Title of Invention	AN APPARATUS AND A METHOD FOR SPINNING A SYNTHETIC YARN
Abstract	An apparatus and method for spining a synthetic yarn, wherein a heated polymeric melt is extruded throuigh a spinneret and the resulting filaments are combined and wound to a package by means of a take-up device located downstream of the spinneret, and an inlet cylinder which has a gas permeable wall is positioned between the inlet cylinder and the cooling tube. The cooling tube connects to an air stream generator in such a manner that an air stream develops in the cooling tube in the direction of the advancing yarn. The air stream is formed by a quantity of air that enters the cooling tube via the inlet cylinder, and the inlet cylinder is subdivided in the direction of the advancing yarn into several zones, each with a different gas permeability, for controlling the quantity of air entering the inlet cylinder. It is thereby possible to influence with advantage the precooling of the yarn and the formation of the air stream.

Title of Invention

AN APPARATUS AND A METHOD FOR SPINNING A SYNTHETIC YARN

Abstract

An apparatus and method for spining a synthetic yarn, wherein a heated polymeric melt is extruded throuigh a spinneret and the resulting filaments are combined and wound to a package by means of a take-up device located downstream of the spinneret, and an inlet cylinder which has a gas permeable wall is positioned between the inlet cylinder and the cooling tube. The cooling tube connects to an air stream generator in such a manner that an air stream develops in the cooling tube in the direction of the advancing yarn. The air stream is formed by a quantity of air that enters the cooling tube via the inlet cylinder, and the inlet cylinder is subdivided in the direction of the advancing yarn into several zones, each with a different gas permeability, for controlling the quantity of air entering the inlet cylinder. It is thereby possible to influence with advantage the precooling of the yarn and the formation of the air stream.

