WO2017148994A1

WO2017148994A1 - Method and device for melt spinning a synthetic thread for technical application purposes

Info

Publication number: WO2017148994A1
Application number: PCT/EP2017/054730
Authority: WO
Inventors: Jürgen Eichel; Thomas Miernik; Marco Müller; Milan Ivanovic; Ralf Wilkehl; Angela Hutter
Original assignee: Oerlikon Textile Gmbh & Co. Kg
Priority date: 2016-03-04
Filing date: 2017-03-01
Publication date: 2017-09-08
Also published as: DE102016002647A1

Abstract

The invention relates to a method and to a device for melt spinning a synthetic thread for technical application purposes. In known godet arrangements, that is, when using multi-entwined godet duos having concordantly rotating godets, the thread is unevenly tempered. An upper limit is thus placed on the maximum achievable thread qualities. In the device according to the invention and in the method according to the invention, the thread is wound alternately about two inversely rotating godets of a godet duo, such that the thread is contacted in alternation by two opposite sides. A very uniform heat treatment of the thread is thus achieved and therefore technical threads of particularly high quality can be produced.

Description

Method and apparatus for melt spinning a synthetic thread for technical applications

The invention relates to a method for melt spinning a synthetic see thread for technical applications according to the preamble of claim 1 and an apparatus for melt spinning a synthetic thread for technical applications according to the preamble of claim 4. A generic device and a generic method for producing a synthetic Thread for technical applications are known from DE 102010048219A1. Here are three spinnerets shown, from each of which a thread is extruded. After cooling and preparation of the threads, they are stretched and relaxed by means of a treatment device. The treatment facility consists of several Galettenduos. Each thread is looped several times around two godets of a godet duo. For this purpose, two axes of the two godets of a godet godet are arranged inclined to each other. The sense of rotation of the two godets of a godet duo is the same. When a thread is passed over the surface of a godet, it has a godet facing the bottom of the thread and a godet facing away from the top of the thread. In the multiple wrapping around the two godets of a godet duo shown here, each thread is guided on both godets with the same thread side, namely the lower side of the thread. Since the godets for the heat treatment of the threads are designed to be heated, it is precisely this heating of the threads always taking place from the same side within a godet dome. This circumstance leads to an uneven heating of the threads and thus also to an uneven stretching or relaxation. The maximum achievable thread quality therefore knows an upper limit. In the apparatus of DE 102010048219A1, four stretched godet duo and one elaxier godet duo are arranged. In the following description, the godet duos are numbered in the direction of the threadline. To achieve better heating of the filaments, the first and second stretched godet duo are operated in opposite directions of rotation. Thus, the threads are heated by means of the second draw godet duo from the opposite side of the thread, as is the case with the first draw godet duo. The directions of rotation of the other godets up to the last godet no longer differ from the direction of rotation of the godets of the second draw godet duo, so that the yarn from the second draw godet duo is always heated from the same side. Furthermore, with such a multiple looping of the threads around the two godets of a godet duo, the wrap angle around each godet is only 180 °. A small contact length between the thread and godet surface has a negative effect on the maximum possible stretching force, which can be applied by means of godet godets on this thread, without this slipping over the surface of the godets. It is therefore an object of the invention to provide a generic method and a generic device by means of which a synthetic thread for technical applications particularly uniformly and quickly treated, that can be stretched and relaxed. This object is achieved by a generic method, wherein a thread entwines the two godets of a godet godet mutually and wherein these two godets rotate with different directions of rotation. Thus, the thread is wound several times around the two godets of a godet by means of a cross-stroke. The thread is constantly changing from two opposite sides of the godets thus contacted also tempered. One galette of a goddess leads the thread from one side, the other godet leads the thread from the opposite side. This creates a particularly large wrap angle of the thread around the godets. Due to this larger wrap angle around the godets, a larger contact length between the surface of the godets, in contrast to a Mehrfachumschlmgung two godets of the same size, which rotate in the same direction. Due to this larger wrap angle or the larger contact length, a greater frictional force arises between the surface of the gills and the thread, so that this thread can be stretched more. The mutual Mehrfachumschlingung leads in particular in the case of heated godets to a particularly uniform heat treatment of the thread, since the thread is tempered from two opposite sides. As a result of this uniform heat treatment, particularly uniform yarn properties and thus a particularly high quality of the yarn can be achieved with the process according to the invention. Furthermore, the thread can be brought very quickly to the desired temperature by means of the thread guide described. On the one hand because of the mutual heat treatment, on the other hand also due to the long contact time between the thread and the godet surfaces, which results from the large wrap angles. A heat treatment is advantageously carried out with heated godets, in the case of cooling, for example in a relaxation treatment but also unheated godets are conceivable.

