CN116685726A - Apparatus for melt spinning and cooling freshly extruded filament bundles - Google Patents

Abstract

The invention relates to a device for melt spinning and cooling freshly extruded filament bundles, comprising at least one spinning nozzle unit held on the underside of a spinning beam. A hollow cylindrical cooling cylinder with a gas-permeable cylinder wall is arranged below the spinning nozzle unit, which cooling cylinder extends in the air space between the filament inlet and the filament outlet. In order to achieve a delayed cooling of the filament strands, the cooling drum has a circumferential stop ring which surrounds the drum wall with a circumferential web in a jacket-like manner over part of its length, so that air is prevented from passing through.

Description

Equipment for melt spinning and cooling freshly extruded monofilament tufts

technical field

The invention relates to an apparatus for melt spinning and cooling freshly extruded monofilament tufts/tows according to the preamble of claim 1 .

Background technique

A device of this type for melt-spinning and cooling freshly extruded monofilament bundles is known from DE 10 2020 109 250 A1.

It is known in the production of synthetic filaments that molten polymer is fed to a spinning nozzle unit. For this purpose, the spin nozzle units are held on the underside of a heated spin beam, which usually carries a plurality of spin nozzle units side by side and carries the melt distribution system and the spin pumps. The spinning nozzle unit has several components in order to filter the polymer melt to the nozzle plate. The nozzle plate has a plurality of nozzle openings through which the fine monofilament strands are extruded. The freshly extruded monofilament sliver is then cooled below its solidification temperature, preferably by a stream of cooling air, in order to subsequently assemble it into a single filament.

When optimizing the production process, it has been found to be advantageous in certain filament types not to cool the monofilament sliver for a certain period of time directly after extrusion. This is achieved in that, for example, a shield with a hollow cylindrical wall is arranged below the spinning nozzle unit, which firstly separates the cooling air from the filaments. Such a device for melt-spinning and cooling freshly extruded monofilament bundles is known from DE 10 2020 109 250 A1.

In known devices for melt spinning and cooling monofilament tufts, a cooling cylinder with a gas-permeable cylinder wall is arranged in an air chamber below the spinning nozzle unit. In this case, the cooling cylinder has a monofilament inlet and a monofilament outlet in order to guide the freshly extruded monofilament tufts through. In the region between the spinning nozzle unit and the cooling cylinder, a hollow cylindrical cylinder section with a gas-permeable wall is arranged, which forms a zone below the spinning nozzle unit for isolating the cooling air from the filaments .

In order to be able to produce a filament type during the spinning process which does not require delayed cooling of the individual filament sliver, extensive reconstruction work is required which avoids shielding below the spinning nozzle unit. Such reconstruction measures have to be carried out directly on the hot spinning beam, but this is practically unacceptable mainly in view of the risk of injury caused by the possibly dripping molten polymer and due to the fact that such measures are carried out above the head. Hardly applicable.

Contents of the invention

It is therefore the object of the present invention to improve an apparatus of this type for melt-spinning and cooling of freshly extruded monofilament tufts in such a way that it can be implemented flexibly with or without delayed cooling by means of simple retrofit measures. Cooling of the monofilament sliver below the spinning nozzle unit.

According to the invention, this object is achieved in that the cooling cylinder has a retaining ring on its periphery, which surrounds the cylinder wall with a peripheral web in a jacket-like manner over part of its length, so that the passage of air is prevented.

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

The invention is distinguished in that the cooling cylinder can be used directly to create a section in which no cooling air is applied to the monofilament sliver. The retaining ring surrounds the cylinder wall over a partial length with a peripheral web, so that air is prevented from passing through the cylinder wall. Thus, a zone is formed in the cooling cylinder created by the retaining ring in which the monofilament sliver is not cooled.

In order to be able to selectively produce filament types with direct cooling below the spinning nozzle unit and filament types with delayed cooling below the spinning nozzle unit, the development of the invention is particularly advantageous, wherein the retaining ring selectively The monofilament inlet of the cooling cylinder or the monofilament outlet of the cooling cylinder are assigned to the cooling cylinder. In the case of a retaining ring assigned to the filament inlet of the cooling cylinder, a section without direct cooling is provided directly below the spinning nozzle unit. Such a transition region is also referred to in the industry as a so-called shroud.