Full Text	The invention relates to an apparatus and a method for spinning a synthetic yarn. This type of spinning apparatus and the method are disclosed in WO 95/15409. In this apparatus and process, an air stream assists freshly extruded filaments in their advance. With that, it is accomplished that the solidification point of the filaments moves away from the spinneret. This leads to a delayed crystallization that favorably influences the physical properties of the yarn. Thus, for example, in the production of a POY yarn, it was possible to increase the withdrawal thus, the draw ratio, without changing for the yarn the elongation values necessary for further processing. The known spinning apparatus comprises a cooling tube and an air stream generator downstream of the spinneret. Between the spinneret and the cooling tube, an inlet cylinder extends with a gas-permeable wall. By the interaction of the inlet cylinder and the air stream generator, a quantity of air is caused to enter the cooling shaft, and to advance within the cooling shaft as an accelerated air stream in direction of the advancing yarn. The inlet cylinder consists of a perforated, gas-permeable material. Therefore, the radially inflowing air quantity is proportional to the applied pressure difference that becomes greater as the yarn speed increases. Thus, the quantity of air entering the inlet cylinder becomes greater with an increasing distance from the spinneret. However, it has shown that besides assisting the advance, it is necessary that the filaments uniformly firm up in their surface layers. While advancing through the inlet cylinder, the filaments are precooled in such a manner that the surface layer has firmed up before entering the cooling tube. In their core, the filaments are still molten when they enter the cooling tube, so that the final solidification occurs only in the cooling tube. Consequently, it is also necessary that all filaments be uniformly precooled. Furthermore, it must be accomplished that a uniform quantity of air is present over the entire cross section of the inlet cylinder, so that each filament in the cooling tube is uniformly assisted in its advance. yarn is determined by the interaction of the filament properties. It is therefore known that for producing a high-quality yarn, each filament within a bundle of filaments must undergo an equal treatment. In the known method and apparatus, the solidification point is deliberately removed from the spinneret, so that the filaments solidify only after passing through a precooling zone in the cooling zone formed by the cooling tube. Thus, the filaments cover a relatively long distance, over which they are exposed to different air streams. U.S. 5,034,182 discloses a spinning apparatus, wherein the inlet cylinder is arranged in a pressure chamber. The inlet cylinder has a screenlike wall, so that based on the overpressure prevailing outside of the inlet cylinder, a greater pressure difference is obtained and, thus, a larger quantity of inflowing air. However, this leads to the problem that the filaments are already exposed to a considerable cooling effect within the inlet zone. It is therefore the object of the invention to further develop a spinning apparatus of the initially described type such that it is possible to make available an air quantity adjusted to the uniform precooling of the filaments and an air quantity necessary for assisting the movement of the filaments. A further object of the invention is to further develop the method and the initially described spinning apparatus such that all filaments of the filament bundle undergo a substantially uniform treatment until their solidification. Accordingly the present invention provides an apparatus for spinning a synthetic yarn, comprising a plurality of individual filaments, and which is wound to a package by means of a takeup device downstream of the spinning apparatus, a spinneret, which has on its underside a plurality of nozzle bores for extruding the filaments; a cooling tube downstream of the spinneret, through which the filaments for the purpose of cooling down advance and which comprises an inlet cone for accelerating an air stream in direction of the advancing yam; an air stream generator for the generation of an air stream within the cooling tube which is connected to the cooling tube in such a manner that the air stream is generated in the cooling tube in direction of the advancing yam; and a gas-permeable inlet cylinder arranged between the spinneret and the cooling tube, through which the filaments advance, and through which a radially inflowing quantity of air is supplied to the inlet cone for generating the air stream within the cooling tube, characterized in that the inlet cylinder is divided in direction of the advancing yarn into several zones, each zone having a different permeability to gas of a wall for controlling the quantity of air entering inlet cylinder and to provide the air stream supporting the advance of the filaments only for pre-cooled filaments. The invention also provides a method of spinning a synthetic yarn, comprising the steps of : combining a filament bundle consisting of a plurality of individual filaments, and which is wound to a package by means of a takeup device downstream of the spinning apparatus, and the filaments are extruded by means of a spinneret with a plurality of nozzle bores; the filaments advance for a cooling treatment through a precooling zone and a cooling zone; the cooling zone is formed by a cooling tube with a vacuum atmosphere, so that an air stream is generated in the tube cross section of the cooling tube in direction of the advancing yarn for assisting the filaments in their advance; and the filaments are combined to the yarn at the end of the cooling zone, characterized in that dependent on a flow profile of the air stream in the cooling tube, the filaments within the filament bundle advance into the tube cross section of the cooling tube such that the filaments are assisted uniformly in their advance and cooled evenly. In accordance with the invention, a solution to the problem lies in that in the direction of the advancing yarn, the inlet cylinder is subdivided into several zones, each with a different permeability to gas for controlling the air quantity entering the inlet cylinder. The invention has not been suggested either by the spinning apparatus known from EP 0 580 977 or the spinning apparatus disclosed in DE 195 35 143. In the known spinning apparatus, the inlet cylinder downstream of the spinneret is constructed with its air permeability varying in the direction of the advancing yarn, so as to realize a cooling the filaments as a function of the yarn advance speed. The purpose of the known spinning apparatus is a complete cooling of the filaments within the inlet cylinder, and they are thus totally unsuited to generate an air stream that assists in the movement of the filaments in the case of only precooled filaments. The invention has the advantage that, irrespective of the filament speed and irrespective of the differential pressure between the spin shaft and the surroundings, it is possible to influence the air quantity flowing into the spin shaft. This makes it possible to exert a purposeful influence on the properties of the filaments that originate from different zones of the spinneret. On the one hand, the influence may lie in that all filaments undergo a precooling for firming up the surface zones, if possible under the same cooling conditions. Furthermore, it is possible to influence the entry of the filaments into the cooling tube, as well as the development of the air stream in the cooling tube, in particular by the air quantity entering into the lower region of the inlet cylinder. The air quantity entering through the wall of the inlet cylinder is proportionately dependent on the gas permeability or the porosity of the wall. In the case of a great gas permeability, a larger quantity of air per unit time is introduced into the spin shaft under otherwise constant conditions. Conversely, in the case of little gas permeability of the wall, a proportionately smaller air quantity enters the spin shaft. The especially advantageous further development of the spinning apparatus has the advantage that a relatively large quantity of air is available for cooling the filaments. A further advantage lies in that a substantially uniform distribution of the air quantity adjusts itself inside the spin shaft. Since in the upper region the filament speed is low, and since furthermore the filaments are spaced from each other relatively wide due to the small distance from the spinneret, the air quantity is able to distribute itself in the upper zone of the inlet cylinder substantially unimpeded over the entire cross section of the spin shaft. With that, it is accomplished that within the filament bundle a uniform air stream is able to develop in the cooling tube. The embodiment of the invention is especially suited to treat the filaments in a relatively weak precooling. From this follows the advantage of a particularly gentle cooling, which means a further improvement in spinning reliability. Spinning reliability means in this instance the quantity of filament breaks. In the lower zone facing the cooling tube, however, a relatively large quantity of air enters the spin shaft, which facilitates the entry of the filament bundle into the cooling tube. This advantageously prevents the filaments from striking the tube wall in the region of the narrowest cross section. However, it is possible to decrease the gas permeability in the upper zone such that the upper zone becomes impermeable to gas. Thus, a quiet zone develops directly downstream of the spinneret. This quiet zone ensures a stable spinning of the filaments, and thus favors the formation of a uniform filament structure. The specially advantageous further development of the spinning apparatus has the advantage that both a uniform distribution of the air quantity is realized inside the spin shaft, and thus a uniform precooling of the filaments. On the other hand, it favors the advance of the filaments into the cooling tube. Since relatively little air enters the spin shaft in the center region of the inlet cylinder, an air stream oriented in the direction of the advancing yarn is already able to develop due to the filament speed. The air quantity supplied directly before the entry into the cooling tube thus forms an air stream that engages each filament substantially uniformly. Since the filament speed increases as the distance from the spinneret becomes greater, and since the spacing between the individual filaments decreases at the same time, a specially advantageous embodiment of the invention provides that the gas permeability of the inlet cylinder is the same within one zone in the direction of the advancing yarn. Thus, the air entering the spin shaft within the zone is dependent on the filament speed. This means that at a higher yarn speed, more air is supplied to the spin shaft. The embodiment of the invention however, makes it possible to generate over the length of the inlet cylinder a flow profile that contains no stepwise changes in the supply of the air quantity. Furthermore, it is possible to realize therewith that irrespective of the yarn speed, the air quantity entering the spin shaft can be maintained substantially unchanged over the length of the zone. The wall of the inlet cylinder may be made from any porous material. In this advantageous embodiment, it is possible to predetermine very precisely the gas permeability or air resistance within the wall. In this instance, the number of the inlet openings of the perforations and the diameter of the inlet openings of the perforations define the gas permeability. The embodiment of the spinning apparatus is especially suited for generating an air stream that assists the filament movement. In this embodiment, a plurality of inlet openings forms the perforation of at least one zone. These inlet openings extend through the wall of the inlet cylinder obliquely with an inclination toward the direction of the advancing yarn, so that an air stream oriented in direction of the advancing yarn enters the inlet cylinder. The particularly advantageous further development accomplishes that a high, substantially uniform radial air stream is generated over the entire circumference of the inlet cylinder. To be able to form the zones within the inlet cylinder, the embodiment of the invention is especially advantageous. In this embodiment, it is possible to stack individual cylinders with the same or with respectively different gas permeability. This may be realized by different mesh sizes of the wire cloth or by a different multilayer arrangement of layers. Furthermore, the embodiment offers the possibility of changing the gas permeability by means of a paper sleeve. In this instance, the advantage consists in that the paper sleeve performs an air filtering, so that no impurities may enter the spin shaft. To generate a uniform flow in the inlet cylinder and to prevent turbulences upon entry into the inlet cylinder, the further development is especially advantageous. To this end, the wall in the interior of the inlet cylinder mounts in the region of at least one zone a plurality of baffles with an inclination extending from the wall in direction of the advancing yarn. In a particularly advantageous further development of the invention, the inlet cylinder connects to the spinneret in heat transferring relationship. Thus, it is possible to heat in particular the upper zone of the inlet cylinder, which leads again to heating the air flowing through the wall, so that a shocklike cooling effect on the filaments is prevented. In the previously described embodiments of the invention, the air stream generator may be formed by a blower in the region of the inlet cylinder, by an injector directly upstream of inlet into the cooling tube, or by a suction device that connects to the cooling tube on the outlet end thereof. The suction device has the special advantage that during spinning all emerging particles, such as for example monomers, are removed from the spin shaft. With that, a contamination of the spin shaft is prevented. To produce a yarn of a very high, uniform quality, the spinning apparatus is especially advantageous. The arrangement of the nozzle bores in accordance with the invention within the spinneret is a further solution to the underlying problem. It accomplishes that in the cooling tube equidirectional and identical air streams oriented in the direction of the advancing yarn engage each individual filament. The invention was not suggested either by the spinning apparatus and by the method known from DE 25 39 840. In the known method and known spinning apparatus, a uniform air stream that is used for treating the filaments is directed in the direction of, transversely, or oppositely to the direction of the advancing yarn. However, this does not apply to the spinning apparatus of the present invention. The vacuum atmosphere present in the cooling tube of the apparatus according to the invention