Melt spinning apparatus for extruding synthetic filaments

Abstract

The invention relates to a melt spinning device for extruding synthetic filaments, in particular polyamide filaments, which release monomer and / or oligomer compounds during extrusion, comprising a spinning block (2) for extruding filaments (F), the spinning block having a spinneret (20) through which the synthetic filaments are extruded at a predetermined first temperature (T1) into an extrusion chamber (5) located between the spinneret and a cooling device for cooling the filaments, the cooling device (6) delimiting a cooling chamber (8) in which the filaments are cooled to a predetermined second temperature (T2), the extrusion chamber being extended from the cooling chamber by a decoupling extension (4) such that in an evaporation section (50) the first temperature (T1) is maintained at an evaporation temperature (TEVP) at which no exhaust gases (70), in particular monomer and / or oligomer compounds, are present in the decoupling extension (4) by condensation (K) resulting in a deposit.

Description

Technical Field

[0001] The present invention relates to a melt spinning apparatus with a decoupling extension for preventing deposits from forming in predetermined sections on the internal components of the melt spinning apparatus, particularly deposits of monomers and / or oligomer compounds that may occur during the extrusion of polyamide filaments. Background Technology

[0002] Prior art generally discloses devices designed to intercept and remove deposits of monomeric and / or oligomeric compounds.

[0003] WO2015014690A1 discloses an apparatus for melt spinning and cooling filament bundles. This apparatus carries at least one spinneret nozzle on a spinning box and has a cooling device below the spinneret nozzle to form a cooling zone. A condensing device is formed between the spinneret nozzle and the cooling device, forming a condensing zone to receive condensed monomers. To achieve controlled condensation of the monomers, according to the invention, the condensing device is formed by a condensing ring coaxially arranged with the spinneret nozzle and connected to the cooling device via a contact surface for temperature control.

[0004] The condenser needs to be cooled so that the monomers can condense on the condenser.

[0005] It has been found that cooling between the spinneret nozzle and the cooling unit is ineffective in intercepting monomers. After a certain period of time, contamination of internal components can be observed, necessitating a production interruption to clean the equipment. Deposits occur particularly frequently in the extrusion chamber adjacent to the spinneret nozzle or spinneret plate. Summary of the Invention

[0006] Therefore, the object of the present invention is to provide a melt spinning apparatus that can reduce or avoid condensation and deposition in the extrusion chamber.

[0007] According to the present invention, this objective is achieved by a melt spinning apparatus.

[0008] According to one aspect of the invention, a melt spinning apparatus is provided for extruding synthetic filaments, particularly filaments made of polyamide, which release monomers and / or oligomers during extrusion. The apparatus comprises: a spinning chamber for extruding the filaments, having a spinneret through which the synthetic filaments are extruded at a predetermined first temperature into an extrusion chamber located between the spinneret and a cooling device for cooling the filaments, wherein the cooling device defines a cooling chamber in which the filaments are cooled to a predetermined second temperature, wherein the extrusion chamber extends from the cooling chamber by a decoupling extension such that, in an evaporation section, the first temperature is maintained at an evaporation temperature, at which no waste gas, particularly monomers and / or oligomers, deposited by condensation, is present in the decoupling extension.

[0009] This melt spinning equipment is particularly capable of producing synthetic filaments made of polyamide. Polyamides tend to form monomers and / or oligomers during extrusion.

[0010] If the ambient temperature drops to a predetermined temperature, monomers and oligomers will form deposits.

[0011] Deposits can damage internal components of melt spinning equipment. If excessive deposits form on internal components, the extrusion of the synthetic filament must be interrupted, which in particular negatively impacts production time, production costs, and the quality of the synthetic filament.

[0012] The melt spinning apparatus of the present invention provides a decoupling extension, which extends the distance between the spinning box and the cooling device, thereby enabling the waste gas collected and formed in the extrusion chamber to be supplied to the extrusion chamber at a temperature that prevents condensation and keeps it in a gaseous state.