In order to cool the monofilament sliver directly below the spinning nozzle, a retaining ring can advantageously be assigned to the monofilament outlet of the cooling cylinder. Thus, the length section/longitudinal section of the cooling channel in which the monofilament sliver is cooled by the cooling air remains unchanged.

In order to be able to retrofit on the cooling cylinder in a simple manner, the development of the invention is preferably implemented, in which the retaining ring is designed to be displaceable/adjustable on the cooling cylinder. Thus, the retaining ring can be automatically guided into different positions, for example by means of lifting cylinders. Alternatively, however, the retaining ring can also be moved manually.

In order to be able to carry out the usual adjustments for filament production, a further development of the invention is provided in which the peripheral web of the retaining ring has a web height by which the penetration of the cylinder wall of the cooling cylinder is reduced. / Permeability is reduced by 10% to 15%. Thus, a length section without filament cooling and a length section with filament cooling can be realized in the usual area.

According to an advantageous development of the invention, the air chamber is connected to a conditioned air generator or a vacuum generator for supplying the cooling cylinder. Thus, different cooling effects can be achieved on the monofilament sliver. With the air chamber connected to the conditioned air generator, the air-conditioned cooling air can be guided radially from the outside to the inside via the cooling cylinder onto the monofilament sliver, so that the cooling air flows out in the same direction as the monofilament .

When using a vacuum generator, cooling air is preferably sucked in via the filament outlets of the cooling cartridge and guided radially from the inside to the outside at the cooling cartridge into the air chamber. In this respect, a cooling air flow is generated counter to the direction of travel of the filaments, which in particular improves the cooling effect.

In order to obtain a uniform air flow over the entire length of the cooling cylinder, the development of the invention has proven to be advantageous in that the air chamber is provided coaxially with the lower air distribution chamber, the air chamber and the air distribution chamber being passed through a perforated plate Connected, the air distribution chamber is passed through in the region of the monofilament outlets of the cooling cartridge by a connection/pipe connection, the air distribution chamber having a connection for a conditioned air generator or a connection for a negative pressure generator. The supply of cooling air or the discharge of used cooling air is thus conducted via the air distribution chamber. In the vertical direction, the air distribution chamber is connected to the air chamber via the perforated plate, so that no radially oriented forced flow occurs in the air chamber due to the supply or discharge of cooling air.

The apparatus according to the invention for melt-spinning and cooling of freshly extruded monofilament tufts is used for the manufacture of filaments and can be used here for the production of filaments with fine monofilament deniers with uniform monofilament sliver cooling to the manufacture Filament with thick monofilament denier.

Description of drawings

Some embodiments of the apparatus for melt-spinning and cooling freshly extruded monofilament tufts according to the present invention are explained in detail below with reference to the accompanying drawings. in:

Figure 1 schematically shows a cross-sectional view of a first embodiment of an apparatus for melt spinning and cooling monofilament tufts according to the invention, and

Figure 2 schematically shows a cross-sectional view of another embodiment of an apparatus for melt spinning and cooling monofilament tufts according to the invention.

Detailed ways

Figure 1 schematically shows a cross-sectional view of a first embodiment of an apparatus for melt spinning and cooling freshly extruded monofilament tufts according to the invention. However, FIG. 1 only shows the important components of the device according to the invention which are important for explaining the invention. Since such equipment for melt spinning and cooling freshly extruded monofilament tufts is sufficiently known, a complete illustration is omitted.

The embodiment shown in FIG. 1 has a spinning nozzle unit 1 which carries a nozzle plate 1.1 on the underside with a plurality of nozzle openings 1.2. The spinning nozzle unit 1 is held below the heated spinning beam 2 and has a melt inlet (not shown here) for receiving a polymer melt.