generates an air stream in direction of the advancing yarn with a flow profile as a function of the tube cross section and with different flow velocities. The spinning apparatus of the present invention has the advantage that the flow profile of the air stream prevailing in the tube cross section is used as a basis for arranging the nozzles bores in the spinneret. Since the air stream engaging the filaments assists the filaments in their advance within the cooling tube, it is especially significant that a substantially uniform assistance in the advance be maintained for each of the filaments over the entire distance. The flow profile of the air stream that develops in the tube is dependent on the inlet geometry of the cooling tube, as well as on the inside condition of the cooling tube, and lastly on the diameter of the cooling tube and the kind of flow. In this connection, different flow velocities may develop inside the tube cross section, which would be bound to lead, in an even distribution of the filaments, to a different treatment within the tube cross section. Thus, the invention offers a possibility of arranging the filaments within the bundle of filaments in such a manner that each filament advances through the cooling tube at substantially the same flow velocity. The especially preferred further development of the spinning apparatus has the advantage that the filament bundle safely enters the cooling tube, and that a less turbulent air stream develops in the inlet region of the cooling tube. In this connection, it has been found that the air stream inside the cooling tube exhibits a flow profile that tends to have a maximum flow velocity in the center of the cooling tube. Thus, the configuration of the spinneret prevents the filaments from entering the cooling tube in the central region thereof. With an oval or round tube cross section, the configuration of the spinning apparatus is especially suited to advance the filaments through the cooling tube in zones of identical flow velocities. The arrangement of the nozzle bores in a closed line of bores further accomplishes that precooling is equalized inside the inlet cylinder. The embodiment of the spinning apparatus is especially of advantage to realize a uniform precooling in the case of a plurality of lines of bores. In a particularly advantageous further development of the spinning apparatus, the filaments advance at substantially the same distance from the wall of the inlet cylinder. This accomplishes an additional equalization of precooling and, thus, a reproducible firming up of surface layers. To realize in the cooling tube a flow profile that is favorable for producing the yam, it has been found that the spacing between the spinneret and the cooling tube should be from at least 100 mm to at most 1000 mm. In this connection, the cooling tube has a diameter in the region of the narrowest tube cross section from at least 10 mm to at most 40 mm. To further delay crystallization of the filaments, and thus produce a yam with higher elongation values, the embodiment of the spinning apparatus will be especially advantageous. This embodiment provides for a heating device between the spinneret and the inlet cylinder for heat treating the filaments. The same effect can also be accomplished by the advantageous further development of the spinning apparatus. In this embodiment, the ambient air is heated outside on the periphery of a zone —preferably the upper zone -of the inlet cylinder to a temperature from 35°c to 350°C. The hot air entering the inlet cylinder thermally treats the filaments as a function of the air temperature before the actual cooling. The apparatus of the present invention, the method of the invention, and the inventive use of a spinning apparatus are suitable to produce textile yams or industrial yams of polyester, polyamide, or polypropylene. It is possible to arrange downstream different treatment devices for the yam to produce, for example, a fully drawn yam (FDY), a partially oriented yam (POY), or a highly oriented yam (HOY. In the following, some embodiments of the spinning apparatus according to the invention are described in more detail with reference to the attached drawings. In the drawing: Figure 1 shows a spinning apparatus with a takeup device downstream thereof; Figure 2 shows an inlet cylinder of the spinning apparatus of Figure 1; Figure 3 shows different wall configurations with a corresponding flow profile; Figure 4 shows a further embodiment of the spinning apparatus according to the invention; Figure 5 shows an embodiment of a flow profile within a cooling tube of the spinning apparatus of Figure 1; and Figure 6 shows several configurations of a spinneret. Figure 1 shows a first embodiment of a spinning apparatus of the present invention for spinning a synthetic yarn. A yarn 12 is spun from a thermoplastic material. To this end, the thermoplastic material is melted in an extruder or a pump. A spin pump delivers the melt via a melt line 3 to a heated spin head 1. The underside of spin head 1 mounts a spinneret 2. From the spinneret 2, the melt emerges in the form of fine filament strands 5. The filaments 5 advance through a spin shaft 6 that is formed by an inlet cylinder 4. To this end, the inlet cylinder 4 extends directly downstream of the spin head 1 and encloses the filaments 5. At the free end of inlet cylinder 4, a cooling tube 8 follows in the direction of the advancing yarn. The cooling tube 8 connects to the inlet cylinder 4 via an inlet cone 9. At the opposite end of inlet cone 9, the cooling tube 8 comprises an outlet cone 10 that terminates in an outlet chamber 11. In the underside of outlet chamber 11, an outlet opening 13 is arranged in the plane of the advancing yarn. On one side of the outlet chamber 11, a suction stub 14 terminates in suction chamber 11. The suction stub 14 interconnects an air stream generator 15 arranged on the free end of suction stub 14 and the outlet chamber 11. The air stream generator 15 is constructed as a suction device. The suction device 15 may comprise, for example, a vacuum pump or a blower, which generates a vacuum in outlet chamber 11 and thus in cooling tube 8. In the plane of the advancing yarn, a lubrication device 16 and a takeup device 20 are arranged downstream of the outlet chamber 11. The takeup device 20 comprises a yarn guide 19. The yarn guide 19 indicates the beginning of a traversing triangle that forms by the reciprocal movement of a traversing yarn guide of a traversing device 21. Downstream of the yarn traversing device 21, a contact roll 22 is arranged. The contact roll 22 lies against the circumference of a package 23 being wound. The package 23 is produced on a rotating winding spindle 24. To this end, a spindle motor 25 drives winding spindle 24. The drive of winding spindle 24 is controlled as a function of the rotational speed of the contact roll, so that the circumferential speed of the package and thus the takeup speed remain substantially constant during the winding. Between the lubrication device 16 and the takeup device 20, a treatment device 17 is arranged for treating the yarn 12. In the embodiment of Figure 1, the treatment device is formed by an entanglement nozzle 18. As a function of the production process, the treatment device may comprise one or more heated or unheated godets, so that the yarn can be influenced in its tension or be drawn before its takeup. Likewise, it is possible to arrange within the treatment device 17 additional heating devices for drawing or relaxing. In the spinning apparatus shown in Figure 1, a polymer melt is delivered to spin head 1 and extruded via spinneret 2 to a plurality of filaments 5. The bundle of filaments is withdrawn by takeup device 20. In this process, the filament bundle advances at an increasing speed into the spin shaft 6 inside of inlet cylinder 4. Subsequently, the filament bundle enters the cooling tube 8 via inlet cone 9. In the cooling tube 8, the suction device 15 generates a vacuum, thereby sucking into cooling shaft 6 ambient air that surrounds the exterior of inlet cylinder 4. The air quantity entering spin shaft 6 is proportional to the gas permeability of wall 7 of the inlet cylinder. The inflowing air leads to a precooling of the filaments, so that the surface layers of the filaments firm up. However, in their core the filaments remain molten. The air quantity, together with the filament bundle, is then taken in, via inlet cone 9, into the cooling tube 8. Due to a narrowest cross section in cooling tube 8, the air stream is accelerated under the action of suction device 15 in such a manner that there exists no longer an air stream in the cooling tube that counteracts the movement of the filaments. With that, stress on the filaments is reduced. To generate in the outlet region of cooling tube 8 as little turbulences as possible, the air stream flows, via outlet cone 10, into outlet chamber 11. To further stabilize the air, the outlet chamber 11 accommodates a screen cylinder 30 that surrounds the filament bundle. The air is then sucked off and removed from outlet chamber 11 via stub 14 and suction device 15. The filaments 5 exit on the underside of outlet chamber 11 through outlet opening 13 and advance into lubrication device 16. By the time the filaments emerge from the cooling tube, they are totally cooled. The lubrication device 16 combines the filaments to a yarn 12. To increase cohesion of the yarn, the yarn 12 is entangled in entanglement nozzle 18, before it is wound. In the takeup device 20, the yarn 12 is wound to package 23. In the arrangement of Figure 1, it is possible to produce, for example, a polyester yarn that is wound at a takeup speed > 7,000 m/min. The spinning apparatus of Figure 1 is characterized in that the air quantity entering inlet cylinder is adapted to the heat treatment of the filaments. In this connection, it is possible to influence with advantage both precooling and the suction stream. Figure 2 shows again the inlet cylinder 4 of Figure 1. In this embodiment, the wall 7 of inlet cylinder 4 is constructed as a perforated sheet element with two different perforations 29 and 26. In an upper zone at the end of the inlet cylinder, which faces spinneret 12, a perforation 29 with small diameters is provided. In the upper zone, the perforation leads to a schematically illustrated flow profile 28. The flow profile 28 that is symbolized by arrows provides a measurement for the air quantity entering spin shaft 6. Within the upper zone, the perforation 29 is identical. Thus, the air quantity increases as the distance from the spinneret becomes larger, due to the vacuum effect in the cooling tube 8 and due to the increasing filament speed. In a lower zone that is formed at the end facing the cooling tube 8, the wall 7 comprises a perforation with a greater opening cross section. As shown by the symbolized flow profile 27, a larger quantity of air will enter the spin shaft 6 in the lower zone. Likewise in this instance, one can see the tendency that the inflowing air quantity increases, as the distance from the spinneret becomes greater. The flow profile shown in Figure 2 above the wall of the inlet cylinder is especially suitable for obtaining a slow and slight precooling of the filaments. This results in particular in a very uniform yarn cross section. Figure 3 shows further embodiments of an inlet cylinder, whose wall 7 forms different flow profiles. In these embodiments, a wire cloth forms the wall 7 in the permeable zones. However, the wire cloth may advantageously be replaced with any other porous material, such as for example a sintered material. In the embodiment of Figure 3.1, the inlet cylinder is divided into an upper and a lower zone. The upper zone I has a greater permeability to gas than the lower zone II. The thereby developing flow profile results in that a larger quantity of air flows into the upper zone than into the lower zone II. Such an arrangement is particularly advantageous to realize a high, uniform cooling action and a uniform distribution of the air quantity within the spin shaft. In particular in the upper zone I, the filament speed is relatively low and the spacing between the filaments relatively large, so that the air quantity is able to distribute evenly in the spin shaft. As previously described with reference to Figure 2, the air quantity increases likewise within one zone based on the unvarying gas permeability. In the embodiment shown in Figure 3.2, an upper zone I, an intermediate zone II, and a lower zone III are formed. In this embodiment, a relatively small quantity of air enters the spin shaft in the intermediate zone II. However, the upper zone I and the lower zone III are designed to admit a larger quantity of air. This arrangement promotes both the distribution of the air quantity within the spin shaft and the entry behavior of the filament bundle into the cooling tube. The large quantity of air in the lower zone III causes the filament bundle to contract to a greater extent when entering the cooling tube, so that the filaments are unable to strike the wall. The wall of the zones II and III is constructed such that a uniform distribution of the air quantity adjusts itself over the length of the zone. To this end, the gas permeability in the wall decreases as the distance from the spinneret increases. Figure 3.3 shows an embodiment, wherein an upper zone I of inlet cylinder 4 has a gas-tight wall 7. The lower zone II comprises a triangular flow profile, with the largest quantity of air entering the spin shaft 6 in the lower region. The arrangement is especially suitable for realizing a uniform formation of the filament strands in the quiet zone. Only when the melt of the filaments has slightly firmed up in the outer region, will an air stream enter the cooling shaft. This arrangement is especially suited for producing yarns with low yarn deniers. In the embodiment of the spinning apparatus shown in Figure 4, a heating device 31 is arranged between the inlet cylinder 4 and the spin head 1. The heating device 4 leads to a thermal treatment of the filaments, so that cooling is further slowed down. In this arrangement of Figure 4, the heating device may be combined with any previously described embodiment of the inlet cylinder. The inlet cylinder 4 comprises an upper zone with a perforation 37 and a lower zone with a perforation 26. Based on the different hole diameters of perforations 37 and 26, symbolically illustrated flow profiles 27 and 28 result. Thus, a smaller quantity of air enters the inlet cylinder 4 in the upper zone than in the lower zone thereof. In comparison with the previously described embodiments of the spinning apparatus, the air stream entering the inlet cylinder 4 of the embodiment shown in Figure 4 is deflected in the direction of the advancing yarn, so that the filaments are assisted with a great flow component in their movement in direction of cooling tube 8 directly upon entry of the air quantity. To this end, the inlet openings 38 of the perforation 37 in the upper zone of the inlet cylinder 4 are arranged in wall 7 obliquely with an inclination in direction