DE102011117458A1 - Device for melt spinning and cooling of synthetic filaments - Google Patents

Abstract

The invention relates to an apparatus for melt spinning and cooling of synthetic filaments. The device has a heated spinning beam which carries on its underside at least one spinneret for extruding the filaments. Below the spinning beam, a cooling device is arranged which has a blowing chamber and a screen cylinder arranged inside the blowing chamber with a gas-permeable wall. The screen cylinder is arranged with an upper end at the distance below the spinneret for receiving the filaments. In order to avoid deposits and condensations at the upper end of the screen cylinder, a separate heating means is provided according to the invention, through which the upper end of the screen cylinder can be heated.

Description

The invention relates to a device for melt spinning and cooling of synthetic filaments according to the preamble of claim 1.

In the production of synthetic filaments, it is well known that a plurality of filaments are cooled after being extruded through a spinneret in a downstream cooling zone to allow the thermoplastic material of the filaments to solidify and thus fuse the filaments into the multifilament filament. To cool the freshly extruded filaments, a stream of cooling air is generated and passed to the filaments. In order to obtain an intensive cooling of the individual filament strands within the filament bundle, systems have proven in which the cooling air flow is fed to the filaments via a screen cylinder. Such a device is for example from the EP 1505180 A1 known.

In the known device, a blow chamber is arranged below a spinning beam, which holds a plurality of spinnerets in a row-like arrangement. The puffer chamber is held on the underside of the spinneret, each spinneret being associated with a screen cylinder within the blast box. The screen cylinders have a gas-permeable cylinder wall, so that a blown into the blow chamber cooling air through the screen cylinder is uniformly directed from all sides to the emerging from the spinneret filaments. A thermal insulation is provided between the spinning beam and the cooling device so that the temperature control of the spinneret required for extruding the filaments is uninfluenced by the downstream cooling of the filaments.

In the extrusion of certain polymers such as polyamides occur more volatile components such as monomers and oligomers, which can be deposited in the environment uncontrolled. Such deposits have now been found increasingly at the upper end of the screen cylinder, which lead to a sticking and closing of the blowing openings in the cylinder wall of the screen cylinder. This results in uneven cooling of the filaments.

To bind such monomers, it is well known in the art to supply a water vapor below the spinneret. This so-called Düsenbeschleierung, such as in the DE 19920682 A1 described, however, has the disadvantage that the water vapor condenses especially on the cold walls of the screen cylinder and leads to water formation.

It is an object of the invention to provide a device for melt spinning and cooling of synthetic filaments of the generic type, in which undesirable deposits are avoided during spinning of polymers on the screen cylinder used to cool the filaments.

This object is achieved in that the upper end of the screen cylinder is assigned a heating means by which the upper end of the screen cylinder is heated.

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

The invention is based on the finding that the deposits of the monomers are essentially dependent on the temperature difference. It was thus observed that hardly or only few deposits have formed on hot components. By heating the upper end of the screen cylinder thus an increased amount of deposits was avoided.

As a heating means are generally active heating means such as a heating jacket suitable, which are arranged on the circumference of an outer wall or inner wall of the screen cylinder.

However, passive heating means which utilize the existing heat are particularly advantageous. Thus, the heating means is preferably formed by a thermally conductive metal ring, which is held with contact at the upper end of the screen cylinder and which protrudes with a free end of heat in a space formed between the screen cylinder and the spinneret. Thus, the heat emitted by the spinneret and the spin beam can be used to advantage to heat the top of the screen cylinder. The thermally conductive metal ring is in this case preferably made of a highly conductive metal, so that the recorded on the warm end by convection heat can be supplied directly to the upper end of the screen cylinder.

Depending on the nature and design of the environment, the hot end of the metal ring can optionally be held in the free space with contact with a heat-conducting component of the spinning bar or free-standing without contact. It is essential here that, in the case of direct contact, the heat release is uninfluenced by the temperature control of the spinneret.

In order to be able to cover at least the non-flowed through end of the screen cylinder, the metal ring at a retaining end on a cylindrical heating collar, which in the screen cylinder protrudes. In addition, it is possible to create a zone below the spinneret, in which the filaments are guided without active cooling.