[0013] This allows for the manufacture and production of synthetic filaments over a longer period of time, and prevents the formation of deposits in the extrusion chamber, at least within a predetermined section, that could impair the quality and manufacturing of the synthetic filaments.

[0014] According to one embodiment of the spinning equipment, the evaporation chamber is connected to the exhaust gas pipeline by fluid conduction, wherein the exhaust gas can be guided to the exhaust gas treatment area in a gaseous state through the exhaust gas pipeline at least at the evaporation temperature.

[0015] To prevent waste gas from forming deposits in the wrong position within the melt spinning equipment, the gaseous waste gas can be treated through the waste gas pipeline in the evaporation chamber.

[0016] The exhaust gas pipeline can be heated to provide a sufficiently high evaporation temperature that prevents condensation of the exhaust gas.

[0017] Evaporation temperature should be understood as the temperature at which the waste gas remains in a gaseous state and does not condense.

[0018] A fluid conduction connection should be understood as a connection that allows gas to be guided in a predetermined direction.

[0019] By allowing the gaseous waste gas to be carried to the waste gas treatment area in the extended channel, the interruption of winding can be avoided, thereby preventing contamination of the internal components of the melt spinning equipment.

[0020] According to another embodiment of the melt spinning equipment, the spinning box is adjacent to an exhaust gas emission device, and an exhaust gas pipeline is formed on the exhaust gas emission device by means of fluid conduction, through which gaseous exhaust gas can be transferred to the exhaust gas treatment area.

[0021] In order to fully process the gaseous waste gas from the extrusion chamber, the waste gas emission device is connected to the extrusion chamber by fluid conduction.

[0022] The exhaust gas remains in a gaseous state in the evaporation chamber because it is at the evaporation temperature, which keeps it in a gaseous state. This means that condensation and deposition of the exhaust gas will not occur in the extrusion chamber.

[0023] According to another embodiment of the melt spinning equipment, at least two-thirds of the extrusion chamber is an evaporation section in which waste gas can be supplied in a gaseous state, and one-third is a condensation section on which waste gas can be condensed into deposits.

[0024] Treating waste gas through an extrusion chamber requires an evaporation section, where the waste gas is in a gaseous state.

[0025] Then, the gaseous waste gas can be transported to the waste gas emission device.

[0026] For a certain proportion of the exhaust gas that cannot be transported to the exhaust gas emission device, the deposits present in the exhaust gas can be condensed in the condensation section.

[0027] The condensation section has a suitable temperature at which the deposits in the exhaust gas can be condensed. This is also attributed to the cooling unit, which is responsible for providing the condensation temperature in the condensation section.

[0028] The cooling system ensures that the condensation section is cooled, thereby lowering its temperature. As a result, the temperature drops from the evaporation temperature to the condensation temperature. The exhaust gas, now at the condensation temperature, can then condense in the condensation section.

[0029] According to another embodiment of the melt spinning equipment, the extrusion chamber and cooling device are designed to exhaust gas through the exhaust gas pipeline by means of countercurrent flow in the opposite direction to the filament travel direction, so that the exhaust gas can be discharged in gaseous form to the exhaust gas treatment area.

[0030] The extrusion chamber and the cooling unit are in a ventable connection. The cooling unit is set to a predetermined cooling temperature via a climate control system.

[0031] In this system, airflow is guided to the cooling device through the air supply of the cooling device, and this airflow is delivered to the filament transversely to the filament travel direction on the one hand, and as a countercurrent in the opposite direction to the filament travel direction on the other hand, it enters the extrusion chamber, and when it does so, it also carries away the gaseous waste gas and guides it to the waste gas pipeline of the waste gas treatment area.

[0032] This avoids contamination of the extrusion chamber by potential impurities and deposits, as deposits exist in the exhaust gas in a gaseous state (e.g., as monomers). Since the exhaust gas remains in a gaseous state, condensation of contaminants does not occur. Condensation of contaminants and deposits only occurs in the exhaust gas treatment zone.