of the advancing yarn. For this purpose, the length and diameter of the inlet opening 38 are selected at a predetermined ratio such that a directed flow forms upon entry into the inlet cylinder 4. The lower zone of inlet cylinder 4 has a perforation 26 with radially directed inlet openings 38. In the interior of inlet cylinder 4, wall 7 mounts several baffles 39. The baffles 39 extend from wall 7 into the interior of inlet cylinder 4 with an inclination in the direction of the advancing yarn. Thus, the quantity of air entering through perforation 26 into the lower zone of inlet cylinder 4 is converted into a flow in direction of the advancing yarn. To optimize the flow conditions in inlet cylinder 4, the baffles 39 could be made in addition adjustable in their inclination. Basically, it should be remarked that the inlet cylinder might be divided into a plurality of zones to realize a uniform flow profile. In addition, by varying the combination of perforation and baffles in the inlet cylinder, it becomes further possible to influence the flow of the cooling air and the cooling of the filaments in the cooling tube. For purposes of providing essentially the same assistance to all filaments of the filament bundle in their advance inside the cooling tube, it is necessary to surround the filaments with an air stream of substantially the same velocity. Figure 5 shows by way of example a flow profile 32 that tends to adjust itself, for example, in the center of cooling tube 8 of the spinning apparatus of Figure 1. The length of the arrows identifies the velocity of the air stream inside the flow profile or cooling tuDe. m ima uuiiueuLxun, une a±±. stream generated by the suction device shows a maximal velocity in the center region of cooling tube 8. For this reason, the filaments advance, for example, along a pitch circle Dl or a pitch circle D2. To this end, it is necessary to arrange the nozzle bores within spinneret 2 accordingly. Figure 6 shows several embodiments of nozzle bore arrangements inside spinneret 2. Figure 6.1 shows a spinneret 2, wherein nozzle bores 33 are annularly arranged in one line of bores 34. In the line of bores 34, the nozzle bores 33 are each arranged in the spinneret equally spaced from one another. The closed line of bores 34 encloses an inlet zone 35 formed in the center region of the spinneret. Figure 6.2 shows a further spinneret 2, wherein two lines of bores 34 and 36 are annularly arranged in the spinneret. The nozzle bores 33 of the two lines of bores 34 and 36 are offset from each other such that the nozzle bores of the inner line of bores 36 are each located between two adjacent nozzle bores of the outer line of bores 34. In their arrangements of the nozzle bores, the spinneret of Figure 6.1 and the spinneret of Figure 6.2 are laid out for the flow profile in the cooling tube shown in Figure 2. The layout is based on a circular cross section of the cooling tube 8 of Figure 1. With that, the flow profile results likewise in a circular arrangement of the nozzle bores. With the use of a cooling tube with an oval cross section or a square cross section, other flow profiles would be bound to result, which would lead to a changed arrangement of the nozzle bores inside the spinneret. In the production of a polyester yarn with a denier of 2.4 dtex, the spinning apparatus of Figure 1 was used. In this process, a spinneret with an areal arrangement of the nozzle bores and a spinneret of the type of Figure 1 were used for comparison. In all, both spinnerets had 55 nozzle bores. The nozzle bores were arranged within a pitch circle of 60 mm. In its narrowest cross section, the cooling tube had a smallest diameter of 16 mm. The spacing between the spinneret and the cooling tube amounted to 260 mm. The cooling tube connected to the inlet cylinder via an inlet cone of 75 mm length. The takeup speed was 6,000 m/min. In the direct comparison, it was found that the spinneret with an areal distribution of the nozzle bores resulted in a yarn that exhibited a very high amount of lint. The yarn had a boiling shrinkage of 9.6% and an elongation of 62%. In the method of the present invention with an annular arrangement of the nozzle bores, a yarn was produced that showed no lint formation. The boiling shrinkage was 3.1% and elongation 56%. With that, the special advantage of the method and the apparatus of the present invention lies in that it is possible to produce a qualitatively superior yarn with a high spinning reliability. The invention is not limited to a certain configuration of the inlet cylinder and the cooling tube. The round shapes shown in the embodiment are exemplary and may be easily replaced with oval shapes or, in the case of rectangular spinnerets, even with angular shapes of the inlet cylinder and cooling tube. The spinneret is correspondingly variable in its shape. 1 Spin head 2 Spinneret 3 Melt line 4 Inlet cylinder 5 Filaments 6 Spin shaft 7 Wall 8 Cooling tube 9 Inlet cone 10 Outlet cone 11 Outlet chamber 12 Yarn 13 Outlet opening 14 Suction stub 15 Suction device 16 Lubrication device 17 Treatment device 18 Entanglement nozzl 19 Apex yarn guide 20 Takeup device 21 Yarn traversing de 22 Contact roll 23 Package 24 Winding spindle 25 Spindle drive 26 Perforation 27 Inflow profile 28 Inflow profile 29 Perforation 30 Screen cylinder 31 Heating device 32 Flow profile 33 Nozzle bores 34 Line of bores 35 Inlet zone 36 Line of bores 37 Perforation 38 Inlet opening 39 Baffle Translation PCT/EP99/04225 AMENDED CLAIMS 1. Apparatus for spinning a synthetic yarn (12), which is formed by combining a plurality of individual filaments (5), and which is wound to a package (23) by means of a takeup device (20) downstream of the spinning apparatus, the spinning apparatus comprising a spinneret (2), which has on its underside a plurality of nozzle bores for extruding the filaments (5); a cooling tube (8) downstream of the spinneret (2), through which the filaments advance for purposes of cooling, and which comprises an inlet cone (9) for accelerating an air stream in the direction of the yarn; an air stream generator (15) connected to the cooling tube (8) in such a manner that the air stream can be generated in the cooling tube (8) in direction of the advancing yarn; and a gas-permeable inlet cylinder (4) arranged between the spinneret (2) and the cooling tube (8), through which the filaments (5) advance, and through which a substantially radially inflowing quantity of air is supplied to the inlet cone (9) for generating the air stream in the cooling tube (8), characterized in that the inlet cylinder (4) is • subdivided in direction of the advancing yarn into several zones, each zone having a different permeability to gas of a wall (7) for controlling the quantity of air entering inlet cylinder (4) for purposes of making available the air stream assisting the movement of the filaments in the case of only precooled filaments (5). TEMP/4446119vl AMENDED SHEET 2. Spinning apparatus of claim 1, characterized in that the inlet cylinder (4) comprise^ an upper zone facing the spinneret (2) and a lower zone facing the cooling tube (8), and that the upper zone is made with a greater gas permeability in the wall (7) than the lower zone. 3. Spinning apparatus of claim 1, characterized in that the inlet cylinder (4) comprises an upper zone facing the spinneret (2) and a lower zone facing the cooling tube (8), and that the upper zone made with a smaller gas permeability in the wall (7) than the lower zone. 4. Spinning apparatus of claim 3, characterized in that the wall (7) of the upper zone is made impermeable to gas. 5. Spinning apparatus of one of claims 2-4, characterized in that at least one intermediate zone is formed between the upper zone and the lower zone, and that the intermediate zone is made with a smaller permeability to gas in the wall (7) than the lower zone and/or the upper zone. 6. Spinning apparatus of one of the foregoing claims, characterized in that the permeability to gas of the wall (7) of inlet cylinder (4) is identical within a zone in direction of the advancing yarn. 7. Spinning apparatus of one of the foregoing claims, characterized in that the gas permeability of the wall (7) of inlet cylinder (4) differs within a zone in direction of the advancing yarn. 8. Spinning apparatus of one of the foregoing claims, characterized in that the wall (7) of inlet cylinder (4) is formed from a perforated sheet element with a zonewise different perforation (26, 29, 37) . 9. Spinning apparatus of claim 8, characterized in that the perforation (37) of at least one zone consists of a plurality of inlet openings (38) that extend obliquely through the wall (7) of inlet cylinder (4) with an inclination toward the direction of the advancing yarn such that an air stream directed in the direction of the advancing yarn enters the inlet cylinder (4). 10. Spinning apparatus of one of claims 1-7, characterized in that a wire cloth with a zonewise different mesh size forms the wall (7) of inlet cylinder (4). 11. Spinning apparatus of claim 8 or \0, characterized in that several perforated sheet elements and/or wire cloths are combined one after the other in the wall of the inlet cylinder. 12. Spinning apparatus of one of claims 8- 11, characterized in that a paper sleeve lies against the wall (7) of inlet cylinder (4) in circumferential contact therewith. 13. Spinning apparatus of one of the foregoing claims, characterized in that the wall (7) mounts in the interior of the inlet cylinder (4), in the region of at least one zone, several baffles (39) that extend from the wall (7) with an inclination in direction of the advancing yarn. 14. Spinning apparatus of one of claims 1-13, characterized in that the inlet cylinder (4) connects in a heat-transferring manner to a spin head (1) mounting the spinneret (2). 15. Spinning apparatus of one of the foregoing claims, characterized in that the air stream generator (15) is a suction device that connects to the cooling tube (8) on the outside thereof. 16. Spinning apparatus of one of claims 1-15, characterized in that the arrangement of the nozzle bores (33) in the spinneret (2) is selected such that the air stream generated as the filaments enter the cooling tube (8) assists the filaments (5) in their advance uniformly over the tube cross section and cools same evenly. 17. Apparatus for spinning a synthetic yarn (12), which is formed by combining a filament bundle consisting of a plurality of individual filaments (5) , and which is wound to a package (23) by means of a takeup device (20) downstream of the spinning apparatus, the spinning apparatus comprising a spinneret (2), which comprises on its underside a plurality of nozzle bores (33) for extruding the filaments (5); a cooling tube (8) downstream of spinneret (2) at a distance therefrom with a free tube cross section for treating the filaments (5), which tube cross section is smaller than the cross section the filament bundle when it emerges from the spinneret (2) ; a suction device (15) that connects to the cooling tube (8) at the outlet end thereof such that an air stream is generated in the cooling tube (8).in direction of the advancing yarn; and an inlet cylinder (4) with a gas permeable wall (7) arranged between the spinneret (2) and the inlet end of cooling tube (8), through which the filaments (5) advance, and through which a substantially radially inflowing guantity of air for generating the air stream is supplied to the cooling tube (8), characterized in that the arrangement of the nozzle bores (33) in the spinneret (2) is selected as a function of the flow profile of the air stream in the cooling tube (8) such that as the bundle of filaments enters the cooling tube (8), the individual filaments (5) are uniformly assisted by the air stream in their advance in the tube cross section and can be cooled evenly. 18. Spinning apparatus of claim 16 or 17, characterized in that at its inlet end, the cooling tube (8) comprises a funnel-shaped inlet cone (9), and that the nozzle bores (33) are arranged around an inlet zone (35) that forms in the center of the filament bundle. 19. Spinning apparatus of claim 18, characterized in that the inlet zone in the spinneret (2) is formed by one or more lines of bores (34, 36) each closed in itself with a plurality of equally spaced nozzle bores (33). 20. Spinning apparatus of claim 19, characterized in that the nozzle bores (33) -of adjacent lines of bores (34, 36) are offset from one another in direction transverse of the spinneret (2) . 21. Spinning apparatus of one of claims 16-20, characterized in that the nozzle bores (33) are annularly arranged in such a manner that the filaments (5) of the filament bundle enter the inlet cylinder (4) at a substantially equal distance from the wall (7) of the inlet cylinder (4). 22. Spinning apparatus of one of the foregoing claims, characterized in that the spacing between the spinneret (2) and cooling tube (8) is from at least 100 mm to at most 1000 mm, and that the, cooling tube has in its narrowest cross section a diameter from at least 10 mm to at most 40 mm. 23. Spinning apparatus of one of the foregoing claims, characterized in that a heating device (31) for thermally treating the filaments is arranged between the spinneret (2) and the inlet cylinder (4). 24. Spinning apparatus of one of claims 1- 22, characterized in that the ambient air surrounding the circumference of at least one zone of inlet cylinder (4) has a temperature from at least 35°C to at most 350°C. 25. Method of spinning a synthetic yarn, which is formed by combining a filament bundle consisting of a plurality of individual filaments, and which is wound to a package by means of a takeup device downstream of the spinning apparatus, wherein the filaments are extruded by means of a spinneret with a plurality of nozzle bores; wherein the filaments advance for a thermal treatment through a precooling zone and a cooling zone; wherein the cooling zone is formed by a cooling tube with a vacuum atmosphere, so that an air stream is generated in the tube cross section of the cooling tube in direction of the advancing yarn for assisting the filaments in their advance; and wherein the filaments are combined to the yarn at the end of the cooling zone, characterized in that as a function of a flow profile of the air stream in the cooling tube, the filaments within the filament bundle advance into the tube cross section of the cooling tube such that the filaments are assisted substantially uniformly in their advance and cooled evenly. 26. Use of a spinning apparatus as defined in the preamble of claim 17, for spinning a synthetic yarn, characterized in that the filaments are extruded by means of a spinneret with annularly arranged nozzle bores. 27. Use of a spinning apparatus of claim 26, characterized in that the nozzle bores are arranged in a closed line of bores with the same spacing between the nozzle bores. 28. Use of a spinning apparatus of claim 27, characterized in that the line of bores is annular. 29. Apparatus for spinning a synthetic yarn, substantially as herein described, with reference to the accompanying drawings.

