JP2017531746A - Apparatus and method for melt spinning and cooling filament groups - Google Patents

Abstract

The present invention relates to an apparatus and method for melt spinning and cooling filament groups. The object of the present invention is to spin many filaments in a minimum space and nevertheless cool uniformly. This object is achieved by a hollow cylindrical air candle having a porous inner cylinder in addition to a porous outer cylinder. In this way, it is possible to guide and cool the filament along the air candle, both inside and outside the air candle. Especially in the production of short fibres, this space-saving structure of the spinning and cooling device has special advantages, especially for economic reasons.

Description

  The present invention relates to an apparatus for melt spinning and cooling a filament group as described in the first part of claim 1 and a method which can be carried out using such an apparatus as described in the first part of claim 9.

  When melt spinning a synthetic fiber strand or yarn, a plurality of thin strand-shaped filaments are extruded through nozzle holes of a spinning nozzle. For this purpose, the melted polymer is supplied to the spinning nozzle under high pressure. In order to form one fiber strand or a plurality of yarns, the plurality of strand-shaped filaments can be combined together or bundled together. Prior to being bundled, the filaments are cooled by a flow of cooling air, so that the melt flow state of the filaments changes to a hardened state after exiting from the nozzle holes. Due to the quality of the fiber strands or yarns, the uniform cooling of all filaments is significant. In known methods and apparatus used to cool a very large number of filaments, a plurality of filaments are extruded from a ring spinning nozzle to form a ring-shaped filament curtain, within the filament curtain, A cooling air flow generated from the radially inner side to the outer side by the air candle formed as a blow candle cools the filament group. Such a device is known, for example, from EP 1 467 005 A1 (EP1467005A1). The cooling air flow that cools the filaments is generated by the blow candle, which has a porous outer cylinder, so that a uniform cooling air flow flows radially around the entire circumference of the blow candle. And cool the filament through the filament curtain.

  In order to be able to follow the trend towards relatively high production speeds and relatively large production outputs, a large number of filaments are extruded using spinning nozzles, which have a very large number of dense nozzle holes. As a result, the filament groups are guided at a relatively high density in the filament curtain. In such a case, in the known method and the known apparatus, the cooling air stream is heated as it passes through the filament curtain from the inside to the outside. This action results in the filaments outside the filament curtain not being cooled as the filaments inside the filament curtain. However, this difference in cooling effect has a very adverse effect on the quality of the fiber strands or yarns. In addition to the uniform cooling of the filament at high production output, the required space of the entire installation is becoming increasingly important. The larger the required space, the more means must be prepared for the manufacturing plant. In EP 1 467 005, in addition to the cooling device for the filament curtain from the inside, another cooling device from the outside is provided in order to achieve uniform cooling for a large number of filaments. . However, this additional cooling device increases the required space per spinning nozzle and thus also increases the required space of the entire installation.

  The object of the present invention is therefore to improve the apparatus and the associated method as described above so that as many filaments as possible can be spun in the smallest space, and at this time all the filaments are uniformly distributed. It is to provide an apparatus and method that is cooled.

  According to the present invention, this problem is solved by guiding the filaments formed as filament bundles inside the air candle in addition to the filaments extending as a filament curtain outside the air candle. At this time, an air candle formed in a hollow cylindrical shape is formed. The inner and outer peripheries of the air candle are associated with the filament in connection with cooling the filament. In order to supply cooling air to the filaments extending inside and outside the air candle, the outer periphery of the air candle on the one hand and the inner periphery on the other hand are at least partly air permeable peripheral walls Is formed. Thereby the parts of the air candle are in particular a perforated outer cylinder and a perforated inner cylinder. At this time, it does not matter whether the cooling air is sucked or blown out using an air candle. With this device, a cooling air flow is generated which flows mainly towards the filaments in the radial direction, and all the filaments can release their thermal energy uniformly into this cooling air flow. With the additional filaments extending inside the air candle, more filaments can be spun in a relatively small space. If the production output is equal, the space required for the entire facility is reduced, thus reducing the cost of providing a manufacturing plant. Likewise, the costs for the steel structure of the equipment and the costs for electrical and fluid technical conductor systems or conduit systems are also reduced.