Below the spinning nozzle unit 1, a cooling cylinder 3 is arranged substantially coaxially with the nozzle plate 1.1. The cooling cylinder 3 has an upper filament inlet 3.1 and a filament outlet 3.2 at the lower end. The cooling cylinder 3 extends within the air chamber 4 with a gas-permeable cylinder wall 3.3. The air chamber 4 surrounds the cooling cylinder 3 in the form of a jacket and is closed from the environment with a wall 4.1. The bottom side of the air chamber 4 adjoins an air distribution chamber 5 which is separated from the air chamber 4 by a perforated plate 7 . The air distribution chamber 5 is passed through by a connecting piece 6 which directly adjoins the filament outlet 3 . 2 of the cooling cylinder 3 coaxially with the cooling cylinder 3 . The air distribution chamber 5 has a lateral air connection opening 8 , which is coupled to an air connection 9 . The conditioned air generator 10 is connected to the air distribution chamber 5 via an air connection 9 . The air chamber 4 and the air distribution chamber 5 are generally embodied height-adjustable. Here, the air chamber 4 is held with its top side below the spinning nozzle 1 on the bottom side of the spinning beam 2 . The seal 13 is arranged between the spin beam 2 and the wall 4 . 1 of the air chamber 4 .

In the air cavity 4 , a retaining ring 11 is arranged for the cooling cylinder 3 . The retaining ring 11 has a circumferential web 12 which surrounds the cooling cylinder 3 in a jacket-like manner and surrounds the cylinder wall 3 . The retaining ring 11 is assigned directly to the filament inlet 3 . 1 of the cooling cylinder 3 . With its peripheral webs 12 , the retaining ring 11 prevents air from entering the cooling cylinder 3 from the air chamber 4 . Thus, a zone without entry of cooling air is formed directly at the filament inlet 3.1.

FIG. 1 shows the apparatus for melt spinning and cooling according to the invention in an operating situation in which a polymer melt is extruded through a spinning nozzle unit 1 into a plurality of filamentary slivers 15 . The monofilament sliver 15 is extruded through the nozzle opening 1.2 of the nozzle plate 1.1 and enters the cooling cylinder 3 through the monofilament inlet 3.1. The conditioned air entering the air chamber 4 penetrates continuously from the outside radially inwards through the air-permeable cylinder wall 3 . 3 of the cooling cylinder 3 in order to cool the monofilament sliver 15 . In the upper region of the cooling cylinder 3 , conditioned air is prevented from entering the cooling cylinder 3 by means of a retaining ring 11 . A zone in which no active cooling of the monofilament sliver 15 takes place thus forms directly below the spinning nozzle 1 . This transition zone, also referred to in the art as a so-called shroud, thus enables a delayed cooling of the monofilament sliver 15 . Thus, titer uniformity can be achieved especially in the case of small monofilament slivers 15 .

In the device shown in FIG. 1 , the retaining ring 11 is designed to be movable. For example, in the case of changes in the drawing speed and thus the titer of the filaments, it may be necessary to cool the freshly extruded filaments directly upon entering the filament inlet 3 . 1 of the cooling cylinder 3 . To this end, the retaining ring 11 is arranged in the lower position on the cooling cylinder 3 and is assigned to the filament outlet 3.2. In this case, the movement of the stop ring 11 can be carried out automatically by means of an actuator or also manually. By displacing the retaining ring 11 to the filament outlet 3.2, the cooling path in the cooling cylinder 3 remains constant overall. The displacement of the retaining ring 11 is shown in dashed lines in FIG. 1 .

The peripheral web 12 on the retaining ring 11 is designed with respect to its web height such that at least 85% to 90% of the active cooling length remains on the cooling cylinder 3 . The peripheral webs 12 of the retaining ring 11 therefore cover a maximum of 15% of the cylinder wall 3 . 3 of the cooling cylinder 3 .

In order to achieve a specific cooling effect, in principle it is also possible to arrange the retaining ring 11 in the central region of the cooling cylinder 3 . In this regard, the active and passive regions on the cooling cylinder 3 can be variably designed by means of the retaining ring 11 .

In order to achieve the greatest possible cooling effect on the monofilament sliver 15 , FIG. 2 shows a cross-sectional view of a further embodiment of a device according to the invention for melt spinning and cooling freshly extruded monofilament bundles. The embodiment according to FIG. 2 is identical to the embodiment according to FIG. 1 in the structure of its device parts, so that in this case only the differences are explained, while otherwise reference is made to the above description.