Full Text

The invention relates to an apparatus and a method for spinning a synthetic yarn.
This type of spinning apparatus and the method are disclosed in WO 95/15409.
In this apparatus and process, an air stream assists freshly extruded filaments in their advance. With that, it is accomplished that the solidification point of the filaments moves away from the spinneret. This leads to a delayed crystallization that favorably influences the physical properties of the yarn. Thus, for example, in the production of a POY yarn, it was possible to increase the withdrawal thus, the draw ratio, without changing for the yarn the elongation values necessary for further processing.

The known spinning apparatus comprises a cooling tube and an air stream generator downstream of the spinneret. Between the spinneret and the cooling tube, an inlet cylinder extends with a gas-permeable wall. By the interaction of the inlet cylinder and the air stream generator, a quantity of air is caused to enter the cooling shaft, and to advance within the cooling shaft as an accelerated air stream in direction of the advancing yarn. The inlet cylinder consists of a perforated, gas-permeable material. Therefore, the radially inflowing air quantity is proportional to the applied pressure difference that becomes greater as the yarn speed increases. Thus, the quantity of air entering the inlet cylinder becomes greater with an increasing distance from the spinneret.
However, it has shown that besides assisting the advance, it is necessary that the filaments uniformly firm up in their surface layers. While advancing through the inlet cylinder, the filaments are precooled in such a manner that the surface layer has firmed up before entering the cooling tube. In their core, the filaments are still molten when they enter the cooling tube, so that the final solidification occurs only in the cooling tube. Consequently, it is also necessary that all filaments be uniformly precooled. Furthermore, it must be accomplished that a uniform quantity of air is present over the entire cross section of the inlet cylinder, so that each filament in the cooling tube is uniformly assisted in its advance.

yarn is determined by the interaction of the filament properties. It is therefore known that for producing a high-quality yarn, each filament within a bundle of filaments must undergo an equal treatment. In the known method and apparatus, the solidification point is deliberately removed from the spinneret, so that the filaments solidify only after passing through a precooling zone in the cooling zone formed by the cooling tube. Thus, the filaments cover a relatively long distance, over which they are exposed to different air streams.
U.S. 5,034,182 discloses a spinning apparatus, wherein the inlet cylinder is arranged in a pressure chamber. The inlet cylinder has a screenlike wall, so that based on the overpressure prevailing outside of the inlet cylinder, a greater pressure difference is obtained and, thus, a larger quantity of inflowing air. However, this leads to the problem that the filaments are already exposed to a considerable cooling effect within the inlet zone.
It is therefore the object of the invention to further develop a spinning apparatus of the initially described type such that it is possible to make available an air quantity adjusted to the uniform precooling of the filaments and an air quantity necessary for assisting the movement of the filaments.
A further object of the invention is to further develop the method and the initially described spinning apparatus such that all filaments of the filament bundle

undergo a substantially uniform treatment until their solidification.
Accordingly the present invention provides an apparatus for spinning a synthetic yarn, comprising a plurality of individual filaments, and which is wound to a package by means of a takeup device downstream of the spinning apparatus, a spinneret, which has on its underside a plurality of nozzle bores for extruding the filaments; a cooling tube downstream of the spinneret, through which the filaments for the purpose of cooling down advance and which comprises an inlet cone for accelerating an air stream in direction of the advancing yam; an air stream generator for the generation of an air stream within the cooling tube which is connected to the cooling tube in such a manner that the air stream is generated in the cooling tube in direction of the advancing yam; and a gas-permeable inlet cylinder arranged between the spinneret and the cooling tube, through which the filaments advance, and through which a radially inflowing quantity of air is supplied to the inlet cone for generating the air stream within the cooling tube, characterized in that the inlet cylinder is divided in direction of the advancing yarn into several zones, each zone having a different permeability to gas of a wall for controlling the quantity of air entering inlet cylinder and to provide the air stream supporting the advance of the filaments only for pre-cooled filaments.
The invention also provides a method of spinning a synthetic yarn, comprising the steps of : combining a filament bundle consisting of a plurality of individual filaments, and which is wound to a package by means of a takeup device downstream of the spinning apparatus, and the filaments are extruded by means of a spinneret with a plurality of nozzle bores; the filaments advance for a cooling treatment through a precooling zone and a cooling zone; the

cooling zone is formed by a cooling tube with a vacuum atmosphere, so that an air stream is generated in the tube cross section of the cooling tube in direction of the advancing yarn for assisting the filaments in their advance; and the filaments are combined to the yarn at the end of the cooling zone, characterized in that dependent on a flow profile of the air stream in the cooling tube, the filaments within the filament bundle advance into the tube cross section of the cooling tube such that the filaments are assisted uniformly in their advance and cooled evenly.
In accordance with the invention, a solution to the problem lies in that in the direction of the advancing yarn, the inlet cylinder is subdivided into several zones, each with a different permeability to gas for controlling the air quantity entering the inlet cylinder.
The invention has not been suggested either by the spinning apparatus known from EP 0 580 977 or the spinning apparatus disclosed in DE 195 35 143. In the known spinning apparatus, the inlet cylinder downstream of the spinneret is constructed with its air permeability varying in the direction of the advancing yarn, so as to realize a cooling the filaments as a function of the yarn advance speed. The purpose of the known spinning apparatus is a complete cooling of the filaments within the inlet cylinder, and they are thus totally unsuited to generate an air stream that assists in the movement of the filaments in the case of only precooled filaments. The invention has the advantage that, irrespective of the filament speed and irrespective of the differential pressure between the spin shaft and the surroundings, it is possible to influence the air quantity flowing into the spin shaft. This makes it possible to exert a purposeful influence on the properties of the filaments that originate from different zones of the spinneret. On the one hand, the influence may lie in that all filaments

undergo a precooling for firming up the surface zones, if possible under the same cooling conditions. Furthermore, it is possible to influence the entry of the filaments into the cooling tube, as well as the development of the air stream in the cooling tube, in particular by the air quantity entering into the lower region of the inlet cylinder. The air quantity entering through the wall of the inlet cylinder is proportionately dependent on the gas permeability or the porosity of the wall. In the case of a great gas permeability, a larger quantity of air per unit time is introduced into the spin shaft under otherwise constant conditions. Conversely, in the case of little gas permeability of the wall, a proportionately smaller air quantity enters the spin shaft.
The especially advantageous further development of the spinning apparatus has the advantage that a relatively large quantity of air is available for cooling the filaments. A further advantage lies in that a substantially uniform distribution of the air quantity adjusts itself inside the spin shaft. Since in the upper region the filament speed is low, and since furthermore the filaments are spaced from each other relatively wide due to the small distance from the spinneret, the air quantity is able to distribute itself in the upper zone of the inlet cylinder substantially unimpeded over the entire cross section of the spin shaft. With that, it is accomplished that within the filament bundle a uniform air stream is able to develop in the cooling tube.
The embodiment of the invention is especially suited to treat the filaments in a relatively weak precooling. From this follows the advantage of a particularly gentle cooling, which means a further improvement in spinning reliability. Spinning reliability means in this instance the quantity of filament breaks.

In the lower zone facing the cooling tube, however, a relatively large quantity of air enters the spin shaft, which facilitates the entry of the filament bundle into the cooling tube. This advantageously prevents the filaments from striking the tube wall in the region of the narrowest cross section.
However, it is possible to decrease the gas permeability in the upper zone such that the upper zone becomes impermeable to gas. Thus, a quiet zone develops directly downstream of the spinneret. This quiet zone ensures a stable spinning of the filaments, and thus favors the formation of a uniform filament structure.
The specially advantageous further development of the spinning apparatus has the advantage that both a uniform distribution of the air quantity is realized inside the spin shaft, and thus a uniform precooling of the filaments. On the other hand, it favors the advance of the filaments into the cooling tube. Since relatively little air enters the spin shaft in the center region of the inlet cylinder, an air stream oriented in the direction of the advancing yarn is already able to develop due to the filament speed. The air quantity supplied directly before the entry into the cooling tube thus forms an air stream that engages each filament substantially uniformly.
Since the filament speed increases as the distance from the spinneret becomes greater, and since the spacing between the individual filaments decreases at the same time, a specially advantageous embodiment of the invention provides that the gas permeability of the inlet cylinder is the same within one zone in the direction of the advancing yarn. Thus, the air entering the spin shaft within the zone is dependent on the filament speed. This means that at a higher yarn speed, more air is supplied to the spin shaft.

The embodiment of the invention however, makes it possible to generate over the length of the inlet cylinder a flow profile that contains no stepwise changes in the supply of the air quantity. Furthermore, it is possible to realize therewith that irrespective of the yarn speed, the air quantity entering the spin shaft can be maintained substantially unchanged over the length of the zone.
The wall of the inlet cylinder may be made from any porous material. In this advantageous embodiment, it is possible to predetermine very precisely the gas permeability or air resistance within the wall. In this instance, the number of the inlet openings of the perforations and the diameter of the inlet openings of the perforations define the gas permeability.
The embodiment of the spinning apparatus is especially suited for generating an air stream that assists the filament movement. In this embodiment, a plurality of inlet openings forms the perforation of at least one zone. These inlet openings extend through the wall of the inlet cylinder obliquely with an inclination toward the direction of the advancing yarn, so that an air stream oriented in direction of the advancing yarn enters the inlet cylinder.
The particularly advantageous further development accomplishes that a high, substantially uniform radial air stream is generated over the entire circumference of the inlet cylinder.
To be able to form the zones within the inlet cylinder, the embodiment of the invention is especially advantageous. In this embodiment, it is possible to stack individual cylinders with the same or with respectively different gas permeability. This may be realized by different mesh sizes of the wire cloth or by a different multilayer arrangement of layers.

Furthermore, the embodiment offers the possibility of changing the gas permeability by means of a paper sleeve. In this instance, the advantage consists in that the paper sleeve performs an air filtering, so that no impurities may enter the spin shaft.
To generate a uniform flow in the inlet cylinder and to prevent turbulences upon entry into the inlet cylinder, the further development is especially advantageous. To this end, the wall in the interior of the inlet cylinder mounts in the region of at least one zone a plurality of baffles with an inclination extending from the wall in direction of the advancing yarn.
In a particularly advantageous further development of the invention, the inlet cylinder connects to the spinneret in heat transferring relationship. Thus, it is possible to heat in particular the upper zone of the inlet cylinder, which leads again to heating the air flowing through the wall, so that a shocklike cooling effect on the filaments is prevented.
In the previously described embodiments of the invention, the air stream generator may be formed by a blower in the region of the inlet cylinder, by an injector directly upstream of inlet into the cooling tube, or by a suction device that connects to the cooling tube on the outlet end thereof. The suction device has the special advantage that during spinning all emerging particles, such as for example monomers, are removed from the spin shaft. With that, a contamination of the spin shaft is prevented.
To produce a yarn of a very high, uniform quality, the spinning apparatus is especially advantageous.