In order to avoid as possible material stresses between the metal ring and the screen cylinder during operation, the metal ring is preferably held without contact with the cylindrical heating collar to an inner wall of the screen cylinder.

The interchangeability can be further improved by the metal ring rests on the upper end of the screen cylinder without additional attachment.

In order to obtain a delayed cooling of the filaments for influencing certain physical properties of the threads, the development of the invention is provided, in which a reheater is arranged between the spinneret and the upper end of the screen cylinder, through which a tempered space between the spinneret and the screen cylinder is formed. In this case, it is advantageous to use the heat energy present in the temperature-controlled free space in order to simultaneously heat the metal ring. So the warm end of the metal ring preferably protrudes into the tempered space of the reheater.

So that the monomers and oligomers can be bound as directly as possible after extrusion, the development of the invention is provided, in which the spinneret is associated with a steam supply device, through which a steam is passed into the free space below the spinneret. Thus, a so-called Düsenbeschleierung is possible, which could be advantageously combined with a suction.

The invention will be explained in more detail with reference to some embodiments of the device according to the invention with reference to the accompanying figures.

They show:

1 1 is a schematic cross-sectional view of an embodiment of the device according to the invention;

2 schematically a longitudinal sectional view of the embodiment of the device according to the invention 1 .

3 1 is a schematic cross-sectional view of another embodiment of the device according to the invention;

4 1 is a schematic cross-sectional view of another embodiment of the device according to the invention;

5 schematically a cross-sectional view of another embodiment of the device according to the invention.

In the 1 and 2 a first embodiment of the device according to the invention is shown in several views. In 1 is the embodiment in a cross-sectional view without representation of a yarn path and in 2 shown in a longitudinal section view with threadline. Unless an explicit reference is made to one of the figures, the following description applies to both figures.

The embodiment of the device according to the invention has a spinning beam 1 on that at its bottom 12 several spinnerets 2 holds next to each other in a row-shaped arrangement. The spinnerets 2 are within the spinner by multiple melt lines 6 with a spinning pump 3 connected. The spinning pump 3 is driven by a pump drive, the spinning pump 3 to every spinneret 2 has a separate funding. The spinning pump 3 is over a melt feed 5 connected to a melt source, not shown here. The spinning beam 1 is heated, so that the spinnerets 2 , the melt line 6 and the spinning pump 3 be heated.

The spinning beam 1 is at the bottom 12 a cooling device 4 assigned. The cooling device 4 is in this embodiment by a blow box 8th formed, located at the bottom 12 of the spinning beam 1 followed. The blow box 8th is through a top box 8.1 and a sub-case 8.2 formed, which are interconnected. Between the top box 8.1 and the sub-box 8.2 is a perforated plate 26 arranged the top box 8.1 and the sub-box 8.2 separate each other. The top box 8.1 closes an upper blow chamber 9 and the sub-case 8.2 a lower blow chamber 10 one.

The blow box 8th points at its top 11 below the spinnerets 2 continuous thread openings 20 on that in the upper blow chamber 9 through inserted screen cylinder 17 and in the lower blow chamber 10 through inserted pipe sockets 25 be continued. For this purpose, the perforated plate 26 several with the screen cylinders 17 and the pipe socket 25 corresponding openings. The screen cylinder 17 are all identical and have a gas-permeable cylinder wall, which in this embodiment by an inner wall 18 and an outer wall 19 is formed. So could the inner wall 18 through a perforated plate and the outer wall 19 be formed by a wire mesh or metal mesh. The pipe socket 25 on the other hand are formed with closed walls. The lower blow chamber 10 is on a long side with an air supply channel 24 connected, through which a cooling air in the lower blowing chamber 10 is initiated. The air supply channel 24 is at an air supply 29 connected. In the area of the pipe socket 25 the lower case knows 8.2 several outlet openings 28 on, so that the filaments the Blaskaten 8th can go through for cooling. The blow box 8th is through two on the blow box 8th attacking lifting cylinders 1.27 and 27.2 designed height adjustable. In operation, the blow box 8th through the lifting cylinders 1.27 and 27.2 against the bottom 12 of the spinning beam 1 pressed.