[0033] According to another embodiment of the melt spinning equipment, the exhaust gas treatment zone has a decoupling extension, which is connected to the exhaust gas emission device of the exhaust gas treatment zone via a first sealing ring on one hand, and to a cooling device via a second sealing ring on the other hand, in the opposite end section of the decoupling extension, in each case in a fluid-sealed manner.

[0034] To ensure reliable treatment of exhaust gases into the exhaust gas treatment zone, the decoupling extension can be fluid-tightly connected to the spinning box and the cooling device on two open sides, respectively. Ideally, the countercurrent from the cooling device forces the exhaust gases into the exhaust gas treatment zone. In the exhaust gas treatment zone, the exhaust gases are then treated or condensed, thus ensuring that the internal components of the melt spinning equipment remain uncontaminated.

[0035] According to another embodiment of the melt spinning apparatus, the decoupling extension has an extension channel that extends the distance between the spinning box and the cooling device, thereby thermally isolating and decoupling the cooling effect of the cooling device, wherein the extension channel is thermally insulated.

[0036] Ideally, the decoupling extension is an extended channel that ensures thermal maintenance of the existing temperature within the extended channel. For this purpose, appropriate insulation can be provided on the extended channel.

[0037] The best insulator is ambient air. Additionally, the material can cover the wall thickness of the extension channel to provide better thermal insulation. The extension channel can contain and include insulating materials in the form of insulating cotton and / or plastic.

[0038] The extension channel can also be reinforced and improved using appropriate metal tubing. In this case, any conceivable insulation is possible. Crucially, the decoupling extension has a sufficiently long extension channel so that there is no passive cooling caused by the cooling device in the evaporation zone of the extrusion chamber, particularly passive cooling via the guide ring at the inlet opening of the cooling device, and that the exhaust gas can be safely directed to the exhaust gas treatment zone.

[0039] According to another embodiment of the melt spinning equipment, the extension channel is fluid-sealed to the cooling device via a second sealing ring and a guide ring located on the inlet opening of the cooling device.

[0040] In addition to the second sealing ring, a guide ring is provided at the inlet opening of the cooling device to ensure that the filaments are guided into the cooling device and that contaminants are deposited.

[0041] The guide ring has a dual function: on the one hand, it guides, and on the other hand, it collects the potential contaminants that may accumulate on the guide ring.

[0042] The guide ring is therefore easy to clean. The possibility of deposits entering the cooling system and clogging it should be avoided.

[0043] According to another embodiment of the melt spinning equipment, the cooling device has a distribution grid for distributing cooling air transversely to the filament travel direction and uniformly in the longitudinal extension direction of the cooling device.

[0044] The distribution grid is designed to provide a uniform and vortex-free airflow to the filaments.

[0045] According to another embodiment of the melt spinning apparatus, an outlet opening is formed in the filament travel direction in the end section of the cooling device opposite to the inlet opening, from which the filament is guided and merged at a bundling point.

[0046] The filaments are bundled together at a bundling point and then fed to a winding device that winds the produced filaments into a bobbin.

[0047] A slug point is the point where filaments are combined so that they can be vortexed and entangled through a vortex nozzle (not shown) to form a single thread.

[0048] Appropriate oiling can also be performed here using an oiling device. The function of the oiling device is to apply oil to the filaments to achieve static electricity elimination, better guidance, and better processability. Attached Figure Description

[0049] The apparatus of the present invention will now be explained in more detail with reference to the accompanying drawings and some exemplary embodiments thereof.

[0050] In the picture:

[0051] Figure 1 A partial cross-sectional view schematically illustrates an exemplary embodiment of a melt spinning apparatus having a decoupling extension according to the invention, and

[0052] Figure 2A partial cross-sectional view of a spinning box having a decoupling extension according to the invention is schematically shown, wherein the temperature gradient along the length of the extrusion chamber of the spinning box in the filament travel direction is shown.