The arrangement of the nozzle bores in accordance with the invention within the spinneret is a further solution to the underlying problem. It accomplishes that in the cooling tube equidirectional and identical air streams oriented in the direction of the advancing yarn engage each individual filament.
The invention was not suggested either by the spinning apparatus and by the method known from DE 25 39 840. In the known method and known spinning apparatus, a uniform air stream that is used for treating the filaments is directed in the direction of, transversely, or oppositely to the direction of the advancing yarn. However, this does not apply to the spinning apparatus of the present invention. The vacuum atmosphere present in the cooling tube of the apparatus according to the invention generates an air stream in direction of the advancing yarn with a flow profile as a function of the tube cross section and with different flow velocities.
The spinning apparatus of the present invention has the advantage that the flow profile of the air stream prevailing in the tube cross section is used as a basis for arranging the nozzles bores in the spinneret. Since the air stream engaging the filaments assists the filaments in their advance within the cooling tube, it is especially significant that a substantially uniform assistance in the advance be maintained for each of the filaments over the entire distance. The flow profile of the air stream that develops in the tube is dependent on the inlet geometry of the cooling tube, as well as on the inside condition of the cooling tube, and lastly on the diameter of the cooling tube and the kind of flow. In this connection, different flow velocities may develop inside the tube cross section, which would be bound to lead, in an even distribution of the filaments, to a different treatment within the tube cross section. Thus, the invention offers a

possibility of arranging the filaments within the bundle of filaments in such a manner that each filament advances through the cooling tube at substantially the same flow velocity.
The especially preferred further development of the spinning apparatus has the advantage that the filament bundle safely enters the cooling tube, and that a less turbulent air stream develops in the inlet region of the cooling tube. In this connection, it has been found that the air stream inside the cooling tube exhibits a flow profile that tends to have a maximum flow velocity in the center of the cooling tube. Thus, the configuration of the spinneret prevents the filaments from entering the cooling tube in the central region thereof.
With an oval or round tube cross section, the configuration of the spinning apparatus is especially suited to advance the filaments through the cooling tube in zones of identical flow velocities. The arrangement of the nozzle bores in a closed line of bores further accomplishes that precooling is equalized inside the inlet cylinder.
The embodiment of the spinning apparatus is especially of advantage to realize a uniform precooling in the case of a plurality of lines of bores.
In a particularly advantageous further development of the spinning apparatus, the filaments advance at substantially the same distance from the wall of the inlet cylinder. This accomplishes an additional equalization of precooling and, thus, a reproducible firming up of surface layers.

To realize in the cooling tube a flow profile that is favorable for producing the yam, it has been found that the spacing between the spinneret and the cooling tube should be from at least 100 mm to at most 1000 mm. In this connection, the cooling tube has a diameter in the region of the narrowest tube cross section from at least 10 mm to at most 40 mm.
To further delay crystallization of the filaments, and thus produce a yam with higher elongation values, the embodiment of the spinning apparatus will be especially advantageous. This embodiment provides for a heating device between the spinneret and the inlet cylinder for heat treating the filaments.
The same effect can also be accomplished by the advantageous further development of the spinning apparatus. In this embodiment, the ambient air is heated outside on the periphery of a zone —preferably the upper zone -of the inlet cylinder to a temperature from 35°c to 350°C. The hot air entering the inlet cylinder thermally treats the filaments as a function of the air temperature before the actual cooling.
The apparatus of the present invention, the method of the invention, and the inventive use of a spinning apparatus are suitable to produce textile yams or industrial yams of polyester, polyamide, or polypropylene. It is possible to arrange downstream different treatment devices for the yam to produce, for example, a fully drawn yam (FDY), a partially oriented yam (POY), or a highly oriented yam (HOY.
In the following, some embodiments of the spinning apparatus according to the invention are described in more detail with reference to the attached drawings.

In the drawing:
Figure 1 shows a spinning apparatus with a takeup device downstream thereof;
Figure 2 shows an inlet cylinder of the spinning apparatus of Figure 1;
Figure 3 shows different wall configurations with a corresponding flow profile;
Figure 4 shows a further embodiment of the spinning apparatus according to the invention;
Figure 5 shows an embodiment of a flow profile within a cooling tube of the spinning apparatus of Figure 1; and
Figure 6 shows several configurations of a spinneret.
Figure 1 shows a first embodiment of a spinning apparatus of the present invention for spinning a synthetic yarn.
A yarn 12 is spun from a thermoplastic material. To this end, the thermoplastic material is melted in an extruder or a pump. A spin pump delivers the melt via a melt line 3 to a heated spin head 1. The underside of spin head 1 mounts a spinneret 2. From the spinneret 2, the melt emerges in the form of fine filament strands 5. The filaments 5 advance through a spin shaft 6 that is formed by an inlet cylinder 4. To this end, the inlet cylinder 4 extends directly downstream of the spin head 1 and encloses the filaments 5. At the free end of inlet cylinder 4, a cooling tube 8 follows in the direction of the advancing yarn. The cooling tube 8 connects to the inlet cylinder 4 via an inlet cone 9. At the opposite end of inlet cone 9, the

cooling tube 8 comprises an outlet cone 10 that terminates in an outlet chamber 11. In the underside of outlet chamber 11, an outlet opening 13 is arranged in the plane of the advancing yarn. On one side of the outlet chamber 11, a suction stub 14 terminates in suction chamber 11. The suction stub 14 interconnects an air stream generator 15 arranged on the free end of suction stub 14 and the outlet chamber 11. The air stream generator 15 is constructed as a suction device. The suction device 15 may comprise, for example, a vacuum pump or a blower, which generates a vacuum in outlet chamber 11 and thus in cooling tube 8.
In the plane of the advancing yarn, a lubrication device 16 and a takeup device 20 are arranged downstream of the outlet chamber 11. The takeup device 20 comprises a yarn guide 19. The yarn guide 19 indicates the beginning of a traversing triangle that forms by the reciprocal movement of a traversing yarn guide of a traversing device 21. Downstream of the yarn traversing device 21, a contact roll 22 is arranged. The contact roll 22 lies against the circumference of a package 23 being wound. The package 23 is produced on a rotating winding spindle 24. To this end, a spindle motor 25 drives winding spindle 24. The drive of winding spindle 24 is controlled as a function of the rotational speed of the contact roll, so that the circumferential speed of the package and thus the takeup speed remain substantially constant during the winding.
Between the lubrication device 16 and the takeup device 20, a treatment device 17 is arranged for

treating the yarn 12. In the embodiment of Figure 1, the treatment device is formed by an entanglement nozzle 18.
As a function of the production process, the treatment device may comprise one or more heated or unheated godets, so that the yarn can be influenced in its tension or be drawn before its takeup. Likewise, it is possible to arrange within the treatment device 17 additional heating devices for drawing or relaxing.
In the spinning apparatus shown in Figure 1, a polymer melt is delivered to spin head 1 and extruded via spinneret 2 to a plurality of filaments 5. The bundle of filaments is withdrawn by takeup device 20. In this process, the filament bundle advances at an increasing speed into the spin shaft 6 inside of inlet cylinder 4. Subsequently, the filament bundle enters the cooling tube 8 via inlet cone 9. In the cooling tube 8, the suction device 15 generates a vacuum, thereby sucking into cooling shaft 6 ambient air that surrounds the exterior of inlet cylinder 4. The air quantity entering spin shaft 6 is proportional to the gas permeability of wall 7 of the inlet cylinder. The inflowing air leads to a precooling of the filaments, so that the surface layers of the filaments firm up. However, in their core the filaments remain molten. The air quantity, together with the filament bundle, is then taken in, via inlet cone 9, into the cooling tube 8. Due to a narrowest cross section in cooling tube 8, the air stream is accelerated under the action of suction device 15 in such a manner that there exists no longer an air stream in the cooling tube that counteracts the movement of the filaments. With that, stress on the filaments is reduced.

To generate in the outlet region of cooling tube 8 as little turbulences as possible, the air stream flows, via outlet cone 10, into outlet chamber 11. To further stabilize the air, the outlet chamber 11 accommodates a screen cylinder 30 that surrounds the filament bundle. The air is then sucked off and removed from outlet chamber 11 via stub 14 and suction device 15. The filaments 5 exit on the underside of outlet chamber 11 through outlet opening 13 and advance into lubrication device 16. By the time the filaments emerge from the cooling tube, they are totally cooled. The lubrication device 16 combines the filaments to a yarn 12. To increase cohesion of the yarn, the yarn 12 is entangled in entanglement nozzle 18, before it is wound. In the takeup device 20, the yarn 12 is wound to package 23. In the arrangement of Figure 1, it is possible to produce, for example, a polyester yarn that is wound at a takeup speed > 7,000 m/min.
The spinning apparatus of Figure 1 is characterized in that the air quantity entering inlet cylinder is adapted to the heat treatment of the filaments. In this connection, it is possible to influence with advantage both precooling and the suction stream. Figure 2 shows again the inlet cylinder 4 of Figure 1. In this embodiment, the wall 7 of inlet cylinder 4 is constructed as a perforated sheet element with two different perforations 29 and 26. In an upper zone at the end of the inlet cylinder, which faces spinneret 12, a perforation 29 with small diameters is provided. In the upper zone, the perforation leads to a schematically illustrated flow profile 28. The flow