For sealing the thread openings 20 is between the bottom 12 of the spinning beam 1 and the top 11 of the blow box 8th a sealing system 13 arranged. The sealing system 13 is through a pressure plate 14 formed firmly with the bottom 12 of the spinning beam 1 connected is. The printing plate 14 is over several insulating panels 16 at the spinning beam 1 held. To seal the pressure plate acts 14 with a foam sealing element 15 together, that at the top 11 of the blow box 8th is held.

As in particular from the illustration in 1 shows, is the sealing system 13 Cut out that way between the spinneret 2 and an upper end of the screen cylinder 17 a free space 21 formed. Here is the upper end of the screen cylinder 17 freely accessible from the inside to a metal ring 23 to be able to record. The metal ring 23 know a free warm end 23.1 on that in the open space 21 protrudes. With an opposite holding end 23.2 lies the metal ring 23 at one end of the inner wall 18 of the screen cylinder 17 at. The holding end 23.2 has a heating collar 23.3 on that in the screen cylinder 17 protrudes. The heating collar 23.3 of the metal ring 23 know while an outer diameter, which is slightly smaller than the inner diameter of the inner wall 18 of the screen cylinder 17 , Thus, a small clearance between the heating collar 23.3 and the inner wall 18 educated. The metal ring 23 is made of a good heat-conducting metal. To prevent the filaments from entering the screen cylinder 17 to support is the warm end 23.1 in relation to the heating collar 23.3 formed with a larger diameter. In that regard, the metal ring 23 executed with a funnel-shaped inner contour.

As from the illustrations in 1 and 2 shows, is the blow box 8th through two on the blow box 8th attacking lifting cylinders 1.27 and 27.2 designed height adjustable. In operation, the blow box 8th through the lifting cylinders 1.27 and 27.2 against the bottom 12 of the spinning beam 1 pressed so that the foam sealing element 15 against the pressure plate 14 is pressed and leads to the sealing of the parting line. In the operating position, the metal ring protrudes 23 with his warm end 23.1 in the open space 21 passing through the heated spinning beam 1 and the heated spinneret 2 is limited. The metal ring 23 is thereby heated to a temperature above 100 ° C and conducts the heat energy over the holding end 23.2 directly into the inner wall 18 of the screen cylinder 17 , The upper end of the screen cylinder 17 becomes directly through the metal ring 23 heated. This can be advantageous settling deposits at the top of the screen cylinder 17 avoid.

To cool the filaments is a cooling air flow through the air supply channel 24 in the lower blow chamber 10 initiated. From the lower blow chamber 10 the cooling air passes evenly over the perforated plate 26 in the upper blow chamber 9 , From the upper blow chamber 9 is the cooling air over the screen cylinder 17 supplied to the filaments. The filaments denoted by the reference numeral 7 are marked pass through the pipe socket 25 in the sub-box 10 and leave via the outlet opening 28 the blow box 8th ,

During prolonged operation deposits are also on the undersides of the spinnerets 2 inevitable, which cause at regular intervals the undersides of the spinnerets 2 need to be cleaned. For this purpose, the blow box will 8th through the lifting cylinders 1.27 and 27.2 in a lower maintenance position (not shown here) out. In the maintenance position of the blow box 8th let the metal rings 23 each from the thread openings 20 remove and replace.

At the in 1 and 2 illustrated embodiment, the metal ring takes 23 that from the spinneret 2 and the spinning beam 1 in the open space 21 delivered heat energy by convection to the warm end 23.1 and leads it over its wall to the stop 23.2 of which this is due to contact with the inner wall 18 of the screen cylinder 17 is handed over. In addition, over that into the interior of the screen cylinder 17 protruding Heizkragenende 23.3 a further warming of the inner wall 18 of the screen cylinder 17 essentially achieved by thermal radiation. In addition, the inner contour of the metal ring forms 23 a cover at the top 11 of the blow box 8th formed thread opening 20 , wherein the funnel-shaped formation of the inner contour of the metal ring 23 the collection of filaments and gases in the screen cylinder 17 favorably supported.

To the heat input into the metal ring over the warm end 211 However, there is also the possibility of the warm end 23.1 with contact to one of the components of the spinner 1 to keep. This is in 3 an embodiment shown. The embodiment 3 is essentially identical to the embodiment according to 1 and 2 , so that at this point only the differences will be explained and otherwise reference is made to the above description.