[0053] List of reference numerals

[0054] 1. Melt spinning equipment

[0055] 10 Parallel Flow

[0056] 12 Against the Current

[0057] 14 Radial Flow

[0058] 15 Exhaust gas flow

[0059] 2 Spinning box

[0060] 20 Spinnerets

[0061] 21 Spinning Assembly

[0062] 3. Exhaust gas emission device

[0063] 30 Exhaust Gas Pipeline

[0064] 32 Waste Gas Treatment Area

[0065] 4 Decoupling Extension

[0066] 41 First sealing ring

[0067] 42 Extended Channel

[0068] 43 Second sealing ring

[0069] 5. Extrusion chamber / hood

[0070] 50 Evaporation Section

[0071] 52 Condensation Section

[0072] 6. Cooling device

[0073] 60 guide ring

[0074] 61 Distributed grid

[0075] 62. Entrance opening

[0076] 63 Exit opening

[0077] 64 Guide Section

[0078] 65 Receive Section

[0079] 7. Winding device

[0080] 8 Cooling Chamber

[0081] 9 Cluster points

[0082] T0 Extrusion Temperature

[0083] T1 Evaporation Temperature

[0084] T2 condensation temperature

[0085] TS Melt Temperature

[0086] TEVP Evaporation Temperature Zone

[0087] TK condensation temperature range

[0088] F filament

[0089] FR Filament travel direction

[0090] H5 Extrusion Chamber Extension Direction Detailed Implementation

[0091] Figure 1 A partial cross-sectional view schematically illustrates an exemplary embodiment of a melt spinning apparatus 1 having a decoupling extension 4 according to the invention.

[0092] Figure 1 A melt spinning apparatus 1 is shown, wherein the distance between the spinneret 20 and the cooling device 6 is extended, such that the cooling effect of the cooling device 6 is decoupled through a thermal gap.

[0093] like Figure 1 As shown, the melt spinning apparatus 1 has a spinning assembly 21, which is fluid-tightly connected to an exhaust gas emission device 3. The exhaust gas emission device 3 is connected in the filament travel direction FR to a decoupling extension 4 according to the invention, which is fluid-tightly connected to a cooling device 6.

[0094] Cooling device 6 is responsible for cooling the filament F. For this purpose, cooling device 6 is supplied with ambient air by radial flow 14. In cooling device 6, the radial flow is introduced into the interior of the cooling device in a particularly uniform manner through distribution grid 61. The filament F is introduced into the interior of the cooling device through inlet opening 62 and exits the cooling device 6 through outlet opening 63.

[0095] Along the path from inlet opening 62 to outlet opening 63, ambient air, as a co-current 10, is drawn into the interior of the cooling device 6 via radial flow 14 and follows the filament F as a co-current 10. The filament F, passing through inlet opening 62 and extending longitudinally along the cooling device 6, is guided toward outlet opening 63. In this process, radial flow 14 is carried away by filament F and guided toward outlet opening 63 in a co-current form. A portion of radial flow 14 is guided as a co-current 12, but it is also guided into inlet opening 62 of the cooling device toward extrusion chamber 5.

[0096] The extrusion chamber 5 mainly comprises two sections: an evaporation section 50 and a condensation section 52. The evaporation chamber 50 is designed such that the predetermined temperature T0 of the filament after leaving the spinneret 20 is not lower than a predetermined first temperature T1. This first temperature can also be referred to as the evaporation temperature T1. The evaporation temperature T1 is high enough that the gaseous exhaust gas remains gaseous and cannot condense in the evaporation section 50 of the extrusion chamber 5 (see also...). Figure 2 ).

[0097] In the condensation section 52, a guide ring 60 is located at the inlet opening 62, and this ring is fluid-tightly connected to the inlet opening via a second sealing ring 43. The function of the guide ring 60 is to guide the filament F toward the cooling device and collect any deposits and contaminants that may be present.

