EP0333789A1

EP0333789A1 - Device and process for treating a bundle of threads using a turbulent air stream

Info

Publication number: EP0333789A1
Application number: EP88907591A
Authority: EP
Inventors: Andreas Lachenmeier
Original assignee: Viscosuisse SA; Rhone Poulenc Viscosuisse SA; Societe de la Viscose Suisse SA
Current assignee: Viscosuisse SA
Priority date: 1987-09-30
Filing date: 1988-09-23
Publication date: 1989-09-27
Also published as: US5008991A; JPH02501395A; WO1989002942A1

Abstract

Pour tourbillonner une mèche mouillée (3) de fils consistant en multifilaments lisses, on utilise des canaux (7) en forme de ''U'' munis de couvercles amovibles (8). Un canal de fil (7) est formé d'une partie inférieure de section circulaire et d'une partie supérieure de section rectangulaire. Ceci garantit un toubillonnement optimal et un bon drainage de l'eau du fil mouillé. La mèche de fils (3) avance à une vitesse comprise entre 100 et 600 m/min.To swirl a wet roving (3) of threads consisting of smooth multifilaments, channels (7) in the form of a ''U'' provided with removable covers (8) are used. A thread channel (7) is formed by a lower part of circular cross-section and an upper part of rectangular cross-section. This guarantees optimal swirling and good water drainage from the wet yarn. The yarn sliver (3) advances at a speed of between 100 and 600 m/min.

Description

Device and method for air swirling a thread sheet

The invention relates to a device for air swirling a wet sheet of smooth hultifilaments, consisting of a nozzle body with U-shaped thread channels, each thread channel being assigned a central compressed air channel at right angles, and a method for swirling the thread sheet.

In order to achieve a good weavability of smooth textile multifilament thread, it is usually necessary to finish. A swirling of the threads supports the sizing effect, so that better weaving results or the degree of sizing can be kept lower. The swirling has to ensure that the fibrils are brought close enough so that they can be glued together by the size. Weak knots are sufficient, especially if the swirling takes place immediately in front of the sizing trough, since the thread is only subjected to little stress and a few knots are lost. In this case, weak knots in small, regular intervals prove to be cheaper than stronger ones, in larger and therefore also uneven intervals. With stronger knots there is also the danger that they will draw in the tissue.

The type of knot can be determined by the diameter of the thread can be influenced: A large thread channel results in fixed knots at relatively large distances; a small diameter results in weaker knots at smaller regular intervals.

In the stretch finishing of multifilament threads made of thermoplastic materials, in particular made of polyamides and polyesters, but also polyethylene and polypropylene, a wet thread is swirled between a stretching trough, which usually contains water, and a visual light trough, thereby blowing off the adhering water during swirling.

This requires a specially suitable swirling device.

Since the thread channel diameter influences the type of intermingling, but the thread channel must be narrow in order to blow off the water with little air, there is a restriction in the choice of the type of intermingling on wet threads. However, since relatively weak knots are sufficient to support the sizing effect, this will not be a disadvantage in stretch sizing, where the threads between the intermingling and the sizing trough are hardly stressed.

Devices for air swirling a group of threads made of dry filament threads are known (EP-A-0 152 919). The known device consists of a swiveling nozzle body which has tubular swirling nozzles provided with a slot, which are closed in operation. The thread guide channel is rectangular, and the thread is guided diagonally in this thread channel. This device is suitable for the intermingling of certain titers with dry threads during the warping or stretch warping process. There is no information on the performance and air consumption of Ver whirling device made. A disadvantage is the time-consuming insertion of a thread group.

From EP-A-0 121 010 a swirling device with a swirling nozzle for producing a textile yarn is known, which has a U-shaped swirling channel. Although the turbulence has improved, the compressed air consumption is still far too high.

EP-A-0 144 617 describes a process for producing a chain with stretching in a water bath, then swirling and subsequent finishing. The description does not give any information about the type of swirling.

The known wet drawing process has the disadvantage that the thread must be largely freed of the adhering liquid before entering a swirling device in order to prevent the dilution of the size liquor. This is achieved by a system of upstream squeezing bars. With a squeezer after the stretching trough, the water can only be removed insufficiently, to about 50%.