In the exemplary embodiment shown in FIG. 2 , the air distribution chamber 5 is connected via an air connection 9 to a vacuum generator 14 . Thus, a negative pressure is generated in the air distribution chamber 5 by means of the negative pressure generator 14 , which diffuses into the air chamber 4 and leads to the intake of cooling air. In this case, cooling air is introduced from the outside into the cooling cylinder 3 via the connecting piece 6 and the filament outlet 3.2. A cooling air flow counter to the direction of travel of the monofilament sliver 15 is thus generated. The cooling air flow is indicated in FIGS. 1 and 2 by arrows, respectively.

Thus, by the pressure reversal in the air chamber 5 , a cooling air flow from the inside to the outside is generated at the cooling cylinder 3 , so that the used cooling air is collected in the air chamber 4 and discharged via the air distribution chamber 5 .

In the embodiment of the invention shown in FIG. 2 , the retaining ring 11 is assigned to the filament outlet 3 . 2 of the cooling cylinder 3 . The cooling air sucked in via the filament outlet 3 . 2 is therefore first guided without deflection against the direction of travel of the filaments. The transition zone formed by the peripheral web 12 in the region of the monofilament outlet 3 . 2 thus leads to an enhanced cooling effect on the monofilament sliver 15 . Furthermore, a higher proportion of cooling air is directed to the monofilament inlet 3 . 1 of the cooling cylinder 3 , so that the monofilament sliver 15 is already actively cooled when it enters the cooling cylinder 3 .

However, in the embodiment of the device according to the invention for melt spinning and cooling freshly extruded monofilament tufts as shown in FIG. Wire entry 3.1. This situation is shown in dashed lines in FIG. 2 . In the dashed position of the stop ring 11 , the stop ring serves to adjust the transition zone without actively cooling the monofilament sliver 15 .

The air supply to the air chamber by means of the air distribution chamber shown in the exemplary embodiment according to FIGS. 1 and 2 is exemplary. In principle, it is also possible to connect the air chamber directly via the air connection to the conditioned air generator or the vacuum generator.

It is also common for such an air chamber to contain a plurality of cooling cylinders which are assigned to a plurality of spinning nozzle units on the spin beam.

Claims (6)

1. Device for melt spinning and cooling freshly extruded filament bundles (15), with at least one spinning nozzle unit (1) held on the underside of a spinning beam (2), with at least one hollow-cylindrical cooling cylinder (3) below the spinning nozzle unit (1) having a gas-permeable cylinder wall (3.3) and extending between a filament inlet (3.1) and a filament outlet (3.2) in an air chamber (4), characterized in that the cooling cylinder (3) has a baffle ring (11) on the circumference, which baffle ring (11) surrounds the cylinder wall (3.3) in a jacket-shaped manner over part of the length with circumferential webs (12) in order to prevent the passage of air.

2. The device according to claim 1, characterized in that the baffle ring (11) is selectively assigned to the filament inlet (3.1) of the cooling cartridge (3) or the filament outlet (3.2) of the cooling cartridge (3).

3. The device according to claim 1 or 2, characterized in that the baffle ring (11) is designed to be movable on the cooling cartridge (3).

4. A device according to any one of claims 1 to 3, characterized in that the peripheral tabs (12) of the baffle ring (11) have a tab height by which the penetration of the cylinder wall (3.3) of the cooling cylinder (3) is reduced by 10 to 15%.

5. The apparatus according to any one of claims 1 to 4, characterized in that the air chamber (4) is connected to an air-conditioning air generator (10) or a negative pressure generator (14).

6. The device according to any one of claims 1 to 5, characterized in that the air chamber (4) is coaxially provided with an air distribution chamber (5) underneath, the air chamber (4) and the air distribution chamber (5) being connected by means of a perforated plate (7), the air distribution chamber (5) being penetrated by a connecting tube (6) in the region of the filament outlet (3.2) of the cooling cartridge (3), the air distribution chamber (5) having a connection for an air-conditioning air generator (10) or a connection for a negative pressure generator (14).