[0098] Therefore, the guide ring 60 is thermally conductive and typically made of metal, thereby ensuring that the cooling effect of the cooling device 6 also extends partially into the extrusion chamber 5. To prevent the thermal effect of the cooling device 6 from further expanding, a decoupling extension 4 is provided adjacent to the guide ring 60. This decoupling extension is an extension channel 42 that has a first sealing ring relative to the exhaust gas emission device 3 and a second sealing ring 43 relative to the cooling device 6.

[0099] The decoupling device 4 advantageously includes a thermally insulating material surrounding the extended channel 42 and isolating it from the environment, ensuring that the heat exchange occurs as little as possible and that the temperature can be maintained above the condensation temperature TK in the evaporation zone TEVP, thereby preventing gaseous exhaust gas from condensing in this zone and affecting the quality of the filament F.

[0100] The exhaust gas emission device 3 is laterally adjacent to the decoupling extension 4.

[0101] The exhaust gas emission device 3 is used to utilize the counterflow 12 from the cooling device to push the exhaust gas, especially the exhaust gas containing monomers and oligomers, toward the exhaust gas pipeline 30 adjacent to the side section of the exhaust gas emission device 3.

[0102] The exhaust gas is carried to the exhaust gas treatment zone 32 via the exhaust gas pipeline 30. The exhaust gas treatment zone 32 can additionally extract the exhaust gas and / or also play a supporting role in the formation of the backflow 12, for example, through a corresponding device that can discharge the backflow 12.

[0103] The spinning box 2 is adjacent to the exhaust gas emission device 3 in a fluid-tight manner. The spinning box 2 has a section in which there is an adjacent spinning assembly 21 with a spinneret 20. Filaments F are formed through the spinneret 20 via capillary openings (not shown). The material used to form the filaments F is a plastic melt, particularly polyamide, which forms monomers and oligomers, as well as undesirable deposits, during extrusion from the spinneret 20, which affect the quality of the filaments F.

[0104] Using the decoupling extension 4 according to the invention, these monomers and oligomers can be intercepted in the extrusion zone or extrusion chamber 5 and guided to the exhaust gas emission device 3.

[0105] Figure 2 A schematic partial cross-sectional view of a spinning box 2 having a decoupling device 4 according to the invention is shown, wherein the temperature gradient along the length H5 of the extrusion chamber 5 of the spinning box 2 in the filament travel direction FR is shown.

[0106] from Figure 2 As can be seen, the temperature gradient across the spinning assembly 21 is shown, where the X-axis represents temperature and the Y-axis represents position in the spinning assembly and extrusion chamber 5.

[0107] At the spinneret, the melt has a maximum temperature T0, which decreases slightly as it exits the spinneret. In the spinning assembly, the melt has a temperature TS. The plastic is converted into a melt or plastic state by an extruder and extruded into filaments FX by the spinning assembly.

[0108] After leaving the spinneret 20, the filament F is formed and undergoes a temperature drop to T0, wherein the filament F raises the ambient temperature in the spinning assembly 21, wherein the temperature is advantageously maintained above the evaporation temperature TEVP, ensuring that the oligomers and monomer compounds remain in a gaseous state and can be discharged through the exhaust gas line 30 shown.

[0109] The temperature only drops to the condensation temperature TK when it reaches the inlet opening 62 of the cooling device, at the guide ring 60. At the condensation temperature T2, the exhaust gas can condense. Condensation preferably occurs on the guide ring 60 to ensure that the cooling device 6 is not damaged or contaminated.

[0110] from Figure 2It can also be seen that the guide ring 60 has a guide section 64 that extends into the inlet opening 62 and has an inclined receiving section 65 that improves the guidance of the filament and is also intended to serve as a deposition surface for oligomers and monomer compounds cooled in this area.

[0111] Since the guide ring 60 is made of thermally conductive material, the cooling effect of the cooling device 6 also points towards the extrusion chamber 5.

[0112] However, the decoupling extension 4 provides thermal decoupling between the spinning assembly and the cooling device, thereby avoiding or reducing the cooling of the evaporation zone 50 of the extrusion chamber 5. As a result, the deposits remain in a gaseous state and can be discharged through the exhaust gas line 30 before they reach the guide ring 60.