In a preferred embodiment of the invention, the thread is formed from a plurality of filaments. These are extruded from a spinneret. For this purpose, a multiplicity of nozzle bores is introduced into the spinneret, which are connected via melt lines to a melt source. Such threads for technical applications can be used in many areas, for example in airbags, seat belts, tire cords or belts. Such threads for technical applications are often referred to in practice as IDY (Industrial Yarn) or as technical yarn.

Preferably, the thread is withdrawn from the spinneret by means of a withdrawal godet duo. In the further course, the thread is stretched by means of at least two stretch godet duo and relaxed by means of at least one relaxation godet duo. Finally, the thread is wound on a winding head to form a bobbin. So it is possible to achieve the high quality requirements, which are necessary if the IDY is to be used for example in airbags or seat belts. In this case, a technical yarn with particularly high strength and low shrinkage or with a particularly high modulus of elasticity and low shrinkage can be produced.

The object is also achieved by a generic device in which a drive device of a godet duo is so pronounced that the two godets of this godet can each be driven with different direction of rotation. Thus, the thread can be guided by mutual wrapping around the two godets of the godet duo. Due to the mutual wrap, a large wrap angle is created around the two godets, which is significantly larger than 180 °. This large wrap angle causes large draw forces to be applied to the thread without the thread slipping over the surfaces of the godets. Such slippage should be avoided in any case, as it would lead to uncontrollable process conditions and thus also to poor yarn quality. Furthermore, the thread is contacted by the godets from both sides, not just from one side. This improves the heat transfer between thread and godets and the thread can be adjusted very quickly and particularly evenly to the temperatures necessary for the treatment.

The drive device preferably consists of two motors. The drive device serves to set the two godets of a godet in rotation. Due to the very low purchase cost of electric motors nowadays, such an arrangement has economic advantages over a combination of a single motor and associated gear. Furthermore, when using two motors, in each case a compact assembly of galette and associated motor, which is very flexible. Such a compact unit can be easily exchanged between different positions in the system. This also saves time and costs in the design.

In a particularly advantageous embodiment of the invention, two axes of the two godets of a godet duo are arranged inclined to one another such that these two axes intersect in their virtual extension. This ensures that the thread does not get in the way of the multiple wrapping around the two godets. After each wrap, the yarn is in fact guided on each godet at an axially offset position. The thread wanders so each wrap around to a projecting end of the godet. In the arrangement shown here is based on cylindrical godets. Alternatively, parallel godet axes and conical godets could be used. The two axes of two godets of a godet duo, as shown in DE 102010048219 A1, are usually arranged skewed relative to one another in order to achieve the so-called yarn offset described above. Such a skewed arrangement would but lead to a collision of the thread with itself in the here implemented cross-wrap.

An angle formed between these two axes is preferably between 4 ° and 20 °. In this area, the optimum compromise lies between the certainty that the thread will not touch itself and the requirement for the smallest possible godet in terms of its axial length. The longer a godet is, the more expensive is its production and the greater are the mechanical loads on the godet in the operation of the system.

A distance between the two godets of a godet to each other is advantageously 400 mm to 1,000 mm. This distance is measured between the two axes of the godets on a support wall. On this carrier wall, which is connected to a machine frame, the two godets are stored. This ensures that there is enough space between the two godets to guide the thread during the threading process to start the process by means of a suction gun. Furthermore, the temperature of the thread can be even if this is in the space between the two godets. The above-mentioned distance in combination with usual godet diameters of 200mm - 280mm and usual rotation speeds leads to an optimal equalization of the temperature. In a further embodiment of the invention, the godets of at least one godet duct are designed to be heated. Thus, the guided on the godets thread can be brought to the temperature necessary for the treatment. In order to stretch or relax the thread between two godet duos, it is expediently heated or cooled by means of the godet duo which precedes the yarn path. In order to limit the heat loss, the two godets of at least one godet duo are arranged within a heating box. Such heating boxes have insulated walls and completely surround a pair of godets. This reduces heat transfer from the godets to the environment through radiation and convention to a minimum.

By means of the process and device features described above, it is possible to produce in particular very high-quality IDY in a particularly economical manner.

The method according to the invention will be explained in more detail below with reference to an embodiment of the device according to the invention with reference to the attached figures.

