughness of the godet jacket promotes the formation of stretching forces. In the embodiment shown in FIG. 2, it is therefore possible to replace the godet jacket 7.4 in advance in order to improve the yarn stretching at the outlet of the godet jacket 7.4 of the godet 6.4.

[0049] It should be noted here that the heated godets 6.2, 6.3 and 6.5-6.6 have substantially the same structure as in the embodiment shown in FIG.

Claims

1. A method for melt spinning, drawing and relaxing a synthetic yarn, comprising guiding the yarn after melt spinning through a stationary arrangement of a plurality of godets having driven godet walls, each with one wrap, some of the godets having heated godet walls, and controlling the peripheral speed and surface temperature of the godet walls such that the yarn is selectively drawn and relaxed in a dry or oiled state.

2. 2. The method according to claim 1, wherein for the process change, only the peripheral speed and the surface temperature of one of the godet circumferences of the godet are changed so that the yarn is drawn at the inlet of the godet circumference or at the outlet of the godet circumference.

3. 3. The method of claim 2, wherein the godet peripheral wall of the godet is selectively driven at a peripheral speed in the range of 1800 to 3500 m / min or at a peripheral speed in the range of 4000 to 5200 m / min.

4. 4. The method of claim 2 or 3, wherein the godet peripheral wall of the godet is selectively heated to a surface temperature in the range of 60 to 110.degree. C. or to a surface temperature in the range of 120 to 160.degree.

5. 5. The method according to claim 2, wherein the yarn is stretched and relaxed by a total of five godets with five heated godet walls, the godet walls of the middle godet being changed in peripheral speed and surface temperature for process changes.

6. 6. The method of claim 5, wherein the godet peripheral wall of the middle godet is replaced during a process change to change the surface roughness.

7. 7. The method of claim 1, wherein the yarn is oiled by oiling the yarn with an emulsion of more than 90% oil before drawing.

8. 8. The method according to claim 1, wherein the yarn is oiled after drawing and relaxation, selectively with an emulsion of 15-50% oil or with an emulsion of 0.5-2% oil.

9. 9. The method according to any one of claims 1 to 8, wherein the yarn is entangled by compressed air in the range of 0.05 to 0.4 bar before drawing.

10. An apparatus for carrying out the method according to any one of claims 1 to 9, comprising a melt spinning apparatus (1), an oil supplying apparatus (5) and a godet apparatus (6), the godet apparatus having a plurality of godets (6.1 to 6.8) with driven godet walls (7.1 to 7.8), some of the godets having heated godet walls, the godet walls (7.1 to 7.8) being formed so that their peripheral speed and surface temperature can be controlled, 1. The device according to claim 1 , wherein the godet walls (7.1-7.6) of the godets (6.1-6.6) in a stationary configuration form a yarn path along which the yarn (2) can be selectively stretched and relaxed in a dry state or in an oiled state.

11. 11. The apparatus according to claim 10, wherein one of the godet jackets (7.2-7.6) of the godets (6.2-6.6) is controllable such that the yarn can be selectively drawn at an inflow section of the godet jacket (7.2-7.6) or at an outflow section of the godet jacket (7.2-7.6).

12. 12. The apparatus according to claim 11, wherein the godet arrangement (6) comprises a total of five godets (6.2-6.6) with heated godet walls (7.2-7.6), the godet wall (7.4) of the middle godet (6.4) allowing the drawing zone to be transferred from the outlet to the inlet or vice versa.

13. 13. The device according to claim 12, wherein the godet wall (7.4) of the middle godet (6.4) is designed to be replaceable.

14. 14. The device according to claim 12 or 13, characterized in that the godet wall (7.4) of the middle godet (6.4) is held in a thermally insulated manner with respect to the adjacent godet walls (7.2, 7.3, 7.6, 7.7).

15. 15. Apparatus according to any one of claims 10 to 14, wherein the oil supply device (5) has a number of switchable stations (5.1, 5.2), by means of at least one of which the yarn can be selectively wetted with an emulsion with an oil content of 15-50% or with an emulsion with an oil content of 0.5-2%.

16. 16. The apparatus according to claim 10, further comprising an interlacing device (10) arranged between the melt spinning device (1) and the godet device (6), by means of which the yarns can be interlaced by compressed air.

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