  Such a hollow cylindrical air candle requires a special arrangement of nozzle holes in the spinning nozzle device. The spinning nozzle device consists of one or more melt distribution devices and one or more spinning nozzles. No nozzle hole is provided in the ring-shaped region adjacent to the air candle of the spinning nozzle device. Further, one nozzle hole zone exists inside and outside the ring-shaped region, and a plurality of nozzle holes are arranged in each nozzle hole zone. Unlike general-purpose spinning nozzle devices that simply have nozzle holes outside the air candle, sufficient cooling can always be achieved using the nozzle hole arrangement proposed here. Thus, a significantly larger number of holes can be placed in the same space. The possibility of using one or more spinning nozzles provides the designer with an opportunity to find the optimal configuration of the device with respect to another problem, such as the sealability of the system.

  Despite the various forms of filament guidance, it is desirable that all filaments be cooled as uniformly as possible. To that end, it is generally necessary that the outer cylinder and the inner cylinder have different air resistances. The air resistance of both cylinders is then adapted to each other so that just this uniform cooling is achieved.

  The air candle has at least one connection, through which cooling air is supplied to or discharged from the air candle.

  In a particularly preferred embodiment of the invention, a separation cylinder is arranged inside the air candle. With this configuration, an outer passage is formed adjacent to the outer cylinder, and an inner passage is formed adjacent to the inner cylinder. This separation facilitates uniform cooling of the filament curtain and the filament bundle because the cooling air of the filament curtain and the cooling air of the filament bundle are not mixed in the air candle.

  This separation inside the air candle makes it possible to influence the flow in the outer passage and the flow in the inner passage separately. In another embodiment of the invention, at least one air connection is correspondingly arranged in each passage for this purpose. If comprised in this way, a mutually different flow state can be adjusted in each channel | path.

  In an alternative arrangement, instead of adjusting the different flow conditions, corresponding measures that influence the flow are used. For this purpose, each of the inner passages and the outer passages is arranged correspondingly with a respective adjustable throttle. In such a case, only one air connection for the air candle is sufficient, and nevertheless, different states can be formed or adjusted in the outer passage and the inner passage. These apertures can also serve as a rectifier.

  Using the apparatus features described above, it is possible to construct a method for uniformly cooling all filaments spun from the spinning nozzle apparatus. At this time, in the spinning nozzle device, many nozzle holes are arranged in a minimum space. Uniform cooling is evidenced by the fact that all formed short fibers are within a desired error range with respect to their properties, for example in a short fiber process.

  The apparatus according to the present invention and the method according to the present invention will now be described in detail with reference to the accompanying drawings with respect to several embodiments of the apparatus according to the invention.

1 is a cross-sectional view schematically showing a first embodiment of an apparatus according to the present invention. 1 is a cross-sectional view schematically showing a first embodiment of a device according to the present invention along a line AA. It is a cross-sectional view schematically showing a second embodiment of the device according to the present invention. FIG. 3 is a cross-sectional view schematically showing a second embodiment of the apparatus according to the present invention, taken along the line AA. It is a cross-sectional view schematically showing a third embodiment of the apparatus according to the present invention.

  Equal signs are used in all drawings. FIG. 1 shows a cross-sectional view of a first embodiment of the device according to the invention for carrying out the method according to the invention.

  The apparatus is composed of a spinning device 1 and a cooling device 11 disposed below the spinning device 1. The spinning device 1 has a spinning nozzle device on its lower surface, and this spinning nozzle device comprises a melt distribution device 4 and a spinning nozzle 5. The spinning nozzle 5 is disposed on the lower surface of the spinning nozzle device and has a plurality of nozzle holes 6. These nozzle holes 6 are arranged in two nozzle hole zones, the first zone is formed by a ring arranged on the outside of the nozzle hole 6 and the second zone is the first zone Is formed by a circular arrangement of the nozzle holes 6. The spinning nozzle 5 is connected to the spinning pump 2 via the melt distributor 4. The spinning pump 2 is connected via a melt supply path 3 to a melt production apparatus (not shown here), preferably to an extruder or a polycondensation apparatus. The spinning pump 2, the melt distributor 4 and the spinning nozzle 5 are heated. For this purpose, so-called spinning beams are usually used, and a plurality of spinning nozzles are held side by side, for example, in a row.

  The cooling device 11 under the spinning device 1 includes an air candle (Luftkerze) 12 and an air passage 20 assigned thereto. The air candle 12 has a porous outer cylinder 13 and a porous inner cylinder 14, which are made of, for example, fleece, foam material, screen woven fabric or sintered material. It's okay.

  The air candle 12 is adjacent to the spinning nozzle 5 at its free end. Since the air candle 12 is concentrically held with respect to the spinning nozzle 5, the air candle 12 is surrounded by the filament curtain 9, and the air candle 12 surrounds the filament bundle 10. The filament group 7 extruded from the spinning nozzle 5 is made up of the filament curtain 9 and the filament bundle 10, and one nozzle hole zone is provided in the spinning nozzle 5 for extruding the filament curtain 9 and the filament bundle 10. Is provided.