At the in 3 illustrated embodiment is the metal ring 23 with his end of stay 23.2 at the upper end of the screen cylinder 17 kept upright. The heating collar 23.3 is on the metal ring 23 very short and only serves to center on the inner diameter of the inner wall 18 of the screen cylinder 17 ,

The warm end 23.1 of the metal ring 23 protrudes into the open space 21 into it. Hereby knows the warm end 23.1 at the circumference several uniformly distributed heat fins 23.4 on top of that at the spinning beam 1 attached plates 14 and 16 to contact. This creates a thermal bridge, the heat transfer into the warm end 23.1 of the metal ring 23 improved.

At the in 3 illustrated embodiment, however, make sure that the on the metal ring 23 occurring thermal expansion to no tension of the metal ring within the free space 21 to lead. To adjust the height of the blow box 8th a driving of the metal ring 23 to ensure is the metal ring 23 preferably at the top of the blow box 8th attached. This situation is in 3 not shown.

For spinning problematic materials with an increased amount of monomers and oligomers, this is in 4 illustrated embodiment particularly suitable. In 4 is a cross-sectional view of the embodiment shown, in its construction and its function substantially identical to the embodiment according to FIG 1 and 2 is, so that at this point only the differences will be explained and otherwise reference is made to the above description.

At the in 4 illustrated embodiment is the blow box 8th with the training of the upper blow chamber 9 and the lower blow chamber 10 identical to the embodiment according to 1 and 2 executed. Likewise, the metal ring 23 at the upper end of the screen cylinder 17 identical to the embodiment according to 1 and 2 executed and sticks out with his warm end 23 in the open space 21 into it. Here is the free space 21 through a reheater 30 tempered. The reheater 30 is this at the bottom of the spinner 1 between the spinneret 2 and the screen cylinder 17 arranged. The reheater 30 know here not shown heaters to a tempered zone immediately below the spinneret 2 to create. The reheater 30 is in this embodiment with a pressure plate 14 on the bottom 12 of the spinning beam 1 held, being to seal the blow box 8th with the foam sealing element 5 on the pressure plate 14 is applied. The reheater 30 is cylindrically indicated, so that adjacent spinnerets have further reheater. The reheater are preferably heated together.

Inside the spinner 1 is a steam supply device 31 formed, consisting of a ring channel 32 and a supply line 33 is formed. The ring channel 32 has one or more blowing openings 34 on, just below the spinneret 2 lead. In operation, the supply line 33 a steam is introduced, passing through the annular channel 32 and the blowing holes 34 below the spinneret 21 distributed. The one at the bottom of the spinneret 2 Escaping water vapor leads to binding of the gases occurring during extrusion of the filaments. Thus, the unwanted deposits on the adjacent components can be further reduced. The steam supply 31 points to everyone on the spinning beam 1 held spinneret 2 separate blow opening 34 on.

In the aforementioned embodiments according to 1 to 4 is the separate heating means for heating the upper end of the screen cylinder 17 is formed as a passive heating means, in which the in the vicinity of the spinneret 2 and the spinner 1 occurring thermal energy is used to heat the upper inlet region of the screen cylinder. In principle, however, there is also the possibility of an active heating means for heating the screen cylinder 17 in the upper end. This is in 5 a further embodiment shown schematically in a cross-sectional view. The embodiment according to 5 is in the structure and function of the cooling device 4 identical to the aforementioned embodiment, so that only the differences are explained at this point to avoid repetition.

At the in 5 illustrated embodiment is in the upper end of the screen cylinder 17 a heating cuff 22 arranged the circumference of the outer wall 19 encloses. The heating sleeve 22 extends over a short area at the top of the screen cylinder 17 , in which no flow takes place. The heating sleeve 22 For example, it is actively heated via resistance heating elements to heat the top of the screen cylinder. The heating sleeve 22 could here with the energy supply of the reheater 30 be linked advantageous.

At the in 5 illustrated embodiment can thus be advantageous condensing the entrained with the filaments of water vapor in the upper region of the screen cylinder 17 avoid. When tempering the screen cylinder 17 Temperatures in the range above 100 ° C are preferably achieved. Thus, for example, during the spinning of a polyamide PA6, the reheater 30 set to a temperature of about 260 ° C.