All known nozzles have disadvantages. They consume too much air or damage the thread. Most interlacing nozzles work with dry threads, with which satisfactory results can be achieved over a certain titer range. On the wet thread, however, the performance drops rapidly because the water is not removed sufficiently and the thread group is therefore unswirled enough.

Another disadvantage of the known twisting devices is that each thread is inserted individually into the Eyelets and combs must be drawn in before and after the thread channels, which is a time-consuming operation

All known nozzles have one or more of the disadvantages mentioned.

The object of the invention is to provide a device for intermingling, in particular in the stretch finishing of filament filament sheets, which largely removes the surface water on the filament with low air consumption, and a perfect intermingling is ensured without filament damage.

Another object is to provide a method with which a large number of threads can be intermingled at the same time and not every thread has to be drawn individually into the eyelets. The thread density (threads / cm) should remain the same before and after the intermingling device.

The object is achieved according to claim 1 in that the nozzle body is provided with at least two U-shaped thread channels and with a closable cover, has a bore 8 'in the area of the cover support, and that each thread channel has a channel which is semicircular in cross section with a radius r and represents a rectangular prism with edge lengths r and 2r.

It has proven expedient to provide the thread channel with a cover. The lid is removed for easy insertion. The air hole should be provided in the middle of the channel.

If the air speed in the thread channel is sufficiently high, most of the surface water is blown off against the direction of the thread so that the air hole can be regarded as the place of separation of the wet area from the dry area. The emerging thread is completely free of surface water and feels dry.

It is particularly advantageous if the lower part of the thread channel, which is provided with a right-angled central air channel, has a semicircular cross section. The thread can easily be guided in the center of a circle without a flat cover narrowing the lumen of the circle. In addition, the design of the nozzle body has considerable advantages in terms of production technology. A precise thread channel without sharp edges can be produced with simple tools by milling.

In a further embodiment, the thread channel can be narrowed at its thread entry and exit sides, if necessary, in order to better blow off the liquid of a wet thread. If the thread channel is narrow at its entrance and exit, but wider in the middle part, there is enough room for swirling, and the water can still be blown off due to the increased air speed.

The lid preferably consists of a 30-50 mm, preferably 40 mm thick metal plate with plane-parallel surfaces. It is arranged to be removable, expediently foldable or displaceable in such a way that an opening for receiving a thread sheet is created. The advantage of the flat closure is that it can be produced in a very simple manner and fits well. Any holes or recesses to supplement the thread channel in the nozzle body are not required. This eliminates the need for an otherwise complex lid design. The lid closure is advantageously monitored by means of compressed air via a control hole in the nozzle body. If the cover is correctly seated, no compressed air can escape through this hole. The lid is held by its own weight (40 mm steel) because there is not enough space between the thread channels for fastening.

It is expedient to set the length of the thread channel to 3 to 12 cm, a preferred length range being 3 to 10 cm. The best results were achieved with a thread channel length of 10 cm. The diameter of the thread channel, on the other hand, is a substantial size and is 1.5 to 2.5 mm. It is expedient to choose from 2.2 to 2.5 mm for coarse fibril titers in the range from 5 to 7 dtex and from 1.5 to 2.0 mm for fine fibril titers, for example up to 3.5 dtex. In order to be able to swirl a thread of, for example, dtex 167 f 30, 5.6 dtex / fibril sufficiently intensely, a thread channel diameter of more than 2 mm is required.

If a thread channel is too large, an aqueous liquid is not blown off, the thread is poorly swirled and a subsequent size is greatly diluted by the water adhering to the thread from the stretching trough. In the event of poor intermingling, the distances between the knots become longer and longer and there are more and more open spaces which reduce the thread running security. If a thread channel is too narrow, depending on the fibril titer, it is also more difficult to swirl a thread group. For example, the knots at 167 f 30 with a thread channel less than 2 mm in diameter are so weak that they can no longer be detected using the needle method.