  An air passage 20 is connected to the air candle 12 for supplying cooling air to the air candle 12. The air passage 20 is connected to a blower 21.1 that supplies cooling air to the air candle 12 or exhausts the cooling air from the air candle 12.

  In the operating state, the melted polymer is fed to the spinning nozzle 5 via the spinning pump 2 and under high pressure via the melt distributor 4. Inside the spinning nozzle 5, the polymer melt is extruded through a plurality of nozzle holes 6 formed in the lower surface, thereby generating a plurality of strand-shaped filaments 8. The extruded filament group 7 forms a ring-shaped filament curtain 9 and a cylindrical filament bundle 10, and these filament curtain 9 and filament bundle 10 are uniformly drawn from the spinning nozzle 5 (here, FIG. (Not shown).

  In order to cool the freshly extruded filament group 7, a cooling medium, preferably cooling air, is supplied to the air candle 12 via the air passage 20 and is located between the outer cylinder 13 and the inner cylinder 14. It is further guided into the space inside the candle 12. The cooling medium now flows uniformly outward through the outer cylinder 13 of the air candle 12 and flows out uniformly inward via the inner cylinder 14. An outflow in the radial direction is generated at the inner peripheral portion and the outer peripheral portion of the air candle 12, and such an outflow flow guides the cooling air flow toward the filament group 7. The cooling air flow enters the filament group 7 and at this time absorbs heat from the filament 8 of the filament group 7, whereby the liquid filament 8 is gradually cured.

  Alternatively, the cooling medium can be discharged from the air candle 12 using the blower 21.1. In this case, ambient air is sucked from the surroundings. This ambient air first acts as cooling air by penetrating through the filament group 7, and at this time, the filament 8 releases its heat to the cooling air. Next, the cooling air flows into the air candle 12 through the outer cylinder 13 and the inner cylinder 14. Cooling air is again discharged from the air candle 12 through the air passage 20.

  The materials of the outer cylinder 13 and the inner cylinder 14 are adapted to each other so that optimum and preferably uniform cooling conditions occur for the filament curtain 9 and the filament bundle 10. To that end, it is possible to use two different fleeces with different air resistances.

  The illustrated structural configuration of the spinning nozzle is merely an example. For example, it is likewise possible for both nozzle hole zones to be formed by two different spinning nozzles 5. Moreover, only one nozzle hole zone may consist of a plurality of spinning nozzles. In order to extrude the plastic melt towards the outer filament curtain 9, it is also possible, for example, to arrange a plurality of cylindrical spinning nozzles in one ring. Furthermore, a mode in which the nozzle holes 6 for pushing out the filament bundle 10 are distributed to a plurality of spinning nozzles is also possible.

  It is also possible to use one or more melt distribution devices 4 and one or more spinning pumps 2 for the supply to one or more spinning nozzles 5.

  FIG. 2 is a cross-sectional view schematically showing the first embodiment shown in FIG. 1 along the line AA.

  In FIG. 2, the concentric arrangement of the filament group 7 and the air candle 12 can be known particularly well. An inner cylinder 14 of an air candle 12 is disposed around the filament bundle 10. An outer cylinder 13 is disposed around the inner cylinder 14. Cooling air is supplied or discharged in the space between both cylinders. Around the outer cylinder 13, the filament 8 of the filament curtain 9 is arranged in a ring shape. The cooling air flows through the filament group 7 mainly in the radial direction, as suggested by the arrows. When positive pressure is present in the air candle 12, the cooling air flows radially outward through the filament curtain 9 and radially inward through the filament bundle 10 (black arrow tip). See directions). When negative pressure is supplied to the air candle 12, the cooling air flows radially inward through the filament curtain 9 and radially outward through the filament bundle 10 (see the direction of the broken arrow tip). ).

  As is apparent from this drawing, as many filaments 8 as possible can be spun and cooled in a minimum space.

  FIG. 3 shows a cross-sectional view of a second embodiment of the device according to the invention for carrying out the method according to the invention. Since many elements correspond to the elements of the first embodiment shown in FIG. 1, only differences are described here.