They show:

Fig.l schematically a front view of an embodiment of the device according to the invention

2 schematically shows a view of the two godets of a gala tendon from below

1 shows schematically a front view of an embodiment of the device according to the invention. From a spinneret 3, a plurality of filaments is extruded during operation of the plant. For this purpose, the spinneret 3 is supplied with a synthetic polymer in liquid form and under pressure. For this purpose, usually an extruder and a spin pump are used. As synthetic polymers many different materials are conceivable, in particular, here are polyethylene terephthalate and polyamide. After the filaments have left the spinneret 3, they are first cooled, which is not shown here for the sake of clarity. Subsequently, the filaments are treated by means of a preparation fluid. This purpose is served by a first preparation roller 4.1, a hold-down device 5 and a second preparation roller 4.2. By means of the lower holder 5 it is ensured that the filaments are guided with sufficient contact over the surfaces of the two preparation rollers 4.1 and 4.2. Between the second preparation roller 4.2 and a withdrawal godet duo 8.1, a collection thread guide 6 is arranged, by means of which the plurality of filaments is combined to form a thread 1. The deduction godet duo 8.1 is used to withdraw the thread 1 from the spinneret 3, whereby a so-called spinning delay occurs. The withdrawal godet duo 8.1 is in addition to a first stretching godet duo 8.2, a second draw godet duo 8.3, a first elaxiergalettenduo 8.4 and a second Relaxiergalettenduo 8.5 part of a treatment device 7, in which the thread 1 withdrawn, stretched and relaxed. Each of these galette duos consists of two godets 9.1 and 9.2, 9.3 and 9.4, 9.5 and 9.6, 9.7 and 9.8 and 9.9 and 9.10, which are each driven by a rear-mounted motor. The two godets of a godet godet each rotate with different directions of rotation, as symbolized by the arrows on the front sides of the godets 9.1 - 9.10. The godets 9.3 - 9.10 are heated. To reduce the heat loss these godets 9.3 - 9.10 are positioned in heaters 17.1 - 17.4. In each case a pair of godets 8.1, 8.2, 8.3 or 8.4 is arranged within a heating box 17.1, 17.2, 17.3 or 17.4. All previously named units for forming a yarn path are held on a machine frame 2. Below the treatment device 7, a winding head 18 is arranged, by means of which the thread 1 is wound into a coil. In order to draw the thread 1 during operation of the system, the two godets 9.3 and 9.4 of the first stretching godet duo 8.2 rotate at a higher speed than the two godets 9.1 and 9.2 of the withdrawal godet duct 8.1. Furthermore, the two godets 9.4 and 9.5 of the second draw godet tube 8.3 rotate at a higher speed than the two godets 9.3 and 9.4 of the first draw godet nozzle 8.2 in order to subject the yarn 1 to a second drawing treatment. The following godets 9.7 - 9.10 of the two ellipse godet duos 8.4 and 8.5 have a speed that is the same or even slightly reduced in contrast to the last draw godet duo 8.3, so that the yarn 1 has the opportunity to relax. The winding head 18 is operated in such a way that no substantial difference in speed of the thread 1 is established between the relaxation belt pair 8.5 and the winding head 18. The treatment device 7 shown here could also be designed differently in the sense of the invention. Thus, it would be conceivable, depending on the desired thread properties, to integrate both less and more godet duos into the treatment device 7 than is the case here. Usually, when producing IDY four used up to six godet duos, which is also not to be interpreted as limiting. Furthermore, it would be conceivable to form the treatment device 7 from a combination of godet duos with a cross-lap wrap according to the invention and conventionally looped godets, or simply simply wrapped godets. Such simply entwined godets have the advantage that no thread misalignment arises on the godets.

In order to illustrate the Kreuzschlummmschlmgungen the thread 1 to the two godets of a godet, is shown in Figure 2 by way of example and schematically a view of the first stretched godet duel 8.2 from below. The other Galettenduos are constructed analogously. In the following description of Fig. 2, the same reference numerals are used as in Fig.1. The two godets 9.3 and 9.4 are held on a support wall 16 and are driven by two motors 15.1 and 15.2 in opposite directions, as symbolized by the two arrows on the right of the godets 9.3 and 9.4. These two motors 15.1 and 15.2 form a drive device 14 of the draw godet 8.2. An axis 10.1 of the godet 9.3 intersects an axis 10.2 of the godet 9.4 at an intersection point 1. 1. An angle 12, which forms between these two axes 10.1 and 10.2, has values between 4 ° and 20 °. A distance 13 between the two axes 10.1 and 10.2 is at the support wall 16 400mm - 1,000mm, the diameter of the godets 9.3 and 9.4 are at values between 200mm and 280mm. In this view from below, the thread misalignment can be seen particularly well, by means of which it is indicated that the thread 1 is guided after each wrap with a smaller distance to the end face on the godet 9.3 or 9.4, as was the case with the previous wrapping , The direction of the yarn path is shown by the arrows on the thread 1 in the middle between the two godets 9.3 and 9.4. After the thread 1 has been inserted into the draw godet duo 8.2 is, it is guided on the upper circumference of the godet 9.3, where it is hidden in this view from below by the galette 9.3. In the following, the thread 1 overcomes the gap between the two godets 9.3 and 9.4. Now the thread 1 wraps around the godet 9.4 from a lower circumference to an upper circumference. The wrap angle of the thread 1 to the galette 9.4 is significantly greater than 180 °. Analog wraps the thread 1 after overcoming the gap between the two godets 9.3 and 9.4 the godet 9.3. This process of looping around the two godets 9.3 and 9.4 repeats four times before the thread 1 leaves the stretched godet duo 8.2 at the top. This is why we speak of a quadruple wrap, and more generally of a multiple wrap of a thread 1 around a gala duet. This quadruple wrapping is chosen by way of example, both smaller and larger wrapping numbers such as a six- or eight-fold wrap are conceivable.