Has as material for the nozzle body with the thread channel hard anodized aluminum has proven to be particularly suitable. Chemical polishing before anodizing can prevent serimetry damage from being caused during turbulence. A black thread makes a white thread particularly well visible. The anodized layer is expediently about 50 μm thick and ensures a long service life. The thread channels are clearly visible and can be checked for cleanliness and general condition.

It is also expedient to arrange the nozzle bodies offset one above the other in the thread running direction. This has the advantage that the blown-off water only drips back onto the threads that are still wet and cannot drip onto threads that have already dried.

Each individual filament yarn filament thread is guided axially parallel to the longitudinal axis of the swirl chamber and swirled at about 100 to 600 m / min, preferably at 200 to 400 m / min, the speed being determined by the visual light process. The relative

Depending on the titer and the number of knots / m, air consumption is less than 1.5 Nm ³ / hour and thread at 3 bar air pressure. At these speeds, the number of knots is independent of the speed. The swirling effect is better if the thread of a family of threads is passed as a ribbon over the air hole.

It is advisable to guide the thread band between a horizontal and two vertically arranged thread guides outside and in front of the thread channel. For this purpose, a horizontally arranged ceramic guide and, for example, a vertically arranged thread guide (comb) at a distance of 3 cm can be provided before and after the thread channel. The distance between the threads should be at least 5 mm, otherwise, especially intertwine wet threads. For this reason, such a family of threads must be divided into several families of partial threads when swirling. For example, it is advisable to divide a group of 8 threads / cm into 4 sets of threads with 2 threads / cm = 5 mm spacing. The swirling device according to the invention also comes with a relatively coarse titer with, for example, dtex 167 f 30 with a relatively small air bore of approximately 0.8 mm compared to known nozzle bores for a same titer, which is responsible for the low compressed air consumption.

It is advisable to divert the thread before and after the thread channel by 5 to 20 degrees using a horizontal thread guide. The angle results from the arrangement of the nozzle bars. It is not possible to have the same angle at all swirling points. At the same time, make sure that there is sufficient distance from the vertical thread guides (comb) to the horizontal thread guides and that there is no excessive deflection on the vertical thread guide. The vertical thread guides (comb) must not be too close to the horizontal, otherwise the thread can no longer lie flat.

To prevent the dilution of a wash liquor, the water, originating from the stretching trough, must be removed from the thread as completely as possible. To blow off the surface water, an amount of air along the thread of at least 0.1 Nm ² / h mm ² thread channel cross-section is necessary. Residual moisture levels of less than 1% are achieved for polyester and less than 10% for polyamide. If this air speed falls below, the adhering water is blown off incompletely, and the swirling performance drops sharply.

The simultaneous insertion of a large number of threads In the thread channel of the nozzle body, thanks to the removable covers of the nozzle body, the advantage is that a part thread group can be inserted together, for example by means of an adhesive tape, without having to separately pull into the individual nozzles. As a result, the partial threads are brought together again in the original thread density. The enormous saving in working time is evident as a further advantage.

The invention will be explained in more detail by way of example with reference to drawings.

Show it:

Fig. 1 shows a device with eight nozzle bars for swirling a thread sheet in perspective

Fig. 1a is an enlargement of a nozzle bar with a

Nozzle body, a cover and thread guide Fig. 2 a swirling point with the cover lifted off in perspective Fig. 3 the nozzle body in cross section Fig. 4 the nozzle body in plan view Fig. 5 a longitudinal section of a thread channel in the swirling area according to AA of Fig. 3 Fig. 6 a cross section through an enlarged thread channel in the intermingling area

Fig. 7 shows a variant of a thread channel with the lid open in plan view

In Fig. 1, a device according to the invention for swirling a coulter is shown in perspective. For example, four nozzle bars 1, 1 ', 1''and1''' are arranged symmetrically on both sides of a carrier 2, offset obliquely one above the other. Each nozzle bar 1 contains an air channel as a carrier for the intermingling body and the thread guide. The compressed air supply is accommodated in the carrier 2 at the same time. One out Wet thread sheet (water application approx. 50%) coming from a water trough (not shown) containing water is divided into two parts in width in order to avoid the carrier 2. In terms of height, the thread family is divided into a plurality of partial thread families, of which the partial thread families 3 and 3 'are shown. Each nozzle bar 1 in turn has, depending on its length, a number of nozzle bodies 6, of which the nozzle bodies 6 and 6 'are shown on the nozzle bar 1 and the nozzle bodies 61 and 61' are shown as examples on the nozzle bar 1 '''. After passing through the nozzle bars 1, 1 ', 1''or1''', the now dry thread sheets, of which the bottom 4 and top 4 'are shown, are combined again and fed to a sizing bath, not shown.