  Here, a separation cylinder 15 is disposed between the outer cylinder 13 and the inner cylinder 14, whereby an outer passage 16 disposed corresponding to the outer cylinder 13 and an inner passage 17 disposed corresponding to the inner cylinder 14 are provided. Is formed. In this way, the possibilities for matching the cooling air flow through the filament bundle 10 and the cooling air flow through the filament curtain 9 are expanded. For this purpose, the outer passage 16 and the inner passage 17 are associated with separate means for influencing the flow. An inner throttle 19 is arranged at the transition between the air passage 20 and the inner passage 17. An outer throttle 18 is disposed at the transition between the air passage 20 and the outer passage 16. The inner restrictor 19 and the outer restrictor 18 can be optimally adjusted with respect to their flow resistance. Both apertures can also have the function of acting as a rectifier. As in the first embodiment shown in FIG. 1, the blower 21.1 is used to supply cooling air to the air candle 12 or used to discharge cooling air from the air candle 12. Also good.

  FIG. 4 is a cross-sectional view schematically showing the second embodiment shown in FIG. 3 taken along line AA. Here, only differences from the first embodiment shown in FIG. 2 will be described. This is because all other elements are equal. As can be seen from the drawings, both embodiments differ only in the separation cylinder 15 that divides the space between the outer cylinder 13 and the inner cylinder 14 into an outer passage 16 and an inner passage 17.

  FIG. 5 shows a third embodiment of the device according to the invention. The third embodiment is configured in the same manner as the second embodiment shown in FIG. 3 except for the differences described below. The outer diaphragm 18 and the inner diaphragm 19 do not exist in this embodiment. Instead, the outer passage 16 and the inner passage 17 each have a separate air supply or air discharge. Furthermore, the air passage 20 is divided by corresponding separating means. A blower 21.1 is arranged corresponding to the outer passage 16, and another blower 21.2 is arranged corresponding to the inner passage 17. Even with such a configuration, the cooling air flow for the filament bundle 10 and the cooling air flow for the filament curtain 9 can be adjusted separately from each other. This variant with two blowers offers various possibilities for cooling air guidance. For example, it is possible to supply positive pressure or negative pressure to both the inner passage 17 and the outer passage 16. Furthermore, alternate control modes are possible. For example, a negative pressure can be supplied to the outer passage 16 and a positive pressure can be supplied to the inner passage 17, or vice versa.

  Short fibers can be produced particularly economically using the apparatus and method described above. In order to produce such short fibers, the filaments are first drawn after cooling, then wound and finally cut. Such polymer fibers are used as an alternative to cotton fibers in the weaving and knitting industry, for example.

Claims (9)

A spinning device (1) having a spinning nozzle device (4, 5) having a plurality of nozzle holes (6) for extruding the filament (8) to form a ring-shaped filament curtain (9); and the spinning device (1 And a cooling device (11) disposed under the air nozzle (12) concentrically held with respect to the spinning nozzle device (4, 5). In the filament curtain (9), and the air candle (12) causes a cooling air flow flowing radially outward or radially inward to the filament curtain (9). In which the outer periphery of the air candle (12) is at least partially perforated with an outer cylinder (1). ) Is formed by an apparatus for melt spinning vital cooled filament groups (7),
The air candle (12) has a hollow cylindrical shape, and an inner peripheral portion of the air candle (12) is formed at least partially by a perforated inner cylinder (14). An apparatus for melt spinning and cooling the filament group (7).   The spinning nozzle device (4, 5) has at least two nozzle hole zones, and a filament bundle (10) formed inside the air candle (12) using one of the zones. 2. The apparatus of claim 1 wherein the is extrudable.   The apparatus of claim 2, wherein the nozzle hole zone is formed using one or more spinning nozzles (5).   The device according to claim 1, wherein the outer cylinder (13) and the inner cylinder (14) have different air resistances.   The apparatus of claim 1, wherein the air candle (12) has one or more air passages (20) for air supply and / or air discharge.   A separation cylinder (15) is disposed inside the air candle (12), whereby an outer passage (16) disposed corresponding to the outer cylinder (13) and a corresponding arrangement corresponding to the inner cylinder (14). The device according to claim 1, wherein a defined inner passage is formed.   One or a plurality of air supply portions are respectively disposed corresponding to the outer passage (16) and the inner passage (17), or one or a plurality of air supply portions are respectively disposed in the outer passage (16) and the inner passage (17). The device according to claim 6, wherein the air discharge portions of each are arranged correspondingly.   7. The device according to claim 6, wherein at least one means for guiding or influencing the flow is respectively arranged corresponding to the outer passage (16) and the inner passage (17).   A method which can be carried out using the apparatus according to claims 1 to 8, wherein the filament (8) of the filament curtain (9) and the filament (8) of the filament bundle (10) are cooled in the same manner. A method characterized by.

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