In Figures 1 and 2, only the production of a single thread 1 for technical applications is shown. In production plants, a plurality of spinnerets are usually held in a row in a spinning beam, this row could extend in the view of Fig. 1 perpendicular to the image plane. By means of this plurality of spinnerets, 4-16 are quite common values, several threads are extruded parallel to each other according to the number of spinnerets. The treatment device 7 is designed in such a way that such a group of threads can be stretched and relaxed from threads guided parallel to one another. The threads of the yarn sheet are doing at a distance of, for example, 2 - 6 mm on the surfaces of the godets 9.1 - 9.10 out. At the beginning of the process during so-called thread application, such a group of threads can also be applied to the godets 9.1 - 9.10 of the treatment device 7 by means of a single suction gun. The winding head 18 is at the parallel Production of several threads so pronounced that this plurality of threads can be wound in parallel on a cantilevered winding spindle of the winding head 18 to a plurality of coils. Under certain circumstances, the threads of the yarn sheet are divided into two adjacent winding heads.

Claims

claims

A method for melt spinning a synthetic thread for technical applications, wherein the thread is treated by Galettenduos, wherein the thread is wound several times around two godets of a godet, the thread after each wrap due to an inclination of both axes of the two godets to each other at an axially offset Led position of the godet is characterized in that the two godets rotate at least one godet with each different direction of rotation, so that the thread entwines these two godets each other.

A method according to claim 1, characterized in that the thread is formed from a plurality of filaments which are extruded from a spinneret.

A method according to claim 1 or 2, characterized in that the thread is withdrawn by means of a Abzugsgalettenduos of the spinneret, that the thread is stretched in the following by means of at least two stretched galettenduos that the thread is subsequently relaxed by means of at least one elaxiergalettenduos and that the thread is finally wound by means of a winding head to form a coil.

Apparatus for melt-spinning a synthetic thread (1) for technical applications, comprising a treatment device (7) for treating the thread (1), wherein a plurality of godets (8.1-8.5) are part of the treatment device (7), two godets (9.3, 9.4) of each Galettenduos (8.2) by means of a Drive means (14) are set in rotation, wherein two axes of these two godets (9.3, 9.4) are arranged inclined to each other, so that the thread (1) several times around these two godets (9.3, 9.4) is feasible characterized in that the drive means (14) is so pronounced that the two godets (9.3, 9.4) at least one godet (8.2) are each driven with different rotational direction, so that a mutual wrap of the thread (1) to the two godets (9.3, 9.4) of a godet duo (8.2) is possible.

Apparatus according to claim 4 characterized. That the drive device (14) has two motors (15.1, 15.2).

Apparatus according to claim 4 or 5, characterized in that the two axes (10.1, 10.2) of the two godets (9.3, 9.4) of a godet (8.2) are arranged to each other such that you have in their virtual extension an intersection (1 1).

Apparatus according to claim 6, characterized in that an angle (12) between the two axes (10.1, 10.2) of the two godets (9.3, 9.4) of a Galettenduos (8.2) is a value between 4 ° and 20 °.

Device according to one of claims 4-7, characterized in that a distance (13) between the two axes (10.1, 10.2) of the two godets (9.3, 9.4) of a godet (8.2) on a support wall (16) has a value between 400mm and 1,000mm.

9. Device according to one of claims 4 - 8, characterized in that the godets (9.3, 9.4) at least one Galettenduos (8.2) are designed to be heated.

10. Device according to one of claims 4 - 9, characterized in that the godets (9.3, 9.4) at least one godet duo (8.2) within a heating box (17.1) are arranged.