With A E F G C H one half of the supporting frame 2 indicates the limitation of the uppermost thread section and with A E J K C H the limitation of the lowest thread section. A E F G = 3 '; A E J K = 3; J K C H = 4; F G C H = 4 '.

Since the water is blown off the threads 3 in the thread channels 7, the nozzle bars 1 have a wet side at the thread inlet and a dry side at the thread outlet. The nozzle bars 1 are therefore offset such that water can only drip onto wet threads from the wet side.

In Fig. 1a, a nozzle body 6 is shown as it is arranged on the nozzle bar 1. A nozzle body 6 generally has 10 to 20 thread channels 7, which are covered with a cover 8.

Vertical thread guides 9 and horizontal thread guides 10 are arranged on the nozzle bar 1. For each nozzle body 6 leads a thread section 3, of which 10 to 20 wet filament threads 31 lead through each thread channel 7 and leave this as a swirled, dry filament threads 41.

2 shows a perspective view of a thread channel 7 in the nozzle body 6 with the cover 8 in the raised state. The thread channel 7 is formed in its lower part as a groove 11 which has a bore 12 in the center for the compressed air. A further bore 8 ′ is provided in the nozzle body 6 and is closed when the cover 8 is seated correctly. A wet thread 3 is fed to the groove 11 via a vertical thread guide 9 and a horizontal thread guide 10, which is guided after the groove 11 as a dry thread 4 via a horizontal thread guide 10 'and a vertical thread guide 9' into a sizing bath. For deflection by an angle α, the thread 3 is laid flat at the thread guide 10 in order to support the swirling. In order not to hinder the laying of the thread on its way, there must be a sufficiently large distance, for example of about 2 cm, between the thread guide 9 and the thread guide 10, and the deflection in the thread guide 9 should be relatively small. The outlet side is mirrored to the inlet side.

Fig. 3 shows a section through the nozzle body 1, which is provided with a plurality of thread channels 7 with the associated bores 12, with the lid 8 closed. The threads 3, 4 run approximately in the middle of the thread channel 7 of the channel 11 and the rectangular prism 16.

When the cover 8 is open, a top view, according to FIG. 4, shows a plurality of thread channels 7 of the nozzle body 1 with the bores 12 for the air supply. The distances between the individual thread channels are a lot times the distances between the incoming and outgoing thread coulters.

5 shows the operating state of a longitudinally cut thread channel 7 of the nozzle body 1 with the lid 8 closed. After the bore 12, which is pressurized with compressed air of 1 to 4 bar, the thread section 3 becomes the swirled thread section 4.

6 shows the dimensional relationships of the optimally designed thread channel 7 according to the invention. It can be seen that the groove 11 represents a semicircle with the radius r, the diameter and the height of the thread channel 7 corresponds to twice the radius 2r of the groove 11; the upper part represents a prism 16 with the height r and the width 2r.

7 shows a variant of the thread channel 7 in plan view. The thread channel 7 consists of an actual swirl channel 15 in the middle and a front entry part 13 for the partial thread family 3 before the swirling and an outlet part 14 for the partial thread family 4 after the swirling by means of compressed air from the bore 12 of a compressed air supply, not shown. The water is blown off by high air speed along the thread.

In operation, for pulling in, according to FIG. 1, a thread sheet on the width AB is divided into individual thread sets with a partial comb, not shown. The thread sections from 3 to 3 'are taped in orderly with an adhesive tape and thus inserted into the opened nozzle body 6 and a comb, not shown, on the width CD. In the CD area, the swirled thread sections 4 are again combined into eight threads per cm, for example. The type of swirl is determined by the diameter of the

Verwi rbe Lungskammer 15 determined, with large diameter stable nodes in large irregular intervals and shorter nodes with smaller diameters in smaller frequent intervals. A small diameter of the inlet part 13 and the outlet part 14 generates high air velocities along the running thread section 3, 4 and results in a good blowing off of the water. The nozzles according to the invention make it possible to achieve a long, stable knot despite the wet threads.