Claims

1. A melt spinning apparatus (1) for extruding synthesized filaments (F), said filaments being particularly made of polyamide, said filaments releasing monomers and / or oligomer compounds during extrusion, said melt spinning apparatus (1) comprising a spinning box (2) for extruding said filaments (F), said spinning box having a spinneret (20) through which the synthesized filaments (F) are extruded at a predetermined first temperature (T1) into an extrusion chamber (5), said extrusion chamber (5) being located between said spinneret (20) and a cooling device for cooling said filaments (F), wherein, The cooling device (6) defines a cooling chamber (8) in which the filament (F) is cooled to a predetermined second temperature (T2), wherein the extrusion chamber (5) is extended from the cooling chamber (8) by a decoupling extension (4) such that in the evaporation section (50), the first temperature (T1) is maintained at the evaporation temperature (TEVP), at which no waste gas (70), in particular monomers and / or oligomers, are deposited in the decoupling extension (4) by condensation (K).

2. The melt spinning equipment (1) according to claim 1, characterized in that, The evaporation chamber (5) is connected to the exhaust gas pipeline (30) by fluid conduction, wherein the exhaust gas can be guided in a gaseous state through the exhaust gas pipeline (30) to the exhaust gas treatment area (32) at least at the evaporation temperature (TEVP).

3. The melt spinning apparatus (1) according to at least one of claims 1 or 2, characterized in that, The spinning box (2) is adjacent to the exhaust gas emission device (3), and the exhaust gas pipeline (30) is formed on the exhaust gas emission device in a fluid conduction manner. Through the exhaust gas pipeline, the gaseous exhaust gas can be transferred to the exhaust gas treatment area (32).

4. The melt spinning apparatus (1) according to at least one of the preceding claims, characterized in that, At least two-thirds of the extrusion chamber (5) is an evaporation section (50) in which the exhaust gas (70) can be supplied in a gaseous state, and one-third is a condensation section (52) in which the exhaust gas can be condensed into deposits.

5. The melt spinning apparatus (1) according to at least one of the preceding claims, characterized in that, The extrusion chamber (5) and the cooling device (6) are designed to exhaust gas through the exhaust gas line (30) by means of a countercurrent (12) in the opposite direction to the filament travel direction (FR), so that the exhaust gas can be discharged in a gaseous state to the exhaust gas treatment area (32).

6. The melt spinning apparatus (1) according to at least one of the preceding claims, characterized in that, The exhaust gas treatment zone (32) has a decoupling extension (4), which is connected to the exhaust gas emission device (3) of the exhaust gas treatment zone (32) via a first sealing ring (41) on the one hand, and to the cooling device (6) via a second sealing ring (43) at the opposite end section of the decoupling extension (4) in each case by means of fluid sealing.

7. The melt spinning apparatus (1) according to at least one of the preceding claims, characterized in that, The decoupling extension (4) has an extension channel (42) that extends the distance between the spinning box (2) and the cooling device (6) so that the cooling effect of the cooling device (6) is decoupled through a thermal gap, wherein the extension channel (42) is thermally insulated.

8. The melt spinning apparatus (1) according to at least one of the preceding claims, characterized in that, The extension channel (42) is fluid-sealed to the cooling device (6) via a second sealing ring (42) and a guide ring located on the inlet opening (62) of the cooling device.

9. The melt spinning apparatus (1) according to at least one of the preceding claims, characterized in that, The cooling device (6) has a distribution grid (61) for distributing cooling air transversely to the filament travel direction (FR) and uniformly in the longitudinal extension direction of the cooling device (6).

10. The melt spinning apparatus (1) according to at least one of the preceding claims, characterized in that, In the filament travel direction (FR), an outlet opening (63) is formed in the end section of the cooling device (6) opposite to the inlet opening (62), from which the filaments (F) are guided and merged at the bundling point (9).

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