profile 28 that is symbolized by arrows provides a measurement for the air quantity entering spin shaft 6. Within the upper zone, the perforation 29 is identical. Thus, the air quantity increases as the distance from the spinneret becomes larger, due to the vacuum effect in the cooling tube 8 and due to the increasing filament speed.
In a lower zone that is formed at the end facing the cooling tube 8, the wall 7 comprises a perforation with a greater opening cross section. As shown by the symbolized flow profile 27, a larger quantity of air will enter the spin shaft 6 in the lower zone. Likewise in this instance, one can see the tendency that the inflowing air quantity increases, as the distance from the spinneret becomes greater.
The flow profile shown in Figure 2 above the wall of the inlet cylinder is especially suitable for obtaining a slow and slight precooling of the filaments. This results in particular in a very uniform yarn cross section.
Figure 3 shows further embodiments of an inlet cylinder, whose wall 7 forms different flow profiles. In these embodiments, a wire cloth forms the wall 7 in the permeable zones. However, the wire cloth may advantageously be replaced with any other porous material, such as for example a sintered material.
In the embodiment of Figure 3.1, the inlet cylinder is divided into an upper and a lower zone. The upper zone I has a greater permeability to gas than the lower zone II. The thereby developing flow profile results in that a larger quantity of air flows into the upper zone than into the lower zone II. Such an

arrangement is particularly advantageous to realize a high, uniform cooling action and a uniform distribution of the air quantity within the spin shaft. In particular in the upper zone I, the filament speed is relatively low and the spacing between the filaments relatively large, so that the air quantity is able to distribute evenly in the spin shaft. As previously described with reference to Figure 2, the air quantity increases likewise within one zone based on the unvarying gas permeability.
In the embodiment shown in Figure 3.2, an upper zone I, an intermediate zone II, and a lower zone III are formed. In this embodiment, a relatively small quantity of air enters the spin shaft in the intermediate zone II. However, the upper zone I and the lower zone III are designed to admit a larger quantity of air. This arrangement promotes both the distribution of the air quantity within the spin shaft and the entry behavior of the filament bundle into the cooling tube. The large quantity of air in the lower zone III causes the filament bundle to contract to a greater extent when entering the cooling tube, so that the filaments are unable to strike the wall. The wall of the zones II and III is constructed such that a uniform distribution of the air quantity adjusts itself over the length of the zone. To this end, the gas permeability in the wall decreases as the distance from the spinneret increases.
Figure 3.3 shows an embodiment, wherein an upper zone I of inlet cylinder 4 has a gas-tight wall 7. The lower zone II comprises a triangular flow profile, with the largest quantity of air entering the spin shaft 6 in the lower region. The arrangement is especially

suitable for realizing a uniform formation of the filament strands in the quiet zone. Only when the melt of the filaments has slightly firmed up in the outer region, will an air stream enter the cooling shaft. This arrangement is especially suited for producing yarns with low yarn deniers.
In the embodiment of the spinning apparatus shown in Figure 4, a heating device 31 is arranged between the inlet cylinder 4 and the spin head 1. The heating device 4 leads to a thermal treatment of the filaments, so that cooling is further slowed down. In this arrangement of Figure 4, the heating device may be combined with any previously described embodiment of the inlet cylinder.
The inlet cylinder 4 comprises an upper zone with a perforation 37 and a lower zone with a perforation 26. Based on the different hole diameters of perforations 37 and 26, symbolically illustrated flow profiles 27 and 28 result. Thus, a smaller quantity of air enters the inlet cylinder 4 in the upper zone than in the lower zone thereof.
In comparison with the previously described embodiments of the spinning apparatus, the air stream entering the inlet cylinder 4 of the embodiment shown in Figure 4 is deflected in the direction of the advancing yarn, so that the filaments are assisted with a great flow component in their movement in direction of cooling tube 8 directly upon entry of the air quantity. To this end, the inlet openings 38 of the perforation 37 in the upper zone of the inlet cylinder 4 are arranged in wall 7 obliquely with an inclination in direction of the

advancing yarn. For this purpose, the length and diameter of the inlet opening 38 are selected at a predetermined ratio such that a directed flow forms upon entry into the inlet cylinder 4.
The lower zone of inlet cylinder 4 has a perforation 26 with radially directed inlet openings 38. In the interior of inlet cylinder 4, wall 7 mounts several baffles 39. The baffles 39 extend from wall 7 into the interior of inlet cylinder 4 with an inclination in the direction of the advancing yarn. Thus, the quantity of air entering through perforation 26 into the lower zone of inlet cylinder 4 is converted into a flow in direction of the advancing yarn. To optimize the flow conditions in inlet cylinder 4, the baffles 39 could be made in addition adjustable in their inclination.
Basically, it should be remarked that the inlet cylinder might be divided into a plurality of zones to realize a uniform flow profile. In addition, by varying the combination of perforation and baffles in the inlet cylinder, it becomes further possible to influence the flow of the cooling air and the cooling of the filaments in the cooling tube.
For purposes of providing essentially the same assistance to all filaments of the filament bundle in their advance inside the cooling tube, it is necessary to surround the filaments with an air stream of substantially the same velocity. Figure 5 shows by way of example a flow profile 32 that tends to adjust itself, for example, in the center of cooling tube 8 of the spinning apparatus of Figure 1. The length of the arrows identifies the velocity of the air stream inside the flow

profile or cooling tuDe. m ima uuiiueuLxun, une a±±. stream generated by the suction device shows a maximal velocity in the center region of cooling tube 8. For this reason, the filaments advance, for example, along a pitch circle Dl or a pitch circle D2. To this end, it is necessary to arrange the nozzle bores within spinneret 2 accordingly.
Figure 6 shows several embodiments of nozzle bore arrangements inside spinneret 2. Figure 6.1 shows a spinneret 2, wherein nozzle bores 33 are annularly arranged in one line of bores 34. In the line of bores 34, the nozzle bores 33 are each arranged in the spinneret equally spaced from one another. The closed line of bores 34 encloses an inlet zone 35 formed in the center region of the spinneret.
Figure 6.2 shows a further spinneret 2, wherein two lines of bores 34 and 36 are annularly arranged in the spinneret. The nozzle bores 33 of the two lines of bores 34 and 36 are offset from each other such that the nozzle bores of the inner line of bores 36 are each located between two adjacent nozzle bores of the outer line of bores 34. In their arrangements of the nozzle bores, the spinneret of Figure 6.1 and the spinneret of Figure 6.2 are laid out for the flow profile in the cooling tube shown in Figure 2. The layout is based on a circular cross section of the cooling tube 8 of Figure 1. With that, the flow profile results likewise in a circular arrangement of the nozzle bores. With the use of a cooling tube with an oval cross section or a square cross section, other flow profiles would be bound to

result, which would lead to a changed arrangement of the nozzle bores inside the spinneret.
In the production of a polyester yarn with a denier of 2.4 dtex, the spinning apparatus of Figure 1 was used. In this process, a spinneret with an areal arrangement of the nozzle bores and a spinneret of the type of Figure 1 were used for comparison. In all, both spinnerets had 55 nozzle bores. The nozzle bores were arranged within a pitch circle of 60 mm. In its narrowest cross section, the cooling tube had a smallest diameter of 16 mm. The spacing between the spinneret and the cooling tube amounted to 260 mm. The cooling tube connected to the inlet cylinder via an inlet cone of 75 mm length. The takeup speed was 6,000 m/min. In the direct comparison, it was found that the spinneret with an areal distribution of the nozzle bores resulted in a yarn that exhibited a very high amount of lint. The yarn had a boiling shrinkage of 9.6% and an elongation of 62%. In the method of the present invention with an annular arrangement of the nozzle bores, a yarn was produced that showed no lint formation. The boiling shrinkage was 3.1% and elongation 56%. With that, the special advantage of the method and the apparatus of the present invention lies in that it is possible to produce a qualitatively superior yarn with a high spinning reliability.
The invention is not limited to a certain configuration of the inlet cylinder and the cooling tube. The round shapes shown in the embodiment are exemplary and may be easily replaced with oval shapes or, in the case of rectangular spinnerets, even with angular shapes

of the inlet cylinder and cooling tube. The spinneret is correspondingly variable in its shape.

1 Spin head
2 Spinneret
3 Melt line
4 Inlet cylinder
5 Filaments
6 Spin shaft
7 Wall
8 Cooling tube
9 Inlet cone
10 Outlet cone
11 Outlet chamber
12 Yarn
13 Outlet opening
14 Suction stub
15 Suction device
16 Lubrication device
17 Treatment device
18 Entanglement nozzl
19 Apex yarn guide
20 Takeup device
21 Yarn traversing de
22 Contact roll
23 Package
24 Winding spindle
25 Spindle drive
26 Perforation
27 Inflow profile
28 Inflow profile
29 Perforation

30 Screen cylinder
31 Heating device
32 Flow profile
33 Nozzle bores
34 Line of bores
35 Inlet zone
36 Line of bores
37 Perforation
38 Inlet opening
39 Baffle

Translation
PCT/EP99/04225
AMENDED CLAIMS
1. Apparatus for spinning a synthetic yarn (12), which is formed by combining a plurality of individual filaments (5), and which is wound to a package (23) by means of a takeup device (20) downstream of the spinning apparatus, the spinning apparatus comprising a spinneret (2), which has on its underside a plurality of nozzle bores for extruding the filaments (5); a cooling tube (8) downstream of the spinneret (2), through which the filaments advance for purposes of cooling, and which comprises an inlet cone (9) for accelerating an air stream in the direction of the yarn; an air stream generator (15) connected to the cooling tube (8) in such a manner that the air stream can be generated in the cooling tube (8) in direction of the advancing yarn; and a gas-permeable inlet cylinder (4) arranged between the spinneret (2) and the cooling tube (8), through which the filaments (5) advance, and through which a substantially radially inflowing quantity of air is supplied to the inlet cone (9) for generating the air stream in the cooling tube (8), characterized in that the inlet cylinder (4) is • subdivided in direction of the advancing yarn into several zones, each zone having a different permeability to gas of a wall (7) for controlling the quantity of air entering inlet cylinder (4) for purposes of making available the air stream assisting the movement of the filaments in the case of only precooled filaments (5).
TEMP/4446119vl
AMENDED SHEET