The in the 1 to 5 illustrated embodiments are exemplary in construction and design of the cooling device. In principle, it is also possible to form the blow box in one piece in such a way that the upper blow chamber 9 an air supply channel is assigned directly, so that a redistribution of the cooling air from a lower blow chamber into an upper blow chamber is eliminated. It is essential here that, due to the generated suction effect, the filaments and gases entering the thread opening meet heated guide surfaces directly on entry into the cooling device in order to minimize the occurrence of deposits. Here, passive or active heating means are preferable to heat the inlet region of the screen cylinder.

LIST OF REFERENCE NUMBERS

1

spinning beam

2

spinneret

3

spinning pump

4

cooling device

5

melt inlet

6

melt line

7

filaments

8th

blow box

8.1

top box

8.2

lower box

9

upper blow chamber

10

lower blow chamber

11

Top blow box

12

Bottom of spinning beam

13

sealing system

14

printing plate

15

Foam sealing element

16

insulation

17

screen cylinder

18

inner wall

19

outer wall

20

thread hole

21

free space

22

Heating jacket

23

metal ring

23.1

warm end

23.2

holding end

23.3

heating collar

23.4

heat fins

24

Luflzufuhrkanal

25

pipe socket

26

perforated plate

27.1, 27.2

lifting cylinder

28

outlet

29

air supply

30

reheater

31

Steam supply means

32

annular channel

33

supply line

34

blowing opening

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1505180 A1 [0002]
• DE 19920682 A1 [0005]

Claims (10)

Device for melt spinning and cooling of synthetic filaments, comprising a heated spinning beam ( 1 ), which at least one spinneret ( 2 ) for extruding the filaments, and with a below the spinning beam ( 1 ) arranged cooling device ( 4 ), which is a blow chamber ( 9 ) and one inside the blow chamber ( 9 ) arranged sieve cylinder with gas-permeable wall, wherein the screen cylinder ( 17 ) with an upper end at a distance below the spinneret ( 2 ) is arranged for receiving the filaments, characterized in that the upper end of the screen cylinder ( 17 ) a separate heating means ( 22 . 23 ) is assigned, through which the upper end of the screen cylinder ( 17 ) is heated. Apparatus according to claim 1, characterized in that the heating means by a heating jacket ( 22 ) formed on the circumference of an outer wall ( 19 ) or inner wall ( 18 ) of the screen cylinder ( 17 ) is arranged. Apparatus according to claim 1, characterized in that the heating means by a thermally conductive metal ring ( 23 ) formed with contact at the upper end of the screen cylinder ( 17 ) and which one with a free end ( 23.1 ) in one between the screen cylinder ( 17 ) and the spinneret ( 21 ) formed free space ( 21 ) protrudes. Device according to claim 3, characterized in that the warm end ( 21.1 ) of the metal ring ( 23 ) in the open space ( 21 ) with contact to a heat-conducting component of the spinning beam ( 1 ) or freestanding without contact. Device according to one of claims 3 or 4, characterized in that the metal ring ( 23 ) at a holding end a cylindrical heating collar ( 23.3 ), which in the screen cylinder ( 17 ) protrudes. Device according to claim 5, characterized in that the metal ring ( 23 ) without contact with the cylindrical heating collar ( 23.3 ) to an inner wall ( 18 ) of the screen cylinder ( 17 ) is held. Device according to one of claims 3 to 6, characterized in that the metal ring ( 23 ) replaceable at the upper end of the screen cylinder ( 17 ) rests. Device according to one of the preceding claims, characterized in that a reheater ( 30 ) between the spinneret ( 2 ) and the upper end of the screen cylinder ( 17 ) is arranged, through which a tempered free space ( 21 ) between the spinneret ( 2 ) and the screen cylinder ( 17 ) is formed. Apparatus according to claim 8, characterized in that the warm end ( 23.1 ) of the metal ring ( 23 ) in the temperate free space ( 21 ) protrudes. Device according to one of claims 1 to 9, characterized in that the spinneret ( 2 ) a steam supply device ( 31 ), through which a vapor in the space below the spinneret ( 2 ) is conductive.

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