The following table shows the measurement results of a thread produced with the twisting nozzle according to the invention in comparison with a known nozzle.

The thread tension was 0.05 cN / dtex in all examples.

1) measured using the needle test method

2) The same elongation at break was aimed for in all tests. Because of the serimetry damage in the known nozzle, the drawing was corrected accordingly. This results in a somewhat too high titer and a somewhat too firm consistency.

The device according to the invention combines the following advantages:

- Easy insertion of a thread in the open nozzle body

- The thread spacing in the partial thread coulter is an integral multiple of the incoming and outgoing thread coulters, so that the partial thread coulters can be taped, inserted as a coulter and can be combined again to form the full thread coulter at the outlet

- low air consumption

- no damage caused by serimetry

- the surface water is completely blown off - no loss of performance through the water

- sufficient swirl intensity even with coarser titers.

The device according to the invention is particularly suitable for interlacing thread sheets made of wet, smooth, synthetic filament threads during stretch finishing, where interlacing is carried out between two work steps. Swirling can also be carried out in the manner described. As a result, unwired threads can be used in the slip. Less swirling is lost from the swirling nozzle according to the invention than when running over travelers, cops, thread brakes, creels, etc.

Claims

Device for air swirling a wet thread sheet (3) made of smooth multifilaments, consisting of a nozzle body (6) with U-shaped thread channels, each thread channel (7) being assigned a central compressed air channel (12) at right angles, characterized in that the nozzle body (6 ) is provided with a closable cover (8), which has a bore (8 ') in the area of the ceiling, and that each thread channel (7) has a groove (11) which is semicircular in cross section with a radius r and a rectangular prism ( 15) with the edge lengths r and 2r.

2. Device according to claim 1, characterized in that the inlet part (13) and the outlet part (14) of the thread channel (7) have a smaller diameter than the channel-shaped / prismatic swirl channel (15).

3. Device according to claim 1, characterized in that the cover (8) is designed as a flat, at least 40 mm thick metal plate.

4. The device according to claim 1, characterized in that the thread channel (7) has a cross section 2r of 1.5 to 2.5 mm.

5. Device according to claims 1 to 4, characterized in that the nozzle body (6) and d e r thread channel (7) are made of aluminum.

6. The device according to claim 5, characterized in that the surfaces of the thread channel (7) and the In are hard anodized on the inside of the cover (8) to a thickness of at least 50 μm.

7. The device according to claim 1, characterized in that the thread channel (7) has a length of 3 to 12 cm.

8. Device according to claims 1 to 7, characterized in that a plurality of nozzle bodies (6) are arranged one above the other in the thread feed direction and offset on a carrier (2).

9. A process for intermingling a wet thread sheet made of smooth multi-filaments, characterized in that the partial threads of the thread sheet (3, 4) run parallel to the longitudinal axis of the thread channel (7) and at a speed of the thread sheet of 100 to 600 m / min with an amount of air swirl at least 0.1 Nm ³ / h mm ² in the thread channel (7).

10. The method according to claim 9, characterized in that the thread sheet (3) from the inlet into the thread channel (7) is guided as a thread band.

11. The method according to claim 10, characterized in that the thread sheet (3, 4) between the outside of the thread channel (7) arranged horizontal thread guides (10, 10 ') and vertically arranged thread guides (9, 9') is guided.

12. The method according to claims 9 to 11, characterized in that the deflection (α) of the thread sheet (3) in the horizontal thread guide (10, 10 ') is 5 to 20 degrees.

13. The method according to claims 9 to 12, characterized ge indicates that a plurality of threads (3) are inserted into the thread channels (7) of the nozzle body (6) at the same time.

14. The method according to claims 9 to 13, characterized in that the distances between the thread channels (7) of the nozzle body (6) is an integer multiple of the distances between the incoming and outgoing threads.