2. Spinning apparatus of claim 1, characterized in that the inlet cylinder (4) comprise^ an upper zone facing the spinneret (2) and a lower zone facing the cooling tube (8), and that the upper zone is made with a greater gas permeability in the wall (7) than the lower zone.
3. Spinning apparatus of claim 1, characterized in that the inlet cylinder (4) comprises an upper zone facing the spinneret (2) and a lower zone facing the cooling tube (8), and that the upper zone made with a smaller gas permeability in the wall (7) than the lower zone.
4. Spinning apparatus of claim 3, characterized in that the wall (7) of the upper zone is made impermeable to gas.
5. Spinning apparatus of one of claims 2-4, characterized in that at least one intermediate zone is formed between the upper zone and the lower zone, and that the intermediate zone is made with a smaller permeability to gas in the wall (7) than the lower zone and/or the upper zone.
6. Spinning apparatus of one of the foregoing claims, characterized in that
the permeability to gas of the wall (7) of inlet cylinder (4) is identical within a zone in direction of the advancing yarn.
7. Spinning apparatus of one of the
foregoing claims, characterized in that the gas

permeability of the wall (7) of inlet cylinder (4) differs within a zone in direction of the advancing yarn.
8. Spinning apparatus of one of the foregoing claims, characterized in that the wall (7) of inlet cylinder (4) is formed from a perforated sheet element with a zonewise different perforation (26, 29, 37) .
9. Spinning apparatus of claim 8, characterized in that the perforation (37) of at least one zone consists of a plurality of inlet openings (38) that extend obliquely through the wall (7) of inlet cylinder (4) with an inclination toward the direction of the advancing yarn such that an air stream directed in the direction of the advancing yarn enters the inlet cylinder (4).
10. Spinning apparatus of one of claims 1-7, characterized in that a wire cloth with a zonewise different mesh size forms the wall (7) of inlet cylinder (4).
11. Spinning apparatus of claim 8 or \0, characterized in that several perforated sheet elements and/or wire cloths are combined one after the other in the wall of the inlet cylinder.
12. Spinning apparatus of one of claims 8-
11, characterized in that a paper sleeve lies against
the wall (7) of inlet cylinder (4) in circumferential
contact therewith.

13. Spinning apparatus of one of the
foregoing claims, characterized in that
the wall (7) mounts in the interior of the inlet cylinder (4), in the region of at least one zone, several baffles (39) that extend from the wall (7) with an inclination in direction of the advancing yarn.
14. Spinning apparatus of one of claims 1-13, characterized in that the inlet cylinder (4) connects in a heat-transferring manner to a spin head (1) mounting the spinneret (2).
15. Spinning apparatus of one of the foregoing claims, characterized in that the air stream generator (15) is a suction device that connects to the cooling tube (8) on the outside thereof.
16. Spinning apparatus of one of claims 1-15, characterized in that the arrangement of the nozzle bores (33) in the spinneret (2) is selected such that the air stream generated as the filaments enter the cooling tube (8) assists the filaments (5) in their advance uniformly over the tube cross section and cools same evenly.
17. Apparatus for spinning a synthetic yarn (12), which is formed by combining a filament bundle consisting of a plurality of individual filaments (5) , and which is wound to a package (23) by means of a takeup device (20) downstream of the spinning apparatus, the spinning apparatus comprising a spinneret (2), which comprises on its underside a plurality of nozzle bores (33) for extruding the

filaments (5); a cooling tube (8) downstream of spinneret (2) at a distance therefrom with a free tube cross section for treating the filaments (5), which tube cross section is smaller than the cross section the filament bundle when it emerges from the spinneret (2) ; a suction device (15) that connects to the cooling tube (8) at the outlet end thereof such that an air stream is generated in the cooling tube (8).in direction of the advancing yarn; and an inlet cylinder (4) with a gas permeable wall (7) arranged between the spinneret (2) and the inlet end of cooling tube (8), through which the filaments (5) advance, and through which a substantially radially inflowing guantity of air for generating the air stream is supplied to the cooling tube (8), characterized in that the arrangement of the nozzle bores (33) in the spinneret (2) is selected as a function of the flow profile of the air stream in the cooling tube (8) such that as the bundle of filaments enters the cooling tube (8), the individual filaments (5) are uniformly assisted by the air stream in their advance in the tube cross section and can be cooled evenly.
18. Spinning apparatus of claim 16 or 17, characterized in that at its inlet end, the cooling tube (8) comprises a funnel-shaped inlet cone (9), and that the nozzle bores (33) are arranged around an inlet zone (35) that forms in the center of the filament bundle.
19. Spinning apparatus of claim 18,

characterized in that the inlet zone in the spinneret (2) is formed by one or more lines of bores (34, 36) each closed in itself with a plurality of equally spaced nozzle bores (33).
20. Spinning apparatus of claim 19, characterized in that the nozzle bores (33) -of adjacent lines of bores (34, 36) are offset from one another in direction transverse of the spinneret (2) .
21. Spinning apparatus of one of claims 16-20, characterized in that the nozzle bores (33) are annularly arranged in such a manner that the filaments (5) of the filament bundle enter the inlet cylinder (4)
at a substantially equal distance from the wall (7) of the inlet cylinder (4).
22. Spinning apparatus of one of the foregoing claims, characterized in that the spacing between the spinneret (2) and cooling tube (8) is from at least 100 mm to at most 1000 mm, and that the, cooling tube has in its narrowest cross section a diameter from at least 10 mm to at most 40 mm.
23. Spinning apparatus of one of the foregoing claims, characterized in that a heating device (31) for thermally treating the filaments is arranged between the spinneret (2) and the inlet cylinder (4).

24. Spinning apparatus of one of claims 1-
22, characterized in that the ambient air surrounding
the circumference of at least one zone of inlet
cylinder (4) has a temperature from at least 35°C to at
most 350°C.
25. Method of spinning a synthetic yarn,
which is formed by combining a filament bundle
consisting of a plurality of individual filaments, and
which is wound to a package by means of a takeup device
downstream of the spinning apparatus, wherein the
filaments are extruded by means of a spinneret with a
plurality of nozzle bores; wherein the filaments
advance for a thermal treatment through a precooling
zone and a cooling zone; wherein the cooling zone is
formed by a cooling tube with a vacuum atmosphere, so
that an air stream is generated in the tube cross
section of the cooling tube in direction of the
advancing yarn for assisting the filaments in their
advance; and wherein the filaments are combined to the
yarn at the end of the cooling zone, characterized in
that as a function of a flow profile of the air stream
in the cooling tube, the filaments within the filament
bundle advance into the tube cross section of the
cooling tube such that the filaments are assisted
substantially uniformly in their advance and cooled
evenly.
26. Use of a spinning apparatus as defined in the preamble of claim 17, for spinning a synthetic

yarn, characterized in that the filaments are extruded by means of a spinneret with annularly arranged nozzle bores.
27. Use of a spinning apparatus of claim 26,
characterized in that the nozzle bores are arranged in
a closed line of bores with the same spacing between
the nozzle bores.
28. Use of a spinning apparatus of claim 27,
characterized in that the line of bores is annular.
29. Apparatus for spinning a synthetic yarn, substantially as herein described, with reference to the accompanying drawings.

Documents:

in-pct-2001-0102-che abstract-duplicate.pdf

in-pct-2001-0102-che abstract.jpg

in-pct-2001-0102-che abstract.pdf

in-pct-2001-0102-che claims-duplicate.pdf

in-pct-2001-0102-che claims.pdf

in-pct-2001-0102-che correspondence-others.pdf

in-pct-2001-0102-che correspondence-po.pdf

in-pct-2001-0102-che description (complete) duplicate.pdf

in-pct-2001-0102-che description (complete).pdf

in-pct-2001-0102-che drawings-duplicate.pdf

in-pct-2001-0102-che drawings.pdf

in-pct-2001-0102-che form-1.pdf

in-pct-2001-0102-che form-19.pdf

in-pct-2001-0102-che form-26.pdf

in-pct-2001-0102-che form-3.pdf

in-pct-2001-0102-che form-5.pdf

in-pct-2001-0102-che others.pdf

in-pct-2001-0102-che pct.pdf

in-pct-2001-0102-che petition.pdf

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Patent Number

221699

Indian Patent Application Number

IN/PCT/2001/102/CHE

PG Journal Number

37/2008

Publication Date

12-Sep-2008

Grant Date

01-Jul-2008

Date of Filing

22-Jan-2001

Name of Patentee

BARMAG AG

Applicant Address

LEVERKUSER STRASSE 65, D-42897 REMSCHEID,

Inventors:

#	Inventor's Name	Inventor's Address
1	NITSCHKE, ROLAND	TUCKINGSCHULSTRASSE 23a, D-58135 HAGEN,
2	MEISE	HANSJORG, LERCHENWEG 51, D-50829 KOLN,
3	HUTTER HANSGERHARD	LOHENGRINSTRASSE 24, D-42859 REMSCHEID,
4	ENDERS ULRICH	SCHWELMER STRASSE 54, D-42897 REMSCHEID,
5	SENGE PETER	AUFENANGERSTRASSE 6, D-44229 DORTMUND,
6	SCHULZ DETLEV	HOHWEG 16, D-4277 RADEVORMWALD,
7	WEIMER DIETER	BERUFSSCHULSTRASSE 29, D-42929 WERMELSKIRCHEN,

PCT International Classification Number

D01D 5/092

PCT International Application Number

PCT/EP99/04225

PCT International Filing date

1999-06-17

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	198 27 518.8	1998-06-22	Germany
2	198 29 046.2	1998-06-29	Germany